Test of character displacement in urban populations of Apodemus sylvaticus

Abstract

We studied the wood mouse, Apodemus sylvaticus, inhabiting parks, cemeteries, suburban woods, and other green areas in the city of Prague. To assess the character displacement and (or) release hypothesis we compared seven samples from local populations occurring sympatrically with Apodemus flavicollis with 10 samples from those localities in which A. flavicollis has never been recorded. The analysis included 1410 specimens of A. sylvaticus collected during the years 1980–1990. Seventeen skull and body characters were measured. Then the data were age- or size-adjusted and treated by principal-component analyses. Factor scores were further subjected to statistical testing. Although the results revealed considerable variation among localities, they did not suggest character displacement and (or) release. Apodemus sylvaticus from populations sympatric with A. flavicollis were morphometrically similar to their conspecifics from other populations collected at the periphery of the city. However, slight but statistically highly significant differences were found between samples from localities in the city centre and those from the periphery. This phenomenon may be interpreted as the effect of urbanisation or isolation by built-up areas.

Evolutionary history of the bank vole Myodes glareolus: a morphometric perspective

“…Furthermore, genetic analyses pointed to a low divergence of the lineages (maximum 1.6% genetic differentiation; Table 2). Cases of morphological differentiation in an even shorter time span are known, but they usually correspond to peculiar conditions such as small, isolated populations in insular conditions (Renaud & Millien, 2001) or fragmented populations as a result of anthropization (Mikulová & Frynta, 2001). The context of divergence between bank vole lineages is very different, as they came into contact regularly during interglacial periods, allowing for significant gene flow between large populations.…”

No recent temporal changes in body size of three Danish rodents

“…Changes (probably temporal) in body size among populations of A. sylvaticus were reported in other studies. For example, Mikulová and Frynta (2001) found slight but statistically significant differences between samples from localities in Prague city Mar. Dec. Fig.…”

Ecological coexistence of low-density populations of Apodemus sylvaticus and A. flavicollis (Mammalia: Rodentia)

“…These two patterns are likely not independent, as it can be suggested that the absence of competition between these two closely related and ecologically similar rodents is due to a too scarce population density of the two Apodemus that therefore do not exploit heavily the available spatial and food resources (e.g., Vandermeer 1975;Aguiar et al 2001;Begon et al 2006). Indeed, it is well demonstrated that these species do actually compete in other areas of their range where their respective population density is higher (e.g., Mikulová and Frynta 2001;Montgomery 2004Montgomery , 2008, as well as in other Apodemus species (Sekijima and Sone 2006). Concerning pattern (i), it should be stated that the low population density of both rodents was also confirmed by the fact that usual rodent predators as Strigiformes (Capizzi and Luiselli 1995) do forage for over 90% on arthropods at the study areas (Strix aluco and Tyto alba being the studied species; Fanfani et al 2001).…”