Effect of a nesting predator on concealment behaviour of potential prey species

Abstract

I examined whether three potential prey species, the House Sparrow (Passer domesticus), Chipping Sparrow (Spizella passerina) and American Robin (Turdus migratorius) conceal and expose themselves differentially in relation to their proximity to Merlin (Falco columbarius) nests. The House Sparrow is the principal prey of Merlins during the survey month (May), while the American Robin is occasionally and the Chipping Sparrow rarely taken as prey. I recorded whether these birds were concealed or exposed at 100 m intervals from 0-400 m away from Merlin nests. Significantly more House and Chipping sparrows were in concealed situations near Merlin nests. The proximity to Merlin nests did not affect the concealment of American Robins.