Note: The following data are preliminary and may change upon further review.

Colony Counts

Rice Island & Other Upper Estuary Islands

The high and low on-colony counts for the week on Rice Island were on April 11th (1,031 terns) and April 16th (0 terns), respectively. The low on-colony counts generally followed research activities (i.e., rocket netting of terns for radio-tagging and color-banding) carried out at the colony site. Those activities are now completed (see below for details). Yesterday evening (4/16), 0 and 378 terns were counted on- and off-colony at Rice Island, respectively. Terns are beginning to roost in larger numbers at sites east of the colony (East Ridge). Thus far, scrape digging has only been observed on-colony. No terns have been observed either roosting or nesting at other upper estuary islands (i.e., Miller Sands Spit and Pillar Rock Sands).

East Sand Island

The high and low on-colony counts for the week on East Sand Island were on April 15th (4,330 terns) and April 10th (950 terns), respectively. Yesterday evening (4/16), we counted 3,375 and 425 terns on- and off-colony at East Sand Island, respectively. Terns are actively digging scrapes, courtship feeding, and copulating at the East Sand Island colony site.

Coastal Sites

Aerial surveys of terns roosting and/or nesting at coastal Washington sites (i.e., Willapa Bay and Grays Harbor) will begin next week and the results will be presented in the next weekly update.

Diet Composition

For the week (10 - 16 April), 57% of the identifiable fish delivered to East Sand Island (N = 196) were salmonids, compared to 86% at Rice Island (N = 107). Year to date, 57% of the identifiable fish delivered to East Sand Island (N = 196) were salmonids, compared to 92% at Rice Island (N = 142). Fish watches are conducted concurrently at both colonies twice each day, once each at high and low tide to control for tidal and time of day effects on diet.

Off-Colony Distribution

Banding and Radio-Tagging

The OSU/CRITFC/RTR research team, with help from Dan Felber (ODFW) and many volunteers (see below), successfully rocket-netted 603 adult terns on the Rice Island colony site. All the captured terns were color-banded with a unique color combination of plastic leg bands, as well as a federal numbered metal leg band. The color-banded terns will be identifiable when perched on nesting or roosting sites. Fifty of the terns were also radio-tagged with small transmitters that were attached to the base on the central tail feathers, and part of the right wing was dyed pink for visual identification at a distance and while in flight. The on-colony attendance and off-colony movements of the fifty radio-tagged terns will be monitored using both fixed-wing aircraft and stationary tracking stations. During the entire rocket-netting operation only one tern was seriously injured. It's wing was broken either by one of the rockets or the leading edge of the net, and it had to be euthanized. Once rocket-netting was completed (April 15th) the sound system and decoys that were used to lure the terns within rocket-netting range were removed from the colony site, as were the rocket nets.

Eight of the 603 captured terns had been previously banded and some of the bands were old and worn. We are attempting to get information to determine where and when these birds were banded.

Radio-Tracking & Resightings of Banded Birds

Seventeen of the color banded terns were resighted at Rice Island and 66 of the color-banded terns were resighted at East Sand Island. Fixed radio receiver stations were set up at Rice and East Sand Islands to monitor attendance of radio-tagged terns at each site. Off-colony distributions of radio-tagged terns will be monitored using fixed-wing aircraft beginning this week.

Gull and Predator Control

There have been no signs of mammalian predators on either Rice or East Sand islands. Limited gull control is being carried out on East Sand Island to enhance prospects for tern colony restoration at that site. During this period, 5 gulls were shot on or near the East Sand Island tern colony.

Tern Hazing

On Monday (April 10th) a suit was filed against the U.S. Army Corp of Engineers by the National Audubon Society, Defenders of Wildlife, Seattle Audubon Society, and the American Bird Conservancy to prevent attempts to dissuade terns from nesting on Rice Island in 2000. A temporary restraining order was issued that prevents all tern hazing by the Corps until at least April 24th, when the matter goes before the U.S. District Court in Seattle.

Media and Other Visitors

We had several people volunteer their help during rocket-netting, and we would like to thank them: Holly Michael, Ben Meyer, Geoff Dorsey, Brad Ryan, Zoe Banks, Mark Nebeker, Gary Salem, Jerry Ronne, Jeremy Sommer, Tanya Sommer, Tim Plawman, Ray Rainbolt, Ron Bramlett, Keith Swindle, Kathy Shinn, Kathy Turco, Gary Shugart, Lynn Ketchum, Pat Wray, Chris Thompson, Ann Edwards, Stacey Lehmann, Eli Bridge, Lisa Hayward, Brian Walker, Matt Richardson, and Charlie Bruce. We would like to give special thanks to Dan Felber (ODFW) for his help in making the rocket-netting such a great success.