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Kent A Prior - One of the best experts on this subject based on the ideXlab platform.
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hierarchical patterns of genetic population structure in black Rat Snakes elaphe obsoleta obsoleta as revealed by microsatellite dna analysis
Evolution, 1999Co-Authors: Stephen C Lougheed, Lisle H Gibbs, Kent A PriorAbstract:We investigated the distribution of variation at six microsatellite loci in the black Rat Snake (Elaphe obsoleta obsoleta). Sampling occurred at three hierarchical scales ranging from communal hibernacula to regional populations, with most locales situated within the Frontenac Axis region of eastern Ontario. We detected no statistically significant pairwise differentiation (FST and RST) between hibernacula within the same subpopulations (interhibernaculum distance <6 km). However, isolation-by-distance was evident among locales within the Frontenac Axis (maximum of 50 km) and among regional populations (maximum of 1500 km). Conservative estimates of Nc derived from heterozygosity values ranged from approximately 600 to 2000. These values suggest relatively large genetic neighborhoods encompassing many communal hibernacula. Our results considered together suggest viscosity of gene flow over relatively short distances (tens of kilometers), but substantial genetic exchange among local hibernacula.
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population genetic structure in the black Rat Snake implications for management
Conservation Biology, 1997Co-Authors: Kent A Prior, H L GibbsAbstract:Assessments of population genetic structure and diversity can be of value in formulating management plans for threatened species. Using randomly amplified polymorphic DNA markers, we found evidence of significant genetic structure among black Rat Snakes ( Elaphe obsoleta) sampled at three spatial scales. Highly isolated (1500–1900 km apart) populations were strongly divergent ( FST = 0.242–0.323), whereas populations more proximal ( 465 km apart) although currently isolated, exhibited far less divergence ( FST = 0.019). A considerable proportion (80%) of total genetic diversity was due to differences among individuals within populations, although differences among populations (8%) also were significant. At the scale of sub-populations ( local populations 15–50 km apart), differentiation was generally modeRate ( FST = 0.058). Our estimates of Nei’s genetic distance for sub-populations (0.014) approximated (mean = 0.044) those obtained in other studies that have assessed differentiation between Snake populations based on variation in allozymes. The majority (ca. 86%) of total genetic variance across five sub-populations was attributable to differences among individuals, although differences among sub-populations (ca. 13%) also were significant. We found little evidence of genetic structure ( FST = 0.006) between pairs of hibernacula, our finest spatial scale (samples 1–2 km apart), if they were located in natural habitats. In contrast, a pair of hibernacula sampled in an urban area exhibited genetic structure equivalent to some sub-population differences ( FST = 0.039), suggesting interrupted gene flow related to urban development. Our results have direct implications for ranking populations in terms of their conservation value and the genetic management of threatened Snakes. Evaluaciones de la estructura genetica y la diversidad de una poblacion pueden ser de gran valor en la formulacion de planes de manejo para especies amenazadas. Utilizando marcadores polimorficos amplificados de ADN, encontramos evidencia de una estructura genetica significativa entre serpientes “Rata negra” ( Elaphe obsoleta) muestreada en tres escalas espaciales. Altamente aisladas (1500–1900 km de separacion) las poblaciones fueron fuertemente divergentes ( FST = 0.242–0.323), mientras que poblaciones mas cercanas (465 km de separacion) que, aunque se encontraban aisladas, exhibieron mucho menos divergenica ( FST = 0.019). Una considerable proporcion (80%) de la diversidad genetica total se debio a las diferencias entre individuos dentro de las poblaciones, sin embargo, diferencias entre poblaciones (8%) tambien fueron significativas. En la escala de subpoblacion ( poblaciones locales separadas entre 15–50 km) la diferenciacion fue generalmente moderada ( FST = 0.058). Nuestras estimaciones de la distancia Genetica de Negi para subpoblaciones (0.014) se aproximo (media = 0.044) a aquellos valores obtenidos en otros estudios que han evaluado la diferenciacion entre poblaciones de serpientes en base a la variacion de sus alozimas. La mayoria (ca. 86%) de la varianza genetica total obtenida entre cinco subpoblaciones fue atribuible a diferencias entre individuos, aunque las diferencias entre subpoblaciones (13%) fueron tambien significativas. Encontramos una ligera evidencia de estructura genetica ( FST = 0.006) entre pares de hibernaculas, nuestra escala espacial mas fina (muestras separadas de 1–2 km), si estas se encontraban en sus habitats naturales. En contraste, un par de hibernaculas muestreado en un area urbana exhibio una estructura genetica equivalente a algunas differencias subpoblacionales ( FST = 0.039), lo cual sugiere un flujo de genes interrumpido relacionada con el desarrollo urbano. Nuestros resultados tienen implicaciones directas en la categorizacion de poblaciones en base a su valor de conservacion, asi como en el manejo genetico de serpientes amenazadas.
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habitat features of black Rat Snake hibernacula in ontario
Journal of Herpetology, 1996Co-Authors: Kent A PriorAbstract:Suitable over-wintering habitat is critical to the survival of Snake populations at higher latitudes. The identification and protection of traditional, communal hibernation sites (hibernacula) is important for the conservation of threatened species, while the assessment of hibernacula availability may help determine the extent to which population distributions are limited by habitat suitability. In this paper, we quantified surface habitat characteristics of 10 hibernacula and the composition of basking trees used by a threatened population of black Rat Snakes (Elaphe o. obsoleta) at the northern limit of the species' range. Hibernacula were typically situated on relatively rocky, south-facing slopes. The co-occurrence of these features was sufficiently unique as to distinguish hibernacula from (1) a series of random sites, but not from (2) a set of intuitively identified "potential hibernacula" in the surrounding landscape. This implies that additional requisite elements (e.g., underground structure and micro-climatic conditions), which we were unable to quantify, set actual hibernacula apart from sites that appear to be otherwise suitable (i.e., "potential hibernacula"). Basking trees found at hibernacula tended to be relatively large and decayed or dying with numerous cavities. Unused trees exhibiting these characteristics were also available at both random sites and potential hibernacula indicating the suitability of those sites for basking. Our results suggest that Rat Snake hibernacula cannot be predictably located by simply searching for key surface habitat features in the landscape. The current data are equivocal as to whether or not this most northern population is limited by the availability of suitable over-winter habitat since the possibility that essential subterranean features of hibernacula are limiting remains to be tested. We recommend the continued use of radio-telemetry to identify and protect additional hibernacula, the preservation of basking trees at known hibernacula, and further research to determine the internal structure and micro-environ- ments of hibernacula.
Jinelle H. Sperry - One of the best experts on this subject based on the ideXlab platform.
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do seasonal patterns of Rat Snake pantherophis obsoletus and black racer coluber constrictor activity predict avian nest predation
Ecology and Evolution, 2016Co-Authors: Brett A Degregorio, Jinelle H. Sperry, Michael P. WardAbstract:Avian nest success often varies seasonally and because predation is the primary cause of nest failure, seasonal variation in predator activity has been hypothesized to explain seasonal variation in nest success. Despite the fact that nest predator communities are often diverse, recent evidence from studies of Snakes that are nest predators has lent some support to the link between Snake activity and nest predation. However, the strength of the relationship has varied among studies. Explaining this variation is difficult, because none of these studies directly identified nest predators, the link between predator activity and nest survival was inferred. To address this knowledge gap, we examined seasonal variation in daily survival Rates of 463 bird nests (of 17 bird species) and used cameras to document predator identity at 137 nests. We simultaneously quantified seasonal activity patterns of two local Snake species (N = 30 individuals) using manual (2136 Snake locations) and automated (89,165 movements detected) radiotelemetry. Rat Snakes (Pantherophis obsoletus), the dominant Snake predator at the site (~28% of observed nest predations), were most active in late May and early June, a pattern reported elsewhere for this species. When analyzing all monitored nests, we found no link between nest predation and seasonal activity of Rat Snakes. When analyzing only nests with known predator identities (filmed nests), however, we found that Rat Snakes were more likely to prey on nests during periods when they were moving the greatest distances. Similarly, analyses of all monitored nests indicated that nest survival was not linked to racer activity patterns, but racer‐specific predation (N = 17 nests) of filmed nests was higher when racers were moving the greatest distances. Our results suggest that the activity of predators may be associated with higher predation Rates by those predators, but that those effects can be difficult to detect when nest predator communities are diverse and predator identities are not known. Additionally, our results suggest that hand‐tracking of Snakes provides a reliable indicator of predator activity that may be more indicative of foraging behavior than movement frequency provided by automated telemetry systems.
E. Bardi - One of the best experts on this subject based on the ideXlab platform.
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TRattamento chirurgico di una lacerazione cutanea in un esemplare di Gonyosoma prasinum (colubro verde della boscaglia) con ausilio di TLRP (Trombocyte- Leucocyte Rich Plasma)
SCIVAC, 2020Co-Authors: A. Vetere, E. BardiAbstract:Un giovane esemplare maschio di Gonyosoma prasinum di un anno (green bush Rat Snake) è stato portato in visita a causa di una grave lesione cutanea (“degloving” o sguantamento). Tale lesione interessava cute e sottocute, esponendo parte dei muscoli del tronco, la vena giugulare di destra e l’esofago. Dopo aver stabilizzato il paziente, è stato effettuato un delicato curettage della ferita. Prima di suturare la lesione, la ferita è stata irrigata con Thrombocyte-Leukocyte Rich Plasma (TLRP) eterologo, per favorirne la guarigione. Trenta giorni dopo il tRattamento con TLRP il paziente ha effettuato l’ecdisi, rivelando una completa riparazione tissutale. Non è stata rilevata una significativa riduzione dei tempi di cicatrizzazione rispetto a quanto riportato in letteRatura, ma il tRattamento con TLRP può aver contribuito ad evitare complicazioni comuni come infezioni o la deiscenza della sutura chirurgica. I derivati piastrinici come il TLRP sono ampiamente utilizzati in medicina veterinaria per promuovere la rigenerazione tissutale. Nella medicina degli animali esotici la letteRatura è ancora carente, ma si stanno rivelando strumenti sicuri e promettenti. La loro applicazione nella traumatologia dei rettili merita quindi di essere approfondita.A one-year-old green bush Rat Snake (Gonyosoma prasinum) was presented for a severe degloving lesion in the cervical region, exposing the underlying subcutaneous and muscular tissue, along with the esophagus and right jugular vein. After patient stabilization, surgical debridement was performed. Before closure, the wound was irrigated with heterologous Thrombocyte-Leukocyte Rich Plasma (TLRP) in order to adjuvate healing. Thirty days after treatment the patient shed its skin, revealing complete re-epitalization underneath. No significant reduction in healing time was noted, but TLRP may have contributed to avoid common complications such as suture dehiscence and wound site infection. Platelet-rich products are widely used to promote wound healing in human and veterinary medicine; liteRature is still lacking, but they are revealing themselves as safe and promising tools in exotic animal regeneRative medicine as well, and their application in reptile traumatology should be further investigated
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TRattamento chirurgico di una lacerazione cutanea in un esemplare di Gonyosoma prasinum (colubro verde della boscaglia) con ausilio di TLRP (Trombocyte- Leucocyte Rich Plasma)
SCIVAC, 2020Co-Authors: A. Vetere, E. BardiAbstract:Un giovane esemplare maschio di Gonyosoma prasinum di un anno (green bush Rat Snake) \ue8 stato portato in visita a causa di una grave lesione cutanea (\u201cdegloving\u201d o sguantamento). Tale lesione interessava cute e sottocute, esponendo parte dei muscoli del tronco, la vena giugulare di destra e l\u2019esofago. Dopo aver stabilizzato il paziente, \ue8 stato effettuato un delicato curettage della ferita. Prima di suturare la lesione, la ferita \ue8 stata irrigata con Thrombocyte-Leukocyte Rich Plasma (TLRP) eterologo, per favorirne la guarigione. Trenta giorni dopo il tRattamento con TLRP il paziente ha effettuato l\u2019ecdisi, rivelando una completa riparazione tissutale. Non \ue8 stata rilevata una significativa riduzione dei tempi di cicatrizzazione rispetto a quanto riportato in letteRatura, ma il tRattamento con TLRP pu\uf2 aver contribuito ad evitare complicazioni comuni come infezioni o la deiscenza della sutura chirurgica. I derivati piastrinici come il TLRP sono ampiamente utilizzati in medicina veterinaria per promuovere la rigenerazione tissutale. Nella medicina degli animali esotici la letteRatura \ue8 ancora carente, ma si stanno rivelando strumenti sicuri e promettenti. La loro applicazione nella traumatologia dei rettili merita quindi di essere approfondita.A one-year-old green bush Rat Snake (Gonyosoma prasinum) was presented for a severe degloving lesion in the cervical region, exposing the underlying subcutaneous and muscular tissue, along with the esophagus and right jugular vein. After patient stabilization, surgical debridement was performed. Before closure, the wound was irrigated with heterologous Thrombocyte-Leukocyte Rich Plasma (TLRP) in order to adjuvate healing. Thirty days after treatment the patient shed its skin, revealing complete re-epitalization underneath. No significant reduction in healing time was noted, but TLRP may have contributed to avoid common complications such as suture dehiscence and wound site infection. Platelet-rich products are widely used to promote wound healing in human and veterinary medicine; liteRature is still lacking, but they are revealing themselves as safe and promising tools in exotic animal regeneRative medicine as well, and their application in reptile traumatology should be further investigated
H. Lisle Gibbs - One of the best experts on this subject based on the ideXlab platform.
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Isolation and characterization of microsatellite loci in the black Rat Snake ( Elaphe obsoleta )
Molecular Ecology Notes, 2003Co-Authors: Gabriel Blouin-demers, H. Lisle GibbsAbstract:We obtained molecular markers useful for population level studies of the black Rat Snake ( Elaphe obsoleta ) by screening genomic DNA libraries enriched for dinucleotide, tetranucleotide, and pentanucleotide microsatellite repeats. Following sequencing of the positive clones, 11 pairs of primers were designed for polymorphic loci and their variability assessed in > 350 individuals from four populations in North America. The loci had between 9 and 40 alleles and observed heterozygosities ranged from 0.071 to 0.87. Some of these pairs of primers also successfully amplified DNA from two other Snake species.
Stephen J. Mullin - One of the best experts on this subject based on the ideXlab platform.
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the foraging ecology of the gray Rat Snake elaphe obsoleta spiloides ii influence of habitat structural complexity when searching for arboreal avian prey
Amphibia-reptilia, 2000Co-Authors: Stephen J. Mullin, Robert J. CooperAbstract:A predator's behavior and success when foraging can be compromised by a variety of environmental factors. We examined the effect of variation in habitat structural complexity on the predatory success of the semi- arboreal gray Rat Snake (Elaphe obsoleta spiloides) foraging for arboreal bird nest contents. Individual Snakes searched for nests in enclosures containing one of eve levels of vegetation density that ree ected the range of structural complexity measured at a e eld site where predator and prey species are common. Subjects were most proe cient at locating prey in enclosures having low levels of structural complexity, and experienced decreased predatory success in barren or highly-complex habitats. Ten behaviors comprised over 95% of the trial duRations, and four of these occurred more often than the other six regardless of variation in structural complexity within the enclosure. Wesuggest that low levels of structural complexity offer Snakes concealment from predation while not obscuring their view of provisioning activity at the nest.
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the foraging ecology of the gray Rat Snake elaphe obsoleta spiloides visual stimuli facilitate location of arboreal prey
American Midland Naturalist, 1998Co-Authors: Stephen J. Mullin, Robert J. CooperAbstract:Abstract We examined the responsiveness of adult gray Rat Snakes to avian prey in enclosures that simulated natural habitat conditions. Subjects searched for arboreal nest contents in the presence or absence of a bird model flown so as to simulate avian provisioning behavior. In the absence of the model, gray Rat Snake latency to capture prey was over 92 % greater than when searching for nest contents with the model. Snakes responded to model flight by turning their heads in the direction of its movement. We conclude that gray Rat Snakes perceive relatively distant visual cues from prey, and that nest provisioning (activity localized around a nest) may facilitate Snakes correctly choosing to ascend trees that contain active nests and ignoring those that do not.
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the foraging ecology of the gray Rat Snake elaphe obsoleta spiloides iii searching for different prey types in structurally varied habitats
Canadian Journal of Zoology, 1998Co-Authors: Stephen J. Mullin, Robert J. Cooper, William H N GutzkeAbstract:Dietary generalists foraging for prey inhabiting different microhabitats may encounter different levels of structural complexity. We examined the effect of variation in prey type on the predation s...
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adaptations facilitating facultative oophagy in the gray Rat Snake elaphe obsoleta spiloides
Amphibia-reptilia, 1996Co-Authors: Stephen J. MullinAbstract:The gray Rat Snake (Elaphe obsoleta spiloides), a facultative oophagic colubrid species, exhibits a stereotyped behavior when ingesting quail eggs. The anterior third of the body is contracted in a forceful series of S-shaped curves, and, at the moment of shell rupture, the region of the body posterior to the egg is rapidly and laterally flexed into a U-shaped bend. The ventral aspect of hypapophyses in the cervical region can be palped along the roof of the dissected esophagus. Scalation along the throat and anterior neck regions is polymorphic, and scale rows are more numerous (increasing distensibility when swallowing eggs) than along areas posterior to the neck. Radiographs reveal that eggs may pass into the gut of large Snakes without being cracked. Once the contents are extracted from the shell, it passes through the remainder of the gut, appearing in the feces with sides folded inward to form a narrow cylinder, tapered at both ends. Gray Rat Snakes appear to possess adaptations facilitating ingestion of bird eggs while not interfering with the potential to ingest other prey types.
