基金Acknowledgments O.B-T is supported by a Fulbright post-doctoral fellowship from the United States - Israel Educational Foundation. This study was funded by an Israel Science Foundation (ISF) grant 1397/10 and by the Israel Nature and Park Authority. We thank R. King and A. Dolev for their help during various phases of the project. This is publication number 844 of the Mitrani Department of Desert Ecology.