Abundance, microhabitat selection and conservation of eyed lizards (Lacerta lepida): a radiotelemetric study

The utility of radiotelemetry as a tool for estimating the size and microhabitat requirements of a population of Lacerta lepida, the largest European lacertid, was investigated in central Spain. Population density estimates based on repeated marking and recapture (3.2 lizards ha−1) were much higher than those based on line transects (0.22 lizards ha−1). The probability of sighting lizards before they could retreat into a refuge was largely increased by our ability to radiolocate them. Rocks were selected as refuges 96% of the times, and the locations of radiotracked lizards were much closer to rocks than randomly expected. Rocks used as retreat sites were larger and had more crevices than those available at random, which suggests that refuge selection was primarily determined by the need to find shelter from predators. Rockrose patches, which were positively selected, might be used as refuge-connecting corridors that combine shelter with opportunities to forage and thermoregulate. Our results emphasize the need for using radiotelemetry to establish baseline information on abundance and to clarify the actuality, extent and pattern of the population declines experienced by species that may function as key links in their ecosystems, but the wariness of which poses a serious problem for monitoring their conservation status.

[1]  R. M’Closkey,et al.  Effects of human disturbance on five-lined skink, Eumeces fasciatus, abundance and distribution , 1998 .

[2]  R. Shine,et al.  A RADIOTELEMETRIC STUDY OF MOVEMENTS AND SHELTER-SITE SELECTION BY FREE-RANGING BROWNSNAKES (PSEUDONAJA TEXTILIS, ELAPIDAE) , 2003 .

[3]  M. Hutchinson,et al.  Adding burrows to enhance a population of the endangered pygmy blue tongue lizard, Tiliqua adelaidensis , 2004 .

[4]  P. Grillet,et al.  Statut passé et actuel du lézard ocellé (Lacerta lepida, sauriens, lacertidés) en France. Implication en termes de conservation , 2005 .

[5]  B. Wakeling,et al.  Lizard species distributions and habitat occupation along an urban gradient in Tucson, Arizona, USA , 2001 .

[6]  L. Vitt,et al.  The Impact of Individual Tree Harvesting on Thermal Environments of Lizards in Amazonian Rain Forest , 1998 .

[7]  P. Regal.  5. THE ADAPTIVE ZONE AND BEHAVIOR OF LIZARDS , 1983 .

[8]  José Martín,et al.  Microhabitat selection by the Iberian rock lizard Lacerta monticola: Effects on density and spatial distribution of individuals , 1997 .

[9]  R. Huey,et al.  Physiological Consequences of Habitat Selection , 1991, The American Naturalist.

[10]  R. Huey,et al.  Temperature , Physiology , and the Ecology of Reptiles , 2008 .

[11]  L. Vitt,et al.  Use of naturally and anthropogenically disturbed habitats in Amazonian rainforest by the teiid lizard Ameiva ameiva , 1999 .

[12]  José Martín,et al.  The effect of Mediterranean dehesa management on lizard distribution and conservation , 2002 .

[13]  R. Jennings,et al.  HABITAT USE BY GILA MONSTERS: THE IMPORTANCE OF SHELTERS , 2003 .

[14]  W. Porter,et al.  Physiological and Ecological Consequences of Sleeping‐Site Selection by the Galapagos Land Iguana (Conolophus Pallidus) , 1984 .

[15]  George W. Cox,et al.  Laboratory Manual of General Ecology , 1967 .

[16]  R. Shine,et al.  Paving the way for habitat restoration: can artificial rocks restore degraded habitats of endangered reptiles? , 2000 .

[17]  L. Carrascal,et al.  Regional distribution of a Mediterranean lizard : influence of habitat cues and prey abundance , 1991 .

[18]  M. Kearney.  Hot rocks and much-too-hot rocks: seasonal patterns of retreat-site selection by a nocturnal ectotherm , 2002 .

[19]  C. Tracy,et al.  A Biophysical Analysis of Daily and Seasonal Utilization of Climate Space by a Montane Snake , 1982 .

[20]  Andrés García,et al.  Lizard Community Response to a Desert Shrubland-Intertidal Transition Zone on the Coast of Sonora, Mexico , 2003 .

[21]  J. Sabo.  Hot rocks or no hot rocks: overnight retreat availability and selection by a diurnal lizard , 2003, Oecologia.

[22]  R. Shine,et al.  Choosing a rock: Perspectives of a bush-rock collector and a saxicolous lizard , 1994 .

[23]  R. Shine,et al.  Invertebrate biodiversity under hot rocks: habitat use by the fauna of sandstone outcrops in the Sydney region , 2003 .

[24]  S. J. Arnold,et al.  Hot Rocks and Not-So-Hot Rocks: Retreat-Site Selection by Garter Snakes and Its Thermal Consequences , 1989 .

[25]  K. Corbett.  The conservation of European reptiles and amphibians , 1990 .