Conservation implications of competition between generalist and specialist rodents in Mediterranean afforested landscape

Abstract

Density dependent habitat selection at the community level is regarded as a major determinant of biodiversity at the local scale, and data on these processes and how they are affected by human activities is highly applicable to conservation. By studying the competitive relationships between a specialist and a generalist we can acquire valuable insights about how different environmental elements determine species abundance and distribution and consequently biodiversity. Here we describe a study of density dependent processes that determine the community structure of two rodents: a specialist-the broad toothed mouse (Apodemus mystacinus), and a generalist-the common spiny mouse (Acomys cahirinus) in a Mediterranean maqui habitat, and how this structure is impacted by anthropogenic planting of pine stands. We carried out two field experiments: The first, based on open field trapping, looking at how rodent communities change with habitat structure. The second experiment was an enclosure study aimed at validating the habitat preferences and competitive relationship between the specialist and the generalist. We identified asymmetric competition relationships in which the specialist was dominant over the generalist. Competition intensity was lower in maqui with [10% oak cover, although both species abundances were high. Competition was found only during the limiting season (summer). Based on these findings we produced management recommendations to keep indigenous small mammals' biodiversity high. Density dependent habitat selection processes play a central role in determining biodiversity, and understanding the mechanisms motivating these processes is needed if alterations in biodiversity in response to human disturbance are to be understood.

A Newly Emerged Cutaneous Leishmaniasis Focus in Northern Israel and Two New Reservoir Hosts of Leishmania major

“…Tallahassee, FL, USA). Traps were dispersed 15–20 m apart, baited with a peanut snack ( Bamba , Osem Ltd. Holon, Israel) attractive to many rodents [20].…”

Habitat overlap between sympatric European hares (Lepus europaeus) and Eastern cottontails (Sylvilagus floridanus) in northern Italy

“…Hurlbert's overlap index is 1.0 when both species use each habitat in proportion to its abundance, 0 when the two species share no resources, and >1.0 when the two species both use certain habitats more intensively than others and the preferences of the two species for resources tends to coincide. We used Manly's α Preference Index to evaluate seasonal habitat preference for the two species in allopatry, and to compare their habitat preference in sympatry (Manly et al 1972;Chesson 1978;Manly et al 1993;Krebs 1999):…”

On the difference between “exclosures” and “enclosures” in ecology and the environment

“…In experimental research, enclosures are units or plots in which living beings are confined, for instance to reveal competitive relationships between different animal species (Manor and Saltz, 2008) or to create a controlled environment for plant pollination studies (Jauker and Wolters, 2008). Enclosures are a powerful tool in aquatic community studies, where they are used to manipulate environmental conditions or communities in ponds (e.g.…”