Species delimitation and species taxonomy are important to most subfields of herpetology. I have argued that a previous controversy about the definition and concept of species resulted in a large part from different authors treating different properties that lineages acquire during divergence as necessary properties of species and therefore treating the species category as a stage in the evolution of lineages. I also proposed that a unified species concept could be achieved by not treating any of the properties in question as necessary properties of species so that all separately evolving metapopulation lineages are species. Although the proposed unified species concept has become increasingly accepted, the traditional interpretation persists. I discuss two cases of such persistence in the field of species delimitation. In one case, a protracted speciation model assumes the traditional interpretation of species by not considering separately evolving lineages to be “true” species until they cross some “conversion” threshold. Use of this model has led to the conclusion that species delimitation methods based on the multispecies coalescent model delimit intraspecific population structure rather than species. Consideration of the results upon which that conclusion was based in the context of the unified concept reveals that the method in question accurately delimited species. In another case, a proposed heuristic criterion for delimiting species, the genealogical divergence index, adopts the traditional interpretation of species by treating an index value above a certain threshold as a necessary property of species—one that is closely related to the traditional monophyly and exclusivity criteria. In the context of the unified species concept, this index is more appropriately used as a coalescent measure of lineage divergence than as a species criterion. In the field of species taxonomy, I have recently proposed a revised concept of subspecies based on the unified species concept. The revised concept makes the subspecies category more significant biologically and avoids problems associated with previous uses that caused some authors to reject that category. Nonetheless, recent authors have continued to avoid recognizing subspecies taxa, causing them to adopt to misleading taxonomies that obscure the existence of lineage structure within many species.

Historical climate and landscape features are important mechanisms that can drive genetic differentiation of lineages. Habitat shifts between forested and open environments during the Quaternary Period contributed substantially to regional diversity in Amazonia and other South American environments. Herein, we used a widely distributed frog species in the Guiana Shield to assess whether the species' spatiotemporal dynamics are related to historical climate changes and other regional landscape features. For that, we used ecological niche models (ENMs) and phylogeographical analyses with a single-locus approach (mitochondrial DNA). We found two genetic clusters spatially structured along the Guiana Shield, with some degree of overlap and low genetic diversity. Part of the genetic differentiation was attributed to spatial distances. Population structure did not match to any strong vicariant barrier that could completely preclude gene flow. However, ENMs detected large unsuitable climatic areas for current and historical periods that likely restricted the dispersion of populations. The divergence time of clusters was relatively recent, dating from the middle-to-late Pleistocene, a period of intense climate oscillations. Although such historical changes seem to have influenced the spatial distribution of the species genealogies, demographic analyses suggested that populations were stable from the Late Pleistocene. Climate shifts may have shaped the patterns of gene flow by reducing or increasing connectivity of populations, depending on the period.

Boana cymbalum has not been collected for the past six decades and is one of the two species of Brazilian frogs formally considered to be extinct. It is also the only species of the B. pulchella group that has never been included in molecular phylogenetic analyses, because no fresh tissue is available. Using specialized historical DNA (hDNA) extraction protocols and high-throughput sequencing, we obtained mitochondrial and nuclear sequences from the 62-yr-old holotype of B. cymbalum. Our results place B. cymbalum as the sister taxon of the clade formed by B. prasina, B. cordobae, and B. pulchella, supporting its inclusion in the B. prasina clade. The scars on the dorsum of adult males suggest male–male combat. Microcomputed tomography revealed the presence of a large postarticular process and a distal prepollex directed laterad to pass ventral to Metacarpal II, two known synapomorphies of the B. pulchella group. On the basis of recordings from 1963, we provide an expanded description of the vocalization of B. cymbalum, consisting of a short, tonal note (Note A) and a longer, multipulsed note (Note B). Finally, we discuss the conservation status of B. cymbalum and the potential application of the newly generated hDNA sequences to screen water bodies near the type locality using environmental DNA in an effort to rediscover this species.

According to Bergmann's rule, organisms that live in colder regions usually have a larger body size, in contrast to those in warmer climates. Conversely, Allen's rule proposes that animals living in cold environments generally have shorter limbs, ears, and other appendages compared with related species in warmer environments. Here, we investigated the geographic variation in body size and limb length of male Minshan's Toads (Bufo minshanicus) across nine different elevations on the eastern Tibetan plateau to assess the validity of Allen's rule and Bergmann's rule. Our results found that mean male body size decreases with increasing altitude, which does not conform to Bergmann's rule. We also found a clear negative linear correlation between altitude and limb lengths after accounting for snout–vent length, supporting Allen's rule. The shorter relative limb length and decreased surface-to-volume ratio of the extremities that we found in Minshan's Toads might improve thermoregulatory capacity in cooler climates through slower heating and cooling. However, selective pressures from alternative climatic factors (e.g., annual mean temperature, potential evapotranspiration, and water deficit) could be responsible for the reduction in extremity length at higher elevations.

Translocated herpetofauna can exhibit irregular space use and movement patterns when compared with resident conspecifics. In Florida, USA, Gopher Tortoises (Gopherus polyphemus) are translocated throughout the state to mitigate habitat loss due to development. The postrelease space use of translocated Gopher Tortoises within soft-release pens can affect population dynamics and population monitoring efficacy, and understanding spatial patterns can aid wildlife managers with population management. We used a combination of time-lapse cameras, animal tracking devices, and burrow distribution surveys to investigate translocated tortoise space use at Eglin Air Force Base, Florida, where tortoises have been translocated since 2015. We investigated 10 soft-release pens that varied in size (4–41 ha) and shape (due to landscape configuration and existing infrastructure). Time-lapse cameras and burrow distribution surveys showed that tortoises used habitat within 20 m of soft-release pens (silt fences) significantly more than the interior of pens. In most pens, the selection of pen-edge habitat resulted in a clustering effect that lessened upon subsequent surveys, after fences were removed. Additionally, our tracking data showed mixed evidence for clustering, where three of the seven tortoises used edge area significantly more than the interior of pens. Such clustering can affect the efficacy of population survey methods while potentially having negative impacts on the health of translocatees by increasing local density.

Habitat management activities commonly are predicated on responses of vegetation and charismatic wildlife groups such as birds and mammals, which can be inadequate proxies for reptile conservation without evidence of their mutual benefit. Reptiles require focused assessments because they typically are underrepresented in research and conservation. Further, populations at their species' range limits may be more vulnerable to extirpation due to different selection pressures. We examined microhabitats of a northern, disjunct population of Common Five-lined Skinks (Plestiodon fasciatus) in the Upper Minnesota River Valley of Minnesota, USA, to quantify key habitat management thresholds better. On four sites, we established plot grids representing a range of vegetation, terrain, canopy, and ground-cover variables. We systematically checked cover objects to document P. fasciatus and measured habitat characteristics at each sampling plot within these grids. Using N-mixture and generalized linear mixed models, we studied skink abundance relative to variables associated with P. fasciatus habitat that also are likely to be directly manipulated by land managers. These two modeling techniques produced very similar results. They showed that P. fasciatus abundance was positively associated with large down woody debris (.15-cm diameter), and negatively associated with canopy closure and herbaceous cover greater than 75%. Models also showed negative associations with stem density of a nonnative shrub, Common Buckthorn (Rhamnus cathartica), and slightly positive associations with a native shrub, Smooth Sumac (Rhus glabra). The effects of shrub density were more pronounced when we assessed pre- and posttreatment effects of shrub management. Posttreatment we observed 97–188% increases in skink detections under cover objects. We developed management targets for each of these habitat traits that were important correlates of P. fasciatus abundance. Our findings will help inform development of best management practices for P. fasciatus in this and potentially other similar northern landscapes. We identified management and research implications and recommended effectiveness monitoring to support adaptive management within a changing landscape and climate.

Sleeping behavior in nonavian reptiles is understudied. In particular, studies of sleep in natural environments and explanatory studies examining sleeping site preference are rare. Here we examine sleeping-perch height and sleeping substrate use in Anolis limifrons, a widespread semiarboreal Central American lizard. We analyze our data both autecologically and combined with published data from four additional species of Anolis. We show that common factors associated with perch use in lizards, such as sex, age, and habitat quality, are not predictive of sleeping perch in A. limifrons. Statistical equivalence analyses demonstrate that males and females as well as adults and juveniles use significantly similar sleeping perches across surveyed sites and that individuals use significantly similar perches in natural and altered habitats. These results may indicate a preponderance of favorable sleeping perches for A. limifrons, spatially uniform selective forces during sleep as opposed to wakeful behavior, or/and generalist sleeping ability in A. limifrons across sex/age classes. This latter explanation may reflect diel inertia from generalist behavior while awake or generalist sleeping behavior distinct from ontogenetically partitioned wakeful behavior. Multivariate analyses of five anole species suggest that species identity is a primary predictor of sleeping-perch use in our studied anole species. Within-species variance in sleeping-perch height is comparable between A. limifrons and additional analyzed species. This result is surprising, given that the additional species show partitioning in sleeping-perch height by age and sex whereas A. limifrons does not, and the additional species are solitary rather than members of multispecies anole assemblages as in A. limifrons.

We describe a new Mexican endemic species of Scincella in the “Lampropholis” group. It is distinguished from the other species in the group by the following combination of characters: two ventrolateral dark lines below the lateral stripe on each side, which begin on the supralabial scales, pass through the tympanic opening, and disappear at the level of the forelimbs; a thick and strongly defined lateral stripe; reddish hue on the tail; limbs that do not overlap when adpressed against the body; enlarged dorsal scales arranged in 54–67 transverse dorsal rows and 24–28 longitudinal rows at midbody. Analyses of mitochondrial DNA sequences support the distinctiveness of the new species, as well as its sister relationship to a clade composed of S. assata and S. cherriei. This is the 12th species of Scincella in the Americas and is known from pine and pine–oak forests throughout the Sierra Madre del Sur in the states of Guerrero and Oaxaca, Mexico.

Describimos una nueva especie endémica mexicana de Scincella en el grupo “Lampropholis.” Se distingue de las otras especies del grupo por la siguiente combinación de caracteres: tiene dos líneas oscuras ventrolaterales debajo de la franja lateral en cada lado, una surge en la abertura timpánica y se desvanece gradualmente a la altura de medio cuerpo, la inferior surge en las escamas supralabiales y se desvanece a la altura de la axila; una franja lateral gruesa y fuertemente definida; cola de color rojizo; extremidades que no se superponen cuando se presionan contra el cuerpo; escamas dorsales más grandes y ensanchadas dispuestas en 54–67 filas dorsales transversales y 24–28 filas longitudinales alrededor de la mitad del cuerpo Los análisis basados en secuencias de mtDNA respaldan la distinción de la nueva especie, así como su relación de especie hermana con el clado conformado por S. assata y S. cherriei. Esta especie representa la número 12 de Scincella en América, se distribuye en bosques de pino y pino-encino de la Sierra Madre del Sur en los estados de Guerrero y Oaxaca, México.

Sphenomorphus taiwanensis Chen and Lue 1987 is a small species of skink endemic to mountains of central Taiwan ranging from medium to high elevations. We report on a new cryptic species of skink allied to S. taiwanensis from mid-elevation cloud forests of northern Taiwan. Sphenomorphus luelaiorum sp. nov. is superficially similar to S. taiwanensis, but can be easily distinguished from the latter by having a smaller adult body size, shorter limbs, narrower head with shorter snout, as well as by a significantly lower number of subdigital lamellae on fingers and toes and a lower number of transverse midbody scale rows. The new species is restricted to mid-elevations from 1,580 to 1,960 m above sea level inhabiting subtropical cloud forests and is parapatrically distributed with respect to S. taiwanensis, which is found in alpine habitats at higher elevations. Ecological niche modeling also demonstrated that the bioclimatic niches of two species do not overlap. Our study brings the number of species in the genus Sphenomorphus to 116; Sphenomorphus luelaiorum sp. nov. is the fourth species of Sphenomorphus recorded in Taiwan. Our study calls for further studies on diversity and evolutionary relationships of skinks in East Asia.