What factors influence the rediscovery of lost tetrapod species?

We created a database of lost and rediscovered tetrapod species, identified patterns in their distribution and factors influencing rediscovery. Tetrapod species are being lost at a faster rate than they are being rediscovered, due to slowing rates of rediscovery for amphibians, birds and mammals, and rapid rates of loss for reptiles. Finding lost species and preventing future losses should therefore be a conservation priority. By comparing the taxonomic and spatial distribution of lost and rediscovered tetrapod species, we have identified regions and taxa with many lost species in comparison to those that have been rediscovered-our results may help to prioritise search effort to find them. By identifying factors that influence rediscovery, we have improved our ability to broadly distinguish the types of species that are likely to be found from those that are not (because they are likely to be extinct). Some lost species, particularly those that are small and perceived to be uncharismatic, may have been neglected in terms of conservation effort, and other lost species may be hard to find due to their intrinsic characteristics and the characteristics of the environments they occupy (e.g. nocturnal species, fossorial species and species occupying habitats that are more difficult to survey such as wetlands). These lost species may genuinely await rediscovery. However, other lost species that possess characteristics associated with rediscovery (e.g. large species) and that are also associated with factors that negatively influence rediscovery (e.g. those occupying small islands) are more likely to be extinct. Our results may foster pragmatic search protocols that prioritise lost species likely to still exist.

Genome of the endangered Guatemalan Beaded Lizard, Heloderma charlesbogerti, reveals evolutionary relationships of squamates and declines in effective population sizes.

Many lizard species face extinction due to worldwide climate change. The Guatemalan Beaded Lizard, Heloderma charlesbogerti, is a member of the Family Helodermatidae that may be particularly imperiled; fewer than 600 mature individuals are believed to persist in the wild. In addition, H. charlesbogerti lizards are phenotypically remarkable. They are large in size, charismatically patterned, and possess a venomous bite. Here, we report the draft genome of the Guatemalan Beaded Lizard using DNA from a wild-caught individual. The assembled genome totals 2.31 Gb in length, similar in size to the genomes of related species. Single-copy orthologs were used to produce a novel molecular phylogeny, revealing that the Guatemalan Beaded Lizard falls into a clade with the Asian Glass Lizard (Anguidae) and in close association with the Komodo Dragon (Varanidae) and the Chinese Crocodile Lizard (Shinisauridae). In addition, we identified 31,411 protein-coding genes within the genome. Of the genes identified, we found 504 that evolved with a differential constraint on the branch leading to the Guatemalan Beaded Lizard. Lastly, we identified a decline in the effective population size of the Guatemalan Beaded Lizard approximately 400,000 years ago, followed by a stabilization before starting to dwindle again 60,000 years ago. The results presented here provide important information regarding a highly endangered, venomous reptile that can be used in future conservation, functional genetic, and phylogenetic analyses.

Effect of climate change on the potential distribution of Helodermaalvarezi (Squamata, Helodermatidae).

Climate change represents a real threat to biodiversity conservation worldwide. Although the effects on several species of conservation priority are known, comprehensive information about the impact of climate change on reptile populations is lacking. In the present study, we analyze outcomes on the potential distribution of the black beaded lizard (Helodermaalvarezi Bogert & Martin del Campo, 1956) under global warming scenarios. Its potential distribution, at present and in projections for the years 2050 and 2070, under both optimistic and pessimistic climate change forecasts, were computed using current data records and seven bioclimatic variables. General results predict a shift in the future potential distribution of H.alvarezi due to temperature increase. The optimistic scenario (4.5 W/m2) for 2070 suggests an enlargement in the species' distribution as a response to the availability of new areas of suitable habitat. On the contrary, the worst-case scenario (7 W/m2) shows a distribution decrease by 65%. Moreover, the range distribution of H.alvarezi is directly related to the human footprint, which consequently could magnify negative outcomes for this species. Our research elucidates the importance of conservation strategies to prevent the extinction of the black beaded lizard, especially considering that this species is highly threatened by aversive hunting.

A new species of Bolitoglossa (Caudata: Plethodontidae) of the Bolitoglossa franklini group from an isolated cloud forest in northern Guatemala.

We describe Bolitoglossa qeqom sp. nov. from an isolated cloud forest in Cerro Guachmalén, Alta Verapaz, Guatemala, based on multiple lines of evidence (morphological, molecular, and biogeographic data). This region comprises a mountain ridge without previous herpetological surveys. The new species is a large salamander with uniform purplish-black coloration and is distinguished by having relatively long legs with only one costal groove between adpressed limbs, numerous maxillary teeth, few vomerine teeth, only one phalange free of webbing in digit III of feet, and a relatively short tail. It is geographically closest to its sister clade of B. lincolni + B. franklini and the xeric Chixoy river canyon appears to be the major biogeographic barrier that isolated the new taxon. The cloud forest inhabited by this species has undergone severe habitat destruction in the region and land conservation actions are urgent.

Toxicity of the feathers of Yellow Grosbeak, Pheucticus chrysopeplus (Passeriformes: Cardinalidae), a chemically defended neotropical bird / Toxicidad de las plumas del Picogrueso amarillo, Pheucticus chrysopeplus (Passeriformes: Cardinalidae), un ave neotropical con defensa química

Abstract Chemical defense is a widespread mechanism on many animals and plants. However, just a few cases are known for avian species. In this study we evaluate the toxicity of Pheucticus chrysopeplus feather extract via lethality test with brine shrimp (Artemia salina) as an in vivo model. Mortality of A. salina was evaluated after 24 hour exposure to artificial seawater, methanol, and the methanolic feather extract. Kruskal-Wallis test showed a significant difference in mortality between treatments (X2 = 65.25, P < 0.0001, n = 50). With this we describe P. chrysopeplus as the first known toxic avian species of Guatemala and Central America, raising awareness about its conservation and the identification of the toxic substance present in its feathers. We also highlight the possible mimicry mechanism taking part between P. chrysopeplus and two sympatric oriole species (Icterus pectoralis and I. pustulatus).(AU)

Resumen La defensa química es un mecanismo que se encuentra presente en varios animales y plantas. Sin embargo, pocos casos son conocidos para especies de aves. En este estudio evaluamos la toxicidad de extractos de plumas de Pheucticus chrysopeplus con un ensayo de letalidad utilizando artemia (Artemia salina) como modelo in vivo. La mortalidad de A. salina se evaluó luego de ser expuesta por 24 horas a agua marina artificial, metanol y extracto metanólico de plumas de P. chrysopeplus. La prueba de Kruskal-Wallis mostró que existe una diferencia significativa entre los porcentajes de mortalidad de los tratamientos evaluados (X2 = 65.25, P < 0.0001, n = 50). Con esto, describimos a P. chrysopeplus como la primera especie de ave tóxica reportada para Guatemala y Centroamérica, resaltando la importancia de su conservación, así como la identificación de la sustancia tóxica presente en sus plumas. También destacamos el posible mecanismo de mimetismo que podría estar ocurriendo entre P. Chrysopeplus y dos especies simpátricas de orioles (Icterus pectoralis e I. pustulatus).(AU)

A new species of Rhadinella (Serpentes: Dipsadidae) from the dry forest of Motagua Valley, Guatemala.

We describe a new species of Rhadinella from the dry forest and thorn scrub of Valle del Motagua, Guatemala, a region and habitat where the congeners were previously unrecorded. This species is related to the group of Rhadinella that have dark dorsal coloration, which mostly or completely obscures a pattern of longitudinal striping characteristic of the majority of species of Rhadinella. The new species has dark gray, almost black, dorsal coloration with barely discernible slightly darker striping. Top of the head is mostly blackish with irregular auburn-orange markings on the internasals, prefrontals, frontal, parietals, loreals, postoculars, temporals, and two ultimate supralabials. Most conspicuous features are an orange-auburn Y-shaped marking along frontal-parietal and interparietal sutures, followed by an orange nuchal collar. The closest relative of the new species, based on morphological similarities, appears to be Rhadinella pilonaorum, which occurs in a relatively mesic habitat of pine-oak forest located about 90 km southwest from the type-locality of the new species.

Envenomation by a wild Guatemalan Beaded Lizard Heloderma horridum charlesbogerti.

BACKGROUND: The Guatemalan Beaded Lizard (Heloderma horridum charlesbogerti) is an endemic venomous lizard that inhabits southeastern Guatemala. Published reports of bites by Beaded Lizard are scarce. This is the first case report of a bite from Heloderma horridum charlesbogerti. CASE REPORT: A 24-year-old man was bitten on the left hand by a juvenile Heloderma horridum charlesbogerti. The lizard remained attached for approximately 15 seconds. The patient experienced severe local pain, dizziness, diaphoresis, vomiting, severe paresthesia in his left hand and arm, and hypotension (70/52 mm/Hg). He was treated with intravenous ketorolac, chlorpheniramine, methylprednisolone, antibiotics, ondansentron, and normal saline. Hematology tests revealed leukocytosis (12,600/mm3). Symptoms improved and the patient was discharged from hospital 24 hours after admission. CONCLUSION: The case reported here shows that bites by Heloderma produce severe clinical effects shortly after the bite. Management consists of waiting for the lizard to relax its bite pressure and using pliers to open lizard's mouth and pull out the bitten extremity, a careful manual search for teeth remnants, and supportive care. In our case, severe pain, unresponsive to non-steroidal anti-inflammatory analgesics, was a major problem. Parethesias resolve quickly but pain may persist for up to 12 hours after the bite. A full recovery is expected.