Eleutherodactylus coqui

POTENTIAL CAUSES FOR AMPHIBIAN DECLINES IN PUERTO RICO

P. A. Burrowes, R. L. Joglar and D. E. Green, Potential causes for
amphibian declines in Puerto Rico, Herpetologica, 2004, 60, 141–154.

Abstract: 
We monitored 11 populations of eight species of Eleutherodactylus in Puerto Rico from 1989 through 2001. We determined relative abundance of active frogs along transects established in the Caribbean National Forest (El Yunque), Carite Forest, San Lorenzo, and in the vicinity of San Juan. Three species (Eleutherodactylus karlschmidti, E. jasperi, and E. eneidae) are presumed to be extinct and eight populations of six different species of endemic Eleutherodactylus are significantly declining at elevations above 400 m. Of the many suspected causes of amphibian declines around the world, we focused on climate change and disease. Temperature and precipitation data from 1970–2000 were analyzed to determine the general pattern of oscillations and deviations that could be correlated with amphibian declines. We examined a total of 106 tissues taken from museum specimens collected from 1961–1978 and from live frogs in 2000. We found chytrid fungi in two species collected at El Yunque as early as 1976, this is the first report of chytrid fungus in the Caribbean. Analysis of weather data indicates a significant warming trend and an association between years with extended periods of drought and the decline of amphibians in Puerto Rico. The 1970’s and 1990’s, which represent the periods of amphibian extirpations and declines, were significantly drier than average. We suggest a possible synergistic interaction between drought and the pathological effect of the chytrid fungus on amphibian populations.

The Impact of Hurricane Hugo on Forest Frogs in Puerto Rico

The Impact of Hurricane Hugo on Forest Frogs in Puerto Rico
Lawrence L. Woolbright
Biotropica
Vol. 23, No. 4, Part A. Special Issue: Ecosystem, Plant, and Animal Responses to Hurricanes in the Caribbean (Dec., 1991), pp. 462-467

Abstract: 
Hurricane Hugo caused extensive damage to the Luquillo Experimental Forest in September 1989 Individually marked Eleutherodactylus coqui were monitored in two study plots from January 1987 through October 1990. Survivorship estimates of adults for the period including the storm were within the normal range from previous years. Juveniles suffered severe reductions, primarily among the smaller size classes. By October 1990 adult population density had increased fourfold over prehurricane levels, although adults were smaller. Juvenile numbers also appeared to be increasing, but had not yet reached prehurricane densities. The rapid increase in density may have resulted from an increase in retreat sites and a decrease in invertebrate predators. Auditory censuses suggested that density changes for other species ranged from a 14 percent increase for the relatively common E. hedricki to an 83 percent decrease for the relatively rare E. richmondi.

Quantitative Assessment of Habitat Preferences for the Puerto Rican Terrestrial Frog, Eleutherodactylus coqui

Beard, Karen H.; Mccullough, Sarah; Eschtruth, Anne K. 2003. Quantitative Assessment of Habitat Preferences for the Puerto Rican Terrestrial Frog, Eleutherodactylus coqui. Journal of Herpetology, Vol. 37, No. 1, :10-17,.

Abstract: 
We conducted a quantitative analysis of adult and juvenile Eleutherodactylus coqui (coquí) habitat preferences in Puerto Rico. The analysis consisted of two surveys: one to quantify potential habitat and another to quantify habitat use. Coquís were found to use most habitats available to them; however, adults and juveniles preferred different plant species, habitat structural components, and heights from the forest floor. Adult and juvenile coquís had opposite associations with many important plant species in the forest (e.g., Prestoea montana and Heliconia carabea) and habitat structural components. Adults had a negative association with leaves and a positive association with leaf litter. Juveniles showed the opposite trend. Adults were more evenly distributed with respect to height than were juveniles, with adults preferring heights around 1.1 m and juveniles preferring heights closer to the forest floor. The quantitative survey technique for determining habitat preferences used in this study generally confirmed coquí habitat preferences known from qualitative assessments.

Quantitative Assessment of Habitat Preferences for the Puerto Rican Terrestrial Frog, Eleutherodactylus coqui

Quantitative Assessment of Habitat Preferences for the Puerto Rican Terrestrial Frog, Eleutherodactylus coqui
Karen H. Beard, Sarah McCullough and Anne K. Eschtruth
Journal of Herpetology
Vol. 37, No. 1 (Mar., 2003), pp. 10-17

Abstract: 
We conducted a quantitative analysis of adult and juvenile Eleutherodactylus coqui (coquí) habitat preferences in Puerto Rico. The analysis consisted of two surveys: one to quantify potential habitat and another to quantify habitat use. Coquís were found to use most habitats available to them; however, adults and juveniles preferred different plant species, habitat structural components, and heights from the forest floor. Adult and juvenile conquís had opposite associations with many important plant species in the forest (e.g., Prestoea montana and Heliconia carabea) and habitat structural components. Adults had a negative association with leaves and a positive association with leaf litter. Juveniles showed the opposite trend. Adults were more evenly distributed with respect to height than were juveniles, with adults preferring heights around 1.1 m and juveniles preferring heights closer to the forest floor. The quantitative survey technique for determining habitat preferences used in this study generally confirmed coquí habitat preferences known from qualitative assessments.
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