Ecologically-similar species were found to develop specific strategies to partition their resources, leading to niche differentiation and divergence, in order to avoid interspecific competition. Our study determines multi-dimensional differentiation of two sympatric top-predators, long-legged buzzards (LLB) and short-toed eagles (STE), which recently became sympatric during their breeding season in the Judean Foothills, Israel. By combining information from comprehensive diet and movement analyses we found four dimensions of differentiation: (1) Geographic foraging area: LLB tended to forage relatively close to their nests (2.35 ± 0.62 km), while STE forage far from their nest (13.03 ± 2.20 km); (2) Foraging-habitat type: LLBs forage at low natural vegetation, avoiding cultivated fields, whereas STEs forage in cultivated fields, avoiding low natural vegetation; (3) Diurnal dynamics of foraging: LLBs are uniformly active during daytime, whereas STEs activity peaks in the early afternoon; and (4) Food-niche: while both species largely rely on reptiles (47.8% and 76.3% for LLB and STE, respectively), LLB had a more diverse diet and consumed significantly higher percentages of lizards, while STE consumed significantly higher percentages of snakes. Our results suggest that this multidimensional differentiation allows the spatial coexistence of these two dense populations in the study area.
|State||Published - 11 Oct 2016|
Bibliographical noteFunding Information:
This research was supported by the Keren Kayemeth LeIsrael (KKL-JNF), the Ministry of Science and Technology (Israel), Smaller-Winnikow Foundation, Israel Nature and Parks Authority (INPA), Hoopoe Foundation (SPNI), Rieger Foundation (USA), Raptor Research Foundation (RFF), the International Center for the Study of Bird Migration at Latrun (Israel) and Kfar-Etzion field school (Israel). GB and KMM were supported in part by NASA grant #NNX11AP61G, US National Science Foundation grant #IOS-1145952 and the Jacob and Lena Joels Memorial Foundation Visiting Professor Award. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. We thank many people for their useful advises and helpful analysis, including O. Spiegel, R. Harel, Y. Orchan, R. Nathan, Y. Bartan, and S. Rotich (Movement Ecology Lab-HUJI); R. Rabinovich, and R. Biton (HUJI); Y. Nissan, R. Talmor, A. Sherman (KKL); F. Kuemmeth and W. Heidrich (E-Obs GmbH); We are grateful to D. Brand, Y. Rozental, H. Mazar, D. Alon, N. Leader, Y. Malichi, O. Hatzofe, for their generous logistical support and research permits. We thank our accompanying committee: U. Motro, A. Lotem, and G. Katzir for their useful guiding. We are grateful to many people who helped during fieldwork, including U. Kaizer, Y. Ben-Ari, O. Sulimani, D. Gad, Y. Miller, G. Perlman, Y. Perlman, Y. Kiat, J. Meyrav, D. Oz, A. Saieg, Y. Motro, D. Oberman, I. Eitan, I. Ben-Dov, Y. Milo, G. Milo, R. Izraeli, Y. Friedemann, B. Porat, D. Gavish, G. Kali, B. Rinat, A. Naor, Y. Sela, E. Haklai, A. Ben-Gigi, N. Laufer, Y. kaufman, E. kaufman, Y. Siman-Tov, U. Levin, D. Ashkenazi, O. Ben-Shabat, T. Levi, D. Barel, A. Goldfarb, I. Shifman, Y. Shamir, H. Ben-Yaakov, B. Trooper, and R. Milgalter. This paper is dedicated to the memory of R. Trabelsy.
© The Author(s) 2016.
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