Roadkills as a complementary information source for biological surveys using rodents as a model

Abstract

Roads affect wildlife in many ways, with roadkills probably the most conspicuous. In Mexico, there is increasing interest in this effect on wildlife. Together, richness and abundance can be used to predict trends for wild populations, and our study analyzes these variables for rodents killed by vehicles and trapped along a 14-km stretch of an A-type roadway in Veracruz, Mexico, from June 2010 to March 2011. Our study area had 2 habitat types: shrubland on lava flow and grassland. Over the course of the study, we monitored this stretch of highway by car for 34 days of effective sampling. When we spotted an animal, we stopped to record it. In the surrounding habitats, traps were set for 28 nights with 36 traps per habitat (total effort: 1,008 trap nights). The richness of trapped rodents was 9 species and for roadkills it was 14. The 2 sampling methods shared 7 species. The differential contribution was 2 species in trapping and 7 in roadkills. The complementarity index was 99.36. For both methods, the dominant species were mice of the genus Peromyscus ( Peromyscus difficilis for the shrubland and Peromyscus maniculatus for the grassland). Roadkills were a very representative source of information for the purposes of biological inventory and even for identifying the dominance pattern in species composition, thus offered a useful method for supplementing information obtained from traditional trapping. Highways threaten biodiversity mainly because they fragment habitats and further expose other habitats to impact by humans, but also because of their potential as a direct mortality factor. Careful interpretation of roadkill data can be a useful tool whose value for biologists has not yet been fully appreciated. Los caminos afectan a la fauna silvestre de muchas maneras, probablemente la más conspicua son los atropellamientos. En México, recientemente, algunos estudios comienzan a señalar con mayor interés el problema. Este estudio se enfoca en evaluar la riqueza y abundancia de roedores atropellados a lo largo de un segmento de 14 km de la carretera tipo A2 en el estado de Veracruz, abarcando desde junio de 2010 hasta marzo del 2011, Además, estos pueden predecir las tendencias de las poblaciones silvestres que habitan en la zona aledaña, compuesta por dos hábitats: malpaís y un llano. Durante el estudio, el camino se revisó desde el auto durante 34 días efectivos de muestreo carretero y un total de 28 noches de trampeo, que representa un esfuerzo de 1008 noches/trampa. Se obtuvo una riqueza de roedores de nueve especies por trampeo contra 14 encontradas atropelladas, con siete especies compartidas entre métodos. La contribución diferencia fue de dos especies por trampeo y siete por atropellamiento. Se obtuvo un índice de complementariedad de 99.36. Las especies dominantes en ambos métodos fueron los ratones del género Peromyscus ( P. difficilis para el malpaís y P. maniculatus para el llano). Los atropellamientos fueron una fuente eficiente de información biológica para inventarios e incluso permitieron identificar patrones de dominancia en la composición de especies. Por tanto, resaltamos su valor complementario a métodos tradicionales de trampeo. Las carreteras represantan una amenaza para la biodiversidad principalmente por que causan fragmentación de los hábitats exponiendo así más de estos al impacto humano, pero también por su potencial como un factor de mortalidad. Podemos explotar esto mediante la cuidadosa interpretación de información proporcionada por los atropellamientos, convirtiéndose en una herramienta útil para biólogos que hasta la fecha ha sido menospreciada.

Biogeography and predictors of wildlife killed on roads at peninsular Florida State Parks

“…Of these predictors, area was most important (based on scaled effect sizes in Table 4). Assuming that living diversity is representatively sampled by WVCs (as observed by González-Gallina et al, 2015 andCanova &Balestrieri, 2019), and given that the observed species-area effect fits long-established expectations (Rosenzweig, 1995), then results here may indicate a similar species-area relationship for living wildlife diversity in the parks. Tests of that relationship must await more complete inventories of wildlife living in Florida State Parks, but results here suggest a strong biogeographic effect on habitat "islands" in the midst of rapid human population growth and land use.…”

“…On the other hand, SR may be more stable than abundance-based measures given varied sampling among parks through the years. For example, WVC surveys efficiently estimate SR of living wildlife, compared to more intensive sampling (Canova & Balestrieri, 2019;González-Gallina et al, 2015).…”

“…Alternatively, regional diversity patterns are affected by natural factors, including species-area and species-energy effects (Storch et al, 2005) and potentially a peninsula effect (Jenkins & Rinne, 2008). Given that WVC diversity reflects wildlife diversity (Canova & Balestrieri, 2019;González-Gallina et al, 2015), natural factors may still relate to WVC diversity and abundance amidst the ever-growing urban sprawl in Florida. We also expected different outcomes among analyses for birds, mammals, reptiles, and overall.…”

Environmental Factors Determinate Roadkill Levels of the Endemic Iberian Species, Iberian Hare (Lepus Granatensis)

“…D'Amico et al (46) has highlighted the relevance of phenology as the most important factor affecting temporal roadkill patterns in small mammals as well as Canal et al (63) showed that these kinds of patterns were repeated over years and ecoregions in a same region as Andalucía. Therefore, it is likely that our results may be repetitive in similar conditions of environments, road features and hare population status, showing the existence of an unknown hare mortality rate and giving them relevance for the species management (73).…”

Dead snakes and their stories: morphological anomalies, asymmetries and scars of road killed Dolichophis caspius (Serpentes, Colubridae) from Romania

“…Road traffic does not only impact snakes, but also other animals (Ashley and Robinson 1996;Glista et al 2007;Baxter-Gilbert et al 2015;Ciolan et al 2017). The high number of mortalities from different animal groups has permitted road mortalities to be employed as study material for feeding ecology (Drygala and Zoller 2013; Kolenda et al 2019), phylogeography (Grill et al 2009;Horcajada et al 2018), temporal trends in populations (Meek 2020) and faunistic studies (Gonzáles-Gallina et al 2016;Teodor et al 2019).…”