Weekly Update for 9/21 – 9/27/2009
9/23/09 ›
All Caspian tern chicks have left the East Sand Island tern colony; a few pre-fledging tern chicks remained on the east beach, adjacent to the tern colony
9/24/09 ›
Approximately 1.75 acres of tern nesting habitat on East Sand Island was sprayed with herbicide by a USACE contractor; the spraying was necessary to prevent the entire tern colony area from becoming vegetated and therefore unsuitable for tern nesting in 2010; 1.75 acres represents a 50% reduction in the amount of tern nesting habitat available to terns on East Sand Island in 2010 compared to 2009
Weekly Update for 9/14 – 9/20/2009
9/16/09 ›
Fifty adult Caspian terns and 35 pre-fledging tern chicks still attending the satellite colony on East Sand Island; no terns observed on the main colony
9/15/09 ›
Approximately 7,500 double-crested cormorants (post-breeding adults and their young) still using East Sand Island as a roost
9/15/09 ›
Census of roosting California brown pelicans conducted on East Sand Island at dusk; 5,486 brown pelicans roosting on East Sand Island at night, less than one-third the peak count of 16,850 on July 22
Weekly Update for 9/7 – 9/13/2009
9/11/09 ›
Final day of regular colony monitoring on East Sand in 2009
9/7 – 9/11/09 ›
Caspian tern diet at East Sand Island colony consisted of 36% salmonids; for the first time since the week ending June 7, salmonids (vast majority likely fall Chinook salmon) were the single most prevalent prey type for East Sand Island terns this past week; impact of East Sand Island terns on survival of fall Chinook smolts is likely higher than in previous years, given the protracted tern nesting season at East Sand Island (terns attending colony more than a month longer this year as compared to previous years)
9/7 – 9/11/09 ›
Colony attendance at the East Sand Island tern colony declined dramatically this past week, due in part to a severe storm that moved through the area at the end of the previous week; an average of 196 adult terns were counted on colony this past week compared to 2,600 the previous week; during a colony-wide disturbance (caused by a red-tailed hawk) only 15 pre-fledging terns remained on the main colony
9/9/09 ›
Vince Patton and Nick Fisher (Oregon Public Broadcasting), along with Deborah Jaques (Pacific Eco Logic), visited East Sand Island to film the California brown pelican roost
9/8/09 ›
Last aerial photo census of the season to estimate number of adult double-crested cormorants on East Sand Island cormorant colony
Weekly Update for 8/31 – 9/6/2009
8/31 – 9/6/09 ›
Unusually large numbers of Caspian terns continue to use the East Sand Island colony site this late in the season; an average of 2,600 Caspian terns were counted on the colony this week
8/31 – 9/6/09 ›
Caspian tern diet at East Sand Island colony consisted of 14% salmonids; the majority of salmonids consumed during recent weeks are likely fall Chinook salmon; anchovy continue to be the primary food source for East Sand Island terns, at 70% of the diet this past week
8/31 – 9/6/09 ›
California brown pelicans continue to build nests on East Sand Island; no evidence of egg-laying has been observed
Weekly Update for 8/24 – 8/30/2009
8/24 – 8/30/09 ›
Caspian tern diet at East Sand Island colony consisted of 20% salmonids; the majority of salmonids consumed during recent weeks are likely fall Chinook salmon; anchovy continue to be the primary food source for East Sand Island terns, at 58% of the diet this past week
8/26/09 ›
Aerial photo census to estimate number of adult double-crested cormorants and the number of late nesting attempts by Caspian terns on East Sand Island
8/24/09 ›
Census of roosting California brown pelicans conducted on East Sand Island; 9,309 brown pelicans counted on island, ca. 7,500 fewer than on 22 July
Weekly Update for 8/17 – 8/23/2009
8/17 – 8/23/09 ›
Approximately 800 nesting pairs of Caspian terns are still sitting on eggs at the East Sand Island colony and another 300-400 pairs are attending young chicks; this number of late nesting attempts by Caspian terns at this colony is unprecedented
8/17 – 8/23/09 ›
Caspian tern diet at East Sand Island colony consisted of 22% salmonids, the highest percentage since the week ending on 7 June; the average percent salmonids in the diet over the past 6 weeks was 7%; the majority of salmonids consumed during recent weeks are likely fall Chinook salmon; anchovy continue to be the primary food source for East Sand Island terns, at 57% of the diet this past week
8/17 – 8/23/09 ›
California brown pelicans continue to build nests on East Sand Island; no evidence of egg-laying has been observed
8/17 – 8/23/09 ›
Continued evidence of predation on Caspian tern fledglings by a great horned owl found near the East Sand Island tern colony
Weekly Update for 8/10 – 8/16/2009
8/10 – 8/16/09 ›
Thousands of active Caspian tern nests remain on the East Sand Island colony, some with eggs or young chicks; counts of terns on-colony remain greater than 5,000 adults; the number of late nesting attempts by Caspian terns at this colony is unprecedented
8/10 – 8/16/09 ›
Caspian tern diet at East Sand Island colony consisted of 79% anchovy and 7% salmonids
8/10 – 8/16/09 ›
Lab tests on a young cormorant found dead on East Sand Island cormorant colony came back positive for Newcastle disease; over the past several weeks approximately 25 double-crested cormorant fledglings at the East Sand Island cormorant colony have been noted with symptoms of Newcastle disease
8/10 – 8/16/09 ›
California brown pelican observed building a nest on East Sand Island; nest construction lasted for several days before nest was abandoned; no evidence of egg-laying
8/10 – 8/16/09 ›
Continued evidence of predation on Caspian tern fledglings by a great horned owl found near the East Sand Island tern colony
8/14/09 ›
Aerial photo census to estimate number of adult double-crested cormorants on East Sand Island cormorant colony
Weekly Update for 8/3 – 8/9/2009
8/3 – 8/9/09 ›
Caspian tern diet at East Sand Island more than 60% anchovies; salmonids 10% of prey
8/8 – 8/9/09 ›
Judy Irving and Mark Bittner (both with Pelican Media) visited East Sand Island
8/3 – 8/9/09 ›
Continued evidence of predation on Caspian tern fledglings by a great horned owl found near the East Sand Island tern colony
8/8/09 ›
The entire double-crested cormorant colony and thousands of roosting brown pelicans took flight from East Sand Island following disturbance by an airboat; USFWS and WDFW notified of disturbance
8/7/09 ›
Census of roosting California brown pelicans conducted on East Sand Island; 14,652 brown pelicans counted on island, ca. 2,200 fewer than on 22 July
8/6/09 ›
Deborah Jaques (Pacific Eco Logic) visited East Sand Island
Weekly Update for 7/27 – 8/2/2009
7/27 – 8/2/09 ›
Average weekly colony attendance of adult Caspian terns at East Sand Island decreased by ca. 3,000 this week compared to previous week; average colony attendance greater than 11,000 adults, an unprecedented high number for this late in the nesting season
7/27 – 8/2/09 ›
Further evidence of predation on tern fledglings by a great horned owl found near the East Sand Island Caspian tern colony
Weekly Update for 7/20 – 7/26/2009
7/20 – 7/26/09 ›
Average weekly colony attendance of adult Caspian terns at East Sand Island increased by ca. 2,000 this week compared to previous week; influx of terns to the East Sand Island colony likely due to visiting subadults or failed breeders from other colonies in region
7/20 – 7/26/09 ›
Further evidence of predation on tern fledglings by a great horned owl found near the East Sand Island Caspian tern colony
7/23/09 ›
Continuous monitoring of East Sand Island Caspian tern and double-crested cormorant colonies discontinued; a reduced level of monitoring will continue at East Sand Island until late August or early September
7/22/09 ›
Census of roosting California brown pelicans conducted on East Sand Island; 16,850 brown pelicans counted on island, the greatest number of brown pelicans ever recorded on East Sand Island by project personnel
7/21/09 ›
82 double-crested cormorant chicks captured and banded at East Sand Island cormorant colony
Weekly Update for 7/13 – 7/19/2009
7/14 – 7/19/09 ›
A total of 47 nesting adult double-crested cormorants were captured at East Sand Island cormorant colony and fitted with satellite telemetry tags for study of post-nesting dispersal and over-wintering areas; 14 of these satellite tags are known to be defective and may not provide useful data; 30 of the remaining 33 working tags are battery-powered and 3 are solar-powered; all are externally mounted using harnesses
7/13 – 7/19/09 ›
Further evidence of predation on tern fledglings by a great horned owl found near the East Sand Island Caspian tern colony
7/15 – 7/16/09 ›
443 Caspian tern chicks captured and banded at the East Sand Island tern colony; during banding it was discovered that there was an unusually large number of tern nests with eggs or very young chicks on the colony, indicating a high degree of asynchrony in lay dates; Mike Wilhelm, Margi Wilhelm, Ian Wilhelm, Herman Biederbeck (ODFW), Peg Boulay (ODFW), Lauren Reinalda (NOAA), Jen Zamon (NOAA), Beth Phillips (NOAA), Dave Craig (Willamette Univ.), Michael Strelow (Willamette Univ.), Jeff Allen (Willamette Univ.), and Kirsten Bixler (OSU) assisted with chick banding at East Sand Island
7/13/09 ›
Aerial photo census to estimate number of fledgling Caspian terns on East Sand Island tern colony
Weekly Update for 7/6 – 7/12/2009
7/6 – 7/12/09 ›
Average weekly colony attendance of adult Caspian terns at East Sand Island increased by ca. 1,000 this week compared to previous week; influx of terns to the East Sand Island colony likely due to visiting subadults or failed breeders from other colonies in region
7/6 – 7/12/09 ›
Gull predation rate on tern chicks at East Sand Island colony declined this week, as did disturbance rate by bald eagles; further evidence of predation on tern fledglings by a great horned owl found near the East Sand Island Caspian tern colony; at least three tern chicks depredated by owl during the week
7/9/09 ›
First double-crested cormorant fledgling observed at East Sand Island cormorant colony
7/9/09 ›
First Caspian tern fledgling observed at East Sand Island tern colony
7/8 – 7/9/09 ›
Chris Milne (Sirtrack Limited) assisted with satellite tagging of double-crested cormorants at East Sand Island
7/7 – 7/9/09 ›
21 nesting adult double-crested cormorants captured at East Sand Island cormorant colony and fitted with satellite telemetry tags for study of post-nesting dispersal and over-wintering areas; satellite tags deployed in mid-June were defective and efforts are underway to recapture previously satellite-tagged cormorants to replace defective tags
Weekly Update for 6/29 – 7/5/2009
6/29 – 7/5/09 ›
Further evidence of predation by a great horned owl near the East Sand Island Caspian tern colony; visits to the tern colony by the owl appear to be more frequent, with at least two tern chicks depredated by the owl during the week
7/3/09 ›
Census of roosting California brown pelicans conducted on East Sand Island; 15,518 brown pelicans counted on island, the greatest number of brown pelicans ever recorded on East Sand Island; this count is ca. 2,500 higher than the previous count (19 June, see below) of pelicans on East Sand Island
7/2/09 ›
Dave Craig, Manka Lou, Melissa Johnson, Hayley Serres, and Jason Niedermeyer (Willamette University) visited the East Sand Island Caspian tern colony
Weekly Update for 6/22 – 6/28/2009
6/27 – 6/28/09 ›
Michael Wilhelm (professional photographer) visited the East Sand Island tern and cormorant colonies
6/22– 6/28/09 ›
Further evidence of the presence of a river otter and a great horned owl were found near the East Sand Island Caspian tern colony; at least two tern chicks apparently fell prey to the owl
6/23/09 ›
Survey conducted of islands in the upper Columbia River estuary; no terns seen at flagged sites on Rice Island (see below) or on other upland areas of Rice Island or other upper estuary dredge spoil islands
Weekly Update for 6/15 – 6/21/2009
6/19/09 ›
Census of roosting California brown pelicans conducted on East Sand Island; 12,879 brown pelicans counted on island, the greatest number of brown pelicans ever recorded on East Sand Island; this count was more than twice the previous high count for pelicans roosting on East Sand Island during the month of June
6/18/09 ›
Survey conducted of islands in the upper Columbia River estuary; no terns seen at flagged sites on Rice Island (see below) or on other upland areas of Rice Island or other upper estuary dredge spoil islands; 29 American white pelicans observed loafing on Miller Sands Spit
6/16/09 and 6/18/09 ›
Dave Craig, Manka Lou, Melissa Johnson, Hayley Serres, and Jason Niedermeyer (Willamette University) visited the East Sand Island Caspian tern colony
6/15 – 6/16/09 ›
13 nesting adult double-crested cormorants captured at East Sand Island cormorant colony and fitted with satellite telemetry tags for study of post-nesting dispersal and over-wintering areas
Weekly Update for 6/8 – 6/14/2009
6/8 – 6/14/09 ›
Two surveys conducted of islands in the upper Columbia River estuary; no terns seen at flagged sites on Rice Island (see below) or on other upland areas of Rice Island or other upper estuary dredge spoil islands
6/8 – 6/14/09 ›
Further evidence of the presence of a river otter and a great horned owl were found near the East Sand Island Caspian tern colony; at least one tern chick apparently fell prey to the owl
6/13/09 ›
The entire double-crested cormorant colony and 4,000 roosting brown pelicans took flight from East Sand Island following a disturbance by an airboat; the USFWS has been notified of this disturbance
6/13/09 ›
First double-crested cormorant chick observed on channel markers in the upper Columbia River estuary
6/13/09 ›
9 American white pelicans observed loafing on Miller Sands Spit in the upper Columbia River estuary
6/9 – 6/10/09 ›
17 breeding adult double-crested cormorants captured at East Sand Island cormorant colony and fitted with satellite telemetry tags to track post-nesting dispersal and over-wintering range
6/8/09 ›
Aerial photo census to estimate number of breeding pairs of double-crested cormorants on the East Sand Island cormorant colony
Weekly Update for 6/1 – 6/7/2009
6/1 – 6/7/09 ›
Two surveys conducted of islands in the upper Columbia River estuary; no terns seen at flagged sites on Rice Island (see below) or on other upland areas of Rice Island or other upper estuary dredge spoil islands
6/1 – 6/7/09 ›
Further evidence of river otters and a great horned owl found near the East Sand Island Caspian tern colony; on one occasion a river otter was seen with pups on the mudflat adjacent to the tern colony
6/1 – 6/7/09 ›
The proportion of salmonids in the diet of East Sand Island Caspian terns was 29%, a significant decline compared to the previous 5 weeks (average 74% salmonids)
6/7/09 ›
Seasonal high count of 732 Brandt’s cormorants on East Sand Island, of which 302 were attending nests
Weekly Update for 5/25 – 5/31/2009
5/25 – 5/31/09 ›
Three surveys conducted of islands in the upper Columbia River estuary (including Rice Island); no terns seen at flagged sites on Rice Island or on other upland areas of Rice Island or other upper estuary dredge spoil islands
5/25 – 5/31/09 ›
Further evidence of river otters and a great horned owl found near the East Sand Island Caspian tern colony; night time disturbances to the Caspian tern colony (reported earlier), however, have not been observed
5/31/09 ›
Boat survey of Astoria/Megler Bridge; 24 double-crested cormorant nests and 143 pelagic cormorant nests counted; 450 roosting cormorants also counted
5/30/09 ›
Seasonal high count of 708 Brandt’s cormorants on East Sand Island, of which 309 were attending nests
5/30/09 ›
First Caspian tern chick observed on East Sand Island tern colony
5/29 – 5/30/09 ›
55 adult Caspian terns captured and banded at the East Sand Island tern colony
5/29/09 ›
Caspian tern eggs collected at East Sand Island, under permits, for contaminant studies
5/28/09 ›
Aerial photo census to estimate number of breeding pairs of Caspian terns on the East Sand Island tern colony
Weekly Update for 5/18 – 5/24/2009
5/23/09 ›
USACE contractor installed stakes and flagging on upland area of Rice Island where Caspian terns were initiating nests; 2 Caspian tern eggs laid at site were collected, under permit, by the USACE contractor to prevent further nesting at the site; collected tern eggs will be used in contaminant studies
5/21 – 5/22/09 ›
Up to 300 Caspian terns observed on upland area of Rice Island near incipient ring-billed gull colony consisting of 37 nesting pairs (different site on Rice Island from site flagged on 5/13); tern courtship behaviors observed and nesting by Caspian terns appeared imminent; USACE notified about situation; USACE deploying contractors to haze terns from site prior to egg-laying
5/21/09 ›
First double-crested cormorant chick observed on East Sand Island cormorant colony
5/20/09 ›
KGW-TV news story on East Sand Island tern and cormorant colonies aired; this story can be viewed at kgw.com
Weekly Update for 5/11 – 5/17/2009
5/11 - 5/17/09 ›
Caspian terns nesting on East Sand Island consumed 84% juvenile salmonids this week, the highest weekly percentage of juvenile salmonids in tern diets ever recorded on East Sand Island
5/16/09 ›
Sue Haig (USGS Forest and Rangeland Ecosystem Science Center) visited East Sand Island
5/15/09 ›
Grant McOmie and camera crew (KGW-TV) visited East Sand Island; news report will be aired on KGW news at 6pm on Wednesday, May 20 or at kgw.com after that date
5/15/09 ›
Feasibility study using human disturbance to dissuade double-crested cormorants from nesting in a discrete area on East Sand Island discontinued due to commencement of egg-laying by cormorants at site; another dissuasion method (pond liner) has shown promise for preventing cormorants from nesting in rocky areas
5/13/09 ›
Heavy rainfall caused standing water to form on part of the East Sand Island Caspian tern colony; colony dried out quickly and terns resumed nesting in flooded area
5/13/09 ›
USACE contractor installed stakes and flagging on upland area of Rice Island where Caspian terns were initiating nests; dissuasion efforts successful in preventing terns from nesting on Rice Island; no terns seen at flagged site in subsequent surveys (5/14-17)
5/11 - 5/12/09 ›
Boat survey of Rice Island; over 200 Caspian terns observed on upland area during counts at dusk; courtship behaviors observed and nesting appears to be imminent; Paul Schmidt (USACE) visited Rice Island
5/11/09 ›
An estimated 23,500 Caspian terns on East Sand Island tern colony (based on counts from blinds), this is the highest ground count yet recorded at this colony. Note: ground counts are estimates of colony attendance and not an accurate measure of the number of nesting pairs using East Sand Island.
Weekly Update for 5/4 – 5/10/2009
5/10/09 ›
Roughly 22,000 Caspian terns on the East Sand Island tern colony, based on counts from blinds. These are highest ground counts yet recorded at this colony. Note: these ground counts are estimates of colony attendance and not an accurate measure of the number of nesting pairs on the colony.
5/10/09 ›
Boat survey of upper Columbia River estuary; 220 Caspian terns observed on upland area of Rice Island; courtship behaviors observed and 85 tern nest scrapes counted; USACE notified about situation and is planning to hire contractors to haze the terns off the site prior to egg-laying
5/4 - 5/10/09 ›
Caspian terns nesting on East Sand Island consumed 80% juvenile salmonids this week, the highest weekly percentage of juvenile salmonids in tern diets on East Sand Island since 2000
5/8/09 ›
Further evidence of the presence of a river otter (perhaps two) and a great horned owl were found near the East Sand Island Caspian tern colony; either one of these predators could be causing the night time disturbances to tern colony (described below)
5/7/09 ›
Double-crested cormorant eggs collected at East Sand Island and from channel markers in the upper estuary for contaminant studies
5/7/09 ›
Night time disturbance noted at the East Sand Island Caspian tern colony; colony monitors conducting night time watches at the colony have yet to identify the cause(s) of these disturbances
5/6/09 ›
No Caspian terns observed in upland areas on Tenasillahe Island in the upper Columbia River estuary; previous surveys suggested that terns might be interested in nesting at that location
5/6/09 ›
Heavy rainfall caused standing water to form on part of East Sand Island Caspian tern colony; tern nests that were flooded did not contain eggs; colony dried out quickly and terns resumed nesting in flooded area
Weekly Update for 4/27 – 5/3/2009
5/1/09 ›
Aerial survey of Columbia River estuary, Willapa Bay, and Grays Harbor; 168 Caspian terns observed on upland area of Tenasillahe Island in the upper Columbia River estuary; subsequent land-based survey revealed 5 Caspian terns at site, none showing signs of nesting
4/29 - 5/1/09 ›
Night time disturbances at East Sand Island Caspian tern colony on 3 consecutive nights; colony monitors conducting night time watches unable to identify cause(s) of disturbances
4/29/09 ›
Evidence of river otters and great horned owls found near the East Sand Island Caspian tern colony; either of these predators could be causing night time disturbances to tern colony (see above)
4/28/09 ›
First Caspian tern egg observed on East Sand Island tern colony
4/28/09 ›
Feasibility study using a green laser to dissuade double-crested cormorants from nesting in a discrete area on East Sand Island discontinued due to commencement of egg-laying by cormorants at site; other dissuasion methods (human disturbance, pond liner) have shown promise for preventing cormorants from nesting in areas where those techniques are used
Weekly Update for 4/20 – 4/26/2009
4/23/09 ›
Ring-billed gull colony on East Sand Island abandoned; presumably caused by disturbance and predation from a river otter
4/21/09 ›
First double-crested cormorant egg observed on East Sand Island cormorant colony
Weekly Update for 4/13 – 4/19/2009
4/13/09 ›
Commenced feasibility studies on methods (i.e., human disturbance, green laser, and pond liner) to dissuade double-crested cormorant from nesting in discrete areas on East Sand Island
Weekly Update for 4/6 – 4/12/2009
4/10/09 ›
First California brown pelicans sight record for Columbia River estuary in 2009, observed near East Sand Island
4/10/09 ›
First Brandt’s cormorants observed on East Sand Island cormorant colony
4/9/09 ›
First double-crested cormorants observed on East Sand Island cormorant colony
4/8/09 ›
Colony monitors began continuous monitoring of East Sand Island Caspian tern and double-crested cormorant colonies
4/7/09 ›
PIT tags spread on the East Sand Island Caspian tern colony for detection efficiency studies
4/6/09 ›
Completed construction of blinds and tunnels at the East Sand Island double-crested cormorant colony
4/6/09 ›
PIT tags spread on the East Sand Island double-crested cormorant colony for detection efficiency studies
Weekly Update for 3/30 – 4/5/2009
4/2/09 ›
First Caspian terns observed on East Sand Island tern colony
Weekly Update FOR 3/23 - 3/29/2009
3/24/09 ›
PIT tags spread on upper estuary piscivorous waterbird colonies for detection efficiency studies
3/23/09 ›
About 3.5 acres of bare sand habitat prepared for nesting terns on East Sand Island by the USACE
3/19/09 ›
First Caspian tern sight record in Columbia River estuary in 2009, seen flying over west end of East Sand Island
Weekly Update FOR 3/16 - 3/22/2009
3/17/09 ›
First Brandt’s cormorant sight record in Columbia River estuary in 2009, seen flying near East Sand Island
3/16/09 ›
Field crew began working in Columbia River estuary
