scholarly journals Mass Mortality of Wood Frogs (Rana sylvatica) in the Ozark National Forest: Is it Acid Rain?

2018 ◽  
Author(s):  
Malcolm L. McCallum ◽  
Tracy Klotz ◽  
William Stephens ◽  
Jennifer Bouldin ◽  
Ken Gillespie ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Rana Sylvatica ◽  
Population Level ◽  
Forensic Analysis ◽  
Mass Mortality ◽  
National Forest ◽  
Wood Frogs ◽  
Future Studies ◽  
Mass Mortality Event ◽  
Ozark National Forest

AbstractWe describe observations of a continuing mass mortality event primarily involving wood frogs, but involving other amphibians to a lesser degree. The investigation took place from Spring 2000 through Spring 2004. No definitive correlations between environmental variables and mortality could be identified. Forensic analysis could not isolate causal pathogens. Although mortality fluctuated during the study, it may have spread to other species. Our report identifies population level problems in the eastern part of the Ozark National Forest but is unable to identify a cause. Future studies that more thoroughly address contaminants, pathogens/parasites, and other potential environmental problems in the Ozark National Forest are warranted.

scholarly journals Frogs adapt to physiologically costly anthropogenic noise

2018 ◽  
Vol 285 (1891) ◽  
pp. 20182194 ◽  
Author(s):  
Jennifer B. Tennessen ◽  
Susan E. Parks ◽  
Lindsey Swierk ◽  
Laura K. Reinert ◽  
Whitney M. Holden ◽  
...  
Keyword(s):  
Stress Responses ◽  
Anthropogenic Disturbance ◽  
Noise Exposure ◽  
Traffic Noise ◽  
Rana Sylvatica ◽  
Population Level ◽  
Ecological Processes ◽  
Wood Frogs ◽  
Selective Pressures ◽  
Anthropogenic Stressor

Human activities impose novel pressures on amphibians, which are experiencing unprecedented global declines, yet population-level responses are poorly understood. A growing body of literature has revealed that noise is an anthropogenic stressor that impacts ecological processes spanning subcellular to ecosystem levels. These consequences can impose novel selective pressures on populations, yet whether populations can adapt to noise is unknown. We tested for adaptation to traffic noise, a widespread sensory ‘pollutant’. We collected eggs of wood frogs ( Rana sylvatica ) from populations from different traffic noise regimes, reared hatchlings under the same conditions, and tested frogs for differences in sublethal fitness-relevant effects of noise. We show that prolonged noise impaired production of antimicrobial peptides associated with defence against disease. Additionally, noise and origin site interacted to impact immune and stress responses. Noise exposure altered leucocyte production and increased baseline levels of the stress-relevant glucocorticoid, corticosterone, in frogs from quiet sites, but noise-legacy populations were unaffected. These results suggest noise-legacy populations have adapted to avoid fitness-relevant physiological costs of traffic noise. These findings advance our understanding of the consequences of novel soundscapes and reveal a pathway by which anthropogenic disturbance can enable adaptation to novel environments.

Population‐level variation in infection outcomes not influenced by pesticide exposure in larval wood frogs ( Rana sylvatica )

2021 ◽  
Author(s):  
Logan S. Billet ◽  
Vanessa P. Wuerthner ◽  
Jessica Hua ◽  
Rick A. Relyea ◽  
Jason T. Hoverman
Keyword(s):  
Pesticide Exposure ◽  
Rana Sylvatica ◽  
Population Level ◽  
Level Variation ◽  
Wood Frogs

Incorporating Additional Tree and Environmental Variables in a Lodgepole Pine Stem Profile Model

1993 ◽  
Vol 8 (3) ◽  
pp. 86-90
Author(s):  
John C. Byrne
Keyword(s):  
Environmental Variables ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Linear Equations ◽  
The United States ◽  
National Forest ◽  
Data Sets ◽  
Tree Form ◽  
Northern Rocky Mountains ◽  
Profile Model

Abstract A new variable-form segmented stem profile model is developed for lodgepole pine (Pinus contorta) trees from the northern Rocky Mountains of the United States. I improved estimates of stem diameter by predicting two of the model coefficients with linear equations using a measure of tree form, defined as a ratio of dbh and total height. Additional improvements were obtained by fitting this model to individual national forest data sets. Other tree and environmental variables tested but found of little use in improving stem profile estimates were crown ratio, habitat series, elevation, slope percent, and aspect. West. J. Appl. For. 8(3):86-90.

Variation in amount of surrounding forest habitat influences the initial orientation of juvenile amphibians emigrating from breeding ponds

2008 ◽  
Vol 86 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Leroy J. Walston ◽  
Stephen J. Mullin
Keyword(s):  
Positive Relationship ◽  
Rana Sylvatica ◽  
Environmental Cues ◽  
Bufo Americanus ◽  
Forest Habitat ◽  
Amphibian Species ◽  
Wood Frogs ◽  
Juvenile Dispersal ◽  
Woodland Ponds ◽  
Emigration Behavior

Juvenile dispersal is important for the persistence of ​amphibian populations. Previous studies have observed nonrandom orientation in juvenile amphibians emigrating from breeding ponds; however, the environmental cues associated with these movements are not well understood. We examined the emigration behavior of recently metamorphosed juveniles of three pond-breeding amphibian species from three woodland ponds. We found that juvenile small-mouthed salamanders ( Ambystoma texanum (Matthes, 1855)), American toads ( Bufo americanus Holbrook, 1836), and wood frogs ( Rana sylvatica LeConte, 1825) exhibited nonrandom orientation upon exiting the breeding ponds. Furthermore, we found a positive relationship between captures of juvenile small-mouthed salamanders and wood frogs and width of the surrounding forest habitat, indicating that these species are selecting areas with broader forested habitat upon exiting the breeding ponds. Our results indicate that migrating juvenile amphibians may rely on direct environmental cues because the orientation of small-mouthed salamanders and wood frogs was influenced by width of the surrounding forested habitat. These observations support previous studies suggesting that maintaining forest habitat, along at least a portion of breeding ponds, is important for the persistence of amphibian populations.

Kin recognition by larval wood frogs (Rana sylvatica): effects of diet and prior exposure to conspecifics

Oecologia ◽  
1991 ◽  
Vol 86 (3) ◽  
pp. 319-324 ◽  
Author(s):  
George J. Gamboa ◽  
Keith A. Berven ◽  
Randy A. Schemidt ◽  
Thomas G. Fishwild ◽  
Kelli M. Jankens
Keyword(s):  
Kin Recognition ◽  
Rana Sylvatica ◽  
Prior Exposure ◽  
Wood Frogs

Sexual differences in color and color change in wood frogs

1991 ◽  
Vol 69 (7) ◽  
pp. 1963-1968 ◽  
Author(s):  
Richard B. King ◽  
Bethia King
Keyword(s):  
Color Change ◽  
Red Light ◽  
Green Light ◽  
Rana Sylvatica ◽  
Sexual Differences ◽  
Wood Frog ◽  
Color Classification ◽  
Wood Frogs ◽  
Evolutionary Response ◽  
Males And Females

An observer-free method of color classification was used to determine whether wood frogs, Rana sylvatica, exhibit sexual differences in color and color change. Males and females captured from breeding aggregations differed significantly in color: females reflected a greater amount of long-wavelength (yellow–red) light and less short-wavelength (blue–green) light than males. The color difference was not just a result of differences in the state of physiological color change at the time of capture but persisted for a month after capture. Males and females also differed in their color-change responses to black and white backgrounds: both sexes changed in brightness, but only males changed in the relative amount of light reflected at different wavelengths. Wood frog color may function in predator avoidance through crypsis. There was a good match between frogs and some of the leaves from the leaf litter surrounding the breeding ponds. Hypotheses for the development of sexual differences in wood frog color include sexual differences in availability of pigment and pigment precursors, morphological color change, and evolutionary response to different selection pressures.

scholarly journals Mass mortality event of White Sea sponges as the result of high temperature in summer 2018

Polar Biology ◽  
2019 ◽  
Vol 42 (12) ◽  
pp. 2313-2318 ◽  
Author(s):  
Alexander Ereskovsky ◽  
Dmitry A. Ozerov ◽  
Anatoly N. Pantyulin ◽  
Alexander B. Tzetlin
Keyword(s):  
High Temperature ◽  
White Sea ◽  
Mass Mortality ◽  
Mortality Event ◽  
Mass Mortality Event

scholarly journals Fitness costs of mating with preferred females in a scramble mating system

2019 ◽  
Vol 30 (3) ◽  
pp. 658-665 ◽  
Author(s):  
Lindsey Swierk ◽  
Tracy Langkilde
Keyword(s):  
Mate Choice ◽  
Mating Systems ◽  
Rana Sylvatica ◽  
Female Offspring ◽  
Operational Sex Ratio ◽  
Male Choice ◽  
Wood Frogs ◽  
Multiple Parameters ◽  
Fitness Benefits ◽  
Male Mate

Abstract Little is known about the operation of male mate choice in systems with perceived high costs to male choosiness. Scramble mating systems are one type of system in which male choice is often considered too costly to be selected. However, in many scramble mating systems, there are also potentially high rewards of male choosiness, as females vary dramatically in reproductive output and males typically mate once per season and/or per lifetime. Using scramble mating wood frogs (Rana sylvatica), we tested whether males gain fitness benefits by mating with preferred females. We conducted choice trials (1 male presented simultaneously with 2 females) and permitted males to mate with their preferred or nonpreferred female. Offspring of preferred and nonpreferred females were reared in the laboratory and field, and we quantified various fitness-relevant parameters, including survivorship and growth rates. Across multiple parameters measured, matings with preferred females produced fewer and lower-quality offspring than did those with nonpreferred females. Our results are inconsistent with the idea that mate choice confers benefits on the choosing sex. We instead propose that, in scramble systems, males will be more likely to amplex females that are easier to capture, which may correlate with lower quality but increases male likelihood of successfully mating. Such male choice may not favor increased fitness when the operational sex ratio is less biased toward males in scramble mating systems but is, instead, a bet-hedging tactic benefitting males when available females are limited.

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