Knowledge gaps and conservation priorities for west African cheloniansMcGovern, Pearson; Luiselli, Luca
doi: 10.1163/15685381-bja10137pmid: N/A
AbstractDefining priorities is important both in research and in conservation, especially when knowledge gaps are hindering successful management. In this review, we quantify the knowledge gaps for all non-marine West African chelonians based on 21 criteria. Additionally, we combine these knowledge gaps with each species’ maximum size, range size, presence in nationally protected areas, and IUCN Red List or TFTSG provisional status to introduce a ranking of species conservation priority in the region. Our analyses revealed a divergence between which species are lacking research studies and which would benefit most from conservation actions, though Cyclanorbis elegans is the species that is both the least-known and most-in-need of conservation. Broadly, Pelomedusidae are in the greatest need of research, yet they are also collectively the least threatened. Conversely, Trionychidae and Testudinidae have received greater research attention in most cases, however, these two families represent the greatest conservation priorities amongst West African chelonians. Our analyses also enabled us to evaluate which criteria representing aspects of chelonian biology have been most overlooked by the scientific community. Priorities for future research include reproductive and long-term population studies, each of which are critical for informing conservation actions and evaluating the results of those actions.
Intra-annual variations of microhabitat use and movements of a critically endangered arboreal day gecko endemic to Reunion Island: implications for conservationChoeur, Arthur; Clémencet, Johanna; Le Corre, Matthieu; Roesch, Markus A.; Sanchez, Mickaël
doi: 10.1163/15685381-bja10125pmid: N/A
AbstractHabitat loss is the leading cause of reptile decline and therefore, habitat studies are crucial to implement conservation actions. We investigated the microhabitat use of the Manapany day gecko (Phelsuma inexpectata), a critically endangered species endemic to Reunion Island (Western Indian Ocean). Anthropogenic disturbances led to a severe fragmentation of the gecko population, and habitat requirements of this species are poorly known, impeding effective restoration work. We (i) investigated intra-annual variations in microhabitat use, (ii) investigated movement rate to better understand habitat use, and (iii) characterised egg-laying sites. We surveyed two gecko populations in remnant natural habitat annually during five years (2015-2019) and monthly in one of the populations during 18 consecutive months. A total of 2621 gecko detections were recorded and 25 egg-laying sites were characterised. Geckos used mainly native plant species, with a high preference for screw pine thickets. We observed seasonal variations in microhabitat preferences and movement rates. Geckos perched higher and thermoregulated motionless in the canopy during winter. In summer, geckos perched lower, spent less time thermoregulating and exhibited saxicolous behaviour, particularly in females. Egg-laying sites were mainly found in rock cavities surrounded by native plants and facing southwards. Our findings confirm the importance of native coastal vegetation for the conservation of this species. Seasonal shifts of microhabitat use indicate that P. inexpectata (i) need habitats with thermal heterogeneity to adapt to seasonal changes in their thermal environment, and (ii) adapt their microhabitat use according to their reproductive phenology, especially for egg-laying in rock cavities.
Comparing activity and space patterns of the European pond turtle, Emys orbicularis (L., 1758) in a Venice Lagoon wetland area: implications for conservation planning and managementLiuzzo, Mirko; Borella, Stefano; Ottonello, Dario; Arizza, Vincenzo; Malavasi, Stefano
doi: 10.1163/15685381-bja10126pmid: N/A
AbstractBehavioural and spatial distribution analyses were quantified during a phase of activity and lethargy in a wild population of the European pond turtle inhabiting a protected internal wetland area of the Venice lagoon. The marked individuals (13 males and 16 females) provided informative radiotracking data to study differential patterns of activity, dispersion and habitat use between the two study periods (“October-November both 2019 and 2020” and “June-July 2020”). The differences in the movements behaviours and habitat selection were affected by period. Movements were higher in the period of activity than lethargy, but they were not influenced by sex and size. The presence of the European pond turtle in the transitional woodland/shrubs and brackish water valley habitats was significantly higher in the period of activity than lethargy. During the latter one, pond turtles were observed to brumate gregariously in a small area for brumation, usually in shallow water. In contrast, all individuals have changed water bodies during the activity period. Part of those movements has occurred towards aquatic habitat with higher salinities 1-17‰ (mean: 10.64‰). These findings provide a set of information to better understand the behavioural ecology of Emys orbicularis in the lagoon area. This is of relevance for management actions and for the conservation of this threatened species.
Interannual variations in diet and nutritional value of plants consumed by the Souss Valley tortoises, Testudo graeca graeca, in west-central Morocco: are they really selective foragers?Hichami, Nawal; Znari, Mohammed
doi: 10.1163/15685381-bja10127pmid: N/A
AbstractA previous study on the feeding habits of Moorish tortoises in west-central Morocco suggests that these animals are selective herbivores, but the nutritional consequences have not been examined. Because of the potassium excretion load, which requires water and/or nitrogen loss, we predicted that tortoises do not have salt glands. Moorish tortoises prefer plants rich in water and protein but low in potassium (PEP index). To this end, we studied the spring diet of adult tortoises in an arid steppe in west-central Morocco during two seasons of relatively dry years (2011-2012) using feces analyses. We also estimated the relative abundance of potential food plants by stratified sampling under the canopy of jujube bushes Ziziphus lotus. We statistically compared diet to plant abundance. Finally, we assessed plant species’ nutritional composition (water, crude protein, and potassium) available to tortoises. Results showed that species assemblages differed significantly between the two plant communities in both years. Nevertheless, tortoises consumed only about 5-6 and nearly the same species at the study site in 2011 and 2012, respectively. The plants consumed by the tortoises had the highest positive PEP index values indicating that there was more water and nitrogen in the food than is needed to excrete potassium.
Evolutionary history drives the geographical distribution of dorsal patterns in the common wall lizard (Podarcis muralis)Dadda, Thomas; Storniolo, Federico; Mangiacotti, Marco; Scali, Stefano; Zuffi, Marco A.L.; Sacchi, Roberto
doi: 10.1163/15685381-bja10131pmid: N/A
AbstractMelanin-based dorsal pattern polymorphisms are common in reptiles and generally evolve under the interaction between opposite selective pressures, notably thermal advantage in cold environments and background matching to avoid predation. When those pressures change over space and time, the relative frequencies of morphs can vary across the species range. However, no previous study has analysed the spatial patterns of variation of morphs under a phylogenetic perspective in addition to the adaptive responses to natural selection. In this study, we focused on the distributional patterns of the three dorsal morphs of Podarcis muralis at wide-range scale to assess how they associate with geography, climate, microhabitat, phylogeny and sexual dimorphism. By using open access data from iNaturalist, we assembled a dataset of 4096 georeferenced points with information on sex and morph. Data were analysed through Bayesian GLMs, and four alternative models were formulated depending on the specific factors affecting morphs’ frequency. The dorsal morphs are not randomly distributed in Europe, but follow clear geographic patterns, vary with altitude and habitats, show sex-specific trends, and correlate with the phylogenetic history of the species. When comparing models, the phylogenetic model always obtained the best performance, and no overlap with other models occurred, thus best explaining the distributional patterns of dorsal morphs. The evolutionary processes, in addition to present environmental pressures, can significantly affect local-scale microevolutionary adaptations, influencing the current distribution of dorsal phenotypes across the species range. More generally, results point out the importance of considering the evolutionary processes when analysing distributional patterns of polymorphisms.
Lack of refuge as a bottleneck for reptiles in intensive woody cropsCanós-Burguete, Marta; Torrijo-Salesa, Mizar; Tortosa, Francisco S.; Guerrero-Casado, José
doi: 10.1163/15685381-bja10132pmid: N/A
AbstractThe lack of refuge has been suggested as one of the main factors affecting reptiles in intensive crops, but this theory has not been explored to any great extent. The aim of this work is to compare the reptile abundance and species richness between traditional and intensive vineyards and olive groves, and to test the acceptance of artificial shelter due to its scarcity in the new intensive woody crop. A total of 288 transects were carried out (144 in olive groves and 144 in vineyards) in six different types of plots: traditional olive groves, traditional vineyards, intensive olive groves with and without artificial refuge, and trellis vineyards with and without artificial refuge. The results showed a greater species richness and abundance of reptiles in the traditional plots than in the intensive plots (independently of the experimental refuges added). An important number of animals were observed using the artificial refuges in olive groves. Furthermore, most of the individuals were located on or escaped to old trees in traditional systems, including an important proportion of reptiles hidden in olive trunk cavities, whereas more individuals were observed on the ground in intensive systems. Our finding suggests the importance for reptile communities of the traditional agricultural systems due to the high availability of the refuge provided by old olive tree trunks and free-standing gobelet vineyards. Our results show that providing refuge may mitigate the negative effects of woody crops intensification on reptile communities.
Remote sensing and citizen science to characterize the ecological niche of an endemic and endangered Costa Rican poison frogGarrido-Priego, Marina; Aragonés, David; Liedtke, H. Christoph; Whitworth, Andrew; Gomez-Mestre, Ivan
doi: 10.1163/15685381-bja10134pmid: N/A
AbstractHabitat encroachment can have devastating effects upon biodiversity, especially amphibians. Phyllobates vittatus is an endemic frog from Costa Rica, where land cover has seen significant changes over recent decades. Here we use remote sensing to create a land cover map of the region and carry out ecological niche modelling to identify the main abiotic factors associated to the distribution of this species. We have informed our models based on our own field observations, those from other researchers, and citizen science participants to obtain a comprehensive database of P. vittatus occurrences. Elevation, forest percentage, distance to lakes and rivers, annual temperature range and precipitation variables were found to shape the ecological niche of P. vittatus, which is mostly located within protected areas. Prior knowledge of the habitat of the species was key to interpret the model output. We identify populations that might be isolated, and areas where presence has not yet been verified or that have not been occupied by the species, thus, identifying potential areas for reintroductions. We also calculated the area of occupancy and recommend that P. vittatus’ status be adjusted to “Endangered”. Future surveys and evaluation of population health and connectivity would help to better ensure the protection of the species in the long-term.
Buccal swabs for amphibian genomicsAmbu, Johanna; Dufresnes, Christophe
doi: 10.1163/15685381-bja10130pmid: N/A
AbstractConservation genetics must find the balance between the technical challenges of DNA sampling while promoting animal welfare. In amphibians, buccal swabs offer a least intrusive source of DNA, but most herpetologists still refrain to use them, partly due to doubts regarding their effectiveness to provide enough material now that next-generation sequencing (NGS) analyses have become routine. In this article, we hope to change their minds through an empirical demonstration that buccal swabs offer DNA amounts and success rates for a widely used NGS approach (RAD-sequencing) that are equivalent to those of more intrusive yet commonly used samples in frogs and toads. We thus call for a shift of DNA sampling practices, and stress the fact that beyond their proven reliability, buccal swabs facilitate the issue of collection permits by increasingly restrictive ethical committees, especially when it comes to endangered species. With this purpose in mind, we share our long-term experience with amphibian buccal swabs through visual and textual pointers.