Food capture and escape behavior of Leposternon microcephalum Wagler, 1824 (Squamata: Amphisbaenia)

Amphisbaenians are fossorial reptiles that have a cylindrical and elongated body covered with scales arranged in rings, and are all apodal, except for the three species of the genus Bipes. The amphisbaenian diet consists of a variety of invertebrates and small vertebrates. As these animals live underground, many aspects of their natural history are difficult to study. Most feeding studies of amphisbaenians have focused on the composition of the diet and feeding ecology, and the data available on feeding behavior are based on precursory observations. The present study describes the food capture behavior of Leposternon microcephalum Wagler, 1824 in captivity. In this experiment we used non-live bait (moist cat food), which was placed near a burrow opening, on the surface of the substrate. Three animals were monitored visually and filmed using cellphone cameras deployed at fixed points, to capture images from the dorsal and lateral perspectives of the study subjects. Two principal types of behavior were observed: the capture of food and defense mechanisms. The strategies used to capture the food were similar to those observed in other fossorial species. Although the backward movement has already been observed and described, we were able to record this movement being used as an escape strategy. These findings enrich our knowledge on different aspects of the natural history of the amphisbaenians.

Phylogenetic history influences convergence for a specialized ecology: comparative skull morphology of African burrowing skinks (Squamata; Scincidae)

Background Skulls serve many functions and as a result, are subject to many different evolutionary pressures. In squamates, many fossorial species occupy a unique region of skull morphospace, showing convergence across families, due to modifications related to head-first burrowing. As different substrates have variable physical properties, particular skull shapes may offer selective advantages in certain substrates. Despite this, studies of variation within burrowers have been limited and are typically focused on a single origin of fossoriality. We focused on seven skink genera (Acontias, Typhlosaurus, Scelotes, Sepsina, Feylinia, Typhlacontias, and Mochlus; 39 sp.) from southern Africa, encompassing at least three independent evolutions of semi-fossoriality/fossoriality. We used microCT scans and geometric morphometrics to test how cranial and mandibular shape were influenced by phylogenetic history, size, and ecology. We also qualitatively described the skulls of four species to look at variation across phylogenetic and functional levels, and assess the degree of convergence. Results We found a strong effect of phylogenetic history on cranial and mandibular shape, with size and substrate playing secondary roles. There was a clear gradient in morphospace from less specialized to more specialized burrowers and burrowers in sand were significantly different from those in other substrates. We also created an anatomical atlas for four species with each element described in isolation. Every bone showed some variation in shape and relative scaling of features, with the skull roofing bones, septomaxilla, vomer, and palatine showing the most variation. We showed how broad-scale convergence in traits related to fossoriality can be the result of different anatomical changes. Conclusions Our study used geometric morphometrics and comparative anatomy to examine how skull morphology changes for a highly specialized and demanding lifestyle. Although there was broad convergence in both shape and qualitative traits, phylogenetic history played a large role and much of this convergence was produced by different anatomical changes, implying different developmental pathways or lineage-specific constraints. Even within a single family, adaptation for a specialized ecology does not follow a singular deterministic path.

Snakes of the Pernambuco Endemism Center, Brazil: diversity, natural history and conservation

The Atlantic Forest is one of the largest and richest tropical rainforests on the planet, being one of the 25 world priorities for conservation. The Atlantic Forest portion located north of the São Francisco River corresponds to the Pernambuco Endemism Center (PEC). We describe the snake composition of the PEC, providing information about the diversity, natural history and geographical distribution of the species, based on records from five scientific collections and additional information from the literature. A total of 78 species of snakes distributed in eight families was registered in the Pernambuco Endemism Center. The Caatinga is the Brazilian biome that most shares species with the PEC, followed by Cerrado. On the other hand, seven species are considered endemic of this region. Most of the snake species in the PEC have been registered in forest (94.8%), followed by “Brejos Nordestinos” (46.1%), Tabuleiros (43.5%), Restingas (14.1%) and Mangroves (5.1%). The PEC snake fauna includes mainly terrestrial species (60.2%) and cryptozoic and/or fossorial species (21.7%), but also presents a high richness of semi-arboreal and arboreal species (29.5%). Vertebrates are the main food item consumed by the species (78% of species), among the main prey are mammals, lizards, and amphibians. Most species show a strictly nocturnal activity period (50%), followed by strictly diurnal (38%). The PEC is the most degraded and least known region of the Atlantic Forest, yet it has revealed a high richness of snake species, including seven endemic species. It is emphasized that regional conservation efforts need to be intensified, because few forests in the region are formally protected, and the majority consist of small and poorly protected fragments, which means that many species in the region may be in risk of extinction.

Comparative mitochondrial phylogeography of two legless lizards (Pygopodidae) from Queensland’s fragmented woodlands

Sclerophyll woodlands and open forests once covered vast areas of eastern Australia, but have been greatly fragmented and reduced in extent since European settlement. The biogeographic and evolutionary history of the biota of eastern Australia’s woodlands also remains poorly known, especially when compared to rainforests to the east, or the arid biome to the west. Here we present an analysis of patterns of mitochondrial genetic diversity in two species of Pygopodid geckos with distributions centred on the Brigalow Belt Bioregion of eastern Queensland. One moderately large and semi-arboreal species, Paradelma orientalis, shows low genetic diversity and no clear geographic structuring across its wide range. In contrast a small and semi-fossorial species, Delma torquata, consists of two moderately divergent clades, one from the ranges and upland of coastal areas of south-east Queensland, and other centred in upland areas further inland. These data point to varying histories of geneflow and refugial persistance in eastern Australia’s vast but now fragmented open woodlands. The Carnarvon Ranges of central Queensland are also highlighted as a zone of persistence for cool and/or wet-adapted taxa, however the evolutionary history and divergence of most outlying populations in these mountains remains unstudied.

Dasypus kappleri (Cingulata: Dasypodidae)

Dasypus kappleri Krauss, 1862, commonly known as greater long-nosed armadillo, is the second largest extant armadillo and readily distinguishable by the prominent spurs on the hind legs. It is diurnal-nocturnal, solitary, and insectivorous. It is a semi-fossorial species ranging east of the Andes across the central lowlands of South America. It occupies a wide range of habitats including rainforest, riparian forest, and grassland. D. kappleri is listed as “Least Concern” by the International Union for Conservation of Nature and Natural Resources in light of its wide distribution, which presumedly contains robust populations.

Fossorial Damaraland mole rats do not exhibit a blunted hypercapnic ventilatory response

Damaraland mole rats (DMRs, Fukomys damarensis ) are a eusocial fossorial species that spend the majority of their life in densely populated underground burrows, in which they likely experience intermittent periods of elevated CO 2 (i.e. hypercapnia). The primary physiological response to hypercapnia in most mammals is to increase depth and rate of breathing (i.e. hyperpnoea), but this response is often blunted in species that inhabit hypercapnic environments. In their natural habitat, DMRs putatively experience a gaseous environment ranging from normocapnic (0.1% CO 2 ) to hypercapnic (6.0% CO 2 ) conditions (Roper et al. 2001 J. Zool. 254 , 101–107). As such, we hypothesized that DMRs would exhibit blunted hypercapnic ventilatory and metabolic responses, relative to those of non-fossorial rodent species. To test this hypothesis, we exposed awake, freely behaving DMRs to normoxic normocapnia (21% O 2 , 0% CO 2 , balance N 2 ) or graded normoxic hypercapnia (21% O 2 , 0, 2, 5, 7 and 10% CO 2 , balance N 2 ), and measured ventilation and metabolism using whole-body plethysmography and indirect calorimetry, respectively. We found that ventilation and metabolism were unchanged during prolonged normocapnia, whereas during graded hypercapnia, ventilation was elevated at 2% CO 2 and above. As a result, O 2 extraction efficiency at the lungs decreased with increasing hyperpnoea. Conversely, metabolic rate did not increase until 10% CO 2 , presumably due to the metabolic cost of hyperpnoea. Taken together, our results suggest that despite their fossorial lifestyle, DMRs do not exhibit adaptations in their ventilatory or metabolic responses to environmental hypercapnia.

NOCTURNAL ARBOREALITY IN SNAKES IN THE SWAMPLANDS OF THE ATCHAFALAYA BASIN OF SOUTH-CENTRAL LOUISIANA AND BIG THICKET NATIONAL PRESERVE OF SOUTHEAST TEXAS

The southeastern United States is home to a diverse assemblage of snakes, but only one species, the Rough Greensnake (Opheodrys aestivus), is considered specialized for a predominantly arboreal lifestyle. Other species, such as Ratsnakes (genus Pantherophis) and Ribbonsnakes/Gartersnakes (genus Thamnophis), are widely known to climb into vegetation and trees. Some explanations given for snake climbing behavior are foraging, thermoregulation, predator avoidance, and response to flood. Reports of arboreality in snake species typically not associated with life in the trees (such as terrestrial, aquatic, and even fossorial species) usually come from single observations, with no knowledge of prevalence of the behavior. Here, we report on arboreality of snake species detected during 8 years of night surveys in the Atchafalaya Basin of south-central Louisiana and 5+ years of night surveys in Big Thicket National Preserve in southeast Texas. We recorded a total of 1,088 detections of 19 snake species between the two study areas, with 348 detections above ground level (32%). The Rough Greensnake and Western Ribbonsnake (Thamnophis proximus) accounted for nearly 75% of total arboreal detections among the two study areas. However, with one exception, all snake species detected more than once between both study areas had at least one arboreal detection. These observations demonstrate that snakes with widely varying natural histories may be found in the trees at night, and for some species, this behavior may be more common than previously believed.

Ground penetrating radar as a non-invasive tool to better understand the population dynamics of a fossorial species: mapping the warrens of southern hairy-nosed wombats (Lasiorhinus latifrons)

Context Management of wildlife that may simultaneously be of conservation concern and pose problems for humans is difficult, particularly when knowledge of their population dynamics is elusive. Culling of southern hairy-nosed wombats (Lasiorhinus latifrons) is often carried out in agricultural areas, with no understanding of potential impacts on the species as a whole. Monitoring fossorial species via non-invasive means (that do not adversely impact animals by damaging their burrows) has always represented a challenge for wildlife researchers. Aim The aim of this research was to map the areal extent of different types of L. latifrons warrens to gain a better understanding of the relationship between the external warren signs and its subterranean structure. The findings will be used in the development of more accurate indices of population abundance to better inform management decisions. Methods Ground penetrating radar (GPR) was used to map warrens at four locations in the western regions of South Australia. Radar data were collected using a Mala X3M GPR system with 250 MHz and 500 MHZ antennas. 3D models of each site were then produced using the ReflexW GPR software processing package. Key results Subterranean warren structure varied from a mix of tunnel types in sandy-loam soil to a complex array of tunnels and caverns under sheet calcrete limestone. Conclusions This was the first non-invasive mapping of wombat warrens and the first mapping of a warren under a layer of calcrete limestone. In sandy-loam soil, the size and extent of the external spoil mound provided some indication of warren complexity. However, there were no external signs of the extent of the calcrete warren. Implications The lack of external cues regarding the extent of the calcrete limestone warren suggests that the current method of estimating population abundance based on a single index of wombats per active burrow is flawed. As a result, any management decisions in regard to culling may be based on inaccurate information. It is apparent that further research needs to be undertaken to develop a range of abundance indices that take into account local conditions such as soil type.