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Identifying the ecological factors that determine the spread of invasive species is key to adequately managing endangered species in freshwater ecosystems. Invasive species are a main threat to turtles, which are targets of major conservation efforts worldwide.In freshwater ecosystems of the south‐western USA, invasive bullfrog (Lithobates catesbeianus) and crayfish species (Faxonius virilis and Procambarus clarkii) represent a major risk to the desert mud turtle (Kinosternon sonoriense sonoriense), state‐listed as a Species of Greatest Conservation Need in Arizona. As a species in the early stages of population decline, the desert mud turtle is a top candidate for the development of management plans to decrease extinction risk.An invasion risk assessment tool was built from available occurrence data for K. s. sonoriense and the invasive bullfrog and crayfish species in Arizona using 5,886 de‐duplicated records from public databases and reports from the Arizona Game and Fish Department. The occurrence density of K. s. sonoriense was calculated state‐wide to define populations in which the level of invasion by bullfrog and crayfish was assessed. The environmental factors associated with the abundance of invasive species in populations of K. s. sonoriense were then analysed.A higher prevalence of crayfish and bullfrog was detected in turtle populations located in perennial streams. Invasive abundance was significantly higher in turtle populations at higher elevation and closer to the main river trunk for both invasive taxa. Higher bullfrog abundance was detected near human settlements, whereas crayfish were more abundant further from human settlements.These results will inform which populations of K. s. sonoriense require intensive surveying and control of invasive species to maintain the health of native desert mud turtle populations. This study provides valuable information regarding the environmental conditions associated with the abundance of invasive species threatening turtle populations, helping to develop science‐based management of freshwater ecosystems. [ABSTRACT FROM AUTHOR]

The painted turtle (Chrysemys picta) is widely distributed from coast to coast in North America with each of four subspecies generally occupying different regions. In the southwestern USA and northern Mexico, where C. p. bellii is the expected native race, populations are small and widelyscattered. Introduced populations of other painted turtle subspecies are reported from various locations in the USA. We discovered a small but dense introduced population of C. p. marginata on the Colorado Plateau in northern Arizona, a region with few, if any, turtles due to aridity and an elevated topography with little surface water. The turtles were in a remote pond constructed to provide cattle with water. Chrysemys p. marginata occur naturally east of the Mississippi River, over 2,000 km away. The nearest native population of C. p. bellii in Arizona is over 160 km away. We observed nesting females, juveniles, and the presence of shelled eggs in females via Xradiography confirming a self-sustaining population. The body sizes and nesting season we observed were consistent with data for those variables from native populations of the taxon. It is unknown exactly how the turtles came to be established in such a remote location, but it is unlikely that they will spread due to the scarcity of perennial water sources in the semi-arid region. Due to increasing drought frequency and duration in the region, small populations like this one, introduced into a novel environment, may be bellwethers for monitoring the effects of climate change. [ABSTRACT FROM AUTHOR]

Sonoran Desert Tortoise (SDT; Gopherus morafkai) populations face threats from habitat loss and fragmentation. Effective management of SDTs in Arizona will require an understanding of the species' age-related habitat needs; however, no published research addresses habitat selection and use in juvenile SDTs. We investigated microhabitat selection of juvenile SDTs in the Mazatzal Mountains in central Arizona. Eleven juvenile SDTs were tracked with radiotelemetry from April 2010 to December 2011. To determine habitat selection, we compared microhabitat characteristics from 117 tracked-tortoise locations to an equal number of random locations during 2 seasons. The summer monsoon (July to September) was the season of greatest SDT activity, whereas winter (December to February) was a season of relative inactivity and hibernation. We found that juvenile SDTs selected enclosed shelters on rocky hillsides with high proportions of boulders and annual vegetation during summer monsoon, and enclosed shelters on steep slopes with a high amount of leaf litter during winter hibernation. Microhabitat selection by juvenile SDTs allowed us to develop a habitat suitability model in a geographic information system (GIS); our model correctly predicted 82% of juvenile tortoise locations in suitable habitat at our site. Results from this study, the first of its kind in the Sonoran Desert, identify key habitat features selected by juvenile SDTs in central Arizona and provide a framework to develop GIS tools to predict juvenile tortoise habitat. [ABSTRACT FROM AUTHOR]

We examined a secondary contact zone between two species of desert tortoise, Gopherus agassizii and G. morafkai. The taxa were isolated from a common ancestor during the formation of the Colorado River (4-8 mya) and are a classic example of allopatric speciation. However, an anomalous population of G. agassizii comes into secondary contact with G. morafkai east of the Colorado River in the Black Mountains of Arizona and provides an opportunity to examine reinforcement of species' boundaries under natural conditions. We sampled 234 tortoises representing G. agassizii in California ( n = 103), G. morafkai in Arizona ( n = 78), and 53 individuals of undetermined assignment in the contact zone including and surrounding the Black Mountains. We genotyped individuals for 25 STR loci and determined maternal lineage using mt DNA sequence data. We performed multilocus genetic clustering analyses and used multiple statistical methods to detect levels of hybridization. We tested hypotheses about habitat use between G. agassizii and G. morafkai in the region where they co-occur using habitat suitability models. Gopherus agassizii and G. morafkai maintain independent taxonomic identities likely due to ecological niche partitioning, and the maintenance of the hybrid zone is best described by a geographical selection gradient model. [ABSTRACT FROM AUTHOR]

Although many species may be vulnerable to changes in climate, forecasting species-level responses can be challenging given the array of physiological, behavioral, and demographic attributes that might be affected. One strategy to improve forecasts is to evaluate how species responded to climatic variation in the past. We used 22 years of capture-recapture data for Sonoran desert tortoises ( Gopherus morafkai) collected from 15 locations across their geographic range in Arizona to evaluate how environmental factors affected spatial and temporal variation in survival. Although rates of annual survival were generally high ( $$ \overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\Upphi } $$ = 0.92), survival of adults decreased with drought severity, especially in portions of their range that were most arid and nearest to cities. In three locations where large numbers of carcasses from marked tortoises were recovered, survival of adults was markedly lower during periods of severe drought ( $$ \overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\Upphi } $$ = 0.77-0.81) compared to all other periods ( $$ \overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{\Upphi } $$ = 0.93-0.98). Assuming continued levels of dependency of humans on fossil fuels, survival of adult tortoises is predicted to decrease by an average of 3 % during 2035-2060 relative to survival during 1987-2008 in 14 of the 15 populations we studied. This decrease could reduce persistence of tortoise populations, especially in arid portions of their range. Temporal and spatial variation in drought conditions are important determinants of survival in adult desert tortoises. [ABSTRACT FROM AUTHOR]

The Sonoyta mud turtle (Kinosternon sonoriense longifemorale) is a member of the unique desert riparian fauna isolated along the Rio Sonoyta watershed in northern Sonora, Mexico, and southern Arizona. This subspecies occupies six sites along the Rio Sonoyta, a pool at Quitovac in Sonora, and one pond at Quitobaquito Springs in Organ Pipe Cactus National Monument in Arizona. Since the mid-1980s, population estimates for the US population have ranged from 39-153 individuals. In 2006-2007, the human-made Quitobaquito Pond began losing water, and discussions were held concerning the fate of the turtles. During three salvage efforts all Sonoyta mud turtles encountered were captured and transported to temporary holding facilities. Because the minimum number of turtles needed for re-establishment was unknown, we conducted a Population Viability Analysis (PVA) to determine the number of Sonoyta mud turtles that should be held in an assurance colony. Results from both our PVA and previous work suggested that juvenile survivorship has the strongest effect on female transition rates from nonreproductive to reproductive age classes and in turn population growth; thus, a wide range of age classes should be maintained in an assurance colony. [ABSTRACT FROM AUTHOR]

We genotyped 180 captive desert tortoises (Gopherus agassizii) from Kingman (n = 45), Phoenix (n = 113), and Tucson (n = 22), Arizona, USA, to determine if the genetic lineage of captives is associated with that of wild tortoises in the local area (Sonoran Desert). We tested all samples for 16 short tandem repeats and sequenced 1,109 base pairs of mitochondrial DNA (mtDNA). To determine genetic origin, we performed assignment tests against a reference database of 997 desert tortoise samples collected throughout the Mojave and Sonoran Deserts. We found that >40% of our Arizona captive samples were genetically of Mojave Desert or hybrid origin, with the percentage of individuals exhibiting the Mojave genotype increasing as the sample locations approached the California, USA, border. In Phoenix, 11.5% were Sonoran-Mojave crosses, and 8.8% were hybrids between desert tortoise and Texas tortoise (G. berlandieri). Our findings present many potential implications for wild tortoises in the Sonoran Desert of Arizona. Escaped or released captive tortoises with Mojave or hybrid genotypes have the potential to affect the genetic composition of Sonoran wild populations. Genotyping captive desert tortoises could be used to inform the adoption process, and thereby provide additional protection to native desert-tortoise populations in Arizona. [ABSTRACT FROM AUTHOR]

Focuses on the effects of timber harvesting on the structure and composition of adjacent old-growth coast redwood forest, California. Effective size of old-growth coast redwood preserves; Correlation among variables related to stand structure and composition, wildlife habitat, and physical environment.

The article offers information on turtle specie Gopherus morafkai. It mentions that the reproductive behavior is known in this species primarily from radio-telemetry and radiography of females. It also mentions that minimum size at maturity for males is unknown, because reproductive status of males needs to be deduced based on opportunistic observation of mating behavior.

Insulin-stimulated glucose uptake requires the activation of several signaling pathways to mediate the translocation and fusion of GLUT4 vesicles from an intracellular pool to the plasma membrane. Our previous studies demonstrated that GLUT4-mediated glucose uptake is a myosin II-dependent process in adipocytes. The studies presented here show that myosin IIA colocalizes with GLUT4 at the plasma membrane after insulin stimulation. We further show that insulin stimulates myosin IIA recruitment to the plasma membrane after GLUT4 vesicle translocation. We also show that myosin II activity is required for proper GLUT4 vesicle fusion at the plasma membrane. Based on our findings, we hypothesize that myosin II is activated upon insulin stimulation and recruited to the cell cortex to facilitate GLUT4 fusion with the plasma membrane. The identification of myosin IIA as a mediator of GLUT4-mediated glucose uptake represents an important advance in our understanding of the mechanisms regulating glucose homeostasis. [ABSTRACT FROM AUTHOR]