Banbury, Barb L.

Ramos, Yanerys M.

English

Biodiversity Informatics

If you want to see two species of West Indian Rock Iguanas(Cyclura spp.) in natural habitat at the same time, your onlychoice of destinations is the Dominican Republic (DR). TheDR shares the island of Hispaniola with the Republic of Haiti;however, the biogeographic boundaries of the island differ sub-stantially from the current political configuration. Two majorislands, referred to as the North and South paleoislands, werejoined when the South Island “caught” the North Island afterthe latter collided with the Bahama Platform. This event prob-ably occurred during the middle of the Tertiary Period. Reeflimestones were deposited in the former marine channel thatseparated the two islands. This area is now a barren valley knownas the Plaine de Cul-de-Sac in Haiti and the Valle de Neiba inthe DR. Much of this valley lies below sea level in the rain-shadow of the Sierra de Neiba. Two of the four large lakes that256 IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 BANBURY AND RAMOST R A V E L O G U EThe Rock Iguanas of Parque Nacional Isla Cabritos1Barb L. Banbury2 and Yanerys M. Ramos31 Updated from an article first published in the Iguana Times8(2):3–7 (summer 2000).2 Natural History Museum, University of Kansas, Lawrence, Kansas(current address: Department of Biological Sciences, University ofMissouri-Rolla; Rolla, Missouri).3 Section of Neurobiology and Behavior, Cornell University, Ithaca,New York (current address: Venus Gardens, San Juan, Puerto Rico).Parque Nacional Isla Cabritos lies in Lago Enriquillo, in the heart of the Valle de Neiba, Dominican Republic.JOHN S. PARMERLEE, JR.IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 257characterize this valley lack outlets to the sea and are saline.Powell et al. (1999) provided a summary of the geological his-tory of Hispaniola, listing pertinent references and document-ing the herpetofauna of biogeographic regions, including theValle de Neiba.Lago Enriquillo is a hypersaline lake situated 40 m belowsea level. It is named after a native-American Taino chieftainwho successfully resisted Spanish efforts to enslave the indige-nous population during the early colonial period. Annual tem-peratures in the area average 28 °C (Hoppe 1989), althoughdaily temperatures often exceed 40 °C during the summermonths. Average annual rainfall is only 642 mm, most of whichfalls during two “rainy seasons,” one in late spring and the otherin late summer and early fall (the latter associated with the hur-ricane season).A small island (12 x 2.0–2.5 km), Isla Cabritos, lies in LagoEnriquillo. It was incorporated into the Dominican system ofnational parks in 1974, and serves as a sanctuary for a flora andfauna that include a number of species endemic to Hispaniola.The plant community on the island is characterized as dry thornforest — and just about every plant is equipped to stick, stab, orscratch the unwary hiker. Cacti, including the tree cactuses,Caguey (Neoabottia paniculata) and Alpargata (Opuntia monil-iformis), Cholla (Opuntia caribaea), and a tall cactus locallyknown as Cayuco (Cereus hexagonus), fill gaps between scrubbytrees. The most common trees are Mesquite (Prosopis juliflora),Ziziphus (Ziziphus rignoni), and Catalpa (Catalpa longissima)(Hoppe 1989).Birds and reptiles are the most conspicuous componentsof the island fauna. Sixty-two species of birds have beenrecorded (Hoppe 1989). Hispaniola’s largest flock of GreaterFlamingos (Phoenicopterus ruber) feed on arthropods and mol-lusks, and Great Blue Herons (Ardea herodias) and Little BlueHerons (Egretta caerulea) fish the shallows. Glossy Ibis (Plegadisfalcinellus) and Roseate Spoonbills (Ajaia ajaja) frequent theshores, and Hispaniolan Palm Crows (Corvus palmarum) callraucously while carefully surveying visiting humans in hopes ofsoliciting (or stealing) a handout. The most famous inhabitantsof the island, however, are the large, endangered reptiles,American Crocodiles (Crocodylus acutus), Rhinoceros Iguanas(Cyclura cornuta), and Ricord’s Iguanas (Cyclura ricordii).In the summer of 1999, we were part of a National ScienceFoundation-funded undergraduate research program working inthe Dominican Republic. In the course of our three-week-longstudies of lizard communities, we made arrangements with theNational Park Service (Dirección Nacional de Parques) to takea day off and visit Isla Cabritos to see crocodiles and iguanas intheir natural habitat.On 12 June 1999, we left our base in Barahona well beforedawn in order to catch an early boat to the island. The boat driv-ers generally prefer to return by early afternoon before the off-shore winds, funneled through the valley from the east, kick uphigh waves. The morning was cloudy and surprisingly cool,exceedingly pleasant for humans, but less than ideal if you aresearching for basking reptiles. Nonetheless, we had high hopesfor success — and were almost immediately rewarded. While wewere still waiting on the dock as the drivers were preparing theboat for our trip, we saw a small crocodile swimming nearby.Although not visibly disturbed by our presence, it swam awayslowly, submerged, and we didn’t see it again.After an uneventful crossing, we docked on the north sideof Isla Cabritos and took a trail that led us to the park station.Cicadas and the ubiquitous crows serenaded us as we wound ourway along the path through the prickly vegetation. The groundunderfoot was sandy, but often gave way to large areas of darkerconsolidated rock. Upon close examination, we observed thatboth rock and sand were composed of coral and shell fragments,relics of the ancient sea life inhabiting the former marine chan-nel. After a short stop at the park station, our driver, now in therole of guide, led us toward the south side of the island to abeach where crocodiles frequently bask.Along the way, our guide took us on a short detour to lookfor iguanas. Almost instantly, we spotted a large male Cycluraricordii. Although we had been alerted to watch for iguanas, wewere unabashedly amazed by his size and demeanor. We tooksome pictures, but the ruckus raised by our excited group scaredthe iguana back into its burrow. A short walk later, we arrived atthe beach. Cautioned to remain quiet, as the crocodiles are verysensitive to human disturbance, we approached from behindsome vegetation along a shoreline dune. Unfortunately, no croc-odiles were basking, but a large individual was swimming justoff the beach. Although it continued to swim away, we got agood look through binoculars and snapped some pictures.TRAVELOGUEAn adult male Ricord’s Iguana (Cyclura ricordii) outside its burrow onIsla Cabritos. Notice the characteristic vegetation.KIM SCHNEIDERThe range of the American Crocodile includes coastalregions of southeastern North America, Central America, north-western South America, Cuba, Jamaica, and Hispaniola. Thespecies was once very abundant in Hispaniola, but is now foundonly at Lago Enriquillo and in the nearby Haitian lake, EtangSaumatre. The depletion of populations has mainly been theresult of habitat destruction, hunting, and nest poaching(Schubert and Santana 1996). At Lago Enriquillo, nesting sitesare scattered along the main shoreline and along the shores ofIsla Cabritos. After hatching, the baby crocodiles, which cannottolerate the high salinity of the lake, must move from the nest-ing beaches to fresh water habitat. Crocodile mothers nesting onIsla Cabritos have to carry their babies from the nesting beachesto areas where freshwater springs, called borbollones, empty intothe lake. We visited Isla Cabritos at the end of the nesting sea-son and saw an empty nest, littered with egg fragments.On the way back from the beach, we stopped again at theiguana burrow and found that the iguana had re-emerged andwas sitting in a small patch of sunlight. This time we were qui-eter and everyone had a chance to take pictures and admire thisbeautiful animal for a few minutes.Cyclura ricordii is endemic to Hispaniola, where it can befound in the Valle de Neiba and on the lower Península deBarahona, where apparently separate populations occur nearPedernales and along the southern shore of Lago Enriquillo.Although the species is common on Isla Cabritos, thanks to thelegal protection provided by the island’s status as a national park,other populations in Hispaniola are of uncertain size and may258 IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 BANBURY AND RAMOSAn adult male Ricord’s Iguana (Cyclura ricordii) outside its burrow onIsla Cabritos.BARB BANBURYAn adult American Crocodile (Crocodylus acutus) in Lago Enriquillo off the southern shore of Isla Cabritos.JOHN BINNSIGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 259TRAVELOGUEbe declining. The separate populations probably are geneticallyas well as geographically isolated from each other, rendering thethreat of extirpation more serious, since unique gene pools couldbe lost forever. Because it is more of a habitat specialist than C.cornuta, C. ricordii is more susceptible to alterations in its habi-tat. Other threats include predation by and competition withexotic species, and hunting (J.A. Ottenwalder, pers. comm.).Captive breeding programs were established in the early 1990’sat the Indianapolis Zoo and Parque Zoológico Nacional(ZooDom) in Santo Domingo (Christie 1996), but becameinactive within a few years due to a lack of animals (W. Christie,pers. comm.). Since the level of success in these programs waslow (J.A. Ottenwalder and W. Christie, unpubl. data), bettercaptive husbandry techniques needed to be developed. In 1999,a successful breeding program was reestablished at ZooDom tohelp ensure a future for this species.4 Major threats to C. ricordiion Isla Cabritos are nest predation by feral cats, and competi-tion for forage with mammalian herbivores that cross the landbridge connecting the island to the shore during dry periods.In the meantime, the weather had cleared and the day washeating up, so we went looking for C. cornuta. Our guide led usto a regularly visited burrow. Almost immediately, we saw afemale, but she quickly retreated. This burrow was situatedunder a limestone ledge, like most of the others we were to see.Ledges or the root systems of trees or bushes provide necessarysupport for large burrows in sandy soil, which would collapse ifnot reinforced. While continuing our search, one member of thegroup spotted a big male. Unlike the other individuals we hadseen previously, he was not at all shy. Instead, he walked directlytoward us before apparently losing interest and wandering away.The guide told us that this male, named “Pancho” by the guides,and a few other individuals had grown accustomed to humanvisitors and their handouts. This might not have been the mostnatural behavior, but it was an excellent opportunity to get aclose look. On the way back to the dock, we saw several moreAn adult male Rhinoceros Iguana (Cyclura cornuta) named “Pancho” by local guides.ROBERT POWELL4 See article on p. 222.Rhinoceros Iguanas and a female C. ricordii, most basking justoutside their burrows. As they were less accustomed to visitorsthan Pancho, we were careful to maintain our distance.Prior to the early 1950s, C. cornuta was very common inthe arid areas of Hispaniola, but populations have declined sub-stantially (Ottenwalder and Powell 2002). Even though the pre-ferred habitat of C. cornuta is not favorable to human settle-ments, the introduction of exotic animals has increased thecompetition with and predation on the iguanas. They have alsobeen illegally hunted for food and the pet trade. Because IslaCabritos is protected, it is one of the few areas where populationdensities appear to be near what are assumed to be pre-Columbian numbers.On the boat ride back to the mainland, we stopped by theborbollones to look for more crocodiles. Instead, we got a closelook at flamingoes. One of them took off and flew over our260 IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 BANBURY AND RAMOSBirds are conspicuous residents of Lago Enriquillo. Most birds in this view are either Great (Ardea alba) or Snowy Egrets (Egretta thula). A fewGreater Flamingos (Phoenicopterus ruber) and Black-necked Stilts (Himantopus mexicanus) are evident, and a single Little Blue Heron (Egrettacaerulea) can be seen in flight (upper left). Notice also the American Crocodile (Crocodylus acutus) in the foreground.JOHN BINNSMale Rhinoceros Iguana (Cyclura cornuta) courting a prospective mate.ROBERT POWELLIGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 261TRAVELOGUEheads (Fig. 10). When we returned to the mainland, several peo-ple were waiting to visit the island. Most were Dominicans, tes-tament to the growing awareness of the unique ecological valueof the Lago Enriquillo area. Educational programs presentedlocally through slide shows and nationally on television illustratenatural communities and feature endangered species. Posters andbrochures about the lake and its species are to be distributedthroughout the country (Schubert and Santana 1996). Thisheightened awareness among Dominicans is critical to the suc-cess of any conservation efforts.Literature CitedChristie, B. 1996. Taxon management account: Ricord’s Iguana, Cycluraricordi. In: S.H. Hammack (ed.), American Zoo and Aquarium AssociationLizard Advisory Group, Taxon Management Accounts, 7 pp. American Zooand Aquarium Assoc., Fort Worth, Texas.Hoppe, J. 1989. Los Parques Nacionales de la República Dominicana. TheNational Parks of the Dominican Republic. Editoria Corripio, SantoDomingo.Ottenwalder, J.A. and R. Powell. 2002. Brief notes on the status ofHispaniolan Rhinoceros Iguanas, Cyclura cornuta. Iguana Times 9:78.Powell, R., J.A. Ottenwalder, and S.J. Incháustegui. 1999. The HispaniolanHerpetofauna: Diversity, endemism, and historical perspectives, with com-ments on Navassa Island, pp. 93–168. In: B. I. Crother (ed.), CaribbeanAmphibians and Reptiles. Academic Press, San Diego, California.Schubert, A. and G. Santana. 1996. Conservation of the American Crocodile(Crocodylus acutus) in the Dominican Republic, pp. 425–433. In: R.Powell and R. W. Henderson (eds.), Contributions to West IndianHerpetology: A Tribute to Albert Schwartz. Contributions to Herpetology,vol. 12. Society for the Study of Amphibians and Reptiles, Ithaca, NewYork.Additional ReferencesAlberts, A.C. (ed.). 2000. West Indian Iguanas. Status Survey and ConservationAction Plan. IUCN/SSC West Indian Iguana Specialist Group. IUCN,Gland, Switzerland and Cambridge, United Kingdom.Alberts, A.C. 2004. Conservation strategies for West Indian Rock Iguanas(Genus Cyclura): Current efforts and future directions. Iguana11:212–223.Alberts, A.C., R.L. Carter, W.K. Hayes, and E.P. Martins (eds.). 2004.Iguanas: Biology and Conservation. University of California Press,Berkeley.Ramer, J. 2004. A survey of Ricord’s Iguana (Cyclura ricordii) and RhinocerosIguanas (Cyclura cornuta cornuta) in Isla Cabritos National Park,Dominican Republic, 2003. Iguana 11:88–95.Ramer, J. and R. Hudson. 2005. Taxon updates: Ricord’s Iguana (Cycluraricordii): Species recovery plan update. Iguana 12:27.Adult female Ricord’s Iguana (Cyclura ricordii) on Isla Cabritos.JOHN BINNSGetting to Lago Enriquillo from Santo Domingorequires a 21⁄2–3 hour drive, taking the road towardBarahona, turning right on the road to Neiba and con-tinuing to La Azufrada. At La Azufrada, you can hire fora modest fee one of the commercial boats or one of theParques boats to take you to the island. Inexpensive parkpermits can be acquired at the main office of DirecciónNacional de Parques in Santo Domingo or at LaAzufrada. The closest tourist accommodations are aboutone hour away in the town of Barahona. However, pen-sions and a few very modest hotels can be found in thenearby town of La Descubierta, along with some smallrestaurants, the best of which is at the “Hotel Iguana,”where the more intrepid traveler may want to stay.Female Rhinoceros Iguana (Cyclura cornuta) outside her burrow onIsla Cabritos.JOHN BINNSJAN RAMERAlthough not normally considered to be human commensals,some Dwarf Geckos, such as this Sphaerodactylus altavelensisenriquilloensis, seem to seek out human companionship. Thisphotograph was taken at the Hotel Iguana in La Descubierta,near Lago Enriquillo.

The Rock Iguanas of Parque Nacional Isla Cabritos

The University of Kansas: Journals@KU

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The Rock Iguanas of Parque Nacional Isla Cabritos

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Biodiversity Informatics

The University of Kansas: Journals@KU