Iguana b&w text Connectivity and Interpond Movements of Painted Turtles Because of the importance of facilitating movement of plants and animals between habitats, protecting the connec- tivity of isolated habitat patches has become an essential component of con- servation biology. For a corridor to be successful, it must allow for increased movement, compared to the uncon- nected state. BOWNE ET AL. (2006. Conservation Biology 20: 780–789) stud- ied the relationship between connectivity and population density in Painted Turtles (Chrysemys picta) in northern Virginia. They examined movement rates and movement probabilities in an agricultural landscape in order to determine persist- ence over a four-year period. The study area consisted of nine ponds, with inter- vening distances ranging from 110–2300 m. On occasion, more distant surround- ing ponds were sampled to check for emigrants from the focal area. Turtles were categorized into five classes: Adult male, adult female, subadult male, subadult female, and juvenile. Of those, adult females were the most sensitive to habitat quality, and would move to more distant ponds. Habitat patch quality was influenced by interpatch distance and patch size and shape. The authors found that connectivity is a function of the behavior of individuals in relation to landscape features and habitat quality. Thus, if the ecology of a species is not taken into account, structural connectiv- ity by itself has little worth. For proper conservation planning, connectivity must consider known behavior of the target species as well as the quality of habitat. Rat Eradications Using New Zealand as a case study, TOWNS ET AL. (2006. Biological Invasions 8:863–891) examined the effects of inva- sive Pacific Rats (Rattus exulans), a small South-East Asian species spread by Polynesians throughout the Pacific, and more recently introduced Norway Rats (R. norvegicus) and Ship (Roof) Rats (R. rattus) on native species. Rats suppress some forest plants, and are associated with extinctions or declines of flightless invertebrates, ground-dwelling reptiles, land birds, and burrowing seabirds. Globally, Ship Rats were associated with declines or extinctions of the largest number of indigenous vertebrate species. Effects of rats on forest trees and seabird populations are sufficiently pervasive to affect ecosystem structure and function. However, data are patchy, and deficien- cies would be reduced by documenting distribution and abundance of indige- nous species before and after eradications of rats on islands. Conservation Implications of Sea Turtle Nesting Beach Loss Historically, Green (Chelonia mydas) and Hawksbill (Eretmochelys imbricata) turtles nested in high densities throughout the Caribbean. Because of hunting by humans, turtle populations have been decimated and populations continue to decline. Population declines and ecolog- ical changes have occurred over many centuries and historical and archeological data provide information that can be used to estimate early geographic ranges and population sizes of sea turtles. MCCLENACHAN ET AL. (2006. Frontiers in Ecology and the Environment 4:290–296) used historical data on use of nesting beaches to determine changes in population sizes for both species in 20 regions of the Caribbean. Historic data show that nesting sites supported large populations in the past, but that those are now extremely depleted. Current Green and Hawksbill populations are 0.33% and 0.27% of their respective his- toric values, 20% of the historic nesting sites have been lost, and 50% of the remaining sites support very low popula- tions. Because historic data have not been used previously, the magnitude of popu- lation declines has been underestimated. Protection efforts have resulted in increases in a few turtle populations, but long-term data are sparse. For successful conservation to occur, short-term data should not be used to infer long-term change. Without proper protection, the remaining nesting beaches could soon be lost. Protection and scientific research funding must be implemented in as many beaches as possible to help recover lost nesting beaches. Invasion and Displacement in Pacific Island Geckos Growing international travel and trade have amplified the spread of invasive species, which causes significant ecologi- cal and economic damage. Invasives can alter successional patterns, mutualistic relationships, community dynamics, ecosystem function, and resource distri- butions. The Common House Gecko (Hemidactylus frenatus) continues to expand its range and is displacing many 54 IGUANA • VOLUME 14, NUMBER 1 • MARCH 2007 CONSERVATION RESEARCH REPORTS C O N S E R V A T I O N R E S E A R C H R E P O R T S Adult female Painted Turtles (Chrysemys picta) were more sensitive than adult males or subadults of either sex to habitat quality. JI M H A R D IN G , W O R LD C H EL O N IA N T R U ST Introduced rats (Rattus spp.) suppress some forest plants, and are associated with extinc- tions or declines of flightless invertebrates, ground-dwelling reptiles, land birds, and burrowing seabirds. Historically, Green (Chelonia mydas; above) and Hawksbill (Eretmochelys imbricata) tur- tles nested in high densities throughout the Caribbean. Because of hunting by humans, turtle populations have been decimated and populations continue to decline. Iguana 14.1 b&w text.QX6 2/25/07 10:46 PM Page 54 IGUANA • VOLUME 14, NUMBER 1 • MARCH 2007 55 other species, such as the ecologically similar but all-female Indo-Pacific Gecko (H. garnotii) on a global scale. DAME AND PETREN (2006. Animal Behaviour 71:1165–1173) predicted that the pres- ence of H. frenatus will cause H. garnotii to consume fewer resources and tested whether H. frenatus would respond to H. garnotii as they would to conspecific males or to conspecific females. The hypothesis that resource competition is the mechanism of displacement of H. garnotii received no support from the experiments. Although geckos consumed fewer resources when they were in pairs, resource consumption of H. garnotii was not negatively affected by H. frenatus. The hypothesis that male aggression toward H. garnotii is the primary mech- anism of invasion of H. frenatus was also rejected. Male H. frenatus responded to H. garnotii as they did to conspecific females, and courted and copulated with them. However, male H. frenatus showed a preference for larger female H. garnotii, which suggested that sexual interference could be a mechanism for displacement of H. garnotii. Tiger Salamanders Disappear in Maryland: Is This the Fate of Other Non-game Species of Conservation Concern? LEE (2006. Bulletin of the Chicago Herpetological Society 41:217–224) docu- mented the demise of the last Maryland population of Eastern Tiger Salamanders (Ambystoma tigrinum) from a site that is owned and managed by the Maryland DNR. This site was purchased by The Nature Conservancy specifically to pro- tect this species and was sold to the state with the stipulation that this salamander be managed in perpetuity. The last breed- ing pond was not monitored, and, over time, silted in, pH and water depth changed, surrounding vegetation shaded the pond, and Bluegills were introduced. Despite warnings from people familiar with the needs of these salamanders and a decline documented by a private indi- vidual, the state refused to take action or listen to advice from local herpetologists. An agency boasting “everything we do is based on the best available science” failed to maintain a viable population under their stewardship since the early 1970s. An agency with a forestry divi- sion, wetland specialists, wetland restora- tion teams, a legal mandate to protect state endangered species, and a state her- petologist, was unable to oversee the wellbeing of a forest-dwelling creature on lands it owns and manages. One can only imagine how well other locally rare and endangered reptiles, turtles, and amphibians are doing under their care. The article raises the obvious question as to how other states oversee non-game species of conservation concern. Survival and Growth of Artificially Incubated American Alligators TEMSIRIPONG ET AL. (2006. Journal of Herpetology 40:415–423) compared arti- ficially incubated and repatriated American Alligator (Alligator mississippi- ensis) hatchlings released within and out- side the maternal alligator’s home range with naturally incubated hatchlings released within and outside the maternal alligator’s home range at three lakes in central Florida. Artificially incubated hatchlings released outside the maternal alligator’s home range had lower recapture probabilities than all other treatments, none of which differed significantly. Artificially incubated hatchlings were about 6% shorter than naturally incu- bated hatchlings at about nine months of age. The authors concluded that repatria- tion of hatchlings might be an economi- cal alternative to repatriation of older juveniles in efforts to restore populations, but that location of release may affect subsequent survival and growth. CONSERVATION RESEARCH REPORTS The Common House Gecko (Hemidactylus frenatus; above) continues to expand its range and is displacing many other species, such as the ecologically similar but all-female Indo- Pacific Gecko (H. garnotii) on a global scale. R O B ER T PO W EL L The last known Maryland population of Eastern Tiger Salamanders (Ambystoma tigrinum) has disappeared from a site that is owned and managed by the Maryland Department of Natural Resources. SU ZA N N E L. C O LL IN S, C N A H Repatriation of American Alligator (Alligator mississippiensis) hatchlings might be an economi- cal alternative to repatriation of older juveniles in efforts to restore populations, but the location of release may affect subsequent survival and growth. Iguana 14.1 b&w text.QX6 2/25/07 10:46 PM Page 55