Social attraction entices cormorants away from fisheries

[Cara J]

Wildlife managers battling to keep double-crested cormorants (Phalacrocorax auritus) from devastating juvenile fish populations might want to try something that waterfowl hunters use all the time: decoys. In a study published in the Wildlife Society Bulletin, researchers tested whether nest areas enhanced with old car and truck tires and filled with decoys would attract the birds — which have been identified as one of the limiting factors of salmonid population recovery — to several locations in the Columbia River Estuary in Oregon away from East Sand Island, a cormorant favorite location. The team led by Yasuko Suzuki first enhanced the nesting habitat in a few different test locations within the Columbia River estuary by providing nesting material in the tires along with old cormorant nests from previous breeding seasons. They also deployed cormorant decoys and solar-powered sound systems that broadcasted cormorant vocalizations in each test plot. To measure how effective these measures were, the researchers took note of the number of nesting pairs occupying the study plots and estimated chick survival rates. They found that the birds were attracted to the enhanced nesting areas and successfully fledged chicks from all test plots except for a plot on a river inlet with [...]

 

Read more: http://wildlife.org/social-attraction-entices-cormorants-away-from-fisheries/