Raptors in the scavenging comunity of the semiarid region of La Pampa, Argentina

MARÍA EUGENIA CABRERA GARCÍA; JOSÉ HERNÁN SARASOLA; PEDRO PEREZ OLEA; JUAN I. ZANÓN MARTÍNEZ; PATRICIA MATEO TOMÁS

Skukuza

Congreso; Raptor Research Foundation Conference; 2018

Carrion consumption by vertebrates (i.e. scavenging) is an important ecological process supporting key ecosystem functions such as disease control and nutrient recycling, contributing even more than predation to the transfer of energy and matter in food webs. Despite being a relevant ecological process, scientific interest on scavenging by vertebrates has only recently emerged and data on scavenger communities are lacking for most terrestrial biomes such as South America. Here, we characterise the structure and composition of the vertebrate scavenger community, underscoring the role of scavenger raptors in these assemblages in the semi-arid region of La Pampa, Argentina. We used motion-triggered remote cameras to monitor a total of 31 carcasses: 22 of domestic ungulates and 9 of wild ungulates during 2017-2018. Of the total species detected, four (36.6%) were birds, all of them raptors: two were obligate (18.2%) and another two were facultative scavengers (18.2%). Southern Caracara (Caracara plancus) was the one that most frequently appeared in the total of carcasses (96.8%) followed by the Turkey Vulture (Cathartes aura; 58.1%), the Chimango Caracara (Phalcoboenus chimango; 51.6%) and the Black Vulture (Coragyps atratus; 32.2%). Some differences were found respect to the type of carcasses: frequency of occurrence of Chimango Caracaras was greater in domestic than in wild ungulate carcasses (68.2% vs. 11.1%), whilst Turkey Vulture and Black Vulture appeared less in domestic carcasses (40.9% vs. 100% and 27.3 vs. 44.4%). Nevertheless, no differences were found respect to the Southern Caracara (95.4 vs. 100%). Provided that raptors are the only avian guild at large carcasses in La Pampa, our results suggest an important role of diurnal raptors in the scavenging dynamics in this region. Furthermore, comparing with other bird scavenger communities worldwide, we can say that our bird scavenger community is smaller than in most other regions (e.g. Europe, Australia and North America).