Carcass permanency time and its implications to the roadkill data

Eur J Wildl Res (2014) 60:543546 DOI 10.1007/s10344-014-0798-z

SHORT COMMUNICATION

Carcass permanency time and its implications to the roadkill data

Pedro Ratton & Helio Secco & Clarissa Alves da Rosa

Received: 14 July 2013 /Revised: 16 January 2014 /Accepted: 21 January 2014 /Published online: 5 February 2014 # Springer-Verlag Berlin Heidelberg 2014

Abstract Roadkill studies are typically conducted without regard to the carcass permanency time on the highway, which may lead to underestimation of roadkill data, especially small animals that are quickly removed by scavengers. To evaluate the carcass duration time on the lane and its relation to the roadkill time event, we conducted an experiment comparing the removal rate of small carcasses between different stretches of a highway and stretches of dirt roads. The rates found in the study were considered high, with 89 % of carcasses being removed in the first 24 h and 66 % within 12 h. The removals were high for both road categories but reached their peaks at different periods of the day, being higher during the day on the highway and at night on dirt roads. We believe that removal on the highway is dictated by higher vehicular traffic and mainly by the action of scavenger birds during the day, while on dirt roads, it is due to the action of different opportunistic scavengers during the night.

Keywords Road ecology . Removal rates . Carcass persistence . Wildlife roadkill . Scavengers

Introduction

Of highway impacts on biodiversity, roadkill is the one that most affects populations of wild vertebrates (Forman and Alexander 1998). Despite roadkill being studied for over 70 years (Davis 1934), the sampling design used in most studies relating wildlife mortality pays little or no attention to permanency time of carcasses on the roads (Slater 2002). The main implication is the underestimation of the number of carcasses, especially small ones, recorded on highways which are mainly removed in the first hours after roadkill by scavengers and traffic. This fact may lead to a false estimate of the roadkill rate and generate incorrect information on the impacts posed by highways (Slater 2002; Santos et al. 2011; Teixeira et al. 2013).

It is known that the carcass permanency time on the highway is influenced by three main factors: the...