Simultaneous consumption of Liolaemus lizards by the raptor Geranoaetus polyosoma in south-central patagonia

Abstract

Interactions between predators and prey have direct effects on the fitness of both parties. Particularly, lizards are predated by a wide variety of taxa, where birds have been proposed to exert a minor predation pressure than other vertebrates, like squamates. In general, cases among the literature report predation events where a single individual has been consumed. Here, we report the finding of seven lizards in the stomach content of a variable hawk (Geranoaetus polyosoma) road-killed in Arid Patagonia. The remains found included three adult individuals and two juveniles of Liolaemus morandae, and one adult of L. kingii, along with an additional tail. All remains showed a similar degree of digestion, which may indicate that lizards were consumed within a short timeframe. This novel finding represents the first confirmed evidence of a raptor preying simultaneously upon multiple lizard species and highlights the potential importance of lizards as dietary items of the variable hawk during the warm season in arid environments of Patagonia. Additionally, it is the first confirmed record of predation upon the Liolaemus lineomaculatus section, a group restricted to Patagonia. This predation event, including several individuals, suggests that predation pressure exerted by birds upon lizards may be underestimated, particularly in regions where other predators are scarce. We provide new information with implications for both lizard population dynamics and raptor foraging ecology, enhancing our knowledge on predator-prey interactions in Arid Patagonia.