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Since becoming established in Hawaii in the late 1990s, incredibly loud choruses of this medium-sized Puerto Rican frog have been disturbing the sleep of Hawaiians, who have enjoyed frog-less nights throughout recorded history. Although the jury is still out, its impact may not be limited to that of human comfort. In forests of its native land, this species attains densities of over 20,000 frogs per hectare and is a known voracious predator on insects. As a result, it is yet another potential competitive threat to Hawaii's already declining native forest birds, and may act synergistically with the numerous exotic birds, reptiles and frogs already established in the islands. Established in the Virgin Islands, Coquis probably go unnoticed there because Virgin Islanders are used to loud choruses of native frogs. But where their choruses of are drowned out by loud choruses of Coqui, other exotic frogs may not be noticed in time to prevent their establishment in Hawaii and elsewhere.
 Coqui eggs develop on land without a tadpole stage!! Similar Species: A few similar eleutherodactylids have invaded the U. S. and elsewhere. The greenhouse frog, E. planirostris, a native of Cuba, is established in Florida, Louisiana, Hawaii, the Bahamas, Jamaica, the Cayman Islands, and Veracruz, Mexico (Conant and Collins 1991, Kraus et al. 1999). It is smaller than E. coqui, has a very faint, irregular chirping call that sounds like a tiny cricket, and usually calls from under leaf litter or in ornamental plant pots, which is why this species is usually only noticed by experienced herpetologists. The Martinique robber frog, E. martinicensis, occurs with E. coqui at a nursery in Kokomo, Maui, and has a similar call type, but coqui choruses easily drown out E. martinicensis (Kraus et al. 1999). This is an important consideration for those monitoring alien anurans in Hawaii and elsewhere, as new arrivals and established populations of E. planirostris, E. martinicensis, and other less vociferous anuran species might be missed due to the presence of calling E. coqui. Coqui calls can reach nearly 100 decibels!! Identification Aids: The Hawaiian Ecosystems at Risk Project (HEAR) web site contains up-to-date information about the biology and distribution of this and many other exotic species in Hawaii, including the low-resolution color photograph presented above, and a ".wav" file of the Coqui's call that you can listen to on-line. Probably the quickest source for identification is the HEAR Caribbean Frogs Pest Alert Flyer, a warning designed to assist in quickly identifying the coqui and other Caribbean frogs before they become naturalized in other locations. The flyer must be downloaded as a ".pdf" file from the HEAR web site. A color plate, range map, and text description of this species appears in the Petersen's Guide to Reptiles and Amphibians of Eastern North America (Conant and Collins 1991 and the more recent 1998 edition). For a color photograph of a calling male, see Crother (1999). For original drawings, see Thomas (1966), Townsend and Stewart (1985), and Hedges (1989). This species is not illustrated in Schwartz and Henderson (1985 or 1991), however, drawings of other Caribbean Elutherodactylus appear in the 1985 book, and might help you to identify a suspicious frog and/or exclude E. coqui. Coqui often parachute from high perches!! Contacts: If you need more information about this species, especially in Hawaii, contact: Fred Kraus If you find this species outside Puerto Rico: In Hawaii, contact the personnel listed on the Alien Caribbean Frogs in Hawaii web site, or someone at the HEAR project. In Florida, contact the Florida Fish and Wildlife Conservation Commission. If all else fails, contact Todd Campbell of the Institute for Biological Invasions at lizardman@utk.edu, who will forward your message to the appropriate person. Coqui and their eggs are often carried on nursery plants!! Please cite this page as:
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November 2000 Todd S. Campbell Contents: Taxonomy - Similar Species - Identification Aids - Contacts - Description - Native Range & Biology - Introduced Range & Biology - Known & Potential Impacts - Management - Literature Cited Description: The family Leptodactylidae is an incredibly diverse radiation of New World frogs from Mexico, Central America, the Caribbean, and South America. Leptodactylid frogs exhibit nearly every life history mode that frogs have to offer. The genus Eleutherodactylus, with over 600 species, is probably the most speciose genus of vertebrates (Crother 1999). With the exception of only one species, eleutherodactylid frogs lay eggs that undergo direct development in terrestrial situations, rather than in water like most frogs. The "tadpole" stage occurs entirely within a terrestrial egg, rather than as a free-living larval stage, and adult features form directly, sometimes bypassing the stages normally present in tadpole ontogeny (Hung and Elinson 1996, Hanken et al. 1997). Thus, a tiny but fully functional froglet hatches directly from the egg. Elutherodactylus coqui is a relatively small treefrog. In Puerto Rico (Townsend and Stewart 1994), mature calling males and "parental males" (males guarding a clutch) averaged about 34 mm in length (range 30-37 mm) from snout to vent (snout-vent length, or SVL), while mature egg-laying females averaged about 41 mm SVL (range 36-52 mm). Like the true treefrogs (family Hylidae), E. coqui has well developed pads at the end of each toe that are used for sticking to surfaces (see photo). E. coqui is extremely variable in coloration. The dorsum (upper surface) is generally gray or gray-brown and uniform in color, or may have either a dark "M" shape between the shoulders, two broad, light dorso- lateral bars (from the snout, through the eye, to the axila of the rear legs) bordered with black spots, and/or a light bar on top of the head between the eyes, and a light underside stippled with brown (Conant and Collins 1991). No subspecies were recognized as of Schwartz and Henderson (1991). Native Range & Biology: Eleutherodactylid frogs are found throughout the geographic range of the family Leptodactylidae. The coqui is native only to Puerto Rico, where it is common on all but the southwest portion of the island along with 20 other species of Eleutherodactylus (Schwartz and Henderson 1991), and has become a sort of "mascot frog" (Crother 1999). This species has been studied extensively in the laboratory with respect to its development, morphology, metabolism, neurophysiology, and reproduction (not reviewed here). The natural history, breeding call acoustics, and reproductive behavior of E. coqui in its native range has been most extensively studied in the Luquillo Experimental Forest (LEF), an over 11,000 ha reserve established in the Mountains of eastern Puerto Rico in 1956. LEF is part of the Long Term Ecological Research Network (LTER), an important program that "seeks to understand ecological phenomena over long temporal and large spatial scales." Coquis reproduce year-round in Puerto Rico, but breeding activity is concentrated in the wet season (Townsend and Stewart 1994). Males call from elevated perches consisting of shallow, exposed depressions, such as the surfaces or axils of leaves (Townsend 1989). This species utilizes internal fertilization (Townsend et al. 1981) and like other eleutherodactylids, the fertilized eggs undergo direct development, rather than passing through a free-living larval (tadpole) stage, so standing water is not required for egg laying (Townsend and Stewart 1985, 1994). Coquis deposit 4-6 clutches of about 28 eggs each (range 16-41) per year, with a development period of 17-26 days, a time between clutches of about eight weeks, and a time between generations (i.e., from egg to egg-laying adult) of about eight months (Townsend and Stewart 1994, Kraus et al. 1999). Males nest in protected cavities near the ground such as dead, curled leaves or rolled palm frond petioles (Townsend 1989). Coquis are known to utilize the nesting cavities of several bird species in Puerto Rico (Perez-Rivera and Dechoudens 1996), including the Bananaquit (Coereba flaveola portoricensis), the Puerto Rican Bullfinch (Loxigilla portoricensis) and Puerto Rican Tody (Todus mexicanus). Males guard the eggs to keep them from drying out (Taigen et al. 1984) and in severely conditions they will leave the nest, gather moisture, and return to rehydrate the eggs (Michael 1995). Males even stay with the froglets for a few days after they emerge (Townsend and Stewart 1986, Townsend et al. 1994). Despite their direct mode of development, metamorphosis remains dependant on thyroid hormone (Callery and Elinson 2000). In fact, the evolution of direct development is thought to be associated with precocious development and activity of the thyroid gland (Jennings and Hankin 1999). Field studies at LEF have revealed some interesting aspects of coqui natural history, behavior, and movement. Homing behavior has been demonstrated in individuals displaced as much as 100 m away from their territories (Gonser and Woolbright 1995). In the evening, coquis climb tree trunks into the canopy, presumably to avoid ground-based nocturnal predators (Stewart 1985), and remain there all night. Then, just before dawn, they jump to the ground from high in trees and land with a "plop" (Beauchat et al. 1984), but on the way down, they "parachute" by spreading their feet and toes and partially extending their legs, which slows their air speed significantly (Stewart 1985). Coquis apparently do not use the webbing between their toes as much as some tropical frogs (e.g., Hyla venulosa and Agalychnis spurrelli), which are capable of parachuting or even controlled gliding by stretching their digital webbing like four tiny bat wings or "foot umbrellas" that would impress even Mary Poppins! Coquis are found in more habitat types than any other eleutherodactylid species in Puerto Rico, and utilize the entire vertical spectrum of their habitat, from forest floor to canopy (Gonser and Woolbright 1995). Coquis often reach densities of over 20,000 frogs per hectare in Puerto Rico, and at such densities, they may consume in excess of 114,000 individual arthropod prey, per hectare, per night (Stewart 1995, Stewart and Pough 1983). Coquis themselves serve as prey for giant crab spiders, Olios sp. (Formanowicz et al. 1981), the Puerto Rican racer (a snake), Alsophis portoricensis (Rodriguez and Leal 1993), and likely augment the diets of many different types of birds and nocturnal mammals. Long term studies at LEF demonstrate the influence of climate and habitat disturbance on populations of this species. Population sizes vary seasonally, generally increasing between June and December, followed by a decline through May, and yearly population sizes depend on the seasonal distribution of rain, rather than the simple average yearly or monthly rainfall (Stewart 1995). A dramatic increase in numbers occurred after Hurricane Hugo hit in September 1989, caused by the augmentation of ground-level habitat structure from vast amounts of downed vegetation, followed by a six-fold increase in adult frogs in 1990, followed by an increase in the number of juvenile frogs in 1991 (Woolbright 1991, 1996). Introduced Range & Biology: This species is established in St. Thomas and St. Crois, U.S. Virgin Islands (MacLean 1982, Schwartz and Henderson 1991), and New Orleans, Louisiana (Conant and Collins 1991, Schwartz and Henderson 1991). It was observed breeding in south Florida at Fairchild Tropical Garden in the early 1970s (Austin and Schwartz 1975), but disappeared at that site by 1976 (Wilson and Porras 1983). Dalrymple (1994) considered E. coqui established in Florida, but Butterfield et al. (1997) considered it absent because it was confined to greenhouses in the greater Miami area. Clearly, the jury is still out regarding the status of this species in Florida. The most recent and clearly successful introductions of the coqui occurred in Hawaii in the mid- to late 1990s (Kraus et al. 1999). Although herpetoculturist literature suggested the species was established by 1996 (e.g., McKeown 1998), these statements were either unsupported with voucher specimens, or when specimens were collected, lacked accurate locality data (Kraus et al. 1999). At present, populations of E. coqui occur in Hawaii on the "Big Island" (11 sites), Maui (~ 30 sites), and Oahu (1 site), where it generally inhabits plant nurseries, parks, hotels and residential areas planted with nursery vegetation, and the forested areas immediately surrounding such sites (Kraus et al. 1999, HEAR 2000). Coquis have been found at many additional Hawaiian locations in the last few years, and an update of Krause et al. (1999) is forthcoming (F. Krause pers. comm.). Modes and routes of transport, or "pathways," are fairly obvious for this species. For over 70 years this species has been known to travel on ornamental vegetation (historical overview in Kraus et al. 1999), and they are regularly found on ornamental bromeliads, palms, bamboos, pots, and shipping containers. Once established, this is probably also the main short-distance pathway for this species (e.g., Kraus et al. 1999). The fact that they undergo direct development enables the eggs and larvae enable them to be transported under a wide variety of conditions, as long as sufficient moisture is available, or the adult male is transported with the eggs. Transport of lone eggs may not be successful in some regions since they must be protected from desiccation throughout development by the adult male. This may not be the case in Hawaii, which receives more rainfall than just about anywhere on earth. Initial import to a new region is probably most often facilitated by ornamental plants, however, other pathways are available. Coquis are amenable to calling, mating, egg laying, and nest guarding in 10-gallon aquaria with minimal furnishings, and survival of froglets to adulthood is very good (Michael 1995). As a result, it is likely that additional populations have become established by herpetoculturists desiring populations of frogs at their homes (Kraus et al. 1999). This practice has precedence in the history of the pet trade in general, and herpetoculture in particular (numerous examples in Wilson and Porras 1983). That said, the popularity of this small, plain, gray frog in the pet trade is very low, but this potential pathway is one of which exotic species risk managers should be aware. That they exhibit direct development makes coquis desirable from a developmental research standpoint, and Elinson et al. (1990) attempted to "make these species more accessible to researchers who are interested in the developmental and evolutionary consequences of terrestrial development." Import of coqui for developmental research is a perfectly legitimate practice and not criticized here. However, exotic species risk managers should be aware that this pathway exists and that scientific researchers using this species in climates amenable to tropical frogs present a risk of release and establishment, albeit a small one. Clearly, researchers should employ proper quarantine methods. Known & Potential Impacts: This small amphibian affects humans in their pursuit of happiness, and their loud call is the main reason they are considered pests. In the U. S. Virgin Islands, the exotic but familiar coqui is just one more in a large suite of vociferous anurans. However, this species is receiving a lot of attention in Hawaii, which completely lacks native amphibians and reptiles. Its mating call is its namesake, a high-pitched, two-note "co-qui" (ko-kee') which attains nearly 100 decibels at 0.5 meters (HEAR 2000). On Hawaii, this species is disturbing residents and hotel guests, and local business owners are concerned that this otherwise unnoticeable exotic species will cause a decline in tourism in certain areas, and many fear that it might lead to widespread local or regional economic problems if allowed to spread. To get an idea of what Hawaiian residents and visitors are going through, listen to the individual frog calls and choruses posted on-line at the Alien Caribbean Frogs in Hawaii web site. The call has been studied extensively in both laboratory and field settings in Puerto Rico, and many results are relevant to the problem at hand. As in other frogs, calls are used to attract mates and function as nocturnal spacing mechanisms (Stewart and Bishop 1994). Because coqui call in dense, deafening choruses, they often minimize the overlap of their call with their nearest neighbors so their call can be heard by females (Brush and Narins 1989), a trick used by many types of frogs that call in high density choruses. Just situate yourself in a chorus of nearly any species of frog or toad and you will hear them avoiding call overlap. The "co" part of the "co-qui" call is thought to initiate vocal interactions with neighboring males, and possibly in signal interference (Stewart and Bishop 1994). In LEF, coqui reach their peak calling effort (maximum number of calls per minute) before 2300 hours (Lopez and Narins 1991). Short, multi-note calls are used in aggressive interactions (Stewart and Bishop 1994), but these aggressive calls are not as loud as the breeding call, and are used mainly at dawn and dusk when frogs move into or out of diurnal retreats, and less frequently during the day (Stewart and Rand 1992). Both males and females use aggressive calls to defend retreat sites and assist in daytime spacing, but the sexes differ in call length, spectral composition, and number and length of notes in the call (Stewart and Rand 1991). In its native range, E. coqui is a voracious insectivore (Kraus et al. 1999, HEAR 2000). Given that their population density reported for at least one site in Hawaii (Kraus et al. 1999) was over 10 times that reported for native rainforest in Puerto Rico (Stewart and Pough 1983), the potential for them consuming a large number of terrestrial invertebrates is clear. Many arthropod species in Hawaii are already in danger of extirpation due to intentionally and unintentionally introduced arthropod predators and parasitoids (briefly reviewed in Kraus et al. 1999). Moreover, the few remaining native forest birds in Hawaii, themselves mostly insectivores, are already under considerable pressure from many fronts, including numerous alien predators, competitors, and parasites. The infiltration of the coqui into native forest areas of Hawaii would be unfortunate, as it might disrupt Hawaii's already tattered food web through consumption of arthropods. Worse yet, many levels of indirect and synergistic interactions could occur between the coqui and other invasive exotics. Dense populations of coqui might indirectly affect native birds by serving as a valuable food source for other exotic predators and competitors of Hawaiian birds, thereby augmenting those populations, putting more pressure on natives. Also, a number of nematode parasites have been identified in this species (Dyer et al. 1995), and it is possible that nematodes or other types of vertebrate parasites could be transported with coquis and infect indigenous fauna (e.g., Goldberg and Bursey 2000). If all this were not enough, new arrivals and established populations of E. planirostris, E. martinicensis, and other less vociferous anuran species might be missed due to the presence of calling E. coqui. This is an important consideration for those monitoring anuran introductions in Hawaii and elsewhere. Such positive interactions, synergisms, or "invasional meltdowns" (Simberloff and Von Holle 1999) are powerful negative forces working against the conservation of native species, and can only lead to further homogenization of earth's biota. Management: That I am aware, no measures are being taken to control or eradicate E. coqui in the U. S. Virgin Islands, Florida or Louisiana, but in Hawaii, at least one hotel manager has consulted a pest control professional (Kraus et al. 1999). To thwart the spread of this species in Hawaii, HEAR has launched a public information campaign which includes their web site and regular radio broadcasts about this species and its whereabouts (Kraus et al. 1999). Toxicants to kill the frogs have been tested in the lab, and field trials may start as early as October 2000 (Fred Kraus, personal communication). Based on results from some physiological studies of metamorphosis inhibition in coqui (Callery and Elinson 2000), control of egg transport on nursery vegetation might be carried out using some type of thyroid inhibitor (e.g., the goitrogen methimazole) applied directly to nursery plants that might contain coqui eggs. However, this is pure conjecture on my part. I am not aware of the efficacy of using such chemicals in this manner, nor the potential for negative effects to non-target organisms. Passive methods might prove effective at reducing the population size of coqui in urban areas with large amounts of spatial complexity. Stewart and Pough (1983) were able to augment population densities of coqui in native habitat using simple artificial retreats (frog boxes). Unintentional augmentation might be occurring in Hawaii, depending on the types of available structures that serve as retreats. Conversely, a reduction in the complexity of "coqui habitat" in Hawaii might depress coqui population densities such that noise levels might be tolerable and other eradication methods might prove more efficient and cost effective. Literature Cited: Austin, D. F. and A. Schwartz. 1975. Another exotic amphibian in Florida, Eleutherodactylus coqui. Copeia 1975(1):188. Beuchat, C. A., F. H. Pough, and M. M. Stewart. 1984. Response to simultaneous dehydration and thermal stress in three species of Puerto Rican frogs. J. Comp. Physiol. B 154:579-585. Brush, J. S. and P. M. Narins. 1989. Chorus dynamics of a Neotropical amphibian assemblage: Comparison of computer simulation and natural behavior. Animal Behaviour 37(1):33-44. Butterfield, B. P., W. E. Meshaka, Jr., and C. Guyer. 1997. Nonindigenous amphibians and reptiles. Pp. 123-138 In: Simberloff, D., D. C. Schmitz, and T. C. Brown. 1997. Strangers in Paradise: Impact and Management of Nonindiginous Species in Florida. Island Press, Washington, DC. Callery,
E. M. and R. P. Elinson. 2000. Thyroid hormone-dependent metamorphosis in a
direct developing frog. Proc. Natl. Acad.
Sci. U. S. 97(6):2615-2620. Conant, R. and J. T. Collins. 1991. The Reptiles and Amphibians of Eastern and Central North America. Houton Mifflin, Boston, MA. Crother, B. I., ed. 1999. Caribbean Amphibians and Reptiles. Academic Press, San Diego, CA. Dyer,
W. G., E. H. Williams, Jr., and L. B. Williams. 1995. Nematode parasites of
a Puerto Rican tree frog, Eleutherodactylus coqui. Trans. Illinois State Acad.
Science 88(1-2):39-41. Elinson, R. P., E. M. Del Pino, D. S. Townsend, F. C. Cuesta, and P. Eichhorn. 1990. A practical guide to the developmental biology of terrestrial-breeding frogs. Biological Bulletin Woods Hole 179(2):163-177. Hawaiian Ecosystems at Risk Project (HEAR). 2000. Alien Caribbean Frogs in Hawaii: problematic frogs trouble people, environment. www.hear.org/AlienSpeciesInHawaii/species/frogs/index.html Fang, H. and R. P. Elinson. 1996. Patterns of distal-less gene expression and inductive interactions in the head of the direct developing frog Eleutherodactylus coqui. Developmental Biology 179(1):160-172. Formanowicz, D. R., Jr., M. M. Stewart, K. Townsend, F. H. Pough, and P. F. Brussard. 1981. Predation by giant crab spiders on the Puerto Rican frog, Eleutherodactylus coqui. Herpetologica 37(3):125-129. Goldberg, S. R. and C. R. Bursey. 2000. Transport of helminths to Hawaii via the brown anole, Anolis sagrei (Polychrotidae). J. Parasitol. 86(4):750-755. Gonser, R. A. and L. L. Woolbright. Homing behavior of the Puerto Rican frog, Eleutherodactylus coqui. J. Herpetology 29(3):481-484. Hanken, J., M. W. Klymkowsky, K. E. Alley, and D. H. Jennings. 1997. Jaw muscle development as evidence from embryonic repatterning in direct-developing frogs. Proceedings of the Royal Society of London Series B Biological Sciences 264(1386):1349-1354. Jennings, D. H. and J. Hanken. 1998. Mechanistic basis of life history evolution in anuran amphibians: Thyroid gland development in the direct-developing frog, Eleutherodactylus coqui. Gen. Comp. Endocrinology 111(2):225-232. Kraus, F., E. W. Campbell, III, A. Allison, and T. Pratt. 1999. Eleutherodactylus frog introductions to Hawaii. Herpetological Review 30(1):21-25. Lopez, P. T. and P. M. Narins. Mate choice in the neotropical frog, Eleutherodactylus coqui. Animal Behaviour 41(5):757-772. Michael, S. F. 1995. Captive breeding of two species of Eleutherodactylus (Anura: Leptodactylidae) from Puerto Rico, with notes on behavior in captivity. Herpetological Review 26(1):27-29. Perez-Rivera, R. A. and E. N. Dechoudens. 1996. Use of bird nests by Eleutherodactylus frogs in the Carite Forest, Puerto Rico. Caribbean Journal of Science 32(2):201-205. Rodriguez-Robles, J. A. and M. Leal. 1993. Effects of prey type on the feeding behavior of Alsophis portoricensis (Serpentes: Colubridae). J. Herpetology 27(2):163-168. Schwartz, A. and R. W. Henderson. 1985. A Guide to the Identification of the Amphibians and Reptiles of the West Indies Exclusive of Hispaniola. Milwaukee Public Museum, Milwaukee, WI. Schwartz, A. and R. W. Henderson. 1991. Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. University of Florida Press, Gainesville, FL. Simberloff, D. and B. Von Holle. 1999. Positive interactions of nonindigenous species: invasional meltdown? Biological Invasions 1:21-32. Stewart, M. M. 1995. Climate driven population fluctuations in rain forest frogs. J. Herpetology 29(3):437-446. Stewart, M. M. and P. J. Bishop. 1994. Effects of increased sound level of advertisement calls on calling male frogs, Eleutherodactylus coqui. J. Herpetology 28(1):46-53. Stewart, M. M. and F. H. Pough. 1983. Population density of tropical forest frogs: relation to retreat sites. Science 221:570-572. Stewart,
M. M. and A. S. Rand. 1991. Vocalizations and the defense of retreat sites by
male and female frogs, Eleutherodactylus coqui. Copeia
1991(4):1013-1024. Stewart, M. M. and A. S. Rand. 1992. Diel variation in the use of aggressive calls by the frog Eleutherodactylus coqui. Herpetologica 48(1):49-56. Taigen, T. L., M. M. Stewart, and F. H. Pough. 1984. Water balance of terrestrial anuran (Eleutherodactylus coqui) eggs: Importance of parental care. Ecology 65(1):248-255. Thomas, R. 1966. A new species of Antillean Eleutherodactylus. Quart. J. Florida Acad. Sci. 28(4):375-91. Townsend, D. S. 1989. The consequences of microhabitat choice for male reproductive success in a tropical frog (Eleutherodactylus coqui). Herpetologica 45(4):451-458. Townsend, D. S. and M. M. Stewart. 1985. Direct development in Eleutherodactylus coqui (Anura: Leptodactylidae): a staging table. Copeia 1985(2):423-436. Townsend, D. S. and M. M. Stewart. 1994. Reproductive ecology of the Puerto Rican frog Eleutherodactylus coqui. J. Herpetol. 28:34-40. Townsend, D. S., M. M. Stewart, F. H. Pough and P. F. Brussard. 1981. Internal fertilization in an oviparous frog (Eleutherodactylus coqui). Science 212:469-471. Wilson, L. D. and L. Porras. 1983. The ecological impact of man on the south Florida herpetofauna. U. Kansas Mus. Nat. Hist. Spec. Publ. No 9. 89 pp. Woolbright, L. L. 1991. The impact of Hurricane Hugo on forest frogs in Puerto Rico. Biotropica 23(4 Part A):462-467. Woolbright, L. L. 1996. Disturbance influence long-term population patterns in the Puerto Rican frog, Eleutherodactylus coqui (Anura: Leptodactylidae). Biotropica 28(4):493-501.
The Coqui page was last updated on 10/08/2001 |