Predation and prey-caching of Eastern Water Skinks Eulamprus quoyii by nesting Nankeen Kestrels Falco cenchroides in eastern New South Wales

Abstract

The breeding diet of a pair of Nankeen Kestrels Falco cenchroides nesting in Beresfield, eastern New South Wales, in 2020 was investigated. By individual prey species, the diet comprised 61.3% reptiles (including two prey species not previously recorded in the Nankeen Kestrel diet—Eastern Water Skink Eulamprus quoyii and most likely Southern Rainbow Skink Carlia tetradactyla), 9.7% birds (including a new prey species—Superb Fairy-wren Malurus cyaneus), 6.4% invertebrates (two crickets: Grylloidea), 3.2% mammals (one House Mouse Mus musculus) and 19.4% unidentified prey items (percentages by number). During 31.5 h of observations, the male delivered 22/31 prey items (71%) and the female delivered 9/31 prey items (29%) to the nest tree. The average delivery rate over the entire nestling period was one prey item per hour. Prey-caching, whereby the female stored lizards in the fork of a tree and later retrieved them and fed them tothe single nestling, was observed. Further studies are needed to obtain well-documented accounts of prey-caching by Australian falcons.

Feast of skinks for Nankeen Kestrels Falco cenchroides breeding on a bird-friendly farm

“…Bollen (1991) found that during the nestling period only the male hunted for the first 2 weeks and he made 0.7 delivery/h to the nest between 0900 and 1900 h and the main prey (by number) was Grass Skink (Paleflecked Garden Sunskink). A recent study by Pryor (2021) reported an average delivery rate over the entire nestling period, to a single young, of 1 prey item/h. The combined rate of delivery of prey by the male and female in 2018 (11.1 items/h) and 2020 (6.0-13.8 items/h over four foraging sessions) was high compared with rates reported when vertebrates were the main prey.…”

“…During the feeding of the brood in 2018, the male passed prey to the female on a perch near the nest, a common behaviour of the species (Debus 2019;Pryor 2021).…”

“…The Nankeen Kestrel Falco cenchroides is a falcon of most open habitats in Australia including farmland with scattered trees and inland shrublands and woodlands (Marchant & Higgins 1993;Debus 2019). Its diet and breeding have been reported in many studies, in various states and territories of Australia (Sharland 1931;Genelly 1978;Olsen et al 1979;Bollen 1991;Paull 1991;Aumann 2001;Starr et al 2004a;Schulz & Lumsden 2009;Leach et al 2015;Tsang et al 2017;Mo 2019;Pryor 2021). The species feeds on a wide range of invertebrate and vertebrate prey.…”

“…Vertebrate prey items include skinks (Scincidae) of various species (e.g. Olsen et al 1979;Bollen 1991;Paull 1991;Tsang et al 2017;Pryor 2021), small birds (e.g. Belcher 1914;Oliver 2004;Tsang et al 2017), and such other vertebrates as bats, frogs and rodents (Leach et al 2015;Tsang et al 2017).…”