Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain)
Abstract The Balearic lizard, Podarcis lilfordi, is present in 43 insular populations in the Cabrera archipelago and around the coasts of Mallorca and Menorca islands (Spain). We studied lizard densities over the entire range of distribution, analyzing observed differences of density in relation to...
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crbrillap:10.1163/156853808783431587 2024-06-23T07:56:24+00:00 Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) Pérez-Mellado, Valentín Martín-Vallejo, Javier Brown, Richard Picornell, Antonia Castro, José Ramón, María Misericordia Terrassa, Bárbara García-Díez, Teresa Hernández-Estévez, José Ángel 2008 http://dx.doi.org/10.1163/156853808783431587 https://brill.com/view/journals/amre/29/1/article-p49_6.xml https://brill.com/downloadpdf/journals/amre/29/1/article-p49_6.xml unknown Brill Amphibia-Reptilia volume 29, issue 1, page 49-60 ISSN 0173-5373 1568-5381 journal-article 2008 crbrillap https://doi.org/10.1163/156853808783431587 2024-06-03T08:11:57Z Abstract The Balearic lizard, Podarcis lilfordi, is present in 43 insular populations in the Cabrera archipelago and around the coasts of Mallorca and Menorca islands (Spain). We studied lizard densities over the entire range of distribution, analyzing observed differences of density in relation to island area, habitat diversity, availability of resources, presence of predators, competitors and human disturbances. The density of the Balearic lizard varies from less than 35 to almost 8000 lizards ha–1, with an average of around 1500 lizards ha–1. In some very small islets we detected no more than 10 individuals. Using a subsample of nine coastal islets (Menorca) we did not find any significant correlation between ground arthropod biomass and lizard density. The combination of island area and its maximal altitude, its so-called biotic capacity, was also uncorrelated with lizard density. In addition, neither degree of island accessibility nor presence/absence of seagull breeding colonies, were able to explain lizard densities. Islands without ship rats (Rattus rattus) showed a significantly higher lizard density, but islands in which rat eradication programs were launched during the study period, showed lower densities than those with rats but no eradication actions. Genetic variability was significantly higher on bigger lizard populations, lacking a correlation with lizard densities. No single independent variable can explain density differences among populations under study. Our results are discussed in the light of available hypotheses on factors affecting population densities. Article in Journal/Newspaper Rattus rattus Brill Amphibia-Reptilia 29 1 49 60 |
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Abstract The Balearic lizard, Podarcis lilfordi, is present in 43 insular populations in the Cabrera archipelago and around the coasts of Mallorca and Menorca islands (Spain). We studied lizard densities over the entire range of distribution, analyzing observed differences of density in relation to island area, habitat diversity, availability of resources, presence of predators, competitors and human disturbances. The density of the Balearic lizard varies from less than 35 to almost 8000 lizards ha–1, with an average of around 1500 lizards ha–1. In some very small islets we detected no more than 10 individuals. Using a subsample of nine coastal islets (Menorca) we did not find any significant correlation between ground arthropod biomass and lizard density. The combination of island area and its maximal altitude, its so-called biotic capacity, was also uncorrelated with lizard density. In addition, neither degree of island accessibility nor presence/absence of seagull breeding colonies, were able to explain lizard densities. Islands without ship rats (Rattus rattus) showed a significantly higher lizard density, but islands in which rat eradication programs were launched during the study period, showed lower densities than those with rats but no eradication actions. Genetic variability was significantly higher on bigger lizard populations, lacking a correlation with lizard densities. No single independent variable can explain density differences among populations under study. Our results are discussed in the light of available hypotheses on factors affecting population densities. |
format |
Article in Journal/Newspaper |
author |
Pérez-Mellado, Valentín Martín-Vallejo, Javier Brown, Richard Picornell, Antonia Castro, José Ramón, María Misericordia Terrassa, Bárbara García-Díez, Teresa Hernández-Estévez, José Ángel |
spellingShingle |
Pérez-Mellado, Valentín Martín-Vallejo, Javier Brown, Richard Picornell, Antonia Castro, José Ramón, María Misericordia Terrassa, Bárbara García-Díez, Teresa Hernández-Estévez, José Ángel Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) |
author_facet |
Pérez-Mellado, Valentín Martín-Vallejo, Javier Brown, Richard Picornell, Antonia Castro, José Ramón, María Misericordia Terrassa, Bárbara García-Díez, Teresa Hernández-Estévez, José Ángel |
author_sort |
Pérez-Mellado, Valentín |
title |
Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) |
title_short |
Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) |
title_full |
Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) |
title_fullStr |
Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) |
title_full_unstemmed |
Population density in Podarcis lilfordi (Squamata, Lacertidae), a lizard species endemic to small islets in the Balearic Islands (Spain) |
title_sort |
population density in podarcis lilfordi (squamata, lacertidae), a lizard species endemic to small islets in the balearic islands (spain) |
publisher |
Brill |
publishDate |
2008 |
url |
http://dx.doi.org/10.1163/156853808783431587 https://brill.com/view/journals/amre/29/1/article-p49_6.xml https://brill.com/downloadpdf/journals/amre/29/1/article-p49_6.xml |
genre |
Rattus rattus |
genre_facet |
Rattus rattus |
op_source |
Amphibia-Reptilia volume 29, issue 1, page 49-60 ISSN 0173-5373 1568-5381 |
op_doi |
https://doi.org/10.1163/156853808783431587 |
container_title |
Amphibia-Reptilia |
container_volume |
29 |
container_issue |
1 |
container_start_page |
49 |
op_container_end_page |
60 |
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1802649466594918400 |