Litter Dynamics Regulate Population Densities in a Declining Terrestrial Herpetofauna

Whitfield, Steven M.; Reider, Kelsey E.; Greenspan, Sasha E.; Donnelly, Maureen A.

doi:10.1643/ce-13-061

Cited by 14 publications

(19 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…; Whitfield et al. ). Many nocturnal species in this system spend daytime hours resting on leaf surfaces or in leaf litter and are therefore also exposed to daytime temperatures.…”

Section: Methodsmentioning

confidence: 97%

“…Amphibians occupy these land-cover types to varying degrees; some species are restricted to forests and others use a range of land-cover types (Kurz et al 2014). Although some frog species in our data set are primarily nocturnal, all have been recorded in daytime field surveys or observed by us during the day (Supporting Information; Whitfield et al 2007;Kurz et al 2014;Whitfield et al 2014). Many nocturnal species in this system spend daytime hours resting on leaf surfaces or in leaf litter and are therefore also exposed to daytime temperatures.…”

Section: Study Area and Assemblagementioning

confidence: 99%

See 1 more Smart Citation

Tropical amphibians in shifting thermal landscapes under land‐use and climate change

Nowakowski

Watling

Whitfield

et al. 2016

Conservation Biology

Self Cite

View full text Add to dashboard Cite

Land-cover and climate change are both expected to alter species distributions and contribute to future biodiversity loss. However, the combined effects of land-cover and climate change on assemblages, especially at the landscape scale, remain understudied. Lowland tropical amphibians may be particularly susceptible to changes in land cover and climate warming because many species have narrow thermal safety margins resulting from air and body temperatures that are close to their critical thermal maxima (CT ). We examined how changing thermal landscapes may alter the area of thermally suitable habitat (TSH) for tropical amphibians. We measured microclimates in 6 land-cover types and CT of 16 frog species in lowland northeastern Costa Rica. We used a biophysical model to estimate core body temperatures of frogs exposed to habitat-specific microclimates while accounting for evaporative cooling and behavior. Thermally suitable habitat area was estimated as the portion of the landscape where species CT exceeded their habitat-specific maximum body temperatures. We projected changes in TSH area 80 years into the future as a function of land-cover change only, climate change only, and combinations of land-cover and climate-change scenarios representing low and moderate rates of change. Projected decreases in TSH area ranged from 16% under low emissions and reduced forest loss to 30% under moderate emissions and business-as-usual land-cover change. Under a moderate emissions scenario (A1B), climate change alone contributed to 1.7- to 4.5-fold greater losses in TSH area than land-cover change only, suggesting that future decreases in TSH from climate change may outpace structural habitat loss. Forest-restricted species had lower mean CT than species that occurred in altered habitats, indicating that thermal tolerances will likely shape assemblages in changing thermal landscapes. In the face of ongoing land-cover and climate change, it will be critical to consider changing thermal landscapes in strategies to conserve ectotherm species.

show abstract

“…; Whitfield et al. ). Many nocturnal species in this system spend daytime hours resting on leaf surfaces or in leaf litter and are therefore also exposed to daytime temperatures.…”

Section: Methodsmentioning

confidence: 97%

Section: Study Area and Assemblagementioning

confidence: 99%

Tropical amphibians in shifting thermal landscapes under land‐use and climate change

Nowakowski

Watling

Whitfield

et al. 2016

Conservation Biology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Forest structure.-Compared to old-growth stands, secondary forests have been found to differ in vegetation structure and leaf litter structure (Lebrija-Trejos et al, 2008;Letcher and Chazdon, 2009;Chazdon, 2014) which are thought to be important habitat components that regulate amphibian and reptile community composition and density (Lieberman, 1986;Heinen, 1992;Herrera-Montes and Brokaw, 2010;Whitfield et al, 2014). The structure of forest vegetation provides species with microhabitats for perching, foraging, breeding, and fleeing predators.…”

Section: Literature Summary Of Mechanismsmentioning

confidence: 99%

Effects of Secondary Forest Succession on Amphibians and Reptiles: A Review and Meta-analysis

Thompson¹,

Donnelly²

2018

Copeia

Self Cite

View full text Add to dashboard Cite

Over the past century, humans have cleared the Earth's forests at an alarming rate and intensity. The majority of global forest cover is categorized as secondary forest, and it is becoming increasingly important to consider secondary forests in addition to old-growth forest in conservation planning for biota. We reviewed the literature to synthesize information on amphibian and reptile communities during secondary forest succession. We summarized literature on mechanisms of community change during forest succession and conducted a meta-analysis to estimate effect sizes for species richness and abundance in human-modified landscapes (agriculture, pasture, and plantation) and old-growth forests compared to regenerating secondary forests. Studies reported strong support for differences in species composition among human-modified landscapes, secondary forest, and old-growth forest as well as species-specific responses to successional forest change. Secondary forest generally had higher species richness and abundance than human-modified landscapes, but lower species richness and abundance than old-growth forests. This result was more pronounced in amphibians than reptiles, and effect size of abundance was more variable than richness among studies. Secondary forests have better conservation value than altered habitats, but they do not necessarily hold the same conservation value for species as old-growth forest.

show abstract

“…This suggests that increasing temperature at the time of the surveys negatively affects our ability to detect frogs when present. This observation also makes biological sense since frogs likely take refuge in leaf litter during the heat of the day (Whitfield et al 2014), which should be taken into consideration in repeated monitoring surveys. The occupancy results suggested a relationship between frog occurrence and forest age.…”

Section: Discussionmentioning

confidence: 96%

“…Amphibian declines can occur anywhere, even in mostly intact and protected forest, for example, the well-protected La Selva Biological Station in northeastern Costa Rica has been experiencing rampant and enigmatic declines of this group of animals in recent history (Whitfield et al 2007). Whitfield et al (2014) observed that leaf litter provides valuable habitat and prey resources making it vital to many amphibian populations in the tropics. Leaf litter is affected by climate dynamics, but also by mammalian taxa that trample, root, and dig through it (Reider et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Assessing the role of habitat and species interactions in the population decline and detection bias of Neotropical leaf litter frogs in and around La Selva Biological Station, Costa Rica

Álvarez¹,

Fernandez²,

Cove³

2019

NBC

View full text Add to dashboard Cite

Worldwide, amphibian populations have been declining rapidly. This decline can be attributed to many factors including climate change, pesticide exposure, and emerging infectious diseases, among other important factors, but few studies have examined the influence of species interactions. In this study, we examined how habitat factors and co-occurring avian and mammalian species, as well as humans, exert direct and indirect effects on Neotropical amphibian population dynamics. We further examined how these habitat and species interactions could affect our ability to reliably detect amphibian presence to robustly estimate population trends. We conducted amphibian visual encounter surveys at 26 randomly selected sites in the La Selva Biological Station, in northeastern Costa Rica, as well as 26 sites across five additional forest fragments in the region. Furthermore, we used camera traps to collect data on avian and mammalian communities and human visitation at those amphibian survey plots. From these data, we were able to estimate species occupancy probabilities for leaf litter frogs across sites and their relationships to habitat and interspecific species interaction covariates. We also conducted an experiment with plastic model frogs to estimate detection probabilities when a population is known to occur at a site with certainty. Our results suggested that strawberry poison dart frog (Oophagapumilio) occupancy was positively related to secondary forest and their detection was negatively related to increasing air temperatures at the times of the surveys. Leaf litter frog occupancy was negatively related to core La Selva sites and human detections at sites, yet their detection was positively related to human trail presence, which might be related to reduced leaf litter cover due to heavy trampling. Our experimental surveys suggested that Neotropical leaf litter frog communities are difficult to detect when present and future studies should explicitly account for this detection bias to effectively monitor population trends.

show abstract

Litter Dynamics Regulate Population Densities in a Declining Terrestrial Herpetofauna

Cited by 14 publications

References 28 publications

Tropical amphibians in shifting thermal landscapes under land‐use and climate change

Tropical amphibians in shifting thermal landscapes under land‐use and climate change

Effects of Secondary Forest Succession on Amphibians and Reptiles: A Review and Meta-analysis

Assessing the role of habitat and species interactions in the population decline and detection bias of Neotropical leaf litter frogs in and around La Selva Biological Station, Costa Rica

Contact Info

Product

Resources

About