Columbia River Estuary

Weekly Update for 8/9 – 8/15/2010

8/9 – 8/15/10 ›

This completes our weekly reporting of field research activities in the Columbia River estuary for 2010

Caspian tern diet at East Sand Island colony consisted of 56% anchovy, 20% herring/sardine, and 4% salmonids

Predator activity has declined at East Sand Island tern and cormorant colonies

8/12/10 ›

Aerial photo census to estimate number of adult double-crested cormorants on East Sand Island cormorant colony

Weekly Update for 8/2 – 8/8/2010

8/2 – 8/8/10 ›

Only 8 Caspian tern chicks remain on the East Sand Island tern colony

8/3/10 ›

101 adult American white pelicans observed on Miller Sands Spit, with ca. 64 mobile chicks; this is the first nesting record for American white pelicans in the Columbia River estuary since this study began in 1997

Weekly Update for 7/26 – 8/1/2010

7/26 – 8/1/10 ›

Predators continue to put higher than normal pressure on Caspian terns and double-crested cormorants nesting on East Sand Island; bald eagles observed on or near Caspian tern and double-crested cormorant colonies and eagles preyed on at least one cormorant fledgling this past week

7/28/10 ›

First Brandt’s cormorant fledgling observed at East Sand Island cormorant colony

7/28/10 ›

Only 20 fledgling-age Caspian tern chicks remain on the East Sand Island tern colony

Weekly Update for 7/19 – 7/25/2010

7/19 – 7/25/10 ›

Predators continue to put higher than normal pressure on Caspian terns and double-crested cormorants nesting on East Sand Island; bald eagles flushed Caspian terns from the colony frequently this past week; gull depredation of tern and cormorant chicks and eggs continued this week; fresh raccoon tracks observed on island

7/23/10 ›

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

7/23/10 ›

Aerial photo census to estimate the number fledgling double-crested cormorants on the East Sand Island colony

7/23/10 ›

Caspian tern chick counts continue to drop as additional birds fledge, by week’s end only 64 chicks were observed on colony; preliminary chick counts suggest that colony productivity may be the lowest ever recorded on East Sand Island

7/22/10 ›

60 adult American white pelicans observed nesting on Miller Sands Spit, with ca. 20 mobile chicks; this is the first nesting record for American white pelicans in the Columbia River estuary since this study began in 1997

Weekly Update for 7/12 – 7/18/2010

7/12 – 7/18/10 ›

Predators continue to put higher than normal pressure on Caspian terns and double-crested cormorants nesting on East Sand Island; bald eagles and peregrine falcons flushed Caspian terns from colony frequently this past week; gull depredation rates on tern and cormorant chicks and eggs were high; fresh raccoon tracks observed on island

7/15/10 ›

8 juvenile double-crested cormorants captured at the East Sand Island colony in order to investigate the relationship between age and leg length; 6 of these birds were also banded with field-readable alphanumeric leg bands

7/14/10 ›

209 near fledging age Caspian tern chicks counted on East Sand Island, many of the chicks counted last week and banded this week (7/13) have fledged; preliminary chick counts suggest that colony productivity may be the lowest ever recorded on East Sand Island

7/14/10 ›

Roughly 100 American white pelicans observed on Miller Sands Spit, with downy young (Andrew Emlen; Oregon Birding Listserv posting); this is the first nesting record for American white pelicans in the Columbia River estuary since this study began in 1997

7/13/10 ›

236 Caspian tern chicks captured and banded at East Sand Island tern colony; Dave Craig (Willamette University) and two of his students assisted with chick banding

7/12/10 ›

Aerial photo census to estimate the number of fledgling Caspian terns and the number of double-crested cormorants attending nests at the East Sand Island colonies

Weekly Update for 7/5 – 7/11/2010

7/5 – 7/11/10 ›

Predators continue to put higher than normal pressure on Caspian terns and double-crested cormorants nesting on East Sand Island; bald eagles and peregrine falcons flushed Caspian terns from colony frequently this past week; gull depredation rates on tern and cormorant chicks and eggs were high; fresh raccoon and river otter tracks observed on island

7/7/10 ›

Minimum of 460 large and an unknown number of downy Caspian tern chicks counted on East Sand Island; preliminary chick counts suggest that colony productivity may be the lowest ever recorded on East Sand Island

7/7/10 ›

18 juvenile double-crested cormorants captured at the East Sand Island colony in order to investigate the relationship between age and leg length; 7 of these birds were also banded with field-readable alphanumeric leg bands

7/7/10 ›

First Caspian tern fledgling observed at East Sand Island tern colony

7/6/10 ›

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

Weekly Update for 6/28 – 7/4/2010

6/28 – 7/4/10 ›

Predators continue to put higher than normal pressure on Caspian terns and double-crested cormorants nesting on East Sand Island; bald eagles flushed Caspian terns from colony 2-3 times per day and preyed on at least one cormorant chick this past week; gull depredation rates on tern and cormorant chicks and eggs were high during these disturbances; fresh raccoon tracks observed on island

7/3/10 ›

Roughly 400 large and an unknown number of downy Caspian tern chicks counted on East Sand Island; preliminary chick counts suggest that colony productivity may be the lowest ever recorded on East Sand Island

7/1/10 ›

Roughly 100 American white pelicans observed on Miller Sands Spit, some sitting on nest structures; the presence of eggs or chicks was not confirmed; if nesting occurs, this would be the first nesting record for American white pelicans in the Columbia River estuary since this study began in 1997

7/1/10 ›

Scott Sebring with NOAA Fisheries visited East Sand Island

6/29/10 ›

22 adult double-crested cormorants captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony; to date 126 adult double-crested cormorants have been captured and banded at the East Sand Island colony this season

Weekly Update for 6/21– 6/27/2010

6/21 – 6/27/10 ›

Predators continue to put higher than normal pressure on Caspian terns and double-crested cormorants nesting on East Sand Island; bald eagles flushed Caspian terns from colony numerous times; gull depredation rates on tern chicks and eggs were high during these disturbances; gull predation on double-crested cormorant chicks increased this past week; night-time disturbances to birds nesting on the west and east ends of the island occurred on two consecutive nights (June 26-27), likely cause by a great horned owl

6/26/10 ›

12 adult double-crested cormorants captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony; to date 104 adult double-crested cormorants have been captured and banded at the East Sand Island colony this season

6/26/10 ›

Shoalwater birding group visited East Sand Island

6/25/10 ›

Aerial photo census to estimate the number of double-crested cormorants attending the East Sand Island cormorant colony

Weekly Update for 6/14 – 6/20/2010

6/14 – 6/20/10 ›

Signs of multiple predators continue to be recorded on East Sand Island; fresh river otter and raccoon tracks observed on island; bald eagles commonly flushed Caspian terns from colony; gull depredation rates on tern chicks and eggs are high during these disturbances; peregrine falcon flushed ring-billed gulls from colony on eastern tip of island; one adult Caspian tern was killed by a peregrine falcon on colony

6/19/10 ›

Satellite Caspian tern colony that formed adjacent to a ring-billed gull colony on the northeastern tip of East Sand Island has been abandoned, presumably due to frequent disturbance by bald eagles and peregrine falcons and possibly nest predation by a raccoon that resides on the island

6/17/10 ›

Adult Caspian tern that was captured and banded at Goose Island (Potholes Reservoir) earlier this year (June 2) was resighted at the East Sand Island tern colony

6/14/10 ›

First Brandt’s cormorant chick observed on East Sand Island cormorant colony; record numbers of Brandt’s cormorants are nesting on East Sand Island this year

Weekly Update for 6/7 – 6/13/2010

6/13/10 ›

10 adult double-crested cormorants captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony

6/7 – 6/13/10 ›

Signs of multiple predators continue to be recorded on East Sand Island; fresh river otter tracks observed on island; bald eagles commonly flushed Caspian terns from colony, gull depredation rates on tern chicks and eggs high during these disturbances; peregrine falcon flushed ring-billed gulls from colony on eastern tip of island

6/7 – 6/13/10 ›

Professor Dave Craig and his student intern from Willamette University visited the East Sand Island Caspian tern colony

6/11/10 ›

Aerial photo census to estimate the number of breeding pairs of double-crested cormorants at the East Sand Island cormorant colony; photos will be counted later in summer and an estimate of colony size available early in fall

6/8 -6/9/10 ›

14 American white pelicans observed loafing on north mudflat of East Sand Island, the first record of white pelicans on East Sand Island

Weekly Update for 5/31 – 6/6/2010

5/31 – 6/6/10 ›

A satellite Caspian tern colony formed adjacent to a ring-billed gull colony on the northeastern tip of East Sand Island, outside the prepared tern nesting habitat; nineteen 1-egg tern nests and one 2-egg tern nest counted; nesting habitat is limited in this area and may accommodate an additional 20 nests

6/1 & 6/3/10 ›

123 adult Caspian terns captured and banded with field-readable alphanumeric leg bands at the East Sand Island tern colony

6/1 – 6/2/10 ›

Heavy rainfall (3.5 inches) caused standing water to form on ca. one third of East Sand Island Caspian tern colony; standing water remained on colony for about 12 hours causing all nests in the flooded areas to fail; flooding occurred early in the chick hatching period, causing loss of a significant number of tern eggs; piles of eggs were observed at the edges of the colony, presumably washed from their nests during the storm

Weekly Update for 5/24 – 5/30/2010

5/30/10 ›

Boat survey conducted of islands in the upper Columbia River estuary; no terns seen in upland areas of dredge spoil islands (i.e., Rice Island, Miller Sands Spit, and Pillar Rock Sands)

5/30/10 ›

To date, 74 breeding adult double-crested cormorants captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony

5/24 – 5/30/10 ›

Signs of multiple predators continue to be recorded on East Sand Island; fresh raccoon and river otter tracks observed on island; bald eagles commonly flushed Caspian terns from colony

5/29/10 ›

Aerial photo census to estimate the number of breeding pairs of Caspian terns on the East Sand Island tern colony and the number of double-crested cormorants attending the East Sand Island cormorant colony

5/28/10 ›

First Caspian tern chick observed on East Sand Island tern colony

5/27/10 ›

First double-crested cormorant chicks observed on East Sand Island cormorant colony; several nests contained multiple chicks each and a few chicks were about 7 days old, indicating that the first chick hatched no later than 21 May

Weekly Update for 5/17 – 5/23/2010

5/17 – 5/23/10 ›

Sign of multiple predators observed on East Sand Island; fresh raccoon and river otter tracks observed on island; bald eagles and peregrine falcon flushed Caspian terns from colony; one adult cormorant was killed by an eagle on the colony

5/22/10 ›

1,708 Brandt’s cormorants counted on East Sand Island cormorant colony, the highest count ever recorded on the island; 391 attended Brandt’s cormorant nests counted; this colony continues to expand in numbers and area occupied; part of this year’s increase due to large influx of sub-adults (100’s), which has not been seen in previous years

5/19 – 5/22/10 ›

32 adult double-crested cormorants captured and banded with field-readable alphanumeric leg bands at the East Sand Island cormorant colony

5/19/10 ›

Winds in excess of 70 mph recorded at East Sand Island; during storm many Caspian terns were blown off their nests and their eggs consumed by gulls

Weekly Update for 5/10 – 5/16/2010

5/10 – 5/16/10 ›

Between 10,000 and 20,000 Caspian terns counted on the main tern nesting area on East Sand Island during the week

5/10 – 5/16/10 ›

Caspian terns continued to prospect for nest sites on the eastern tip of East Sand Island, just above the high tide line and outside the 3.1 acres of habitat prepared for Caspian terns on the main colony site; incipient satellite colony area staked and flagged to discourage tern nesting other than at main colony site

5/10 – 5/16/10 ›

Feasibility study using pond liner to dissuade double-crested cormorants from nesting in a small area of the colony on East Sand Island has been successful; another nest dissuasion method (ribbon tape in a tree) has not been successful in preventing cormorants from nesting

5/10 – 5/16/10 ›

Sign of multiple predators observed on East Sand Island; infrared trail camera captured an image of a raccoon on island; bald eagles frequently flushed Caspian terns from colony

5/13/10 ›

First census of roosting California brown pelicans conducted on East Sand Island at dusk; 2,546 brown pelicans roosting on East Sand Island at night, the highest count ever recorded on East Sand Island so early in the season

5/12/10 ›

Scott Dunmire, Mike Francis, and Chris Pinney with the U.S. Army Corps of Engineers – Walla Walla District along with John Piccininni and Scott Bettin with the Bonneville Power Administration visited East Sand Island

5/10/10 ›

Boat surveys of upper Columbia River estuary dredge spoil islands; 150 Caspian terns observed on upland area of Rice Island; courtship behaviors observed and tern nest scrapes (16) counted; incipient tern colony on Rice Island staked and flagged to discourage tern nesting

Weekly Update for 5/3 – 5/9/2010

5/3 – 5/9/10 ›

Caspian terns continuing to prospect for nest sites on the upper beach at the eastern tip of East Sand Island, outside the 3.1 acres of habitat prepared for Caspian terns on the main colony site; incipient satellite colony staked and flagged to discourage tern nesting other than at main colony site

5/3 – 5/9/10 ›

Sign of multiple predators observed on East Sand Island; fresh raccoon tracks observed on island; bald eagles frequently flushed terns from colony; one adult Brandt’s cormorant killed on colony by a bald eagle

5/6 – 5/9/10 ›

Boat surveys of upper Columbia River estuary dredge spoil islands; up to 600 Caspian terns observed on upland area of Rice Island; courtship behaviors observed and tern nest scrapes counted; incipient colony staked and flagged to discourage tern nesting

5/8/10 ›

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

5/8/10 ›

Double-crested cormorants nesting on western satellite colonies on East Sand Island took flight following a disturbance by three trespassers from a fishing boat who disembarked and entered the colony; large numbers of cormorant eggs lost to gull predation during this disturbance; the Corps was notified of this trespass and associated disturbance

5/7/09 ›

First aerial photo census to estimate number of double-crested cormorants attending the East Sand Island cormorant colony

5/6/10 ›

Andrea Hanson and Michelle Schuiteman from ODFW visited East Sand Island

5/5/10 ›

First Caspian tern egg observed in satellite colony on southeast beach of East Sand Island; egg apparently depredated by a gull by next day

Weekly Update for 4/26 – 5/2/2010

4/26 – 5/2/10 ›

Six satellite-tagged double-crested cormorants from 2009 re-sighted on East Sand Island cormorant colony; all six cormorants still had their tags

4/26 – 5/2/10 ›

Sign of multiple predators observed on East Sand Island; 10 fresh Caspian tern carcasses found on east beach; fresh raccoon tracks observed on island; bald eagles frequently flushed terns from colony; one adult cormorant killed on colony by a bald eagle

5/2/10 ›

Aerial survey of Columbia River estuary, Willapa Bay, and Grays Harbor; 75 Caspian terns observed on upland area of Rice Island in the upper Columbia River estuary; no other Caspian terns observed in upland areas on Pillar Rock Sands or elsewhere during the survey; USACE notified about situation on Rice Island

5/1/10 ›

Dan Roby (OSU) and Paul Schmidt (USACE) led a group of 20 visitors on a field trip to East Sand Island following a ceremony to designate the Columbia River estuary as part of the Western Hemisphere Shorebird Reserve Network

4/28/10 ›

Satellite Caspian tern colony forming high on southeast beach of East Sand Island; incipient colony staked and flagged to discourage tern nesting

4/26 – 4/27/10 ›

Boat surveys of upper Columbia River estuary; ca. 200 Caspian terns observed on upland area of Pillar Rock Sands in upper Columbia River estuary; courtship behavior observed but no nest scrapes seen; USACE notified about situation on Pillar Rock Sands

Weekly Update for 4/19 – 4/25/2010

4/25/10 ›

Caspian terns began building nest scrapes near the high-high tide line on the southeast beach where there was a ring-billed gull colony in previous years; this location is far removed from area that was prepared and designated for tern nesting on East Sand Island and outside the area adjacent the colony that was staked and flagged to prevent tern nesting; the USACE was notified of situation

4/25/10 ›

Night time disturbance noted at the East Sand Island Caspian tern colony; colony monitors conducted night time watches at the colony and have yet to identify the cause(s) of this disturbance

4/19 – 4/25/10 ›

Sign of multiple predators observed on East Sand Island; fresh raccoon and river otter tracks observed on island; bald eagles frequently flushed terns and cormorants from colonies and two adult cormorants were killed by eagles on the colony

4/24/10 ›

First Caspian tern egg observed on East Sand Island tern colony; egg was depredated by a gull following a colony-wide disturbance caused by a bald eagle

4/19/10 ›

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

Weekly Update for 4/12 – 4/18/2010

4/12 – 4/18/10 ›

Sign of multiple predators observed on East Sand Island; tern and gull carcasses found on beach; peregrine falcons frequently flushed Caspian terns from colony; bald eagles frequently flushed terns and cormorants from colonies; tracks of river otter observed on north beach with freshly killed ducks near its den; fresh raccoon tracks observed on island

4/13/10 ›

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

Weekly Update for 4/5 – 4/11/2010

4/9/10 ›

PIT tags spread on East Sand Island tern and cormorant colonies for smolt PIT tag detection efficiency studies

4/9/10 ›

Completed construction of blinds and tunnels at East Sand Island double-crested cormorant colony

4/8/10 ›

3.1 acres of suitable bare sand habitat prepared for nesting Caspian terns on East Sand Island colony site by USACE

4/8/10 ›

First double-crested cormorants observed on East Sand Island colony; ~ 1,500 cormorants on rip-rap near east end of colony

4/7/10 ›

Commenced feasibility study on efficacy of taping trees to dissuade double-crested cormorants from nesting in small area of cormorant colony on East Sand Island

Weekly Update for 3/29 – 4/4/2010

4/1/10 ›

First Caspian terns observed on East Sand Island tern colony

4/1/10 ›

Commenced feasibility study on efficacy of pond liner to dissuade double-crested cormorants from nesting in small area of cormorant colony on East Sand Island

Weekly Update FOR 3/22 - 3/28/2010

Nothing to report

Weekly Update FOR 3/15 - 3/21/2010

3/21/10 ›

3.1 acres staked out on East Sand Island Caspian tern colony site in preparation for restoration of tern nesting habitat prior to the 2010 nesting season

3/21/10 ›

Photo monuments placed on East Sand Island to orthorectify aerial photography of tern and cormorant colonies used to estimate colony size

3/17/10 ›

Seasonal field crew began work in Columbia River estuary

3/16/10 ›

First California brown pelican observed on East Sand Island by project staff in 2010

Weekly Update FOR 3/8 - 3/14/2010

3/10/10 ›

First Caspian tern sighted in Columbia River estuary by project staff in 2010; one Caspian tern seen flying near East Sand Island

Weekly Update FOR 3/1 - 3/7/2010

3/4/10 ›

First double-crested cormorants sighted in Columbia River estuary by project staff in 2010; unlike Caspian terns, however, double-crested cormorants over-winter in small numbers in the Columbia River estuary and were present prior to this observation (D. Jacques, Pacific Eco Logic, personal communication)

3/4/10 ›

First Brandt’s cormorants sighted in Columbia River estuary by project staff in 2010; < 10 Brandt’s cormorants seen flying near and roosting on pile dikes adjacent to East Sand Island