Below are summaries for management actions on or near East Sand Island.
Update as of Oct. 13, 2016
Individual adult Double-crested cormorants culled for the reporting period: 239
Total to date: 2,923
Individual adult Brandt's cormorants taken for the reporting period: 1
Total to date: 4
Individual adult Pelagic cormorants taken for the reporting period: 0
Total to date: 1
Nests oiled for the reporting period: 0
Total to date: 1,092
Update as of Oct. 6, 2016
The Corps resumed culling operations near East Sand Island on Oct. 3.
In order to meet the Corps’ year two management objectives and remain on track to meet NOAA Fisheries’ Biological Opinion guidelines by 2018, the Corps will cull up to 720 adult double-crested cormorants in October.
Individual adult Double-crested cormorants culled for the reporting period: 290
Total to date: 2,684 (corrected Oct. 13, 2016)
Individual adult Brandt's cormorants taken for the reporting period: 1
Total to date: 3
Individual adult Pelagic cormorant taken for the reporting period: 0
Total to date: 1
Nests oiled for the reporting period: 0
Total to date: 1,092
Information on the management plan and how the decisions were made can be found in Chapter 5 of the Double-crested cormorant Final EIS, which is posted in the Related Links section on this page.
Update as of Sept. 8, 2016
The Corps has regularly monitored the ESI cormorant colony following the initiation of breeding in July and August. Currently, there are approximately 3,900 active double-crested cormorant nests on East Sand Island; nearly all nests contain between two and four chicks. The majority of double-crested cormorant chicks appear to be similarly aged in terms of their development, meaning the egg laying and hatching likely happened around the same time following return of adults to ESI in late June. Juveniles are showing continuous activity (walking around, flapping their wings, etc.), but none have been observed conducting short flights within or outside of the colony. Based on the timing of egg laying and hatching, juveniles should begin to develop flight skills soon; the Corps will monitor and document the timing of these activities.
It should be noted that no management actions, including culling and egg oiling, have occurred since May, and no culling is planned at this time. However, boat-based culling may occur after the chicks have fledged from their nests. The Corps may resume management activities later in the season (late September or early October) based on monitoring results over the next few weeks as chicks begin to fledge from their nests.
Members of the public are reminded that visitors are not allowed on East Sand Island. The Corps’ guidelines regarding access to ESI are designed to minimize the impact to nesting birds. The Corps is concerned that any visitation might trigger another dispersal event.
Update as of Aug. 3, 2016
Observers note some nesting behaviors
After approximately 23,000 Double-crested cormorants returned to East Sand Island in late June, on July 3 observers noted nesting behaviors from about 19,500 individuals. Throughout July the number of nesting cormorants seen in aerial photographs decreased to a low of 8,500 on July 18, when the Corps’ monitoring crew and biologists conducted on-island monitoring. They noted cormorants incubating nests with clutches of three to four eggs.
While the number of nesting birds has decreased since the cormorants returned to the island, in mid-July approximately 15,300 cormorants were seen loafing on the island, suggesting that while they are not nesting, many of the birds remain and are feeding in the lower estuary. All management actions, including culling and egg oiling, have been suspended since May but may resume later in the season if the number of cormorants on East Sand Island meets the criteria outlined in Chapter 5 of the Double-crested Cormorant Final Environmental Impact Statement and Management Plan.
The Corps has been conducting weekly on-island surveys since July 18 and plans to continue monitoring the active nests on the island through surveys and aerial photography to document nesting and juvenile fledging activities.
Members of the public are reminded that visitors are not allowed on East Sand Island. The Corps’ guidelines for anyone accessing ESI are designed to minimize the impact to the nesting birds. The Corps is concerned that any visitation might trigger another dispersal event.
Update as of June 29, 2016
Double-crested cormorants are returning to East Sand Island
More than six weeks after Double-crested cormorants abandoned their nesting sites on East Sand Island in the lower Columbia River, several thousand have returned to the nesting area in the past few days and Corps observers expect numbers to increase in the coming weeks.
On May 16, observers found that cormorants in the colony had abandoned about 8,600 nests. As outlined in chapter 5 of the Double-crested cormorant Management Plan and Final Environmental Impact Statement, culling was immediately suspended. The Corps, U.S. Fish and Wildlife and U.S. Department of Agriculture – Animal Plant Health Inspection Service – Wildlife Services continue to research why the cormorants initially abandoned their nests, but the cause remains undetermined.
On June 22 Corps observers reported thousands of cormorants returning to the ESI nesting area. Cormorant numbers on the island continue to increase, while the number of cormorants roosting on the Astoria-Megler Bridge is decreasing. Observers have often seen eagles flushing cormorants as small groups attempted to return the ESI. It appears that a group of cormorants large enough to resist being flushed by the eagles allowed them to re-establish the colony.
The number of cormorants actively nesting is not known at this time, but researchers are analyzing aerial photos of the island taken after the recolonization began and will have an estimated number of cormorants nesting population estimate by early July. All culling activity remains suspended but may resume later in the season if the number of cormorants on East Sand Island meets the criteria outlined in Chapter 5 of the Double-crested cormorant Final Environmental Impact Statement and Management Plan.
Members of the public are reminded that visitors are not allowed on East Sand Island. The Corps’ guidelines for anyone accessing ESI are designed to minimize the impact to the nesting birds. The Corps is concerned that any visitation might trigger another dispersal event.
Update as of May 26, 2016
Culling activities are suspended.
Independent monitors surveying the East Sand Island double-crested cormorant colony reported on Monday, May 16, 2016 that all nests had been abandoned. From field reports, including aerial photography, it appears that a significant disturbance to the colony occurred between May 13 and early May 16. This disturbance resulted in nest abandonment and the subsequent loss of cormorant eggs from predation by gulls, eagles and crows.
We are following protocols outlined in the Final Environmental Impact Statement that guide management activities following a potential dispersal event. In accordance with these protocols, all culling and egg-oiling activities have ceased and cormorant monitoring in the lower Columbia River estuary continues. There has been no nest oiling since the evening of May 11 and we suspended boat-based culling May 16 upon learning of the on-island colony situation.
We don't know the cause of the disturbance and wildlife biologists from several federal agencies are gathering information toward determining its cause. Investigation of the colony area did not find any mammalian tracks. Federal biologists observed as many as 16 bald eagles on the colony on May 17. We are monitoring the colony to see if birds return.
Double-crested cormorant breeding season typically peaks mid-June through July so there is time for birds to produce young this year, should they return. We will know more about the success of this year's colony at the end of this summer.
The decision to resume culling and nest oiling this year hinges primarily on the number of double-crested cormorants that return to the colony and their behavior.
While we have suspended culling activities, we continue our work on many environmental restoration projects on the Columbia River estuary continue to improve salmon recovery and support their lifecycle. To learn more about these efforts, please visit www.salmonecovery.gov.
For additional information on the Cormorant Management Plan, please reference the Final Environmental Impact Statement.
May 12-18, 2016
Individual adult Double-crested cormorants culled for the reporting period: 209
Total to date: 2394
Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 2
Individual adult Pelagic cormorant taken for the reporting period: 1
Total to date: 1
Nests oiled for the reporting period: 1092
Total to date: 1092
May 5-11, 2016
Individual adult Double-crested cormorants culled for the reporting period: 691
Total to date: 2185
Individual adult Brandt's cormorants taken for the reporting period: 2
Total to date: 2
Nests oiled for the reporting period: 1092
Total to date: 1092
April 28 - May 4, 2016
Individual adult Double-crested cormorants culled for the reporting period: 469
Total to date: 1494
Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0
Nests oiled for the reporting period: 0
Total to date: 0
April 21-27, 2016
Individual adult Double-crested cormorants culled for the reporting period: 314
Total to date: 1025
Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0
Nests oiled for the reporting period: 0
Total to date: 0
April 14-20, 2016
Individual adult Double-crested cormorants culled for the reporting period: 440
Total to date: 711
Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0
Nests oiled for the reporting period: 0
Total to date: 0
April 6-13, 2016
Individual adult Double-crested cormorants culled for the reporting period: 271
Total to date: 271
Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0
Nests oiled for the reporting period: 0
Total to date: 0