2013 Updates

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Weekly Update for 8/12 – 8/18/2013

8/12 – 8/18/13 ›

This completes our regular weekly reporting of field research activities in the Columbia River estuary for 2013

8/12 – 8/18/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated around 4,600 birds this week; almost all fledglings produced during the first tern nesting effort this season have now left the colony; both fledglings and their parents are dispersing from the colony area and many are now loafing on the south, east, and north beaches adjacent to the colony; adult terns that remain on colony are tending nests with eggs or newly-hatched chicks; by weeks end ca. 280 downy tern chicks were counted on colony; most remaining tern nests that contain eggs or young chicks will likely fail in the coming weeks because of the lateness of the season

8/12 – 8/18/13 ›

Caspian terns have not attempted to re-nest in areas outside the 1.58-acre designated tern colony area on East Sand Island; earlier in the breeding season terns attempted to nest in several satellite colonies on the upper beach of East Sand Island near the designated tern colony area, and some terns laid eggs in these satellite colonies; all of these nesting attempts failed, as no tern chicks were observed at any of the satellite colonies during the 2013 breeding season

8/12 – 8/18/13 ›

Double-crested cormorants (adults and fledglings) are leaving the designated colony area on East Sand Island to roost on the south and north beaches; bald eagles have not been observed disturbing nesting or roosting cormorants on East Sand Island for more than one month

8/12 – 8/18/13 ›

Continuous daytime monitoring of the cormorant nest dissuasion areas outside the designated cormorant colony area on East Sand Island has ceased for the 2013 breeding season; previous monitoring and hazing efforts were successful in preventing cormorants from nesting in the dissuasion areas, where no egg-laying by cormorants was detected during the 2013 breeding season

8/5 – 8/11/13 ›

Double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 are beginning to disperse in larger numbers from East Sand Island and the Columbia River estuary; 70 of the 83 satellite tags (84%) that were deployed in April are still functioning; by week's end, 29 of the 70 satellite-tagged cormorants (41%) were detected on or near East Sand Island; dispersal from East Sand Island is mostly to the north, with 28 satellite-tagged cormorants (40%) detected along the coast from Willapa Bay, WA to Barkley Sound, B.C.; of these 28 tagged cormorants,19 (68%) were detected on Sand Island in Grays Harbor, WA; the remaining 13 satellite-tagged cormorants not detected on East Sand Island or along the coast to the north (19%) were detected to the east near the Astoria-Megler Bridge (3), near Rice Island (9), and at a small colony in the lower Columbia River near Troutdale, OR (1)

8/12 – 8/18/13 ›

High count of ca. 840 Brandt’s cormorants and ca. 340 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this week; fledglings are leaving the designated colony area on East Sand Island to roost on surrounding beaches

Weekly Update for 8/5 – 8/11/2013

8/7/13 ›

Seventh set of high-resolution aerial photography taken of East Sand Island by Bergman Photographic to count the numbers of Caspian terns and double-crested cormorants on the island; once completed, tern and cormorant counts from aerial photography will be provided in a later report

8/7/13 ›

Island-wide count revealed ca. 3,850 California brown pelicans roosting on East Sand Island

8/5 – 8/11/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated around 5,800 birds this past week; both fledglings and adults are dispersing from the colony and large numbers are now loafing on the south, east, and north beaches; Caspian terns that recently initiated nesting attempts are beginning to abandon those nesting attempts; those terns that continue to incubate eggs or brood young chicks will likely fail in the coming weeks

8/5 – 8/11/13 ›

Caspian terns have not attempted to re-nest in the northeast and southeast satellite colonies that were completely washed out during the high tide series over a month ago; nesting Caspian terns have abandoned all nesting attempts within the ring-billed gull colony; no tern chicks were observed at any of the satellite colonies during the 2013 breeding season

8/5 – 8/11/13 ›

Double-crested cormorants (adults and fledglings) are leaving the designated colony area on East Sand Island to roost on the south and north beaches; for more than a month there have been no observed disturbances to the nesting or roosting cormorants by bald eagles

8/5 – 8/11/13 ›

Continuous daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony has ceased for the 2013 breeding season; previous monitoring and hazing efforts were successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying was detected during the 2013 breeding season

8/5 – 8/11/13 ›

More double-crested cormorant chicks have been seen on the East Sand Island colony with symptoms consistent with Newcastle disease; cormorant chicks with Newcastle disease-like symptoms were collected and submitted for necropsy to pathologist Rob Bildfell, DVM, at the Oregon State University Veterinary Diagnostic Laboratory; in past years cormorants from East Sand Island have tested positive for Newcastle disease, but negative for the highly virulent or velogenic form of the virus (“Exotic Newcastle Disease”) that can severely impact commercial poultry operations; symptoms have not been observed in adult cormorants

8/5 – 8/11/13 ›

Double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 are beginning to disperse in larger numbers from East Sand Island; 70 of the 83 satellite tags that were deployed are still functioning; by week's end, 47 of the 70 tags were detected at or near East Sand Island; 9 tags were detected in Gray’s Harbor, WA; 4 tags were detected on the Astoria-Megler Bridge; 3 tags were detected in Willapa Bay, WA; 3 tags were detected on Rice Island; 1 tag was detected at a small colony in the lower Columbia River near Troutdale, OR; 1 tag was detected near Tacoma, WA; and 1 tag was detected in Barkley Sound on Vancouver Island, BC

8/5 – 8/11/13 ›

High count of ca. 1,060 Brandt’s cormorants and ca. 500 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this week; fledglings are leaving the designated colony area on East Sand Island to roost on surrounding beaches

Weekly Update for 7/29 – 8/4/2013

7/29 – 8/4/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 5,500 and ca. 7,000 birds this past week, lower than counts in previous weeks; there are fewer terns remaining on the designated colony area as most chicks have fledged and both fledglings and adults are now loafing on the south, east, and north beaches; a new wave of egg-laying by Caspian terns has continued on the designated colony area with hundreds of adult terns now attending new nests with 1-2 eggs; most, if not all, of these late nesting attempts are expected to fail

7/29 – 8/4/13 ›

Double-crested cormorants (adults and fledglings) are leaving the designated colony area on East Sand Island to roost on the north beach; pre-fledging cormorant chicks are continuing to form large crèches and are moving about the colony; for more than a month there have been no observed disturbances to the cormorant colony by bald eagles

7/29 – 8/4/13 ›

Double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 are beginning to disperse in larger numbers from East Sand Island; by week's end, 45 of 71 operable satellite transmitters were detected at or near East Sand Island; 26 transmitters were detected elsewhere: 13 on Rice Island; 4 in Gray’s Harbor, WA; 3 on the Astoria-Megler Bridge; 3 in Willapa Bay, WA; 1 at a small colony in the lower Columbia River near Troutdale, OR; 1 near Tacoma, WA; and 1 in Barkley Sound on Vancouver Island, BC

7/29 – 8/4/13 ›

High count of ca. 1,165 Brandt’s cormorants and ca. 560 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, lower than the high counts in previous weeks

Weekly Update for 7/22 – 7/28/2013

7/25/13 ›

Island-wide count revealed ca. 3,275 California brown pelicans roosting on East Sand Island, primarily on south beach and west jetty

7/23/13 ›

Four Brandt’s cormorants were fitted with a GPS transmitters to determine the feasibility of using these tags to assess the off-colony movements and foraging behavior of active breeders from the East Sand Island colony; two of these birds were also fitted with CTD (Conductivity/Temperature/Depth) tags to record the salinity, temperature, and depth of the water during dives; in total, 6 Brandt’s cormorants have been fitted with GPS transmitters at the East Sand Island colony in 2013

7/21/13 ›

Sixth set of high-resolution aerial photography taken of East Sand Island by Bergman Photographic to estimate the numbers of Caspian terns and double-crested cormorants nesting on the island; once completed, tern and cormorant counts from aerial photography will be provided in a later report

7/22 – 7/28/13 ›

All three California brown pelican nests with eggs on the grassy slope southeast of the Caspian tern colony have failed and the nests have been abandoned (cause unknown); to our knowledge this was the first breeding attempt (i.e., egg-laying) ever by California brown pelicans on East Sand Island or anywhere in the State of Oregon

7/22 – 7/28/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 7,400 and ca. 9,500 birds this past week, similar to counts conducted the previous two weeks; a large number of tern chicks have fledged and are now roosting on the northeast, southeast, and east beaches; a new wave of egg-laying by Caspian terns was observed throughout the colony this week; chicks continue to hatch sporadically around the colony, but generally do not persist for more than a few days before being depredated by gulls

7/22 – 7/28/13 ›

Caspian terns have not attempted to re-nest in the northeast and southeast satellite colonies that were completely washed out during the high tide series over a month ago; nesting Caspian terns remain in and amongst the ring-billed gull colony, where some appear to be sitting on eggs (no chicks observed); ca. 600 Caspian terns (adults and fledglings) are loafing on the south/southeast beach immediately adjacent to the tern dissuasion area, but no active tern nests have been observed in this area

7/22 – 7/28/13 ›

Double-crested cormorants (adults and fledglings) are leaving the designated colony area on East Sand Island to roost on the north beach; pre-fledgling cormorant chicks are continuing to form large crèches and are moving about the colony; for three consecutive weeks there have been no observed disturbances to the cormorant colony by bald eagles

7/22 – 7/28/13 ›

More double-crested cormorant chicks have been seen on the East Sand Island colony with symptoms consistent with Newcastle disease; three cormorant chicks with Newcastle disease-like symptoms were collected and submitted for necropsy to pathologist Rob Bildfell, DVM, at the Oregon State University Veterinary Diagnostic Laboratory; in past years cormorants from East Sand Island have tested positive for Newcastle disease, but negative for the highly virulent or velogenic form of the virus (“Exotic Newcastle Disease”) that can severely impact commercial poultry operations; symptoms have not been observed in adult cormorants

7/22 – 7/28/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 61 of 73 operable satellite transmitters were detected at or near East Sand Island; 12 transmitters were detected elsewhere: three on Rice Island; three in Gray’s Harbor, WA; two in Willapa Bay, WA; one on the Astoria-Megler Bridge; one at a small colony in the lower Columbia River near Troutdale, OR; one near Tacoma, WA; and one in Barkley Sound on Vancouver Island, BC

7/22 – 7/28/13 ›

High count of ca. 1,375 Brandt’s cormorants and ca. 870 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts in previous weeks

Weekly Update for 7/15 – 7/21/2013

7/20/13 ›

Boat-based survey of the upper Columbia River estuary; main objectives of the survey were to locate piscivorous waterbird colony and roost sites and count the number of birds/nests at each site; 207 double-crested cormorant nests and 44 pelagic cormorant nests counted on the Astoria-Megler Bridge, most of which contained chicks; 600 loafing double-crested cormorants counted on west end of Rice Island; 109 loafing American white pelicans counted on Miller Sands Spit

7/17/13 ›

266 Caspian tern chicks captured and banded with field-readable alphanumeric leg bands at the East Sand Island tern colony

7/16 – 7/18/13 ›

72 double-crested cormorant chicks were captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony; in total, 421 cormorant chicks have been banded at the East Sand Island colony in 2013

7/15/13 ›

One adult Brandt’s cormorant was fitted with a GPS transmitter to determine the feasibility of using these tags to assess the off-colony movements and foraging behavior of active breeders from the East Sand Island colony; in total, 2 Brandt’s cormorants have been fitted with GPS transmitters at the East Sand Island colony in 2013

7/15/13 ›

Eight members of various chapters of the Audubon Society and Cindy Studebaker with the U.S. Army Corps of Engineers – Portland District visited East Sand Island

7/15 – 7/21/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 7,250 and ca. 10,300 birds this past week, similar to counts conducted the previous week; a large number of tern chicks have fledged and are now roosting on the north, south, and east beaches

7/15 – 7/21/13 ›

Caspian terns have not attempted to re-nest in the northeast and southeast satellite colonies that were completely washed out during the high tide series four weeks ago; nesting Caspian terns remain in and amongst the ring-billed gull colony, where some appear to be sitting on eggs (no chicks observed); ca. 500 Caspian terns are loafing on the south/southeast beach immediately adjacent the tern dissuasion area (no nesting observed)

7/15 – 7/21/13 ›

Double-crested cormorants (adults and fledglings) are leaving the designated colony area on East Sand Island to roost on the north beach; pre-fledgling cormorant chicks are continuing to form large crèches and are moving about the colony; for two consecutive weeks there have been no recorded disturbances to the cormorant colony by bald eagles

7/15 – 7/21/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 57 of 73 operable satellite transmitters were detected at or near East Sand Island; 17 transmitters were detected elsewhere: five on Rice Island, four in Gray’s Harbor, WA, three on the Astoria-Megler Bridge, three in Willapa Bay, WA, one at a small colony in the lower Columbia River near Troutdale, OR, and one in Barkley Sound on Vancouver Island, BC

7/15 – 7/21/13 ›

As was the case in previous years, California brown pelicans are building and attending nests on East Sand Island; on 17 July, three pelican nests were counted on a grassy slope southeast of the tern colony, all of which contained pelican eggs (one nest with 3 eggs and the other two nests with one egg each); to our knowledge this is the first breeding attempt (i.e., egg-laying) by California brown pelicans on East Sand Island or anywhere in the State of Oregon; the nearest California brown pelican colony is on the Channel Islands in Southern California

7/15 – 7/21/13 ›

High count of ca. 1,200 Brandt’s cormorants and ca. 1,000 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts the previous 5 weeks

7/15 – 7/21/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen, with evidence of fresh peregrine falcon predation on fledgling and adult piscivorous waterbirds this past week

Weekly Update for 7/8 – 7/14/2013

7/13/13 ›

7/12/13 ›

First double-crested cormorant fledgling observed at the East Sand Island cormorant colony

7/12/13 ›

Aerial survey of Puget Sound; main objective of the survey was to detect and photograph double-crested cormorant breeding colonies; estimates of numbers of young produced at each colony will be provided in a later report, once photography has been interpreted

7/9/13 ›

Fifth set of high-resolution aerial photography taken of East Sand Island by Bergman Photographic to estimate the numbers of Caspian terns and double-crested cormorants nesting on the Island; counts of active Caspian tern and double-crested cormorant nests will be provided in a later report once counts from photography have been completed

7/8 – 7/14/13 ›

349 double-crested cormorant chicks were captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony

7/8 – 7/14/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 6,200 and ca. 10,500 birds this past week, generally lower than counts conducted the past several weeks; most of the recently hatched chicks and recently laid eggs have been depredated by gulls; terns are beginning to abandon re-nesting attempts on East Sand Island following this most recent surge in nesting failure

7/8 – 7/14/13 ›

Caspian terns have not attempted to re-nest in the northeast and southeast satellite colonies that were completely washed out during the high tide series three weeks ago; nesting Caspian terns remain in and amongst the ring-billed gull colony, where some appear to be sitting on eggs (no chicks observed); ca. 75 Caspian terns are loafing on the south/southeast beach immediately adjacent the tern dissuasion area

7/8 – 7/14/13 ›

Adult cormorants nesting in the designated cormorant colony area on East Sand Island are beginning to leave the colony during the day, leaving their chicks unattended; cormorant chicks are growing larger and more mobile, and many are forming large crèches that are moving about the colony; bald eagle disturbance to nesting cormorants decreased, with no recorded disturbances to the colony this past week

7/8 – 7/14/13 ›

Eight double-crested cormorant chicks have been seen on the East Sand Island colony with symptoms consistent with Newcastle Disease; in past years cormorants from East Sand Island have tested positive for Newcastle Disease, but negative for the highly virulent or velogenic form of the virus (“Exotic Newcastle Disease”) that can severely impact commercial poultry operations; symptoms have not been observed in adult cormorants

7/8 – 7/14/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorants were not observed in either dissuasion area (east or west) at any time during the past 3 weeks, requiring no cormorant hazing activities during that time; previous hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date

7/8 – 7/14/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 61 of 73 operable satellite transmitters were detected at or near East Sand Island; 12 transmitters were detected elsewhere: three on Rice Island, three on the Astoria-Megler Bridge, three in Gray’s Harbor, WA, one in Willapa Bay, WA, one at a small colony in the lower Columbia River near Troutdale, OR, and one in Barkley Sound on Vancouver Island, BC

7/8 – 7/14/13 ›

High count of ca. 1,060 Brandt’s cormorants and ca. 1,000 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts the previous 4 weeks

7/8 – 7/14/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen, with evidence of fresh bald eagle and peregrine falcon predation on fledgling and adult piscivorous waterbirds this past week

Weekly Update for 7/1 – 7/7/2013

7/5/13 ›

First Caspian tern fledgling observed on East Sand Island

7/1/13 ›

Island-wide count revealed ca. 2,750 California brown pelicans roosting on East Sand Island, mostly on south beaches

7/1 – 7/7/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 5,500 and ca. 12,000 birds this past week, generally lower than counts conducted the past several weeks; a second wave of chick hatching occurred this week along the perimeter of the colony and in areas affected by flooding on 23 May; depredation rates by gulls on these newly hatched chicks are high; the northeastern and eastern portions of the main colony area have been abandoned by nesting terns; these areas are now occupied by loafing adult terns

7/1 – 7/7/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony increased this past week; eagles flew over the colony more frequently, causing more adult terns to temporarily leave their nests unattended (50-100%), for greater lengths of time (up to 2 minutes) this week relative to the past several weeks; these disturbances also led to an increase in gull nest predation on tern eggs and chicks this past week relative to previous weeks

7/1 – 7/7/13 ›

Caspian terns have not attempted to re-nest in the northeast and southeast satellite colonies that were completely washed out during the high tide series two weeks ago; nesting Caspian terns remain in and amongst the ring-billed gull colony, where some appear to be sitting on eggs; ca. 100 Caspian terns continue to prospect on the south/southeast beach, where about 20 adult terns appear to be sitting on nests

7/1 – 7/7/13 ›

Many adult cormorants nesting in the designated cormorant colony area on East Sand Island are not remaining on the colony during the day, leaving their chicks unattended; cormorant chicks are growing larger and more mobile, and many are forming large crèches that are moving about the colony; bald eagle disturbance to nesting cormorants increased this past week, causing complete nest failure in some sections of the colony

7/1 – 7/7/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorants were not observed in either dissuasion area (east or west) the past two weeks; cormorant hazing activities were not conducted on East Sand Island this past week, nor the previous week; previous hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date

7/1 – 7/7/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 63 of 73 operable satellite transmitters were detected at or near East Sand Island; 13 transmitters were detected elsewhere: 7 on Rice Island; 2 on the Astoria-Megler Bridge; 2 in Willapa Bay, WA; one at a small colony in the lower Columbia River near Troutdale, OR; one in Barkley Sound on Vancouver Island, BC

7/1 – 7/7/13 ›

High count of ca. 1,175 Brandt’s cormorants and a minimum count of ca. 1,000 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts the previous three weeks

7/1 – 7/7/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen, with evidence of fresh bald eagle predation on a ring-billed gull chick this past week

Weekly Update for 6/24 – 6/30/2013

6/24 – 6/30/13 ›

Estimated numbers of adult Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 7,000 and ca. 11,500 birds this past week, generally lower than counts conducted the past several weeks; as chicks get older and more mobile, it has become increasingly difficult to track the success of individual nesting attempts, but thousands of tern chicks are present on-colony

6/24 – 6/30/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony continued; no change in frequency or severity of disturbances this past week compared to the previous 6 weeks

6/24 – 6/30/13 ›

Caspian terns have not attempted to re-nest in the northeast and southeast satellite colonies that were completely washed out during the high tide series the previous week; nesting Caspian terns remain in and amongst the ring-billed gull colony, where some appear to be sitting on eggs; ca. 400 Caspian terns continue to prospect on the south/southeast beach; only 7 of these terns appear to be sitting on nests

6/24 – 6/30/13 ›

Nesting cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; cormorant chicks are growing larger and more mobile, and some are leaving their nests; multi-chick nests are still common, with some nests containing as many as 5 chicks; bald eagle disturbance to nesting cormorants has not been observed the previous two weeks

6/24 – 6/30/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorants were not observed in either dissuasion area (east or west) this past week; hence, cormorant hazing activities were not conducted on East Sand Island for the first time this breeding season; previous hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date

6/24 – 6/30/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 63 of 76 operable satellite transmitters were detected at or near East Sand Island; 13 transmitters were detected elsewhere: 5 on the Astoria-Megler Bridge; 3 in Willapa Bay, WA; 3 in the upper Columbia River estuary; one at a small colony in the lower Columbia River near Troutdale, OR; one on the Chehalis River near Aberdeen, WA

6/24 – 6/30/13 ›

Continuation of PIT-tagged fish deposition study on the double-crested cormorant colony at East Sand Island; 84 PIT-tagged fish fed to cormorants on the colony to determine the rate at which consumed PIT tags are deposited on-colony, as opposed to off-colony

6/24 – 6/30/13 ›

High count of ca. 1,330 Brandt’s cormorants and a minimum count of ca. 1,050 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts the previous three weeks

6/24 – 6/30/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen, with evidence of fresh falcon predation on a ring-billed gull chick this past week

Weekly Update for 6/17 – 6/23/2013

6/22/13 ›

Aerial surveys of Columbia River estuary, Willapa Bay, and Grays Harbor; main objectives of the surveys were to detect and photograph new and previously known double-crested cormorant breeding colonies; estimates of numbers of active nests at each colony will be provided in a later update, once photography has been interpreted

6/22/13 ›

Fourth set of high-resolution aerial photography taken of East Sand Island by Bergman Photographic to estimate the numbers of Caspian terns and double-crested cormorants nesting on East Sand Island; counts of active Caspian tern and double-crested cormorant nests will be provided in a later update once counts from photography have been completed

6/21/13 ›

First glaucous-winged/western gull chick observed on East Sand Island gull colony

6/17 – 6/23/13 ›

35 adult double-crested cormorant were captured at the East Sand Island cormorant colony and banded with field-readable alphanumeric leg bands; in total, 201 adult double-crested cormorants have been banded in 2013

6/17 – 6/23/13 ›

Estimated numbers of Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 5,000 and ca. 14,000 birds this past week, generally lower than counts conducted the past several weeks; as chicks get older and more mobile, it has become increasingly more difficult to track the success of individual nesting attempts, but thousands of tern chicks are present on-colony; nests located at the periphery of the colony continue to experience high rates of egg depredation by gulls, with terns continuing to re-lay in these areas following egg loss

6/17 – 6/23/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony continued; no change in frequency or severity of disturbances this week compared to the previous 5 weeks; no major colony disturbances observed this past week

6/17 – 6/23/13 ›

Caspian terns in the northeast and southeast satellite colonies were completely washed out during the high tide series this past week; over 200 Caspian terns remain in and amongst the ring-billed gull colony, where ca. 80 terns appear to be sitting on nests; 200-300 Caspian terns continue to prospect on the south/southeast beach; only two of these birds appear to be sitting on nests

6/17 – 6/23/13 ›

Nesting cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; cormorant chicks are growing larger and more mobile; multi-chick nests are still common, with some nests containing as many as 5 chicks; bald eagle disturbance to nesting cormorants was not observed this past week

6/17 – 6/23/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorants continue to show little interest in the dissuasion areas this past week; prospecting cormorants were hazed in the west dissuasion area only 2 times this past week, with up to ca. 350 adult cormorants counted in that area; dissuasion activities in the east dissuasion area were not conducted again this past week because cormorants have recently shown little interest in nesting there; hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date; California brown pelican continue to roost on some of the beaches surrounding the cormorant nest dissuasion areas, with some pelicans flushed from these areas during our cormorant dissuasion efforts

6/17 – 6/23/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 70 of 77 operable satellite transmitters were detected at or near East Sand Island; 7 transmitters were detected elsewhere, three on the Astoria-Megler Bridge; two in Willapa Bay, WA; one in Grays Harbor, WA; and one at a small colony in the lower Columbia River near Troutdale, OR

6/17 – 6/23/13 ›

High count of ca. 1,670 Brandt’s cormorants and a minimum count of ca. 1,000 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts the previous two weeks

6/17 – 6/23/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen, with evidence of fresh eagle and falcon predation on nesting colonial waterbirds observed on both ends of the island once again this past week

Weekly Update for 6/10 – 6/16/2013

6/13/13 ›

5 double-crested cormorant adults were captured and banded with field-readable alphanumeric leg bands at East Sand Island cormorant colony

6/10/13 ›

Aerial survey of the Oregon Coast; main objectives of the surveys were to detect and photograph new and previously-known breeding colonies of double-crested cormorants

6/10/13 ›

Island-wide count revealed ca. 3,200 California brown pelicans roosting on East Sand Island, mostly on south beaches

6/10 – 6/16/13 ›

Estimated numbers of Caspian terns on the 1.58-acre designated tern colony area on East Sand Island fluctuated between ca. 9,000 and ca. 14,000 birds this past week, similar to counts conducted the past several weeks; many chicks located in interior areas of the colony have survived and are now partially feathered; nests located at the periphery of the colony continue to experience high rates of egg depredation by gulls, with terns re-laying in these areas following egg loss

6/10 – 6/16/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony continued; no change in frequency or severity of disturbances this week compared to the previous 4 weeks; just after sunset on 15 June there was a major disturbance to the tern colony causing 100% of the terns and brown pelicans roosting nearby to flush from the island for nearly 20 minutes; the next day a severed tern chick head and wing were found on the north beach suggesting that the disturbance the previous night had been caused by an avian predator

6/10 – 6/16/13 ›

Caspian terns continue to prospect for nest sites on the northeast, southeast, and south satellite colonies despite complete nest failure at these 3 satellite colonies 3 weeks ago due to inundation during a high high tide series; as many as 130 and 40 terns were counted in the southeast and northeast satellite colonies, respectively; there are currently no tern eggs in either of these satellite colonies; ca. 40 Caspian terns were counted in an upland area east of the south satellite colony, 5 of which appeared to be sitting in nest scrapes; significant disturbance and predation by peregrine falcons and glaucous-winged/western gulls continue at the satellite colonies on the east beaches

6/10 – 6/16/13 ›

Nesting cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; most of the double-crested cormorant nests contain chicks covered in down, with many nests containing 3- to 5-chick broods; bald eagle disturbance to nesting cormorants increased again this past week, causing nesting Brandt’s cormorants to abandon their nests on a portion of their colony; these birds returned to the colony and were once again attending nests with eggs by the end of the week

6/10 – 6/16/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorants continue to show little interest in the dissuasion areas this past week; prospecting cormorants were hazed in the west dissuasion area only 3 times this past week, with up to ca. 430 adult cormorants counted in that area; dissuasion activities in the east dissuasion area were not conducted again this past week because cormorants have recently shown little interest in nesting there; hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date; California brown pelican continue to roost on some of the beaches surrounding the cormorant nest dissuasion areas, with some pelicans flushed from these areas during our cormorant dissuasion efforts

6/10 – 6/16/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 75 of 78 operable satellite transmitters were detected at or near East Sand Island; only 3 transmitters were detected elsewhere, two on the Astoria-Megler Bridge and one at a small colony in the lower Columbia River near Troutdale, OR

6/10 – 6/16/13 ›

High count of ca. 1,700 Brandt’s cormorants and a minimum count of ca. 1,000 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, similar to the high counts the previous week

6/10 – 6/16/13 ›

Weekly Update for 6/3 – 6/9/2013

6/8 -6/9/13›

Aerial surveys of Columbia River estuary, Willapa Bay, Grays Harbor, the entire outer Washington coast, the Strait of Juan de Fuca, the Gulf and San Juan Islands, and Puget Sound; main objectives of the surveys were to detect and photograph new and previously known double-crested cormorant breeding colonies; nesting double–crested cormorants were detected at 8 different colony sites along the outer Washington coast and Strait of Juan de Fuca, including Tunnel Island, Point of Arches, White Rock, Jagged Island, Half Round Rock, Hoh Head, Erin, and Petrel Island; nesting double–crested cormorants were detected at 8 different colony sites in the Salish Sea region of Washington, including Smith Island, Minor Island, Williamson Rocks, Snohomish River Mouth, Goose Island in Cattle Pass, Mandarte Island, the Crofton Outflow Towers, and Drayton Harbor; estimates of numbers of active nests at each of these colonies in coastal Washington will be provided in a later update, once photography has been interpreted

6/8/13 ›

Third set of high-resolution aerial photography taken of East Sand Island by Bergman Photographic to estimate the numbers of nesting Caspian terns and double-crested cormorants on East Sand Island; counts of active Caspian tern and double-crested cormorant nests will be provided in a later update once counts from photography have been completed

6/8/13 ›

First Brandt’s cormorant chick observed on East Sand Island cormorant colony

6/3 – 6/9/13 ›

Numbers of Caspian terns on the 1.58-acre designated tern colony area on East Sand Island have held steady or increased slightly this week; many chicks located in interior areas of the colony have survived at least 10 days; some nests contain three-chick broods; nests located at the periphery of the colony continue to experience high rates of egg depredation by gulls, with terns re-laying in these areas following egg loss

6/3 – 6/9/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony continued; no change in frequency or severity of the disturbances this week compared to the previous 3 weeks

6/3 – 6/9/13 ›

Caspian terns continue to prospect for nest sites on the northeast, southeast, and south satellite colonies despite complete nest failure at these 3 satellite colonies 2 weeks ago due to inundation during a high high tide series; on 3 June, 150 and 75 terns were counted in the northeast and southeast satellite colonies, respectively; at least one tern egg was laid in each of these satellite colonies but subsequently disappeared, apparently depredated by gulls; aerial survey on 8 June revealed 193 Caspian terns on an upland area east of the south satellite colony, 72 of which appeared to be sitting in nest scrapes; aerial survey on 10 June revealed ca. 470 Caspian terns in the area of the ring-billed gull colony, 178 of which appeared to be sitting in scrapes; no Caspian terns seen loafing or prospecting for nest sites at the west end of East Sand Island, in the western-most cormorant dissuasion area

6/3 – 6/9/13 ›

Nesting cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; approximately 75% of the double-crested cormorant nests contain chicks, some with 3- or 4-chick broods; bald eagle disturbance to nesting cormorants increased this past week; as many as 10 bald eagles observed on the western end of the colony preying on adult cormorants and eating cormorant eggs; despite this increase in bald eagle activity on the cormorant colony, no large flushes of cormorants from the colony were observed

6/3 – 6/9/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorant use of the dissuasion areas declined this past week; prospecting cormorants were hazed up to 2 times/day in the west dissuasion area, with up to ca. 1,400 adult cormorants counted in that area; dissuasion activities in the east dissuasion area were not conducted again this past week because cormorants have recently shown little interest in nesting there; hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date; California brown pelican continue to use of the beaches surrounding the cormorant nest dissuasion areas, with some pelicans flushed from these areas during our cormorant dissuasion efforts

6/3 – 6/9/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 76 of 78 operable satellite transmitters were detected at or near East Sand Island; only 2 transmitters were detected elsewhere, one on the Astoria-Megler Bridge and one in Troutdale, OR

6/3 – 6/9/13 ›

Continuation of PIT-tagged fish deposition study on the double-crested cormorant colony at East Sand Island; 77 PIT-tagged fish fed to cormorants on the colony to determine the rate at which consumed PIT tags are deposited on-colony, as opposed to off-colony

6/3 – 6/9/13 ›

High count of 1,720 Brandt’s cormorants and a minimum count of ca. 1,000 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, up from the high count the previous week

6/3 – 6/9/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; 5 Caspian tern carcasses, 3 ring-billed gull carcasses, and 3 double-crested cormorant carcasses found this past week, all apparently killed by avian predators

Weekly Update for 5/27 – 6/2/2013

5/31/13 ›

Second aerial survey of lower Columbia River and upper estuary; main objectives of the flight were to detect the possible formation of new piscivorous waterbird colonies; no new tern or cormorant colonies detected; 60-80 double-crested cormorant nests observed on power transmission towers in lower Columbia River near Troutdale, OR; ca. 200 American white pelicans seen on Miller Sands Spit in the upper estuary

5/28/13 ›

First Caspian tern chick observed on East Sand Island tern colony

5/27/13 ›

First double-crested cormorant chick observed on East Sand Island cormorant colony

5/27 – 6/2/13 ›

Numbers of Caspian terns on the 1.58-acre designated tern colony area on East Sand Island remained approximately stable; high count during week of ca. 11,700 adult terns on-colony, similar to high counts the previous 2 weeks; number of active tern nests on-colony also appears approximately stable; scattered showers continued to cause significant erosion on-colony; water collecting along the silt fencing on the east side of the colony caused some nest failure and abandonment of Caspian tern nests; California brown pelicans observed on tern colony, disturbing nesting terns and, on one occasion, eating tern eggs

5/27 – 6/2/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony continued; this past week multiple eagle flyovers occurred throughout the day causing 10-25% of the colony to flush, resulting in 0-10 egg depredations by gulls along the colony edge per flush event

5/27 – 6/2/13 ›

All Caspian tern satellite colonies, with the exception of the one in the ring-billed gull colony, were completely washed out during last week’s high tide series; number of adult terns in the ring-billed gull colony fluctuates between 70-150 birds, with about 10 attending nests; no Caspian terns seen loafing or prospecting for nest sites at the west end of East Sand Island, in the western-most cormorant dissuasion area

5/27 – 6/2/13 ›

Nesting double-crested cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; final count of high resolution photography taken on 24 May revealed about 15,050 cormorant nests between the two privacy fences on that date; bald eagle disturbance to nesting cormorants declined this past week, with only one recorded disturbance

5/27 – 6/2/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island cormorant colony; double-crested cormorant use of the dissuasion areas declined this past week; prospecting cormorants were hazed up to 4 times/day in the west dissuasion area, with up to 700 adult cormorants counted in that area; dissuasion activities in the east dissuasion area were not conducted again this past week because cormorants have recently shown little interest in nesting there; hazing efforts have been successful in preventing cormorants from nesting in the dissuasion areas, where no cormorant egg-laying has been detected to date; California brown pelican use of the beaches surrounding the cormorant nest dissuasion areas has increased, with up to 3,000 pelicans counted; dissuasion activities caused some pelicans to flush on three separate occasions

5/27 – 6/2/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 73 of 78 operable satellite transmitters were detected at or near East Sand Island; only 3 transmitters were detected elsewhere in the estuary, all on the Astoria-Megler Bridge; other locations visited by satellite-tagged cormorants this week included Grays Harbor, WA (1 tagged individual) and Troutdale, OR (1 tagged individual); 44 satellite-tagged cormorants (56%) have been confirmed to be nesting on East Sand Island between the two privacy fences

5/27 – 6/2/13 ›

Continuation of PIT-tagged fish deposition study on the double-crested cormorant colony at East Sand Island; 70 PIT-tagged fish were fed to cormorants on the colony to determine the rate at which consumed PIT tags are deposited on-colony, as opposed to off-colony

5/27 – 6/2/13 ›

36 double-crested cormorant adults were captured and banded with field-readable alphanumeric leg bands at East Sand Island cormorant colony

5/27 – 6/2/13 ›

High count of 1,617 Brandt’s cormorants and a minimum count of 766 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, up from the high count the previous week; most Brandt’s cormorants are incubating eggs on the cormorant colony

5/27 – 6/2/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; two ring-billed gull carcasses and one double-crested cormorant carcass found, likely killed by avian predators

Weekly Update for 5/20 – 5/26/2013

5/24/13 ›

Second set of high-resolution aerial photographs taken of the tern and cormorant colonies on East Sand Island by Bergman Photographic; photos will be counted to estimate size of the double-crested cormorant and Caspian tern colonies during late incubation; a preliminary count of the cormorant colony indicates that there were over 8,000 active cormorant nests between the two privacy fences on 5/10; a more accurate count of the number of active cormorant nests in the 5/24 photography will be completed by June 1

5/24/13 ›

Island-wide count revealed over 1,000 California brown pelicans roosting on East Sand Island, mostly on south and east beaches

5/23/13 ›

Colonel John Eisenhauer, Kevin Bryce, Joyce Casey, Sondra Ruckwardt, Mike Langsley, and Cindy Studebaker with the U.S. Army Corps of Engineers – Portland District visited East Sand Island

5/20 – 5/26/13 ›

Numbers of Caspian terns nesting in the 1.58-acre designated tern colony area on East Sand Island remained approximately stable compared to the previous week; high count during week of ca. 11,700 adult terns on the colony, similar to the high count the previous week; heavy rains on 23 May caused significant erosion and flooding on the tern colony; 85% of tern nest scrapes on colony had standing water in them for several hours; the majority of terns on colony continued to incubate despite the flooding; however, others temporarily abandoned their nest scrapes and eggs; after the rain subsided and the colony dried out, terns that had abandoned their nests returned and began incubating again

5/20 – 5/26/13 ›

Caspian terns continued prospecting for nest sites along the upper beaches to the northeast, east, and south of the main Caspian tern colony on East Sand Island; as high tide levels increased this past week, these satellite colonies began to fail; as of 25 May, both the NE and SE satellite colonies were completed washed out by the high tides; the majority of nests on the south beach satellite colony have also failed as a result of high high tides; the number of terns nesting within the ring-billed gull colony on the upper northeast beach increased from 7 the previous week to 35 this past week; up to 300 Caspian terns seen loafing and prospecting for nest sites on the west end of East Sand Island, in the western-most cormorant dissuasion area; cormorant dissuasion activities in this area (active hazing) have apparently precluded terns from initiating nesting at the west end of East Sand Island

5/20 – 5/26/13 ›

Nesting double-crested cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; average clutch size increased during the week with most nests containing 4-5 eggs; bald eagles continued to displace cormorants from their nests on the rip rap along the southern edge of the cormorant colony by walking through the colony eating cormorant eggs; to date this eagle disturbance, with associated gull depredation of cormorant eggs, has not caused any sections of the cormorant colony to completely fail

5/20 – 5/26/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island double-crested cormorant colony; double-crested cormorants attempting to build nests in the west dissuasion area were hazed up to 11 times/day, with up to 600 adult cormorants counted in that area; dissuasion activities in the east dissuasion area were not conducted this past week because cormorants have shown little interest in nesting there; to date, hazing efforts have been successful in preventing cormorants from nesting; no cormorant egg-laying has been detected in either of the dissuasion areas

5/20 – 5/26/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 71 of 80 operable satellite transmitters were detected at or near East Sand Island; only 4 transmitters were detected elsewhere in the estuary, all on the Astoria-Megler Bridge; other locations visited by satellite-tagged cormorants this week included Willapa Bay, WA (1 tagged individual); Grays Harbor, WA (1 tagged individual); and Troutdale, OR (1 tagged individual); 40 satellite-tagged cormorants (50%) have been confirmed to be nesting on East Sand Island between the two privacy fences

5/20 – 5/26/13 ›

High count of 1,182 Brandt’s cormorants and 342 active Brandt’s cormorant nests on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, up from the high count the previous week; some Brandt’s cormorants are incubating eggs on the cormorant colony

5/20 – 5/26/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; one unidentified carcass and one ring-billed gull carcass found, likely killed by avian predators; sub-adult bald eagle observed killing and eating one adult Caspian tern at the south beach satellite colony

Weekly Update for 5/13 – 5/19/2013

5/13 – 5/19/13 ›

Number of Caspian terns nesting in the 1.58-acre designated tern colony area on East Sand Island leveled off this past week; high count during week of ca. 11,100 adult terns on the colony, down slightly from the high count the previous week; most terns attending nest scrapes with eggs

5/13 – 5/19/13 ›

Bald eagle disturbance at the East Sand Island Caspian tern colony increased this past week; adult and sub-adult bald eagles observed stealing fish from terns returning to the colony to feed their mates, causing 50-100% of terns to flush from the colony; during each disturbance, 20-30 glaucous-winged/western gulls loafing at the perimeter of the colony consumed 30-60 tern eggs from unattended nests colony-wide; most egg loss occurred along the NE edge of the colony, with nest loss reaching up to 15 yds into the colony; terns that had their nest contents depredated by gulls continued to attend their nests and some have re-laid

5/13 – 5/19/13 ›

Caspian terns continued prospecting for nest sites along the upper beaches to the northeast, east, and south of the main Caspian tern colony on East Sand Island; up to 650, 100, and 400 adult terns, respectively, were counted in each of these incipient satellite colony areas; nesting behaviors (i.e., copulation and digging nest scrapes) and egg-laying were observed in each satellite colony; the number of tern eggs counted in each satellite colony varied widely due to a high rates of nest failure; to date, USACE contractors have installed stakes, rope, and flagging on ca. 2.0 acres of potential tern nesting habitat outside the 1.58-acre designated tern colony area on the upper beaches at the east end of the island; up to 200 Caspian terns seen loafing and prospecting for nest sites on the west end of East Sand Island, in the western-most cormorant dissuasion area; cormorant dissuasion activities in this area (active hazing) have apparently precluded terns from initiating nesting at the west end of East Sand Island

5/13 – 5/19/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island double-crested cormorant colony; double-crested cormorants attempting to build nests in the west dissuasion area were hazed up to 10 times/day, with up to 410 adult cormorants counted in that area; dissuasion activities in the east dissuasion area were not carried out this past week since cormorants have shown little interest in nesting there; to date, hazing efforts have been successful in preventing cormorants from nesting; no cormorant egg-laying detected in either of the dissuasion areas

5/13 – 5/19/13 ›

Nesting double-crested cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; clutch size increased during the week with most nests containing 3-5 eggs; bald eagle disturbance to the cormorant colony increased during the latter half of the week, especially in the western part of the colony; adult eagles were observed walking through the colony eating cormorant eggs and, occasionally, adult cormorants; gulls followed the eagles, taking cormorant eggs and adding to cormorant nest failure

5/13 – 5/19/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 73 of 80 operable satellite transmitters were detected at or near East Sand Island; only 3 transmitters were detected elsewhere in the estuary, all on the Astoria-Megler Bridge; other locations visited by satellite-tagged cormorants this week included Willapa Bay, WA (2 tagged individuals); Grays Harbor, WA (1 tagged individual); and Troutdale, OR (1 tagged individual)

5/13 – 5/19/13 ›

High count of 966 Brandt’s cormorants on the designated cormorant colony area between the two privacy fences on East Sand Island this past week, down from the high count the previous week; Brandt’s cormorants have initiated egg-laying on the island, but the numbers of active nests seems to have leveled off since the previous week

5/13 – 5/19/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; 2 double-crested cormorant carcasses and one Caspian tern carcass found, likely killed by avian predators; bald eagles observed killing and eating at least one double-crested cormorant; river otter seen on west end of Caspian tern colony

5/17/13 ›

Boat-based survey of the upper Columbia River estuary; main objectives of the survey were to locate prospective piscivorous waterbird colony sites and estimate the number of breeding birds at existing colonies; 165 double-crested cormorant nests and 63 pelagic cormorant nests counted on the Astoria-Megler Bridge; 163 double-crested cormorant nests counted on 7 channel markers located near Rice Island; ca. 220 nesting American white pelicans counted on Miller Sands Spit; Rice Island not surveyed

Weekly Update for 5/6 – 5/12/2013

5/6 – 5/12/13 ›

Caspian terns continuing to fill in the 1.58-acre designated tern colony area on East Sand Island; high count during week of ca. 12,400 adult terns on the colony, with most terns attending nest scrapes with eggs; European beach grass encroaching the core colony area on the extreme western end

5/6 – 5/12/13 ›

Caspian tern colony on East Sand Island continues to be disturbed by bald eagles that visit the colony routinely in the early morning and late afternoon; these disturbances cause 75-100% of nesting terns to flush and leave their nest unattended for up to a minute before they return to the colony; when tern nests are left unattended, 15-20 glaucous-winged/western gulls comb the colony and take between 7 -15 tern eggs/disturbance from the colony, generally from nests that are located at the periphery of the colony; a major colony disturbance occurred at 2100 hours on 7 May, causing 100% of the terns to leave their nests for 20-30 minutes (cause of disturbance unknown)

5/6 – 5/12/13 ›

Caspian terns continued prospecting for nest sites on the east end beaches of East Sand Island near the existing ring-billed gull colony; throughout the week ca. 100-250 Caspian terns were counted in this area, with nesting behaviors observed (i.e., copulation and digging nest scrapes); 5 tern eggs were discovered in nest scrapes on the southeast beach on 9 May, all of these tern nests had subsequently failed by 12 May (cause unknown); a new satellite tern colony was initiated on the south beach adjacent to the main Caspian tern colony, and at least one tern egg had been laid on this satellite colony by 12 May; to date, USACE contractors have installed stakes, rope, and flagging on ca. 2.0 acres of potential tern nesting habitat outside the 1.58-acre designated tern colony area on East Sand Island; these nest dissuasion materials have displaced prospecting Caspian terns on the east beach to the south and north of the ring-billed gull colony; up to 50 Caspian terns seen loafing and prospecting for nest sites on the west end of East Sand Island, in the western-most cormorant dissuasion area; nest dissuasion activities in this area (see below) have prevented terns from initiating nesting

5/6 – 5/12/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island double-crested cormorant colony; double-crested cormorants attempting to build nests in the dissuasion areas were hazed up to 10 times/day and 5 times/day in the west and east dissuasion areas, respectively; cormorants showed more interest in nesting on the west dissuasion area (up to 450 cormorants counted) as compared to the east dissuasion area (up to 100 cormorants counted); hazing efforts have been successful in keeping cormorants from nesting in the dissuasion areas; to date, no cormorant eggs have been observed or collected in either of the dissuasion areas

5/6 – 5/12/13 ›

Nesting double-crested cormorants continue to fill in the designated cormorant colony area on East Sand Island between the two privacy fences; due to the large number of nesting cormorants in this area, accurate counts of adults from the observation blinds are no longer possible; nesting behaviors (courtship displays, nest-building) continue and egg-laying is well underway; bald eagle disturbances to the cormorant colony decreased this week compared to the previous week, with only 3 disturbances recorded (12 recorded the previous week)

5/6 – 5/12/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in April 2013 resided on the island this past week; by week's end, 75 of 81 operable satellite transmitters were detected at or near East Sand Island; only 4 transmitters were detected elsewhere in the estuary, 3 at the Astoria-Megler Bridge and 1 in the upper estuary; other locations visited by satellite-tagged cormorants this week included Grays Harbor, WA (1 tagged individual) and Longview, WA (1 tagged individual)

5/6 – 5/12/13 ›

High count of 1,290 Brandt’s cormorants on the designated cormorant colony area between the two privacy fences on East Sand Island; Brandt’s cormorants have initiated egg-laying on the island

5/10/13 ›

Island-wide count revealed ca. 775 California brown pelicans roosting on East Sand Island, mostly on southeast and south beach

5/6 – 5/12/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; 9 Caspian tern carcasses found, likely killed by avian predators; bald eagles observed killing and eating at least one double-crested cormorant; river otter seen on west end of island

5/10/13 ›

First set of high-resolution aerial photographs taken of East Sand Island by Bergman Photographic to estimate the number of active cormorant nests on the East Sand Island cormorant colony

5/9/13 ›

Contractors from Newellan LLC visited East Sand Island

5/6/13 ›

First Brandt’s cormorant egg observed on the designated cormorant colony area between the two privacy fences on East Sand Island

Weekly Update for 4/29 – 5/5/2013

5/2 – 5/4/13 ›

15 double-crested cormorant adults were captured and banded with field-readable alphanumeric leg bands at East Sand Island cormorant colony

5/1/13 ›

Commencement of PIT-tagged fish deposition study on the double-crested cormorant colony at East Sand Island; PIT-tagged fish are fed to cormorants on the colony to determine the rate at which consumed PIT tags are deposited on-colony, as opposed to off-colony

4/29 – 5/5/13 ›

Caspian terns continuing to fill in the 1.58-acre designated tern colony area on East Sand Island; by the end of the week ca. 9,800 adult terns were counted on the colony, with most observed digging nest scrapes and/or sitting in nest scrapes with eggs

4/29 – 5/5/13 ›

Caspian tern colony on East Sand Island continues to be disturbed by a single adult bald eagle that visits the colony routinely in the early morning and late afternoon; these disturbances cause 90-100% of nesting terns to flush and leave their nest unattended for up to a minute before they return to the colony; when tern nests are left unattended, 15-20 glaucous-winged/western gulls comb the colony and take between 4-10 tern eggs/disturbance from the colony, generally from nests that are located at the periphery

4/29 – 5/5/13 ›

Caspian terns prospecting for nest sites on the east end beaches of East Sand Island near the existing ring-billed gull colony; by the end of the week ca. 1,500 Caspian terns were counted in this area, with some pre-nesting behaviors observed (i.e., copulation and digging nest scrapes); on 30 April, one Caspian tern egg was laid and later depredated by a glaucous-winged/western gull on this incipient satellite colony; no additional tern eggs were detected on the satellite colony later in the week; to date, USACE contractors have installed stakes, rope, and flagging on ca. 1.5 acres of potential tern nesting habitat outside the 1.58-acre designated tern colony area on East Sand Island; these nest dissuasion materials have displaced prospecting Caspian terns on the east beach to the south and north of the dissuasion; a recent neep tide series has opened up tern nesting habitat along the high-high tide line north of the installed dissuasion; if terns attempt to nest in this area they will likely fail during the next spring tide series

4/29 – 5/5/13 ›

Ground-based surveys of a pier at Tongue Point, OR in the upper Columbia River estuary; 230 loafing Caspian terns counted on pier on 29 April; 102 loafing Caspian terns counted on pier on 1 May

4/29 – 5/5/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island double-crested cormorant colony; double-crested cormorants attempting to build nests in the dissuasion areas were hazed up to 10 times/day and 4 times/day in the west and east dissuasion areas, respectively; cormorants showed more interest in nesting on the west dissuasion area (up to 700 cormorants counted) as compared to the east dissuasion area (up to 350 cormorants counted); hazing efforts have been successful in keeping cormorants from nesting in the dissuasion areas; to date, no cormorant eggs have been observed or collected in the dissuasion areas

4/29 – 5/5/13 ›

Double-crested cormorants continue to fill in the designated colony area on East Sand Island between the two privacy fences; due to the large number of cormorants in this area, accurate counts of adults from the observation blinds are no longer possible; nesting behaviors (courtship displays, nest-building) continue and egg-laying has commenced on-colony; bald eagle disturbances to the cormorant colony have increased this week compared to the previous week, with 12 disturbances recorded (only one recorded the previous week); as a result, the incidence of glaucous-winged/western gull depredation on cormorant eggs has also increased compared to the previous week

4/29 – 5/5/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in 2013 have remained on the island this past week; by week's end, 68 of 81 operable satellite transmitters were detected at or around East Sand Island; only 8 transmitters were still being detected elsewhere in the estuary, 7 at the Astoria-Megler Bridge and 1 in the upper estuary; other locations visited by satellite-tagged cormorants included Grays Harbor (2 tagged individuals), two historical cormorant colonies on the outer Washington coast north of Grays Harbor (2 tagged individuals), the west coast of Vancouver Island, B.C. (1 tagged individual), Longview, WA (1 tagged individual), Troutdale, OR (1 tagged individual), and West Salem, OR (1 tagged individual)

4/29 – 5/5/13 ›

High count of 1,141 Brandt’s cormorants on the designated colony area between the two privacy fences on East Sand Island; nest building and courtship displays observed

4/29 – 5/5/13 ›

Up to 100 California brown pelicans counted roosting on East Sand Island, mostly on southeast and south beach

4/29 – 5/5/13 ›

Contractors from Newellan LLC visited East Sand Island on 30 April and 4 May; Dr. Helen Diggs (attending veterinarian for the OSU Institutional Animal Care and Use Committee), Richard Diggs, and Nao Kumada (graduate student from Japan) visited East Sand Island on 29 April

4/29 – 5/5/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; 2 glaucous-winged/western gull carcasses found, likely killed by bald eagles; bald eagles observed killing and eating at least one adult Caspian tern and one adult double-crested cormorant

Weekly Update for 4/22 – 4/28/2013

4/28/13 ›

Paul Schmidt (USACE-Portland District) and three contractors (Newellan LLC) visited East Sand Island

4/27/13 ›

First double-crested cormorant egg observed on the designated colony area between the two privacy fences on East Sand Island

4/25/13 ›

First Spit

4/24/13 ›

First aerial survey of Columbia River estuary, Willapa Bay, and Grays Harbor; main objectives of the flight were to detect the possible formation of new Caspian tern and/or double-crested cormorant colonies; no new tern colonies were detected in the upper estuary, Willapa Bay, or Gray's Harbor

4/23/13 ›

First Caspian tern egg observed on East Sand Island tern colony; egg depredated by glaucous-winged/western gull

4/22 – 4/28/13 ›

Caspian terns continuing to fill in the 1.58-acre designated tern colony area on East Sand Island; by the end of the week ca. 6,750 terns were counted on the colony with most observed digging and/or sitting in nest scrapes

4/22 – 4/28/13 ›

Caspian tern colony on East Sand Island continues to be disturbed by bald eagles that visit the colony routinely in the early morning and late afternoon; these disturbances cause some, but not all, terns to take flight for up to 1 minute before settling back down on colony; nighttime disturbances to the Caspian tern colony reported last week have diminished, with no nighttime colony disturbances noted since 4/21

4/22 – 4/28/13 ›

Caspian terns prospecting for nest sites on the east end beaches of East Sand Island near the existing ring-billed gull colony; by the end of the week ca. 1,000 Caspian terns were counted in this area, with some pre-nesting behaviors (i.e., copulations and digging of nest scrapes) observed; to date no tern eggs have been observed on this satellite colony; to date, USACE contractors have installed stakes, rope, and flagging on ca. 0.25 acres of potential tern nesting habitat outside the 1.58-acre designated tern colony area on East Sand Island

4/22 – 4/28/13 ›

Continued daytime monitoring of the dissuasion areas on the East Sand Island double-crested cormorant colony; daily hazing of double-crested cormorants attempting to build nests in the dissuasion areas increased this week (up to 9 times/day) as compared to last week (1-2 times/day); cormorants showing more interest in the west dissuasion area (up to 2,200 cormorants counted) as compared to the east dissuasion area (up to 400 cormorants counted); hazing efforts have been mostly successful in keeping cormorants out of the dissuasion areas; to date, no cormorant eggs were observed or collected in the dissuasion areas

4/22 – 4/28/13 ›

Double-crested cormorants continue to fill in the designated colony area on East Sand Island between the two privacy fences with more than 7,000 cormorants counted in that area by the end of the week; nesting behaviors (courtship displays, nest-building) continue and egg-laying has commenced on-colony; bald eagle disturbances to the cormorant colony have declined this week as compared to the previous week, with only one disturbance recorded; this week, ca. 1,000 double-crested cormorants continue to loaf on north beach throughout the day

4/22 – 4/28/13 ›

Most of the double-crested cormorants that were satellite-tagged on East Sand Island in 2013 have returned to the island this past week; by week's end, 66 of 81 operable satellite transmitters were detected at or around East Sand Island; only 6 transmitters were still being detected elsewhere in the estuary, 4 at the Astoria-Megler Bridge and 2 in the upper estuary; other locations visited by satellite-tagged cormorants included the Grays Harbor/Chehalis River area (4 tagged individuals), Longview (2 tagged individuals), Puget Island (1 tagged individual), Troutdale (1 tagged individual), and Bonneville Dam (1 tagged individual)

4/22 – 4/28/13 ›

High count of 432 Brandt’s cormorants on the designated colony area between the two privacy fences on East Sand Island; nest building and courtship displays observed; no Brandt’s cormorant eggs were observed

4/22 – 4/28/13 ›

Up to 33 California brown pelicans counted roosting on East Sand Island, mostly on southeast beach

4/22 – 4/28/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; one gull carcass and one Caspian tern carcass found, likely killed by peregrine falcon and bald eagle, respectively

Weekly Update FOR 4/15 – 4/21/2013

4/17/13 ›

First double-crested cormorants (347) observed in designated colony area between the two privacy fences

4/16/13 ›

Continuous daytime monitoring of the dissuasion areas on the East Sand Island double-crested cormorant colony began on 16 April; daily hazing (1-2 times/day) of double-crested cormorants attempting to build nests in the dissuasion areas commenced this week; the high count of double-crested cormorants in the dissuasion areas was 2,200 seen at first light on Tuesday (4/16); hazing efforts have been mostly successful in keeping cormorants out of the dissuasion areas; no cormorant eggs were observed or collected in the dissuasion areas this week

4/15 – 4/21/13 ›

Double-crested cormorants started to fill in the designated colony area on East Sand Island between the two privacy fences; nesting behaviors (courtship displays, nest-building) were observed on-colony; repeated bald eagle disturbance to the cormorant colony during mid-morning caused all birds to flush to the beaches early in the week; by Saturday (4/20), cormorants remained on colony for most of the day and throughout the night; by the end of the week over 2,000 cormorants observed on-colony

4/15 – 4/21/13 ›

After the first full week of tracking, most of the 83 satellite-tagged double-crested cormorants remain in the Columbia River estuary, but several dispersed outside the estuary; the most popular roosts for satellite-tagged cormorants were East Sand Island and the Astoria-Megler Bridge, where 57 and 65 tagged individuals, respectively, roosted at least once; other popular roost sites include the upper estuary (12 tagged individuals), Puget Island (8 tagged individuals), Longview (15 tagged individuals), and Willapa Bay (10 tagged individuals); other locations visited included: the Cowlitz River between Lexington and Mayfield Lake; the Columbia or Lewis rivers between Kalama and the Willamette River; the Willamette River up to Harrisburg, Oregon; the Troutdale area near a small established cormorant colony on transmission towers; Grays Harbor; the Chehalis River near Elma, Washington; the Sammamish River near Redmond, Washington; the Columbia River near Hood River, Oregon

4/15 – 4/21/13 ›

Ground-based surveys initiated to look for double-crested cormorant breeding colonies at the Astoria-Megler Bridge, Puget Island, Longview, the Lewis River, Troutdale, Oregon City, and Willapa Bay; no nesting activity observed at sites other than the Astoria-Megler Bridge and Troutdale power transmission towers; evening roost sites confirmed on Puget Island, in Longview, and on the Lewis River; roosting cormorants also observed above Willamette Falls in Oregon City; 39 double-crested cormorant nests counted on the transmission towers south of Lady Island near Troutdale, Oregon (35 nests counted in 2012)

4/15 – 4/21/13 ›

Caspian terns started to fill in the 1.58-acre designated tern colony area on East Sand Island; terns began digging nest scrapes immediately after arrival on-colony; courtship-feeding and copulating also observed; by the end of the week nearly 3,000 terns observed on-colony

4/15 – 4/21/13 ›

Caspian tern colony on East Sand Island flushed repeatedly by bald eagles; 2-4 eagle-caused colony flushes occur each day beginning around 1800 hours, resulting in all terns taking flight for up to 1 minute before settling back down on colony; nighttime disturbances to the Caspian tern colony also noted this past week; cause(s) of nocturnal disturbances to tern colony unknown

4/15 – 4/21/13 ›

Peregrine falcon regularly seen attacking ring-billed gulls on colony near the East Sand Island Caspian tern colony

4/15 – 4/21/13 ›

Caspian terns (25-100) loafing on the east end beaches of East Sand Island below the rack line; no nest scrapes or nesting attempts observed

4/15 – 4/21/13 ›

No Brandt’s cormorants observed on East Sand Island colony during week; high count of Brandt’s cormorants off-colony (near waterline on south side of island) was 300 individuals

4/15 – 4/21/13 ›

Signs of multiple predators observed on East Sand Island; bald eagles and peregrine falcons regularly seen; fresh river otter and raccoon tracks also observed on the island this past week; one gull carcass and one Caspian tern carcass found, likely killed by peregrine falcon

Update FOR 3/14 – 4/14/2013

4/14/13 ›

First high-tide colony count at the East Sand Island Caspian tern colony; 482 terns counted on colony; throughout the week of 4/8-14, 50-200 Caspian terns were seen loafing on beaches at the east end of East Sand Island

4/12 – 4/15/13 ›

83 double-crested cormorants captured in nest dissuasion area of East Sand Island cormorant colony and satellite-tagged; capture of double-crested cormorants for satellite-tagging took place during 4 consecutive nights and is now complete; satellite-tagged cormorants will be tracked to monitor whether hazed individuals relocate to the designated colony area on East Sand Island, leave East Sand Island and nest at another colony site, or leave East Sand Island to prospect other colony sites and return to East Sand Island and nest later in the season

4/11/13 ›

First cormorants (thousands) observed on East Sand Island cormorant colony site, all in the cormorant nest dissuasion area; 70-75% were double-crested cormorants, the remainder were Brandt’s cormorants

4/11/13 ›

Completion of East Sand Island colony preparations (i.e., building of observation blinds and above-ground tunnels, camp set up, laying out of colony grids, spreading PIT tags for detection efficiency studies, placing photo monuments for analysis of aerial photography, moving stick nests and tires to designated cormorant colony area for capture and banding)

4/7/13 ›

First Caspian terns (75) observed on East Sand Island tern colony

4/2/13 ›

First California brown pelican sighted in Columbia River estuary by project staff in 2013; one seen flying near East Sand Island; no brown pelicans have been seen since (as of 4/14) and none have yet been recorded on East Sand Island

3/24 - 3/27/13 ›

Independent contractor (Bear Power) refurbished the two visual barrier (“privacy”) fences built on the East Sand Island double-crested cormorant colony in 2011 and 2012; this feasibility study is designed to test whether cormorant nesting on East Sand Island can be restricted to the designated colony area between the two fences (4.5 acres of nesting habitat); if cormorants initiate nesting outside the designated colony area they will be hazed prior to egg-laying

3/24/13 ›

First Caspian tern sighted in Columbia River estuary by project staff in 2013; one seen flying over west end of East Sand Island

3/18/13 ›

First double-crested cormorants sighted in Columbia River estuary by project staff in 2013; several seen flying near East Sand Island

3/16/13 ›

First Brandt’s cormorants sighted in Columbia River estuary by project staff in 2013; seen on pile dikes adjacent to East Sand Island and flying over the island

3/14 – 4/14/13 ›

Signs of multiple predators observed on East Sand Island; as many as 14 bald eagles and tracks of a peregrine falcon were observed on the island; a single bald eagle caused repeated disturbance and colony flushes at the Caspian tern colony on 4/14

3/14/13 ›

Seasonal field crew began work in Columbia River estuary; commenced East Sand Island colony preparations (i.e., building of observation blinds and above-ground tunnels, camp set up, laying out of colony grids, spreading PIT tags sown for detection efficiency studies, placing photo monuments for analysis of aerial photography, moving stick nests and tires to designated cormorant colony area for capture and banding)