We conducted a detailed study of prey selection by a breeding pair of Falco columbarius (Merlin) on the Wells College campus in central New York. We identified prey from corpses and feathers (110 positive identifications from 112 prey items). Of the 16 prey species, swallows (35 Hirundo rustica [Barn Swallow], 7 Tachycineta bicolor [Tree Swallow], and 4 Stelgidopteryx serripennis [Northern Rough-winged Swallow]) predominated, comprising 41.8% of prey items (estimated 29.9% of biomass). Barn Swallows and Passer domesticus (House Sparrow) were the 2 most common species taken, both appearing throughout the nesting period (31.8% and 19.1% of prey items, respectively). As the season progressed, the proportion of juveniles taken increased to 90% by the latter half of July. We observed the female consuming the heads of freshly killed prey before plucking and delivering the food item to nestlings on 4 occasions, and we recovered 5 headless corpses of Merlin prey. We never found discarded heads of prey. These observations are in contrast to reports that Merlins typically discard the heads of prey. We propose nutritional explanations for selective consumption of the heads of prey by predatory birds. Five young fledged from our study nest, indicating high reproductive success. Our report of successfully breeding Merlins feeding principally on swallows is unique, and shows that the dietary emphasis on swallows did not compromise reproduction. Our results illustrate the flexibility of Merlins to local prey availability and reinforce the vulnerability of avian prey in open areas to Merlin predation.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 28 • No. 4