VAN NUS T & KLEEFSTRA R (2017) Spring and summer diet of Peregrine Falcons Falco peregrinus on two eastern Dutch Wadden Sea islands in relation to food availability. LIMOSA 90 (1): 13-24.

Since 2006 a growing number of Peregrine Falcons breed annually on the eastern Dutch Wadden Sea islands. In spring and summer 2013 and 2014, their diet was studied on the islands of Rottumeroog and Rottumerplaat by collecting prey remains and pellets, and by observing hunting flights. Diet was compared to the availability of potential bird preys, as derived from high tide roost counts of waterbirds, additional sightings of (migrating) birds and surveys of breeding birds. Throughout spring and summer, about a quarter of the Peregrine Falcon diet consisted of waders, with a preference for medium sized species (c. 125-300 g; Grey Plover, Red Knot, Redshank, Bar-tailed Godwit) and large waders (>300 g; Oystercatcher, Curlew, Whimbrel, Woodcock). In spring, when numbers of waders peaked, waders were the main prey item on both islands. The proportion of waders in the diet was nevertheless considered to be surprisingly low given the large number of waders present on the high tide roosts. Also gulls and ducks were taken relatively seldom, given the fact that these species groups together represented about half of the available prey at the island. In summer, and especially in the period when food availability was lowest, pigeons and also passerine birds were important prey for the falcons on the islands. Strikingly, on both islands, about a third of the entire diet during spring and summer consisted of, mainly domesticated, pigeons. Judging from the pigeon rings found in the pellets, and from the weekly appearance of pigeons during weekends, the great majority of these birds will have been homing pigeons. Diet studies in Great Britain, the southwest Dutch Delta and the German Wadden Sea also show that domesticated pigeons are a main prey for breeding Peregrine Falcons. For remote, uninhabited islands like Rottumeroog and Rottumerplaat this was an unexpected finding.

[free pdf] [dutch summary]