The Progress
Alternate Nesting Colony Sites
2008
Crump Lake island
In 2008 the USACE began to impliment the Caspian Tern Management Plan. That same year the East Sand Island population was still the largest in the world with 10,700 pairs. Two one-acre islands, in Fern Ridge Reservoir and in Crump Lake, were constructed before the beginning of the breeding season, and both implemented the use of social attraction. About 430 Caspian tern breeding pairs nested on the newly made island in Crump Lake, five of which were identified as having been banded at East Sand Island. There was no nesting at the Fern Ridge Reservoir site, however nine terns reportedly visited the island [5].
2009
Crump Lake colony
The next year the East Sand Island population experienced an increase in breeding pairs, jumping to 12, 087. Before the 2009 breeding season, two more islands were constructed in the Summer Lake Wildlife Area (in the East Link Management Unit and in Dutchy Lake). The Crump Lake island (constructed in 2008) again attracted nesting terns increasing to 700 breeding pairs, 18 of which were banded East Sand Island birds. Caspian terns nested on both the new island in the Summer Lake Wildlife Refuge with 8 breeding pairs on one and 7 on the other. Five of the terns found in these colonies were banded East Sand Island terns [5].
2010
The colony at Sheepy Lake
In 2010 the East Sand Island population was down to 8,283 breeding pairs. Before the breeding season, four islands were constructed in Summer Lake Wildlife Area (Gold Dike impoundment) in Lower Klamath NWR (Orems Unit and Sheepy Lake) and in Tule Lake NWR. A drought in the Upper Klamath basin the same year left 3 of the 4 islands unsurrounded by water and thus unsuitable for Caspian tern colonization. The new island at Sheepy Lake, however, was quickly colonized by 258 breeding pairs who were successful in raising a total of 168 young. The islands constructed in previous years, which formerly had successful colonies, experienced low to no nesting success in 2010 due to poor weather and decreased forage fish availability [5].
2011
The most recent update on the progress of the Caspian Tern Management Plan was released in 2011. The East Sand Island population, still the largest in the world, continued to decrease reaching 7,000 breeding pairs, and for the first time recorded at this colony there was 100% nesting failure and not a single fledgling was raised. This was likely due to colony disruption by bald eagles, egg and chick predation by gulls and adverse weather conditions. Juvenile salmonids were still an important component of their diet, estimated at 36% which was an increase from previous years (30% from 2000 to 2010) [5].
USACE reduced the nesting area on East Sand Island from 3.1 to 2 acres. This decrease resulted in the highest nesting density of Caspian terns on record in the Columbia River Estuary. No new islands were built in 2011; islands built in previous years continued to be monitored. Six of the eight islands were surrounded by water and thus suitable for colonization. Four of these supported nesting colonies, but success rates were very low due to poor weather conditions and predation from great horned owls and from gulls. In total 92 terns were banded East Sand Island terns that had been redistributed [5].
USACE reduced the nesting area on East Sand Island from 3.1 to 2 acres. This decrease resulted in the highest nesting density of Caspian terns on record in the Columbia River Estuary. No new islands were built in 2011; islands built in previous years continued to be monitored. Six of the eight islands were surrounded by water and thus suitable for colonization. Four of these supported nesting colonies, but success rates were very low due to poor weather conditions and predation from great horned owls and from gulls. In total 92 terns were banded East Sand Island terns that had been redistributed [5].
2012
The Caspian Tern Management to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary extends to 2015 and, therefore, work on the restoration plan is still in progress. To keep following the progress, look for updates of the restoration at
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