scholarly journals CALL BROADCASTING AND AUTOMATED RECORDERS AS TOOLS FOR ANURAN SURVEYS IN A SUBARCTIC TUNDRA LANDSCAPE

2014 ◽  
pp. 47-52
Author(s):  
Gad Perry ◽  
R. Nicholas Mannan ◽  
David E. Andersen ◽  
Clint W. Boal
Keyword(s):  
Population Ecology ◽  
Wilcoxon Test ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Inclement Weather ◽  
Pseudacris Maculata ◽  
Chorus Frogs ◽  
Limited Applicability ◽  
Chorus Frog ◽  
Breeding Seasons

Relatively little is known about population ecology of anurans in arctic and subarctic tundra regions, in part because it is difficult to survey anurans in these landscapes. Anuran survey protocols developed for temperate regions have limited applicability in arctic and subarctic tundra landscapes, which may lack roads and vehicle access, and experience variable and inclement weather during short anuran breeding seasons. To evaluate approaches to address some of the limitations of surveying anurans in tundra landscapes, we assessed the effectiveness of using breeding call broadcasts to increase detection of Boreal Chorus Frogs (Pseudacris maculata) and Wood Frogs (Lithobates sylvaticus) near Cape Churchill, Manitoba, Canada. We also evaluated how counts of anurans derived from automated audio recorders compared with those obtained simultaneously by observers. We detected on average 0.4 additional Wood Frogs per survey when we broadcasted calls (x = 0.82, SD = 1.38), an increase of > 40% compared to surveys without broadcasts (x = 1.24, SD = 1.51; Wilcoxon test; Z = 2.73, P = 0.006). In contrast, broadcasting Boreal Chorus Frog calls did not increase the number of chorus frog detections (Wilcoxon test; Z < 0.001, P > 0.90). Detections of Wood Frogs in a 100-m radius were lower via automated recorders (x = 0.60, SD = 0.87 SD) than by observers during simultaneous surveys (x = 0.96, SD = 1.27 Z = 2.07, P = 0.038), but those of Boreal Chorus Frogs were not different (x = 1.72, SD = 1.31;x = 1.44, SD = 1.5; Z = 1.55, P > 0.121). Our results suggest that broadcasting calls can increase detection of Wood Frogs, and that automated recorders are useful in detecting both Wood Frogs and Boreal Chorus Fogs in arctic and subarctic tundra landscapes.

scholarly journals Apparent widespread decline of the Boreal Chorus Frog (Pseudacris maculata) in eastern Ottawa

2014 ◽  
Vol 128 (2) ◽  
pp. 151 ◽  
Author(s):  
David C. Seburn ◽  
Kari Gunson ◽  
Frederick W. Schueler
Keyword(s):  
Forest Cover ◽  
Current Status ◽  
Future Research ◽  
Pseudacris Maculata ◽  
Chorus Frogs ◽  
Wetland Connectivity ◽  
Stochastic Events ◽  
Chorus Frog ◽  
Wetland Cover

The Boreal Chorus Frog (Pseudacris maculata) was once common in the eastern Ottawa area. To assess its current status, we conducted auditory surveys at 184 wetlands in 2011 and 2012. Boreal Chorus Frogs were heard at only five (2.7%) of the surveyed sites. These five sites were spatially aggregated, with only 0.5–7.5 km between any two sites. Sites occupied by Boreal Chorus Frogs in eastern Ottawa were surrounded by significantly greater agricultural cover (at 1.0-, 1.5-, and 2.0-km radii), less forest cover (1.0- and 2.0-km radii), and less wetland cover (1.5- and 2.0-km radii) than occupied sites in western Ottawa. Sites in eastern Ottawa that were apparently unoccupied were surrounded by significantly greater agricultural cover (only at the 2.0-km radius), similar forest cover (all radii), and less wetland cover (all radii) compared with occupied sites in western Ottawa. Boreal Chorus Frog populations are commonly subject to extirpation resulting from stochastic events. The reduced wetland cover in eastern Ottawa may be accompanied by reduced wetland connectivity, making recolonization of wetlands difficult or impossible. Our data do not show whether wetland connectivity has been reduced, but future research should address this important topic.

scholarly journals Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba

2008 ◽  
Vol 122 (2) ◽  
pp. 129 ◽  
Author(s):  
Matthew E. Reiter ◽  
Clint W. Boal ◽  
David E. Andersen
Keyword(s):  
Boreal Forest ◽  
Forest Edge ◽  
Habitat Associations ◽  
Probability Of Detection ◽  
Spatial And Temporal Variation ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Landscape Types ◽  
Species Specific ◽  
Monitoring Protocols

Distribution, abundance, and habitat relationships of anurans inhabiting subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be applicable across large roadless areas of northern landscapes. In addition, arctic and subarctic regions of North America are predicted to experience changes in climate and, in some areas, are experiencing habitat alteration due to high rates of herbivory by breeding and migrating waterfowl. To better understand subarctic anuran abundance, distribution, and habitat associations, we conducted anuran calling surveys in the Cape Churchill region of Wapusk National Park, Manitoba, Canada, in 2004 and 2005. We conducted surveys along ~1-km transects distributed across three landscape types (coastal tundra, interior sedge meadow–tundra, and boreal forest–tundra interface) to estimate densities and probabilities of detection of Boreal Chorus Frogs (Pseudacris maculata) and Wood Frogs (Lithobates sylvaticus). We detected a Wood Frog or Boreal Chorus Frog on 22 (87%) of 26 transects surveyed, but probability of detection varied between years and species and among landscape types. Estimated densities of both species increased from the coastal zone inland toward the boreal forest edge. Our results suggest anurans occur across all three landscape types in our study area, but that species-specific spatial patterns exist in their abundances. Considerations for both spatial and temporal variation in abundance and detection probability need to be incorporated into surveys and monitoring programs for subarctic anurans.

scholarly journals Has the Western Chorus Frog (Pseudacris triseriata) Declined in Western Ottawa, Ontario?

2011 ◽  
Vol 125 (3) ◽  
pp. 220
Author(s):  
David C. Seburn ◽  
Kari Gunson
Keyword(s):  
Land Use ◽  
Forest Cover ◽  
Historical Data ◽  
Current Status ◽  
Historical Records ◽  
Breeding Sites ◽  
Median Distance ◽  
Chorus Frogs ◽  
Historical Sites ◽  
Chorus Frog

To determine whether the Western Chorus Frog has declined in western Ottawa, we conducted auditory surveys at historical locations as well as at various other wetlands. Western Chorus Frogs were detected at 12 of 18 historical locations. Wetland habitat remained at all historical locations where the species was not detected. There was no difference in the year of historical records for sites where Western Chorus Frogs were (median 1987.5) and were not (median 1987.5) detected. In the present study, Western Chorus Frogs were also detected at 30 locations where they had not been previously reported. Historical sites where Western Chorus Frogs were not detected were not significantly farther away from known Western Chorus Frog sites (median distance: 2.2 km) than historical sites where Western Chorus Frogs were detected (median distance: 1.4 km). Land use variables for historical sites where Western Chorus Frogs were and were not detected did not vary significantly at any spatial scale from 0.5 to 2.0 km. Western Chorus Frogs were detected in areas with up to 50% forest cover and up to 86% agricultural cover at the 1.0-km radius. The lack of historical data makes it difficult to assess the current status of the Western Chorus Frog in western Ottawa. The species may have declined, remained approximately the same (by shifting to different breeding sites), or even increased its distribution (by colonizing additional sites).

Use of Olfactory Cues by Newly Metamorphosed Wood Frogs (Lithobates sylvaticus) during Emigration

Copeia ◽  
2012 ◽  
Vol 2012 (3) ◽  
pp. 424-431 ◽  
Author(s):  
Viorel D. Popescu ◽  
Bekka S. Brodie ◽  
Malcolm L. Hunter ◽  
Joseph D. Zydlewski
Keyword(s):  
Olfactory Cues ◽  
Wood Frogs ◽  
Lithobates Sylvaticus

Expression profiles of metamorphosis-related genes during natural transformations in tadpoles of wild Wood Frogs (Lithobates sylvaticus)

2012 ◽  
Vol 90 (9) ◽  
pp. 1059-1071 ◽  
Author(s):  
Laia Navarro-Martín ◽  
Chantal Lanctôt ◽  
Christopher Edge ◽  
Jeff Houlahan ◽  
Vance L. Trudeau
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Rana Sylvatica ◽  
Fold Increase ◽  
Gonadal Development ◽  
Specific Expression ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Expression Levels ◽  
Gene Expression Levels

Numerous studies using laboratory-reared tadpoles have shown the importance of thyroid hormones (TH), thyroid receptors (TR), and deiodinase (Dio) enzymes during anuran metamorphosis. Our study focuses on the analysis of thyroid-related genes in tadpoles of wild Wood Frogs ( Lithobates sylvaticus (LeConte, 1825); also known as Rana sylvatica (Cope, 1889)) during metamorphosis. Results showed that, in concordance with laboratory-reared studies, thyroid receptor beta (trb) gene expression profiles presented the most marked changes. At climax and compared with premetamorphic stages, brains, tails, and gonad–mesonephros complex (GMC) tissues increased trb expression levels 5-, 21-, and 41-fold, respectively (p < 0.05). In addition, gene expression levels of brain deiodinase type II and III showed opposite trends, where 3-fold decrease and 10-fold increase were, respectively, found. This finding supports the idea that thyroid hormone, as it has been demonstrated in laboratory-reared tadpoles, is also involved in natural metamorphosis in wild tadpoles. Interestingly, and contrary to our predictions, we observed that whole brain corticotropin-releasing factor (crf) and crf receptor 1 (crfr1) gene expression levels significantly decrease through metamorphosis in wild L. sylvaticus tadpoles. Further analyses are required to determine if a role of TH in the timing of anuran gonadal development exists, as well as the importance of cell-specific and tissue-specific expression of crf and crfr1 to metamorphosis.

scholarly journals Postbreeding movement patterns and habitat use of adult Wood Frogs (Lithobates sylvaticus) at urban wetlands

2018 ◽  
Vol 96 (6) ◽  
pp. 521-532
Author(s):  
Murdoch E.D. Taylor ◽  
Cynthia A. Paszkowski
Keyword(s):  
Habitat Use ◽  
Urban Environments ◽  
Urban Wetlands ◽  
Movement Behaviour ◽  
Riparian Areas ◽  
Long Distance ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Aspen Parkland ◽  
Migratory Movements

Habitat loss and degradation linked to urbanization threaten amphibian populations globally, yet studies examining amphibian behaviour and habitat use in cities are rare. Through the use of radiotelemetry, we examined the postbreeding (May–October) movement behaviour and habitat use of adult Wood Frogs (Lithobates sylvaticus (LeConte, 1825)) at natural and constructed urban wetlands in Edmonton, Alberta, located in the semiarid, aspen parkland of Canada. Movement from breeding wetlands was limited, with most tracked individuals remaining within 25 m of ponds in grassy riparian areas. Long-distance migratory movements were rare and only occurred at natural sites with relatively high proportions of forested land surrounding wetlands. In general, tracked frogs showed a preference for habitat close to water that provided shelter from desiccation and predation (e.g., unmowed grass and stands of shrubs). Our findings have implications for the management of wetlands and conservation of amphibian populations in urban environments.

scholarly journals TRANSMISSION OF BATRACHOCHYTRIUM DENDROBATIDIS TO WOOD FROGS (LITHOBATES SYLVATICUS) VIA A BULLFROG (L. CATESBEIANUS) VECTOR

2012 ◽  
Vol 48 (3) ◽  
pp. 575-582 ◽  
Author(s):  
Sasha E. Greenspan ◽  
Aram J. K. Calhoun ◽  
Joyce E. Longcore ◽  
Michael G. Levy
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Wood Frogs ◽  
Lithobates Sylvaticus

scholarly journals Environmental drivers of ranavirus in free-living amphibians in constructed ponds

2018 ◽  
Author(s):  
T.E. Youker-Smith ◽  
P.H. Boersch-Supan ◽  
C.M. Whipps ◽  
S.J. Ryan
Keyword(s):  
Host Density ◽  
Environmental Parameters ◽  
Environmental Drivers ◽  
Natural Environments ◽  
Laboratory Findings ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Frog Virus ◽  
Essential Components ◽  
Constructed Ponds

AbstractAmphibian ranaviruses occur globally, but we are only beginning to understand mechanisms for emergence. Ranaviruses are aquatic pathogens which can cause > 90% mortality in larvae of many aquatic-breeding amphibians, making them important focal host taxa. Host susceptibilities and virulence of ranaviruses have been studied extensively in controlled laboratory settings, but research is needed to identify drivers of infection in natural environments. Constructed ponds, essential components of wetland restoration, have been associated with higher ranavirus prevalence than natural ponds, posing a conundrum for conservation efforts, and emphasizing the need to understand potential drivers. In this study, we analyzed four years of Frog virus 3 prevalence and associated environmental parameters in populations of wood frogs (Lithobates sylvaticus) and green frogs (Lithobates clamitans) in a constructed pond system. High prevalence was best predicted by low temperature, high host density, low zooplankton concentrations, and Gosner stages approaching metamorphosis. This study identified important variables to measure in assessments of ranaviral infection risk in newly constructed ponds, including effects of zooplankton, which have not been previously quantified in natural settings. Examining factors mediating diseases in natural environments, particularly in managed conservation settings, is important to both validate laboratory findings in situ, and to inform future conservation planning, particularly in the context of adaptive management.

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