Effect of climatic fluctuations on body mass of a Mediterranean vole, Microtus cabrerae

Abstract

The Cabrera vole (Microtus cabrerae) is a microtine rodent endemic to the Mediterranean bioclimatic region of the Iberian peninsula. We investigated body mass variation in a population monitored during monthly trapping sessions from April 1997 to April 1999. No significant differences in body mass were found between adult males and females; also no seasonal pattern of body mass variation was detected. Likewise, no correlation was found between the monthly body mass average and rainfall, probably due to the peculiar characteristics of the habitats used by M. cabrerae. These consist of areas with high soil moisture and high phreatic level; thus, these features act as a buffer and maintain fresh vegetation when rainfall is scarce. Consequently, body mass of the population does not depend directly on rainfall. Body mass and body condition scarcely fluctuated before summer 1998, but decreased significantly from that season to winter 1998, in coincidence with the severe drought recorded in summer-autumn 1998, which affected the quality of food available to the Cabrera vole, and resulted also in a suppression of reproduction up to 3 months. Given the predicted climate change trend in the Iberian peninsula, the particular reproduction characteristics of the Cabrera vole, and the destruction of their habitats by human activities, we strongly recommend the protection of the habitats occupied by this rodent species.

Breeding characteristics of the Lusitanian pine vole, Microtus lusitanicus

“…Th us, whereas in the northeast of the Iberian Peninsula and in southern France sexually active individuals were detected all year (Claramunt, 1976 ;Paradis and Guédon, 1993 ), in southern Spain the species can show a seasonal reproduction, with a marked diminution of sexual activity between July and September (Palomo et al, 1989 ). Th is is consistent with the fact that vole species living in Mediterranean climate zones, such as M. californicus (Cockburn and Lidicker, 1983 ), M. guentheri (Cohen-Shlagman et al, 1984), and M. cabrerae (Fernández-Salvador et al, 2005a, 2005b, can stop reproduction during the summer, which is the critical season because of high temperatures and dry environment. In fact, the reproduction all year round reported in French populations has been related to orchard management practices that alleviate summer drought (Paradis and Guédon, 1993 ).…”

Vegetation analysis in colonies of an endangered rodent, the Cabrera vole (Microtus cabrerae), in southern Portugal

“…For explanation of variables, see Table 1 Variable obtain water for metabolism (MacArthur 1972). Colonies with higher levels of moisture depend less on the rainfall to maintain vegetation growth even during drought (Ferna´ndez-Salvador et al 2005), allowing higher food quality for voles (Noy-Meir et al 1989;Caughley and Sinclair 1994) for longer periods. High cover of trees and shrubs were associated with tall perennial grasslands and some annual grasslands with low moisture conditions, possibly providing microclimate characteristics that prevent high water losses from the soil and herbs.…”

“…SG_m 2 grass richness per square metre, HMG perennial grass cover, TG annual grass cover, d_roa road distance, md_hh mean herbaceous height, tree tree cover, shr shrub cover, ruder percentage of ruderal species, moist percentage of moisture indicator species, clay soil clay content, sand soil sand content, nitr soil nitrogen content, pH soil pH, orgm soil organic matter content, pf2 soil field capacity, dim colony dimension, abun vole abundance class, graz grazing presence; filled star represents one binary variable obtain water for metabolism (MacArthur 1972). Colonies with higher levels of moisture depend less on the rainfall to maintain vegetation growth even during drought (Ferna´ndez-Salvador et al 2005), allowing higher food quality for voles (Noy-Meir et al 1989;Caughley and Sinclair 1994) for longer periods. High cover of trees and shrubs were associated with tall perennial grasslands and some annual grasslands with low moisture conditions, possibly providing microclimate characteristics that prevent high water losses from the soil and herbs.…”

Documenting the biogeographic history ofMicrotus cabreraethrough its fossil record

“…However, it is not found in areas with arid Mediterranean climates characterized by long summer droughts, since water scarcity strongly interferes with its reproduction and development (Fernández Salvador et al. ). This species occurs mainly at medium altitudes, in brushwood near small streams, in riverside areas with sedges or rushes or in fields of tall grass, and is frequently associated with oak Quercus spp.…”