Reptile Abundance Research Articles

Factors Affecting the Presence and Abundance of Amphibians, Reptiles, and Small Mammals under Artificial Cover in Southern California

Artificial cover objects (ACOs) are known to attract small terrestrial vertebrates, but the actual parameters that attract species to ACOs can vary across geographic regions and climates. For this study ACOs were placed in coastal sage scrub and grassland habitats in southern California and surveyed weekly for small terrestrial vertebrates over a 4-yr period. We observed 1643 individuals of 34 taxa during 143 survey sessions totaling 16,312 ACO days. Overall species richness and abundances under ACOs were highest from February to April. Our results showed that the probability of encountering a reptile under an ACO was highest in February and March under large wooden ACOs containing moist soil, when temperatures under the ACO were relatively mild, and when minimum air temperatures were low. At the community level, encounter probabilities for small mammals were highest for large wooden ACOs and ACOs with low soil moisture, with several species differences. Amphibians of three species were only captured in low numbers primarily under wooden ACOs from November to March. Use of ACOs in research and monitoring is an inexpensive and simple way to document and capture a wide variety of small terrestrial vertebrates. Species richness and abundance can be maximized over short periods using ACOs and can be equally important for long-term monitoring, particularly once the factors that make ACO use effective for small terrestrial vertebrates of a certain region have been investigated.

Analysing How Pre-Fire Habitat Legacy and Post-Fire Management Influence the Resilience of Reptiles to Fire

At the landscape scale, the Mediterranean region is a mosaic of habitats occupied by plants and animals with different resilience to fire. One of these habitats, the pine plantation, is characterized by its structural simplification and susceptibility to fire. Despite its high flammability, few studies have compared the response of animal communities between pine plantations and other autochthonous woodlands. For five years after a large fire in southwestern Europe, we surveyed reptiles in two natural habitats (oak forest, scrubland) and a pine plantation managed with salvage logging, a post-fire practice which consists of the complete harvesting and removal of death burnt trees. Reptile abundance and species composition were examined to assess differences in the reptile community between these habitats. Differences between burnt and unburnt transects were limited to the first year after the fire, while, over the entire five-year period, differences in species composition and abundance were due to vegetation type instead of fire. The pine logged area showed a delay in the recovery of vegetation and also in the appearance of many reptile species after the fire. At the reptile species level, we found evidence of both positive responses to fire (for lizards with high heliothermic activity) and negative ones (for specialist snake species). Overall, our results confirm the resilience of the reptile community to fire. The mosaic of habitats in the Mediterranean region and the openness caused by fire can increase the reptile biodiversity (landscape- plus pyro-diversity effects), but some practices such as salvage logging coupled with fire regime shifts (larger and more frequent fires) can compromise the conservation of the biodiversity in fire-prone regions.

Converting rangelands to reserves: Small mammal and reptile responses 24 years after domestic livestock grazing removal

AbstractWith one million species threatened with extinction and more than a third of terrestrial Earth now devoted to crop or livestock production, many conservation organisations are acquiring land, destocking and converting them to national parks or conservation reserves. When pastoral properties are acquired, destocking is often the first management action. Species responses to destocking are varied and largely associated with changes in ground vegetation complexity. However, studies over short timeframes may fail to capture the often slow and episodic recovery post‐destocking, particularly in arid and semi‐arid ecosystems. In this study, we examined the response of small mammals and reptiles between 6 and 24 years since destocking in mallee (Eucalytpussp.) andCasuarinavegetation communities in semi‐arid Australia. As casuarina sites were closer to water than mallee, they were subject to higher domestic livestock grazing intensity, and higher grazing pressure from invasive goats and native kangaroos after livestock were removed. We related faunal abundance and diversity to time‐since‐destocking, fractional cover, rainfall and temperature and described compositional dynamics. We found that the vegetation types had distinct fauna communities and unique recovery trajectories. In mallee, reptile abundance and diversity increased with time‐since‐destocking but did not change in casuarina. Small mammal response to time‐since‐destocking was non‐linear and strongly influenced by rainfall. Overall, the mallee community showed signs of recovery, but recovery was less evident in the more degraded casuarina. We highlight that destocking ex‐pastoral properties is rarely a restoration ‘quick‐fix’ and land managers must deal with a complex legacy of impacts, when converting pastoral land to conservation reserves.

Обзор современной фауны пресмыкающихся Капланкырского заповедника и сопредельных территорий

The Kaplankyr Nature Reserve and encapsulated Shasenem and Sarykamysh nature sanctuaries are located at the junction between southern and northern types of deserts. Landscape diversity in this region therefore determines the richness of the herpetofauna. A critical review of literature devoted to the study of this territory and adjacent areas shows that an inventory process has not yet been completed. Thus, based on literature data our own materials, a list of reptile species from this region was compiled comprising 25 reptile species. Phrynocephalus guttatus salsatus are excluded from the list reptiles of the reserve, as erroneously identified, while information on the landscape distribution and abundance of reptiles is presented. Based on the criteria of the IUCN (2017), the state of the herpetofauna was assessed. In the Kaplankyr nature reserve and the Sarykamysh nature reserve, species of reptiles that are quite rare for Turkmenistan are protected including Alsophylax pipiens and Gloydius halys caraganus. We recommend to attach the salt marsh Gazaklyshor (Kazakhlyshor) to the territory of the reserve located 28 km west of the KZ - Kulantakyr cluster. This site is very interesting in geological and landscape terms as it contains three species / subspecies of roundheads (Ph. guttatus salsatus, Ph. ocellatus bannikovi, and Ph. helioscopus turcomanus), including the Kazakhlyshorskaya toadhead agama Ph. guttatus salsatus one of the rarest lizards of the saline deserts of Central Asia.

Diversity of Amphibians and Reptiles at Chiremera Locality, Vanduzi - Mozambique

Diversity of amphibians and reptiles was studied at Chiremera locality in Manica Province, Mozambique. To the best of our knowledge, no herpetofauna study has been done at the Chiremera locality. Globally the herpetofauna of Mozambique remains poorly documented compared to other areas of southern Africa [1]. The study aims to assess the diversity of amphibians and reptiles at Chiremera locality. The data was collected using two techniques: Visual Search and Intercept and pit fall traps. The data was collected in two habitat types: wild areas and human altered areas. We recorded on the wild areas 91 individual of amphibians (18 species, 10 genera and 9 families). The human altered areas had a total of 27 individual amphibians, (4 species, 4 genera and 4 families). Hemisus marmoratus (marbled snout-burrower) was the most abundant species in the two habitats, accounting for 26.3% of all individuals identified. The Shannon winner of amphibians was higher at the wild areas (H '= 2, 1) and lower in the human altered area (H' = 1, 2). A total of 24 individual reptiles were recorded on the wild areas (7 species, 7 genera and 5 families). In contrast to human altered areas we recorded (5 species, 3 Genera, and 3 families). Bitis arietans (puff adder) was the most abundant reptile accounting for 26% of all individuals identified. The Shannon wiener of reptiles was (H’=1, 6) at the wild areas and (H’=1, 5) at the human altered areas. Four rare species namely Hyperolius acuticeps (sharp-headed long reed frog), Hyperolius benguellensis (Benguella long reed frog), Ptychadena subpunctata (spotted ridged frog) all amphibians and Naja mossambica (Mozambique spitting cobra) - reptile were detected during our study. The result of the current study revealed that effect of human altered areas on the richness and abundance of amphibians and reptiles.

An examination of the import of live reptiles from Indonesia by the United States from 2000 to 2015

Millions of reptiles are both legally and illegally traded annually. However, the number of species being exploited for the live animal trade far exceeds any other demand, such as for use in the exotic leather trade. The huge diversity and abundance of reptiles traded globally is concerning as commercial consumer demand can result in unsustainable harvests which could lead to species declines or even extinctions. With this study we examine the trade between two of the significant countries involved in the global reptile trade: Indonesia and the United States (US). Between 2000 and 2015, the US imported at least 234 070 live reptiles encompassing 83 CITES-listed species and 810 534 live reptiles encompassing 118 non-CITES listed species from Indonesia. Besides the export of its native reptiles to the US, Indonesia also plays a role as re-exporter of live reptiles from other countries; specifically, those of the Asian region and Australia. Moreover, not only did we detect fraudulent trade, we also found potentially unsustainable trade levels for several species. This is concerning for a couple of reasons, not the least of which is the fact that reptiles are still very much an understudied group of animals, whereby biological information and the status of wild populations are lacking for many species, information that is crucial in assessing whether harvest for trade is sustainable or a threat to species.

Response of reptiles to weed-control and native plant restoration in an arid, grass-invaded landscape

Introduced grasses are a major threat to dryland ecosystems world-wide because of their ability to transform plant communities and change fire regimes. These structural and functional shifts are often assumed to impact wildlife but this has rarely been measured directly. Likewise, evaluation of weed removal programs rarely considers benefits to fauna, thereby limiting information that could inform management decisions. We used an experimental approach to test the impacts of removing invasive buffel grass (Cenchrus ciliaris), a globally significant invader of dryland systems, on reptiles, a prominent component of the Australian desert fauna. A combination of mechanical and herbicide treatment was applied to replicate plots in areas that had been invaded for at least two decades and changes to ground cover and plant and reptile assemblages were monitored over six years and compared to still-invaded control plots. Following treatment, native plants re-established without the need for reseeding or planting, especially during a period of high rainfall, when positive effects on reptiles also became apparent. The abundance and species richness of reptiles increased at all plots during the mesic period, but less so in control plots, and remained higher at treated plots thereafter, although this was only significant at some times. Post-treatment 27 of 36 species were captured more frequently in treated plots and only four species, all with very low captures, were captured more often in invaded control plots. This consistent trend among species suggests negative impacts of buffel grass on reptiles are likely caused by broad factors such as reduced prey or habitat diversity. Together with concurrent research at the same sites, our results provide experimental evidence that removing buffel grass from heavily invaded areas, even at small scales, benefits a variety of native flora and fauna. Until landscape-scale options are available, restoration of smaller areas within buffel-invaded landscapes can help to preserve native seed banks and adult plants, reduce fire impacts, and provide patches of favourable habitat for fauna. The creation of ‘islands’ of restored native vegetation deserves further consideration as an effective intervention that could help to achieve short and long-term conservation goals in grass-invaded dryland ecosystems.

Wintry habitat selection of the Zapallaren tree iguana (Liolaemus zapallarensis, Müller & Hellmich, 1933) and its abundance in Changa beach, Coquimbo, northern Chile

Urban development modifies the habitat of reptiles where we expect, the individuals to select available sites with the quality necessary for their permanence. The aim of this study was to determine the variables that favored the habitat selection and abundance of The Zapallaren Tree Iguana Liolaemus zapallarensis, an endemic species of Chile, during a winter season in Changa beach, Coquimbo, in northern Chile. Between June and September 2017, we made 30 random visits to 18 plots of 900 m2 each. We estimated a resource selection probability function for presence-absence and abundance data using local habitat (e.g. slope, distance from the protection wall to the sea at low tide, interior height of the wall, mean height of the vegetation, rocky surface, and vegetal surface) and climatic variables (temperature, atmospheric pressure, direction and wind speed, solar radiation, and mean cloudiness) as predictors. Vegetation cover was the most important habitat variable explaining the presence of L. zapallarensis. In addition, increase in cloudiness and wind speed decreased the probability of selection. Manly’s selectivity measure varied according to the established home ranges and the availability ratios within them. Finally, increase in cloudiness and wind speed decreased the abundance. Overall, our results show that the characteristics related to habitat and local climate influences the resource selection that favors the survival of reptiles. This work shows that beach sectors in urban contexts under anthropic pressure have important available resources that favor the presence and abundance of reptiles.

Reptile responses to anthropogenic habitat modification: A global meta‐analysis

AbstractAimThe aim was to determine how reptile populations respond to anthropogenic habitat modification and determine whether species traits and environmental factors influence such responses.LocationGlobal.Time period1981–2018.Major taxa studiedSquamata.MethodsWe compiled a database of 56 studies reporting how habitat modification affects reptile abundance and calculated standardized mean differences in abundance (Hedges’ g). We used Bayesian meta‐analytical models to test whether responses to habitat modification depended on body size, clutch size, reproductive mode, habitat specialization, range size, disturbance type, vegetation type, temperature and precipitation.ResultsBased on 815 effect sizes from 376 species, we found an overall negative effect of habitat modification on reptile abundance (mean Hedges’ g = −0.43, 95% credible intervals = −0.61 to −0.26). Reptile abundance was, on average, one‐third lower in modified compared with unmodified habitats. Small range sizes and small clutch sizes were associated with more negative responses to habitat modification, although the responses were weak and the credible intervals overlapped zero. We detected no effects of body size, habitat specialization, reproductive mode (egg‐laying or live‐bearing), temperature or precipitation. Some families exhibited more negative responses than others, although overall there was no phylogenetic signal in the data. Mining had the most negative impacts on reptile abundance, followed by agriculture, grazing, plantations and patch size reduction, whereas the mean effect of logging was neutral.Main conclusionsHabitat modification is a key cause of reptile population declines, although there is variability in responses both within and between species, families and vegetation types. The effect of disturbance type appeared to be related to the intensity of habitat modification. Ongoing development of environmentally sustainable practices that ameliorate anthropogenic impacts is urgently needed to prevent declines in reptile populations.

Long-term benefits and short-term costs: small vertebrate responses to predator exclusion and native mammal reintroductions in south-western New South Wales, Australia

Abstract ContextThe success of conservation fences at protecting reintroduced populations of threatened mammals from introduced predators has prompted an increase in the number and extent of fenced exclosures. Excluding introduced species from within conservation fences could also benefit components of insitu faunal assemblages that are prey for introduced predators, such as reptiles and small mammals. Conversely, reintroduced mammals may compete with smaller mammals and reptiles for resources, or even prey on them. AimsIn a 10-year study from 2008, we examine how small terrestrial vertebrates respond to the exclusion of introduced predators, the feral cat (Felis catus) and red fox (Vulpes Vulpes), introduced herbivores and the reintroduction of regionally extinct mammal species. MethodsDifferences in the yearly relative abundance of reptiles and mammals according to habitat type and whether sites were fenced or not, were tested using multivariate generalised linear models. Next, we calculated univariate P-values to identify individual species that showed significant relationships, positive and negative, with any of the explanatory variables. Key resultsTotal captures of reptiles were lower inside the conservation fence in all years, whereas total captures of small mammals were markedly higher inside the fenced area, notably in dasyurids. ConclusionOur results showed that conservation fences can deliver benefits for some fauna (but not all) beyond facilitating the reintroduction of highly threatened mammals. ImplicationsOur results demonstrated the consequential impacts of introduced predators on the Australian small mammal fauna, and showed that predator-exclusion fences can be an effective conservation intervention for this guild.

Uzungwa Scarp Nature Forest Reserve: a unique hotspot for reptiles in Tanzania

While knowledge of African vertebrate biodiversity has increased dramatically in recent years, the field of herpetology which encompasses many threatened and endemic species, has lagged behind, and many areas have not been adequately explored. Intensive field work was conducted during the rainy season from December 2017 to April 2018 to assess reptile occurrence mostly in previously unexplored areas of the Uzungwa Scarp Nature Forest Reserve (USNFR) which is part of the Udzungwa Mountain ranges in the Eastern Arc Mountains (EAM), and adjacent agricultural areas. Bucket pitfall traps, funnel traps, night transects and opportunistic search methods were used to sample reptiles across four zones: in lowland, submontane and montane forests of the USNFR, and in neighboring farmlands. Forty-five reptile species across 14 families were recorded, mostly concentrated on the lowland and submontane forests. The number of endemic and threatened species in the USNFR reaches 20 and 14 respectively, and most are found in the submontane forest. Nineteen species were new records for the USNFR, five of them representing range extensions. Reptile species richness, abundance and diversity differed significantly across the four zones, except between montane and farmland zones and between lowland and submontane. However, farmland zone was discordant from other zones in terms of species composition. This study adds to the importance of the EAM not only in harbouring large numbers of species but also as an important hotspot for endemic and threatened reptiles. It also calls for proper land-use practices in farms adjacent to protected areas for sustainable conservation of biodiversity.

Are reptile responses to fire shaped by forest type and vegetation structure? Insights from the Mediterranean basin

Socioeconomic factors (e.g. rural abandonment, monoculture plantations) and global warming are changing fire regimes (fire intensity, extent, and frequency) in fire-prone regions such as the Mediterranean Basin. Understanding the factors that shape responses of animal communities to fire is a key objective for biodiversity conservation. Given the substitution of native forests to pine plantations in many regions of the world, we studied whether forest type influences the responses to fire of reptile communities, in the African rim of the Western Mediterranean. Reptiles were sampled and vegetation structure measured in 2015 and 2016. We used generalized linear mixed models to examine the influence of fire, forest type (cork oak and pine), habitat structure and climate factors on two reptile-community metrics (abundance, species richness). Given possible differences in reptile detectability between unburnt and burnt transects, we used distance sampling models to estimate the density of the five commonest reptile species. The response of reptiles to fire varied between the two forest types: reptile abundance did not change with fire in cork oak forest, and increased with fire in pine plantation. Species richness was higher in cork oak forests, and increased from unburnt to burnt areas. Two out of five commonest lizards in the region, Acanthodactylus erythrurus and Podarcis vaucheri, responded positively to fire in pine plantation and remained similar in cork oak forest. Reptile communities were more similar between burnt and unburnt cork oak forests than between burnt and unburnt pine plantations, due to the reduced effect of fire on the former tree (a resprouter species) than on the latter (a seeder species). This work is the first field-based study examining the effects of fire on animal communities from north-western Africa. Overall, our results show that the response of reptiles to fire is shaped by forest type, and this conclusion has to be considered in fire-prone regions.

Variable reptile responses to introduced predator control in southern Australia

Context Australia harbours an immense diversity of reptiles, which are generally expected to have frequent and diverse trophic interactions with introduced mammalian carnivores. Nevertheless, the potential for predatory or competitive interactions is likely to be contingent on multiple processes, including the importance of reptiles in the diet of introduced predators, alongside overlaps in their body sizes and ecological niches that would influence the strength of their interactions. In Australia’s temperate and relatively productive mesic environments there is little understanding of how introduced mammalian predators affect reptile assemblages. Aims The aim was to investigate the effects that a European red fox (Vulpes vulpes; 5–7kg) suppression program had on the abundance and species richness of a reptile community, with species ranging in size from the largest local ectothermic predator, the lace monitor (Varanus varius; 4–7kg), to small terrestrial reptiles (mostly 10–150g). Methods We utilised two sampling designs (baited camera monitoring stations and pitfall trapping) to evaluate the effects of fox suppression and other site-level ecological covariates (fire regime and habitat vegetation characteristics) on the lace monitor and small terrestrial reptiles. Reptile abundance and richness at site level were estimated from count-related abundance models. Key results For lace monitors, significantly higher abundances occurred in poison-baited areas relative to control areas. This suggests that fox suppression can affect the populations of the lace monitor via mesopredator release arising from reduced competition and, possibly, predation. For small terrestrial reptiles, neither abundance nor species richness were influenced by fox suppression. Individual abundances of the three most common small reptile species matched the overall pattern, as only responses to structural parameters of the habitat were detected. Conclusions Fox suppression can have different impacts for different reptile taxa, pending their ecological niche, as only the largest species was affected. Implications Increase in lace monitor abundance may change food web dynamics in fox-suppressed sites, such as by increasing predation pressure on arboreal marsupials.

Comparisons of Reptile Assemblages in Two Subdivisions of the Sonoran Desertscrub Biotic Community

Anthropogenic disturbances can have negative effects on species assemblages. This study was established to form baseline data on the environmental structure and reptile assemblages within a planned energy corridor in Pinal County, Arizona, prior to construction. We emphasized evaluating the differences in reptile assemblages in two subdivisions of the Sonoran Desertscrub, the Lower Colorado River Valley (LCV) and Arizona Uplands (AZU). Surveys were conducted on 50 sites (LCV = 15; AZU = 35) along the proposed 67.1-km long energy corridor through environmental surveys and 50 drift-fence trapping arrays with 400 box funnel traps. Vegetation height, number of burrows, and percent rock, ground cover, and coarse woody debris were significantly higher in the AZU than in LCV. Eighteen reptile species (n = 995 captures) were detected on the energy corridor including 8 lizard species (n = 952 captures) and 10 snake species (n = 43 captures). Species richness, evenness, and capture rates were not significantly different between the LCV and AZU; however, species diversity was significantly higher in the LCV. Reptile abundance (LCV = 281; AZU = 714) differed in the two subdivisions, yet rank-abundance curves revealed no difference in dominance of species. Post hoc examination revealed that the geographic separation of sites within the LCV and the location of the study area (along the ecotone) may have contributed to our results. We conclude that both subdivisions are equally important to the maintenance of local biotic diversity and recommend that any future land set-asides consider both subdivisions.

Species composition and abundance estimates of reptiles in selected agroecosystems in southern Western Ghats, India

Species composition and abundance of reptiles in selected agroecosystems in Thrissur plains, near Palghat Gap, southern Western Ghats in India, was studied from January 2017 to May 2017. The agroecosystems surveyed were coconut, cashew & rubber plantations, home garden, paddy field, and botanical garden. Time-constrained visual encounter surveys of a total effort of 360 man-hours were done in the field. Coconut and cashew plantations reported the highest species richness with 11 species each, while the highest number of sightings (159) were recorded from botanical garden. Bronze Grass Skink Eutropis macularia was the most abundant species in agroecosystems. Correspondence analysis was done to compare the reptilian diversity in the agroecosystems. The reptile fauna of home garden and paddy field were found to be more distinct than the rest of the agroecosystems. A total of 17 species of reptiles were recorded during the study, thus highlighting the significance of agroecosystems in acting as important buffer landscapes for reptiles.

Rapid increase of Australian tropical savanna reptile abundance following exclusion of feral cats

Feral cats have been responsible, in part, for the extinction of many species of mammal, bird and reptile globally, especially on islands. Whilst there is extensive evidence of the predatory impacts of cats on mammals and birds, far less is known about their ecological impacts on reptiles, especially in continental situations. We conducted a field experiment to evaluate the impact of feral cats on terrestrial vertebrates in tropical savanna environments of northern Australia. Three experimental treatments were applied to six 64 ha plots to compare and contrast responses of reptile abundance and species richness to predator exclusion and the additive effects of frequent fire. Replicated pitfall-trapping was undertaken in each plot on seven sampling occasions between November 2013 and November 2015. We analysed relative abundance and species richness data using generalized linear mixed models. There was a significant increase in the abundance of reptiles over a two year period in cat-excluded plots with reptile abundance increasing at twice the rate in cat-exclusion plots compared with cat-accessible plots and there was an additive effect of time-since-fire. Cat exclusion had a positive effect on reptile species richness over time, however the evidence for this pattern was weak when seasonal variation was taken into account. Predation by cats, in synergy with other disturbance processes, could adversely impact reptile species and communities elsewhere in the world where feral cats have been established and warrants further investigation.

Small mammal and reptile persistence in desert grasslands during a period of low rainfall – Part 1

The abundance of Australia's arid zone vertebrates is typically driven by fluctuations in rainfall, which dictate productivity across functional groups. Many species fluctuate from highly abundant during high rainfall periods to low abundance during low rainfall periods. Although these fluctuations are well documented, little is known regarding the factors affecting fauna persistence during periods of low rainfall. We examined the relationship between several influential factors and the richness and abundance of nocturnal small mammal and reptiles in the spinifex sand plains of central Australia. The study was conducted during a period of low rainfall following the decline of most vertebrate species in the area. Mammals showed species-specific responses, with varying dependencies on cover and climatic factors, whilst reptiles showed a surprisingly limited response to resource abundances and rainfall. The most consistent factor associated with small mammal and reptile abundances was the presence of large predators. Cats had greater suppressive effects on small mammals whilst reptiles declined with greater wild dog presence. These results likely represent a combination of selective foraging and seasonal fluctuations in activity of the two predators. Our results highlight the importance of controlling predator numbers during low rainfall periods to reduce their potential suppressive effects.

Response of reptile and amphibian communities to the reintroduction of fire in an oak/hickory forest

Fire can have diverse effects on ecosystems, including direct effects through injury and mortality and indirect effects through changes to available resources within the environment. Changes in vegetation structure such as a decrease in canopy cover or an increase in herbaceous cover from prescribed fire can increase availability of preferred microhabitats for some species while simultaneously reducing preferred conditions for others. We examined the responses of herpetofaunal communities to prescribed fires in an oak/hickory forest in western Kentucky. Prescribed fires were applied twice to a 1000-ha area one and four years prior to sampling, causing changes in vegetation structure. Herpetofaunal communities were sampled using drift fences, and vegetation attributes were sampled via transects in four burned and four unburned plots. Differences in reptile community structure correlated with variation in vegetation structure largely created by fires. Amphibian community structure differed on a yearly basis, indicating that sampled communities were likely influenced by environmental factors other than the burning. We found taxa-specific differences in abundances for Coluber constrictor, Diadophis punctatus, Sceloporus undulatus, Lithobates clamitans and snakes as a group, being more abundant in burned areas while Anaxyrus sp., Notophthalmus viridescens and Plethodon glutinosus were more abundant in unburned areas. Differences in amphibian taxa abundances may have been influenced by availability of aquatic breeding habitat and yearly weather variation. Our results suggest that the vegetation structure changes caused by prescribed fire can have indirect impacts on reptile abundances and community structure, while not significantly impacting amphibian communities.

Patterns of diversity along a habitat size gradient in a biodiversity hotspot

AbstractHabitat destruction and loss are the gravest threats to wildlife worldwide. We examined the correlation between habitat patch size and species richness and abundance of mammals and reptiles in a biodiversity hotspot in California. Within nine forest fragments standardized for age, topography, climate, and vegetation cover, we tested the effects of patch size and isolation on biodiversity. To measure species richness and abundance, we used wildlife cameras for meso‐and‐large vertebrates, mark‐and‐recapture analyses for small mammals, mark‐and‐resight analysis for reptiles, and standard dragging techniques for tick collections because they are frequent ectoparasites on vertebrates in oak woodland habitats. Our results show that meso‐and‐large vertebrate richness and abundance increase with patch area as does tick density. Surprisingly, small mammal species richness and abundance peak in intermediate‐sized fragments. Resource limitation and competition at the smallest habitats and predation at the largest patches may be responsible for this pattern. Further, there is a significant decrease in invasive species richness with habitat patch size. We found that habitat destruction and fragmentation are acting upon species and communities in context‐dependent ways that is critical to conservation planning, land use design, and ecosystem function.

The role of fire history, land-use, and vegetation structure on the response of Mediterranean lizards to fire

Fire is a critical component of terrestrial ecosystems and essential to understand the composition and diversity of communities in fire-prone regions. Nevertheless, fire does not act alone, and other factors such as land-use type and vegetation structure can also operate at different scales, prompting the response to fire of ectotherm communities such as reptiles. We have evaluated the influence of environmental factors on the abundance, diversity, and richness of reptile communities in Serra da Estrela Natural Park (northern Portugal), at both the landscape and micro-habitat scales. In spring 2014 and 2015, 20 transects were surveyed eight times, the vegetation structure and composition were measured, and the extent of land-use types around each transect calculated in this Mediterranean community. At the landscape scale, reptile abundance was higher in natural woodlands and more complex habitats (higher vegetation heterogeneity and plant richness), and reptile evenness was affected by vegetation heterogeneity and time since fire. By contrast, species richness was not related to any environmental factor measured in this study. Only two lizard species were common in the park, Psammodromus algirus and Podarcis guadarramae. Their relative abundances increased with contrasting habitat variables as the former is a ground-dwelling lizard specialist that prefers heterogeneous (unburnt) habitats and the second is a rock lizard that selects open (burnt) stands. At the micro-habitat scale, the probability of reptile presence, reptile abundance, and reptile richness increased with plant richness and decreased with tree cover. This study highlights the importance of several environmental factors, that operate from micro-habitat to landscape scales to understand the response of reptiles to fire.