Nonparental Infanticide in Colonial Eleonora’s Falcons (Falco eleonorae)

Steen, R., Miliou, A., Tsimpidis, T., Selås, V., Sonerud, G.A. Nonparental Infanticide in Colonial Eleonora’s Falcons (Falco eleonorae). Journal of Raptor Research 2016.



Recording behavior at nests of breeding raptors was traditionally accomplished by direct observations (Bildstein and Bird 2007), a time-demanding method for achieving continuous monitoring for extended periods. Video technology has enabled efficient remote in situ monitoring of prey deliveries and other behaviors at raptor nests (Dawson and Bortolotti 2000, Steen 2009, Steen et al. 2011, 2012). Such video monitoring has revealed rare cases of raptor behavior, such as parental infanticide (Korňan and Macek 2011, Solaro and Sarasola 2012, Franke et al. 2013). Here we provide camera documentation of a case of nonparental infanticide in colonial Eleonora’s Falcons (Falco eleonorae) in Greece.

We studied Eleonora’s Falcons breeding in a colony on the islet of Anidro in the eastern part of the Aegean Sea, Greece (37u249N, 26u299E). Anidro is a small (0.3 km²) uninhabited islet, with scattered vegetation dominated by tree spurge (Euphorbia dendroides). The vegetation is heavily grazed by domestic goats, which are seasonally brought to the islet. Eleonora’s Falcons feed their nestlings almost exclusively with small birds migrating from Europe to Africa during August and September (Walter 1979, Gangoso et al. 2013). The young stay in the nest for approximately 35–37 d (Vaughan 1961).

We used cameras to study a total of 12 breeding pairs over three breeding seasons: four breeding pairs during 14–20 September 2013, four during 6–16 September 2014, and four during 7–16 September 2015. The main objective of our study was recording food provisioning by Eleonora’s Falcons. In 2014 and 2015, when conspecific nest predation was documented, we used Reconyx HyperFire Professional PC900 and PC850 camera traps (Reconyx, Inc., Holmen, WI U.S.A.), customized for close-up recording. In both years cameras were installed about 1 m from each nest when the nestlings were approximately 1 wk old. We used one Reconyx PC900 at each nest in 2014, and one Reconyx PC900 and one PC850 at each nest in 2015. The camera trap captured still images at a rate of two frames per sec during movements at the nest. In total, we monitored with cameras 24 hr/d for about 80 d, an average of about 6.7 d per nest.