Monitoring Population Trends of Eleutherodactylus Frogs

Funk, W. Chris; Almeida‐Reinoso, Diego; Nogales-Sornosa, Fernando; Bustamante, Martín R.

doi:10.1670/0022-1511(2003)037[0245:mptoef]2.0.co;2

Cited by 39 publications

(28 citation statements)

References 11 publications

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“…Estimation of population size via CMR method is the most precise way to monitor population trend over time [31] but it is only suitable when the density of the population is high enough to ensure a sufficient recapture rate in a reasonable number of encounter events. In this study, only two species among eight were encountered frequently enough for using CMR models and only in habitats of high density despite a high number of encounter occasions.…”

Section: Discussionmentioning

confidence: 99%

Monitoring Strategy for Eight Amphibian Species in French Guiana, South America

et al. 2013

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Although dramatic amphibian declines have been documented worldwide, only few of such events have been quantitatively documented for the tropical forests of South America. This is due partly to the fact that tropical amphibians are patchily distributed and difficult to detect. We tested three methods often used to monitor population trends in amphibian species in a remote lowland tropical forest of French Guiana. These methods are capture-mark-recapture (CMR), estimation of the number of calling males with repeated counts data and distance sampling, and rates of occupancy inferred by presence/absence data. We monitored eight diurnal, terrestrial amphibian species including five Dendrobatidae and three Bufonidae. We found that CMR, the most precise way of estimating population size, can be used only with two species in high density patches where the recapture rate is high enough. Only for one of the species (Dendrobates tinctorius), a low coefficient of variation (CV = 0.19) can be achieved with 15 to 20 capture events. For dendrobatid species with day-calling males, audio surveys yield a better probability of detection with only 8 audio surveys needed; quantitative estimates can be achieved by computing the number of calling males inferred from audio counts or distance sampling analysis. We therefore suggest that an efficient monitoring protocol for Neotropical amphibian species should include a combination of sighting and audio techniques, and we discuss the need of implementing a large-scale monitoring in order to provide a baseline for comparison with future changes.

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Section: Discussionmentioning

confidence: 99%

Monitoring Strategy for Eight Amphibian Species in French Guiana, South America

et al. 2013

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“…This technique gives a good estimate of population size for territorial frogs (Driscoll 1998). Capture-mark-recapture techniques might allow to obtain better estimates of densities for species living on the ground (Funk et al 2003), but the capture of individuals on trees is generally impossible, and it is therefore diYcult to apply capture-recapture to arboreal species. Transect surveys were performed after dusk, between 16.45 and 20.45, when calling activity is high (Savage 2002).…”

Section: Sampling Protocolmentioning

confidence: 99%

Assessing the value of secondary forest for amphibians: Eleutherodactylus frogs in a gradient of forest alteration

et al. 2007

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Secondary forests constitute a growing portion of forested areas worldwide. They might have a substantial role for the conservation of biodiversity in tropical areas, but there is little information on their potential to support forest species and the recovery of faunal communities. We studied two forest frogs (Eleutherodactylus diastema and E. Wtzingeri) in an area of Costa Rica composed of a mosaic of primary forest, young secondary forest and pasture, and we compared the density of calling males in areas with diVerent forest alteration. Autoregressive models were used to compensate for potentially undesired eVects of spatial autocorrelation and pseudoreplication. Both species were most abundant in riparian, primary forest. However, E. Wtzingeri was also abundant in riparian secondary forests, and its density far from the river was similar in primary and secondary forest, suggesting that river proximity can inXuence the recovery of secondary forest for amphibians. Conversely, the density of E. diastema was similar in secondary forest and pasture, stressing interspeciWc diVerences for recovery rate. These frogs have a keystone role in nutrient cycling and food webs, and their prompt recovery might represent an important step for the functional recovery of forests. Nevertheless, the strong interspeciWc diVerences stress the complexity of these processes.

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“…Several reptile studies that have previously compared distance sampling with capture–recapture or removal plots also showed an underestimation using the distance sampling method. They all suggested that imperfect centerline detection was the most likely reason for this bias (Funk et al 2003, Leuteritz et al 2005, Grant and Doherty 2007, Smolensky and Fitzgerald 2010). However, other reptile studies have obtained comparable estimates using distance sampling and capture–recapture methods (Cassey and Ussher 1999, Swann et al 2002, Kacoliris et al 2009) probably because the g0 correction they used was sufficient to correct the bias (Swann et al 2002) or because the hypothesis of g0 = 1 was respected (Cassey and Ussher 1999, Kacoliris et al 2009).…”

Section: Discussionmentioning

confidence: 99%

Filter Media Pore Space Analysis Based on Geometrical Characteristics

et al. 2016

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The efficiency of filter media can be improved by applying nanofibers to the surface of the microstructure. In order to gain a deeper insight into the influence of the nanofiber geometry on filtration efficiency in terms of pressure loss, separation efficiency, and dust holding capacity, the microstructure is analyzed by geometrical pore space characteristics such as the degree of vertices function, the spherical contact distribution function, and the pore size distribution function. The pore space characteristics are investigated by using a distance transform and a 3D pore space graph generated by the Ma‐Sonka‐Algorithm with the P‐simple‐points extension.

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Monitoring Population Trends of Eleutherodactylus Frogs

Cited by 39 publications

References 11 publications

Monitoring Strategy for Eight Amphibian Species in French Guiana, South America

Monitoring Strategy for Eight Amphibian Species in French Guiana, South America

Assessing the value of secondary forest for amphibians: Eleutherodactylus frogs in a gradient of forest alteration

Filter Media Pore Space Analysis Based on Geometrical Characteristics

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