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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124, No. 2, June 2012 
The Wilson Journal of Ornithology 124(2):406-408, 2012 
House Crow (Corvus splendens) Attempt to Cooperatively Kleptoparasitize 
Western Osprey (P and ion haliaetus) 
Reuven Yosef , 14 Assaf Zvuloni , 2 and Nufar Yosef-Sukenik 1 2 
ABSTRACT.—The House Crow (Conus splendens) 
is a bioinvader to the Red Sea region and has been show n 
to negatively impact indigenous species. We describe 
attempts by House Crows to acquire an ordinarily inac¬ 
cessible, high quality food source by mobbing Western 
Osprey (Pondion haliaetus ) in large coordinated groups. 
The crows mobbed perched Osprey that had success 
fully caught fish in 17b observed attempts to steal the 
otherwise inaccessible food source. However, crows suc¬ 
ceeded in forcing Osprey to abandon fish on only seven 
occasions (—4%). The crows then jointly fed on the 
abandoned fish. The consistency in mobbing Osprey and 
the low rate of success suggests House Crows are aware 
of the energetic value of fish. Received 5 Decern her 2011. 
Accepted 3 March 2012. 
Kleptopara.sitism is a behavior in which one ani¬ 
mal takes food or inanimate objects from another 
(Brockman and Barnard 1979). The kleptoparasitc 
profits by acquiring prey or objects that it could not 
obtain itself, or by saving time and energy required 
to obtain it. KJeptoparasitism may be intra- or 
interspecific (e.g., Yosef 1991, Yosef and Yosef 
2010. Yosef et al. 2011). Garcia et al. (2010) sug¬ 
gested animals with specialized feeding methods, 
or with large or high-energy food, or with extended 
handling time of large or cumbersome prey, are 
most likely to be kleptoparasilised. 
Some kleptoparasitic species achieve their goal 
by mobbing in large numbers. Mobbing is defined 
as the attack initiated against a potential enemy or 
predator (cf. Altmann 1956) and has been shown 
to occur in many different situations for a variety 
of purposes (e.g., Ostreiher 2003). 
The House Crow (Corvus splendens). a bioin¬ 
vader to the Eilat/Aqaba region of Israel, nega¬ 
tively impacts indigenous and migratory avian 
species (Yoset 2009) and is considered a threat to 
1 Ben Gurion University at Eilat. P. O. Box 272. Eilat. 
Israel. 
2 Israel Nature and Parks Authority. P. O. Box 667, Eilat, 
Israel. 
Department ot Education, Tel Aviv University. Ramat 
Aviv, Israel. 
J Corresponding author; e-mail: ryosef@bezeqint.net 
biodiversity (e.g.. Britton 1980. Feare and Mun- 
groo 1990. Chuan Urn et al. 2003). We describe 
attempts at cooperative mobbing by House Crows 
that use kieptoparasitism to access a food source 
that is otherwise unattainable: fresh fish caught in 
the Red Sea by Western Osprey ( Pandion haliae- 
tus). We investigated whether House Crows have 
developed strategies similar to those of ravens (cf. 
C. corns: Bugnyar and Heinrich 2003. 2005: C. 
ruftcollis: Yosef and Yosef 2010, Yosef et al. 2011) 
to access large, inaccessible or qualitative food 
sources with minimal effort. 
METHODS 
Study Species .—The Western Osprey is cosmo¬ 
politan in occurrence and is a Holarctie breeder 
(Ferguson-Lees and Christie 2001). It is a passage 
migrant in most parts of Israel. However, at Eilat 
it occurs throughout the year; these may be mostly 
dispersing juveniles Hedged on islands and archi¬ 
pelagos in the Red Sea (e.g., Straits of Than and 
Dahlak Islands; Safriel et al. 1985). 
The House Crow is a bioinvader in the Eilal- 
Aqaba region since the late 1970s and has estab¬ 
lished breeding populations on both sides of the 
international boundary (Israel and Jordani. It is 
a little-studied species in the region but. because 
of its ability to exploit human settlements in the 
desert, populations have reached pest dimensions 
in Israel (Yosef 2009). 
We undertook periodic observations at known 
feeding perches of Western Osprey along the Israeli 
shoreline between March and June 2011 at the 11 
most popular perches where distances can range from 
30 to I (X) m from the perched Osprey. We observed 
the behavioral sequence of interactions between the 
two species during 213 hrs of observation from 
the shoreline. All observations were with 15 * 50 
Swarovski binoculars and a 20 X 60 telescope. 
OBSERVATIONS 
Western Osprey successfully caught a fish on 
176 (15.5%) observed occasions during spring 
(Mar-Jun) 2011. We observed Osprey perch at 
