Amphibia-Reptilia

Lucchini, Nahla; Kaliontzopoulou, Antigoni; Val, Guillermo Aguado; Martínez-Freiría, Fernando

doi: 10.1163/15685381-bja10024pmid: N/A

AbstractSnakes frequently exhibit ontogenetic and sexual variation in head dimensions, as well as the occurrence of distinct colour morphotypes which might be fitness-related. In this study, we used linear biometry and geometric morphometrics to investigate intraspecific morphological variation related to allometry and sexual dimorphism in Vipera seoanei, a species that exhibits five colour morphotypes, potentially subjected to distinct ecological pressures. We measured body size (SVL), tail length and head dimensions in 391 specimens, and examined variation in biometric traits with respect to allometry, sex and colour morph. In addition, we analysed head shape variation by recording the position of 29 landmarks in 123 specimens and establishing a low-error protocol for implementing geometric morphometrics to European vipers. All head dimensions exhibited significant allometry, while sexual differences occurred for SVL, relative tail length and snout height. After considering size effects, we found significant differences in body proportions between the sexes and across colour morphs, which suggests an important influence of lowland and montane habitats in shaping morphological variation. By contrast, head shape did not exhibit significant variation across sexes or colour morphs. Instead it was mainly associated to allometric variation, where the supraocular and the rear regions of the head were the areas that varied the most throughout growth and across individuals. Overall, this study provides a thorough description of morphological variability in Vipera seoanei and highlights the relevance of combining different tools (i.e. linear and geometric morphometrics) and analyses to evaluate the relative contribution of different factors in shaping intraspecific variation.

Bardier, Cecilia; Székely, Diana; Augusto-Alves, Guilherme; Matínez-Latorraca, Nicolás; Schmidt, Benedikt R.; Cruickshank, Sam S.

doi: 10.1163/15685381-bja10025pmid: N/A

AbstractThe use of individual phenotypic features as non-invasive marks through photo-identification (photo-ID) has many advantages for individual-based field studies. However, since error rates vary between species, matching techniques, and image qualities, it is important to assess error rates to evaluate the reliability of photo-ID. We tested the performance of this method in the Pacific Horned Frog, Ceratophrys stolzmanni, a threatened anuran with a variable dorsal coloration. We compared the effectiveness of visual (i.e. human recognition) versus software-assisted recognition techniques (Wild-ID and APHIS), and assessed the potential applicability of these techniques to identify post-metamorphic individuals (froglets). The three techniques differed in their performance. The visual technique was the only one to produce type I errors between pairs of images (i.e. matching images which are not true matching pairs), however it also produced fewer type II errors (i.e. not identifying true matching pairs of images) than the software-assisted techniques. For froglets, we found that similarity scores calculated by photo-ID software did not differ significantly between groups of froglets and older individuals, supporting the idea that colour patterns in this species remain stable after metamorphosis. The lack of type I errors and the substantial reduction in required time achieved through the use of software, make software-assisted techniques (particularly Wild-ID) a valid and convenient matching technique for C. stolzmanni. We propose that photo-ID can also be applied to froglets of this species, since the pattern at this stage appears to be as variable as in adults and maintained through life.

Van Drunen, Stephen G.; Linton, Jessica E.; Bogart, James P.; Norris, D. Ryan

doi: 10.1163/15685381-bja10028pmid: N/A

AbstractUnderstanding population demography and dispersal of species at risk is integral for evaluating population viability, identifying causes of decline, and assessing the effectiveness of recovery actions. In pond-breeding amphibians, juvenile survival and dispersal are key components linked to population and metapopulation stability but little is known about this life stage. We use mark-recapture methods to estimate juvenile daily apparent survival, dispersal distance, and initial dispersal orientation during summer and fall dispersal of endangered Ambystoma jeffersonianum and their unisexual dependents (Ambystoma laterale – jeffersonianum). Over four years (2015-2018), 1018 juveniles (612 bisexual, 406 unisexual) were marked and 192 (19%) were recaptured at least once. Total captures varied widely between years, with the highest number of captures (88% of all individuals) occurring in 2017. Cormack-Jolly-Seber estimates of daily apparent survival were low in all years (0.76-0.95) but was higher for unisexuals than bisexuals. The majority of juveniles (71%) did not disperse further than 10-40 m after which movement appeared to cease. While most juveniles remained close to their natal pond, at least 2% of juveniles in 2017 travelled further than 100 m. Dispersal orientation varied by year and there was no difference in either dispersal orientation or distance between bisexual and unisexual individuals. This work is the first to estimate and compare juvenile survival and dispersal of sympatric A. jeffersonianum and A. laterale – jeffersonianum individuals, the results of which help inform population viability assessment and increase our understanding of juvenile dispersal dynamics and habitat use.

Andreani, Tainã L.; Bastos, Rogério P.; Dias, Tailise M.; Prado, Cynthia P.A.; Morais, Alessandro R.

doi: 10.1163/15685381-bja10029pmid: N/A

AbstractMale anurans emit different call types in specific social contexts. Such calls represent a communication pathway for species recognition, mate choice, and male-male competition mediation. The acoustic parameters of these calls can be under directional and/or stabilizing selection due to female choice, which influences intra- and inter-individual call variation. Herein, we investigated the inter-year variation of the advertisement and aggressive calls of the gladiator frog Boana goiana, analysing a temporal series encompassing 18 years of sampling (1996-2014). We measured and analysed the following acoustic parameters: call duration, call repetition rate, number of pulses, pulse duration, pulse repetition rate, and dominant frequency. For both call types, the dominant frequency was classified as a static parameter (CVintra < 5%), while call duration was a dynamic parameter (CVintra > 12%). The advertisement call of B. goiana presents the attributes that could allow individual recognition in the chorus, and we suggest that the aggressive calls might also be important for the individual recognition process. Pulse duration of the advertisement and aggressive calls decreased over the years, as well as the repetition rate of the aggressive calls, which could be related to male body size decrease over the years probably related to habitat alteration. This study provides data on the variation of anuran acoustic features over the longest time span ever analysed. Such studies are less invasive and useful for conservation purposes, since they can detect changes in the reproductive behaviour of populations that might be under environmental modification pressure.

Jośko, Paulina; Pabijan, Maciej

doi: 10.1163/15685381-bja10031pmid: N/A

AbstractIn Central Europe, water frog species coexist in assemblages consisting of Pelophylax lessonae, P. ridibundus and their hybridogenetic hybrid, P. esculentus. Population compositions are poorly understood, partly because of difficulties in distinguishing hybrids from parentals by means of morphology alone. Environmental change and human-mediated, cryptic introductions of non-native water frog species have modified local assemblages. In this contribution we examined the structure of nine water frog populations inhabiting mostly large fish ponds in the Upper Vistula river valley of southern Poland using morphology and PCR-based genotyping of single loci in the nuclear and mitochondrial genomes. We found four different water frog population compositions: two with only P. ridibundus, one composed of P. lessonae and P. esculentus, three with P. ridibundus and P. esculentus, and three containing all three water frog taxa. Historical data show that the area was previously inhabited by lessonae-esculentus populations. We propose that both ecological and genetic replacement by expanding P. ridibundus may have contributed to the decline of the former. Overall, 18% of P. ridibundus frogs contained introgressed P. lessonae mtDNA, however, the frequency of introgressants was most pronounced in populations with a high proportion of P. esculentus. Exotic water frogs were not detected in the study area. Our results bear significance for water frog population dynamics and conservation in Central Europe and highlight the importance of long-term monitoring for the detection of changes in population composition in these amphibians.

Balaguera-Reina, Sergio A.; Pinzón-Barrera, Catalina; Farfán-Ardila, Nidia; Vargas-Ortega, David; Densmore, Llewellyn D.

doi: 10.1163/15685381-bja10033pmid: N/A

AbstractPopulation numbers of the American crocodile in Colombia have shown an increasing trend during the last decades. However, the lack of monitoring programs has restricted our understanding about this species’ ecology, limiting the ability to develop sound conservation plans. We assessed the effectiveness and robustness of the Individual Identification Pattern Recognition (IIPR) method for remotely monitoring American crocodile populations based on photographs taken by researchers, tourists, locals, and employees at the Tayrona National Natural Park (TNNP). We catalogued a total of 97 events from 2008 to 2020; 34.02% of which were suitable to analyze using IIPR. We identified eight individuals across 33 events that required only 4.71 ± 1.70 transverse scute lines to obtain complete identification, with the lowest levels of variation in the post occipital and nuchal regions compared with the dorsal area. The probabilities of repeating both the most and least common patterns found in the TNNP were 1.88 × 10−6 and 1.81 × 10−12, respectively, and the probabilities of repeating the same pattern of each individual identified ranged between 48.73 × 10−11 and 15.24 × 10−8. Animals B and C were continuously identified between 2012 and 2020 along the Arrecife beach coastline, whereas animals A, H, E, and F were occasionally registered between 2008 and 2019 at the Cañaveral beach. Overall, the IIPR method looks as a promising tool for monitoring American crocodile populations in the TNNP albeit some improvements in data collection that must be done to increase the number of useful events and analysis quality.

Mouadi, Jalal; El Mouden, El Hassan; Bouazza, Abdellah; Aourir, Mohamed

doi: 10.1163/15685381-bja10034pmid: N/A

AbstractThe Atlas day gecko, Quedenfeldtia moerens, a Moroccan endemic lizard, is strictly diurnal and widely distributed across the dry Atlas Mountains. We quantified thermoregulation in adult males and adult females during their active season in the L’kest Mountain at 1300 m a.s.l., Anti-Atlas region of Morocco. The operative temperatures and air temperatures were sampled using data-loggers in the field from 2016 to 2018. Body temperatures of active lizards and substrate temperatures in the field were simultaneously measured. Finally, we measured preferred body temperatures (Tset) in a laboratory thermal gradient for 24 adult geckos. Mean Tset was 33.3 ± 0.3°C, with the mean 25% and 75% quartiles being 32.3 ± 0.3°C and 34.6 ± 0.3°C, respectively. Active lizards rarely reached their Tset range from March to June, but spent most of the day within Tset in July and August. Our study suggests that Q. moerens have higher Tset than its congeneric Q. trachyblepharus living at high altitude. Likewise, thermoregulatory effectiveness of Q. moerens showed an increase from spring to summer while it was the opposite for Q. trachyblepharus.

Liu, Jinlong; Dujsebayeva, Tatjana N.; Chirikova, Marina A.; Song, Qi; Gong, Xiong; Guo, Xianguang

doi: 10.1163/15685381-bja10035pmid: N/A

AbstractThe status of Eremias stummeri in China has been a matter of controversy for over two decades, although it is well acknowledged that this species occurs in Northeast Kyrgyzstan and Southeast Kazakhstan. To date, whether its occurrence extends to the adjacent Chinese region (possibly in the Ily River Valley) has not been confirmed yet. To overcome constraints on field surveys imposed by the region’s remoteness and rugged terrain, we targeted areas of further field inventories by estimating the potential distribution of the species. Ecological niche modeling (ENM) enabled us to predict a continuous distribution area from Kazakhstan to the Chinese part of the Ily River Valley in Zhaosu county for the species’ occurrence. We conducted extensive field surveys in the predicted area. In 2017, for the first time, the occurrence of E. stummeri in China was confirmed with a single find in Zhaosu county. Further morphological and multilocus phylogenetic analyses congruently supported the taxonomic status of the recently discovered population as E. stummeri. In contrast to its distribution continuity between Kazakhstan and China, the ENM indicates distribution discontinuity between Kazakhstan and Kyrgyzstan. This geographic distribution pattern of E. stummeri is supported by morphological and molecular evidence, which highlights that individuals from China and Kazakhstan are more closely related to each other than to those from Kyrgyzstan. The mismatch between mitochondrial and nuclear phylogeographic pattern implies that historical mitochondrial introgression occurred from E. stummeri individuals from Kyrgyzstan to those from Kazakhstan.

Talarico, Lorenzo; Ciambotta, Marco; Tiberi, Andrea; Mattoccia, Marco

doi: 10.1163/15685381-bja10026pmid: N/A

AbstractAmphibians are experiencing an ascertained global decline, which causes include the introduction of alien species and the (anthropogenic) hybridization between native and exotic taxa. Detecting introductions and assessing their impact on populations of native species is crucial for amphibian conservation. We used mitochondrial and nuclear markers to reveal introgressive hybridization between the native Bombina pachypus and the exotic B. variegata (probably introduced from Albania) in a population from a protected area of central Italy. Almost all genotyped individuals were genetically admixed, showing a larger proportion of the allochthonous genome. To our knowledge, this study provides the first evidence of successful hybridization between the two species (we found both putative F1 and backcrosses), hence representing a new threat to the conservation of the endangered, Italian-endemic B. pachypus.

De la Quintana, Paola; Aparicio, James; Pacheco, Luis F.

doi: 10.1163/15685381-bja10027pmid: N/A

AbstractWe used radio-telemetry to record how Caiman yacare (Cy) and Melanosuchus niger (Mn) responded to the intrusion of the Maniqui river into Cedral Lagoon in the Bolivian Amazon. Nine M. niger and 3 C. yacare were followed between December 2015 and May 2016. Both species showed a gradual reduction in mean monthly range from December (19.96 ha Mn and 1.74 ha Cy) to May 2016 (0.08 ha Mn and 0.24 ha Cy). Habitat use was fairly constant throughout the months for both species, Melanosuchus niger used mainly open swampy forests and Cyperaceae Marshes, while C. yacare used more islands and flooded grasslands. This study shows that both species of caimans responded to changes in depth and vegetation types, as their habitat as a whole was changed by river intrusion.