Directionality of drinking passes by bats at water holes: is there cooperation?

Throughout the literature there is little consideration or documentation of how interspecific cooperation may be important to species coexistence. Three types of cooperation have been observed: 1) mutually facultative, a rather loose form of cooperation leading to coexistence, 2) mutually obligate, the tightest cooperation, leading to coexistence or extinction relative to the relationships strength, and 3) nonmutually facultative, obligate for one, but facultative for the other, an extension of parasitism, that would predictably lead to either coexistence of both or extinction of the obligate (Tokeshi, 1999). For bats, cooperative interactions such as eavesdropping (Fenton and Morris, 1976; Bell, 1980; Barak and Yom-Tov, 1989), following behavior (Wilkinson, 1992), and imitative learning (Gaudet and Fenton, 1984) occur within and among species. Group foraging is also commonly found in several species (e.g., Dwyer, 1970; Bradbury and Vehrencamp, 1976; Sazima and Sazima, 1977; Howell, 1979; Barak and Yom-Tov, 1989) that exhibited co-ordinated flight; presumably an advantageous behavior that effects efficient foraging (Wilkinson, 1995). Acta Chiropterologica, 4(2): xxx–xxx, 2002 PL ISSN 1508-1109 © Museum and Institute of Zoology PAS