Determinants of species richness patterns in the Netherlands across multiple taxonomic groups

We examined the species richness patterns of five different species groups (mosses, reptiles and amphibians, grasshoppers and crickets, dragonflies, and hoverflies) in the Netherlands (41,500 km²) using sampling units of 5 × 5 km. We compared the spatial patterns of species richness of the five groups using Spearman’s rank correlation and used a stepwise multiple regression generalized linear modelling (GLM) approach to assess their relation with a set of 36 environmental variables, selected because they can be related to the several hypotheses on biodiversity patterns. Species richness patterns of the five groups were to a certain extent congruent. Our data suggest that environmental heterogeneity (in particular habitat heterogeneity) is one of the major determinants of variation in species richness within these five groups. We found that for taxonomic groups comprising a low number of species, our regression model explained more of the variability in species richness than for taxonomic groups with a large number of species.     

The desolation of Smaug: The human-driven decline of the Sungazer lizard (Smaug giganteus)

The Sungazer (Smaug giganteus) is a threatened lizard species endemic to the Highveld grasslands of South Africa. The species faces risks from habitat loss and fragmentation, and illegal harvesting for traditional medicine and the pet trade. Despite these threats, the current conservation status of the species was poorly validated. We visited 79 Sungazer populations recorded in 1978 to assess population change since the initial surveys, and surveyed an additional 164 sites to better define the distribution and estimate the current population size. We interrogated all known historical trade data of the species. One-third of Sungazer populations have been extirpated over the past 37 years. The distribution includes two allopatric populations, with the smaller Mpumalanga population experiencing a significantly higher decline. The species has an extent of occurrence (EOO) of 34 500 km², and an area of occupancy (AOO) of 1149 km². The interpreted distribution is 17 978 km², and just under 60% remains untransformed grassland. We estimate a population size of 677 000 mature individuals, down 48% from the estimated historical population, prior to commercial agricultural development. A total of 1194 live Sungazers were exported under permit from South Africa between 1985 and 2014, with a significant increase in numbers exported over the last decade. Without any evidence of captive breeding, we believe that these animals are all wild-caught. Based on the AOO, level of decline, fragmentation within the distribution and suspected level of exploitation, we recommend classification of the species as Vulnerable under IUCN Red List Criteria A2acd and B2ab(ii–v). The establishment of a protected area network, genetic research and further investigations into the pet and traditional medicine trades are urgently needed.     

Drivers of reptile and amphibian assemblages outside the protected areas of Western Ghats,India

Biodiversity conservation in forested landscapes outside protected areas is important to sustain populations of species with restricted ranges. However, such habitats face many anthropogenic threats, including logging, extraction of firewood and leaf-litter for mulch in plantations. In this study, we determined the effects of forest degradation on amphibians and reptiles in forests outside protected areas by measuring their species richness and community composition across a disturbance gradient from near pristine to highly degraded forests in Agumbe, Western Ghats, India. Twenty-one strip 15 m × 150 m transects were laid across the disturbance gradient and diurnal visual encounter surveys were conducted. Sampling was repeated three times per transect covering the dry, intermediate and wet seasons. Amphibian and reptile communities were affected by the decrease in canopy cover and leaf litter volume, respectively. Our results indicate that the collection of firewood and leaf-litter can severely affect amphibian and reptile populations. Structured conservation planning outside of protected areas is therefore imperative.     

Reptile, amphibian, and lemur diversity of the Malahelo Forest, a biogeographical transition zone in southeastern Madagascar

Ambatorongorongo Mountain lies at the historical intersection betweenhumid, spiny, and littoral forests in southeastern Madagascar. We report theresults of surveys of the herpetofauna and lemurs occurring in Malahelo Forest,a small (<25 ha) forest fragment lying on the western slope ofAmbatorongorongo Mountain. There are at least 41 reptile, 11 amphibian, and 7lemur species in this forest, including several that are endemic to southeasternMadagascar and are at severe risk of extinction. The species richness of theMalahelo fauna is comparable to that of even the largest forest reserves in theregion. We also evaluate the similarity of the Malahelo herpetofauna to that ofnearby humid, spiny, and littoral forests to assess the biogeographic affinitiesof its amphibians and reptile assemblages. Both groups contain speciescharacteristic of each of the three surrounding forest types, but thebiogeographic patterns appear to differ for amphibians and reptiles. Overall,the herpetofauna and lemurs of the Malahelo Forest indicate that it is a remnantof a biogeographic transition zone between the major forest types ofsoutheastern Madagascar. The combination of high species richness, regionalendemics, and unique herpetofaunal and lemur assemblages should make MalaheloForest a high conservation priority, and we give recommendations for protectingwhat remains of this important transitional forest.     

Palaeoenvironment and palaeoclimate of the Mousterian-Aurignacian transition in northern Iberia: the small-vertebrate assemblage from Cueva del Conde (Santo Adriano, Asturias)

The transition from the Middle Palaeolithic (Mousterian) to the Upper Palaeolithic (Aurignacian) has been one of the prominent themes in the archaeology of the European Palaeolithic for more than 20 years. One of the most controversial questions concerning this period is the extinction of the Neanderthals and their replacement by modern humans. In this context, Cueva del Conde, located in the northern part of the Iberian Peninsula, is an archaeo-palaeontological site that records the Mousterian to Aurignacian transition. It has been excavated since the beginning of the 20th century, first by the Conde de la Vega del Sella and systematically by a team from the University of Oviedo since 2001. Three main zones have been identified: the External Zone, dated to approximately 39 110 ± 520 BP (level N104); the Entrance Platform, dated between 38 250 ± 390 BP and 34 730 ± 500 BP; and Gallery A with a radiocarbon date of approximately 31 540 ± 400 BP (level N2a2). The small-vertebrate assemblages recovered from the water-screening of all sediment from the excavation campaigns represent at least 21 small mammal, amphibian and squamate taxa. The small-vertebrate associations in the three zones suggest a patchy landscape, dominated by humid meadows and woodland areas with the existence of water in the vicinity of the cave. The climate shows a more continental pattern during the Mousterian, though it was milder during the Aurignacian. The small vertebrates of the Cueva del Conde Mousterian and Aurignacian levels suggest a climate that differed from modern day temperatures, between −1.1 and −4.4 °C (mean annual temperature), placing these assemblages during Interstadials 9 to 7 (Is9 to 7).     

西藏两栖爬行动物多样性的补充调查及现状

本文简要介绍了作者于 1998年到西藏从事两栖爬行动物调查的结果 ,并对西藏地区两栖爬行动物的分布格局及其生存现状进行了讨论     

Detecting the small island effect and nestedness of herpetofauna of the West Indies

To detect the small island effect (SIE) and nestedness patterns of herpetofauna of the West Indies, we derived and updated data on the presence/absence of herpetofauna in this region from recently published reviews. We applied regression‐based analyses, including linear regression and piecewise regressions with two and three segments, to detect the SIE and then used the Akaike's information criterion (AIC) as a criterion to select the best model. We used the NODF (a nestedness metric based on overlap and decreasing fill) to quantify nestedness and employed two null models to determine significance. Moreover, a random sampling effort was made to infer about the degree of nestedness at portions of the entire community. We found piecewise regression with three segments performed best, suggesting the species–area relationships possess three different patterns that resulted from two area thresholds: a first one, delimiting the SIE, and a second one, delimiting evolutionary processes. We also found that taxa with lower resource requirement, higher dispersal ability, and stronger adaptation to the environment generally displayed lower corresponding threshold values, indicating superior taxonomic groups could earlier end the SIE period and start in situ speciation as the increase of island size. Moreover, the traditional two‐segment piecewise regression method may cause poor estimations for both slope and threshold value of the SIE. Therefore, we suggest previous SIE detection works that conducted by two‐segment piecewise regression method, ignoring the possibility of three segments, need to be reanalyzed. Antinestedness occurred in the entire system, whereas high degree of nestedness could still occur in portions within the region. Nestedness may still be applicable to conservation planning at portions even if it is antinested at the regional scale. However, nestedness may not be applicable to conservation planning at the regional scale even if nestedness does exist among sampling islands from a portion.     

Long-term climate record inferred from early-middle Pleistocene amphibian and squamate reptile assemblages at the Gran Dolina Cave, Atapuerca, Spain

The Gran Dolina cave site is famous for having delivered some of the oldest hominin remains of Western Europe (Homo antecessor, ca. 960 ka). Moreover, the evidence of lithic industries throughout the long vertical section suggests occupation on the part of hominins from the latest early Pleistocene (levels TD3/4, TD5, and TD6) to the late middle Pleistocene (level TD10). The Gran Dolina Sondeo Sur (TDS) has furnished a great number of small-vertebrate remains; among them some 40,000 bones are attributed to amphibians and squamates. Although they do not differ specifically from the extant herpetofauna of the Iberian Peninsula, the overlap of their current distribution areas (= mutual climatic range method) in Spain can provide mean annual temperatures (MAT), the mean temperatures of the coldest (MTC) and warmest (MTW) months, and mean annual precipitation (MAP) estimations for each sub-level, and their change can be studied throughout the sequence. Results from the squamate and amphibian study indicate that during hominin occupation the MAT (10-13 °C) was always slightly warmer than at present in the vicinity of the Gran Dolina Cave, and the MAP (800-1000 mm) was greater than today in the Burgos area. Climatic differences between “glacial” and “interglacial” phases are poorly marked. Summer temperatures (MTW) show stronger oscillations than winter temperatures (MTC), but seasonality remains almost unchanged throughout the sequence. These results are compared with those for large mammals, small mammals, and pollen analysis, giving a scenario for the palaeoclimatic conditions that occurred during the early to middle Pleistocene in Atapuerca, and hence a scenario for the hominins that once lived in the Sierra de Atapuerca.