Factors affecting mammalian carnivore use of riparian ecosystems in Mediterranean climates

Abstract

Riparian ecosystems serve as movement and dispersal corridors; however, the factors that determine their use by multiple species of carnivores remain unknown. Two hypotheses can explain carnivore presence in riparian ecosystems. Higher riparian plant richness, diversity, and structure provide the resources used by carnivores (resting sites, cover, and food). Alternatively, areas with higher water availability allow species to withstand water loss and thermal gradients in the high summer temperatures. In southern Portugal we surveyed 70 transects 2 km long along riparian ecosystems during the wet winter months and again in the dry summer months, recording signs of carnivore species and the environmental context in which they occurred (vegetation descriptors, surrounding landscape, and waterway type and condition). Five carnivore species used riparian ecosystems (stone marten [Martes foina], Eurasian badger [Meles meles], common genet [Genetta genetta], Egyptian mongoose [Herpestes ichneumon], and red fox [Vulpes vulpes]). Riparian ecosystems had a diverse and heterogeneous plant community with a mix of obligate riparian, Mediterranean sclerophyllous, and exotic species. Most carnivore species responded to water channel type and standing water availability in both seasons, except for the stone marten in the wet season, which uses areas with rich riparian vegetation. Our results suggest that the use of riparian ecosystems is linked to water availability that provides water, prey, and external temperature regulation.

A riparian conservation network for ecological resilience

“…For example, Hilty and Merenlender (2004) found that, although native mammalian predators (e.g., coyote, Canis latrans; raccoon, Procyon lotor) preferred wider riparian corridors, they nonetheless used narrower, human-disturbed corridors in agricultural landscapes. In addition, wildlife movement through road underpasses associated with rivers and streams is well documented (Clevenger and Waltho, 2000;Santos et al, 2011). Although disturbed riparian corridors are not the equivalent of undisturbed ones (Battin, 2004), this body of literature suggests that species will use disturbed riparian corridors when undisturbed ones do not exist.…”

“…The use of riparian areas for movement is species-specific (Gilbert-Norton et al, 2010;Lees and Peres, 2008). Nonetheless, multiple terrestrial species rely on riparian areas at some point in their life history (Naiman and Decamps, 1997), most commonly for migration through human-modified landscapes (Santos et al, 2011). Additionally, a variety of species use riparian corridors for access to water, escape from predators, cover, food, nesting habitat, and dispersal or movement between habitat patches (Brost and Beier, 2012).…”

Riparian vegetation research in Mediterranean-climate regions: common patterns, ecological processes, and considerations for management

“…Riparian zones in med-regions and other semiarid environments also host a large proportion of the surrounding biome's wildlife species for some portion of their life history (Patten, 1998;Seavy et al, 2009a). Examples of high diversity include mammalian carnivores (Matos et al, 2009;Santos et al, 2010), birds (Leal et al, 2011), and beetles (da Silva et al, 2011).…”

Distribución del meloncillo (Herpestes ichneumon) en la provincia de Granada

“…Es posible que se trate de zonas de paso donde no haya poblaciones estables, zonas en las que el esfuerzo de muestreo no haya sido suficiente, en las que los individuos se encuentren en baja densidad o en las que el hábitat no sea el más apropiado. Puesto que los meloncillos en el sur de la Península tienen cierta preferencia por los sistemas acuáticos y ambientes riparios (Santos et al 2011), es probable que estos ambiente hayan jugado un papel crucial en la colonización de la provincia de Granada, en primer lugar a través de la cuenca del río Genil, e incluso de la del río Guadalhorce, y en segundo lugar a través de las grandes cuencas de los ríos Guadiana Menor y Guadalfeo (al norte y al sur de Sierra Nevada, respectivamente). De ser así, estas cuencas cumplirían de forma eficaz la función de corredores naturales, a través de los cuales los individuos dispersantes podrían estar colonizando ambas vertientes del macizo de Sierra Nevada.…”