Karen von Seckendorf Hoff, Ron Marlow, and Todd Esque (University of Nevada, Reno), Anders Rhodin (Chelonian Research Foundation, Lunenberg, Massachussetts), Alison Whitlock (University of Massachusetts, Amherst), Hal Avery (U.S. Geological Survey, Biological Resources Division, Riverside, California), Tej Kumar Shrestha (Tribhuvan University, Kirtupur Kathmandu, Nepal), Bill Boarman (U.S. Geological Survey, Department of Biology, University of California, Riverside, California), Dick Buech (U.S. Dept. of Interior Forest Service, Grand Rapids, Minnesota), Joan Milan (University of Massachusetts, Amherst, Massachusetts), Steve Garber (Rutgers University, Piscataway, New Jersey), Bryan Jennings (University of Texas, Austin), and Rico Walder (Tennessee Aquarium, Chattanooga, Tennessee).
The capacity of chelonians to grow, resist pathogens, and successfully reproduce depends upon their ability to acquire and process adequate amounts of foods that meet their nutritional requirements. The potential for nutritional constraints to affect herbivorous chelonians is magnified because many plant species are usually needed to meet all energy and nutrient requirements. Thus, nutritional constraints associated with food quality and abundance have important consequences for the management and conservation of herbivorous turtle and tortoise metapopulations inhabiting environments with modified plant communities.
Exotic annual and perennial plants have become major components of arid plant communities within the geographic range of the desert tortoise, Gopherus agassizii. Some hypothesized effects of exotic plant introductions on desert tortoise nutrition include: (1) reduction in food choice due to decline in species diversity of forage plants, and (2) nutrient imbalances due to the consumption of lower quality forage plants that do not meet minimum nutritional requirements. The objectives of this study were to: (1) compare the nutrient content of native and exotic annuals known to be consumed by free-living desert tortoises, and (2) determine the food preferences of tortoises fed exotic versus native plant species.
Fifteen desert tortoises were used in a selectivity trial in outdoor enclosures at The Living Desert, Palm Desert, California. The exotic annual species of filaree (Erodium cicutarium) and splitgrass (Schismus barbatus) were fed to one group of tortoises. The annual woody bottlewasher (Camissonia boothii) and the perennial shrub, wishbone bush (Mirabilis bigelovii) were fed to a second group of tortoises. A mix of all four plant species was provided to a third group of tortoises. Selectivity of forage plants was determined by measuring the consumption rates of each plant species by tortoises within morning feeding intervals.
For tortoises fed the two exotic annuals there were significant preferences for Schismus over Erodium. For tortoises fed native plants, there was no difference in preference for Mirabilis versus Camissonia. Tortoises fed a mix of native and exotic plants preferred Schismus over all other native and exotic plants. This finding was in direct contrast to field studies indicating that wild desert tortoises prefer native plants over exotic plants.
Nutrient contents for native and non-native plants were compared. Native plants were higher in crude protein than Schismus, but were similar to Erodium. Essential amino acids were greater in native plants versus non-native plants. Energy concentration was similar for all plants, and is not an adequate parameter for determining food quality. Dietary fiber, a nutritional challenge to all herbivorous vertebrates, was greater in exotic species than in native species. Schismus had a higher concentration of heavy metal ions than filaree or both native plant species.
Data on the food selectivity, nutritional quality, and digestive performance of tortoises fed native versus exotic plants are used to assess the potential for maintaining viable metapopulations of desert tortoises in habitats characterized by high relative abundances of exotic plants.
Geometric tortoises (Psammobates geometricus) and common parrot-beaked tortoises (Homopus areolatus) occur sympatrically in the isolated Harmony Flats nature reserve (10 ha) between the towns of Strand and Gordons Bay, Western Cape Province, South Africa. The reserve is completely surrounded by urban development and isolated from any surrounding natural environments. Since its establishment in 1986, the reserve and tortoise populations have been under severe environmental stress in the form of frequent unnatural fires, alien vegetation encroachment, and lack of recruitment from surrounding areas. Despite efforts to inform local residents about the value of the reserve in terms of its floristic component and the endangered tortoises occurring there, lack of public concern for this reserve has resulted in at least three deliberately lit wildfires, each destroying a portion of the two tortoise communities. Close monitoring of population numbers indicated that H. areolatus has been able to successfully cope with these fires in terms of population numbers, whereas P. geometricus experienced an 88% drop in numbers over a period of seven years, with little recruitment from resident breeding pairs. Possible reasons for the decline of P. geometricus appear to be (1) its specialised habitat requirements, (2) low recruitment rates, (3) slow recovery after catastrophes (its inability to cope with frequently recurring fires), (4) competition with the more successful H. areolatus, and (5) the possibly negative impact of disease following relocation to this site.
A preliminary population viability analysis of the geometric tortoise population indicated that, should prevailing threats continue to operate, this most southern population of the species faced extinction before the end of this century. Steps to enhance its continued survival were initiated and by December 1993 the population appeared on its way to recovery. Population numbers were up, young were added to the population, and the habitat had recovered adequately. However, on New Years Eve 1993 a deliberately lit wildfire wiped out approximately 80% of the recovered habitat and 78% of the remaining resident geometric tortoise population. The H. areolatus population was also reduced by approximately 51%. Steps to rescue remaining geometric tortoises from surrounding areas have been put into operation, but there is no guarantee that the same catastrophe will not recurr.
It is clear that the right areas (such as the Harmony Flats nature reserve) situated in the wrong places are often extremely vulnerable to non-stochastic, human-induced catastrophes and that the success of these areas as viable sites depends exclusively upon the ability of management authorities to eliminate or at least mitigate potential sources of threat.
The wood turtle, Clemmys insculpta, is found in the United States from the Midwest to the Northeast. Iowa, Minnesota, and Wisconsin list the wood turtle as either Endangered or Threatened. We wanted to know why wood turtles are uncommon in the Eastern Great Lakes region. In cooperation with Minnesota Department of Natural Resources Nongame Program, we studied wood turtles living on rivers in northeast Minnesota. We have studied their movements, habitat use, nesting behavior, and nesting success.
What have we learned?
The behavior of wood turtles has seasonal patterns. They are terrestrial in summer and aquatic in winter. Spring and fall are transitional periods, when they spend cool nights in the water and warm days on land. Wood turtles use a variety of habitats, most of which are common. However, nesting habitat is not abundant. Preferred nesting sites are bare sand or gravel areas such as cutbanks and sand bars. Females traveled as far as 4.3 miles to nest, presumably because nesting areas are few. We found loss of nests to egg predators such as skunk and fox to be high. Furthermore, most wood turtles living on the Cloquet River are old; only 20% of turtles were <15 years old. We believe that the wood turtle population in the Great Lakes region is probably below historic levels because: (1) nesting areas are degrading and disappearing due to recreational disturbance and streambank restoration programs, (2) egg predators such as opossum, raccoon, and skunk are expanding their range, (3) adults are killed by vehicles when crossing roads, especially females seeking nesting areas in spring, and (4) in some regions, adults are collected and sold into the pet trade. We are most concerned about the lack of nesting areas and destruction of nests by egg predators.
What are we doing about these concerns?
We are developing a set of standards and guides for managing riverine and riparian habitats to benefit wood turtle populations.
We are informing fisheries and recreation managers of the potential negative impact of streambank restoration programs on wood turtle nesting areas and of potential disturbance from other sources.
We are testing ideas for protecting nesting areas from egg predators. For example, we fenced part of an abandoned gravel pit. Whereas 70% of nests outside the fence were destroyed, all 18 nests inside the fence survived (we counted 190 hatchlings leaving the fenced area!).
We are exploring ideas for creating new nesting areas; one has been created in the Superior National Forest, and others are planned. We will monitor their efficacy.
We are testing ideas for enumerating and monitoring wood turtle populations at the watershed level so that managers can determine their status at will.
We recognize that it will take a partnership of numerous private and public entities to effectively manage wood turtles across entire watersheds. Our goal is to provide the knowledge that will allow this to happen.
A study area of approximately 110 square miles is depicted, showing general land use and primary physiographic features, including gross habitat boundaries. Wetlands are delineated based on National Wetland Inventory maps and Soil Conservation Survey maps in conjunction with United States Geological Survey 7.5 minute quadrangle maps. Generated by Computer Aided Drafting and Design (CADD), the poster illustrates six proposed transportation corridors, each approximately 13 miles long, superimposed on the study area. Consistent with environmental assessment principles of overlaying resource maps (e.g., McHarg Techniques), the relationships between alternative transportation corridors and the study area can be assessed.
Based on field investigations, wetland functions and values associated with habitats intercepted by each corridor are annotated by using a new system of clustered icons in order to summarize characteristics of primary concern. In combination with navigation/
The Habitat Conservation Planning (HCP) process is a mechanism of the Endangered Species Act intended to reduce conflicts between economic development and endangered species conservation. Washington County is the fastest growing county in Utah and is inhabited by nine species listed under the United States Endangered Species Act and 41 candidate species. Many of these species habitats are slated for urban growth. Therefore, in 1991 Washington County initiated the HCP process to receive a federal permit allowing incidental take of desert tortoises, Gopherus agassizii, and their habitat. Issuance of the permit is contingent upon the plan offsetting habitat losses by enhancing the prospects for long-term survival of impacted species. Mitigation actions being considered include: establishment of an ecological preserve; acquisition of habitat; withdrawal of livestock grazing; and funding of monitoring, research, and education programs. We present a case history of the Washington County HCP process and the biological considerations necessary for the successful development and implementation of a plan that insures the continued survival of federally protected species.Return to List
This study documents the detrimental effects of human recreation on the North American wood turtle, Clemmys insculpta, in Connecticut. We observed two North American wood turtle populations for 20 years, from 1974 through 1993. One hundred thirty-three different wood turtles were observed a total of 1,176 times. Human and wood turtle demographics were monitored throughout this period. The data support the following conclusions: (1) following a period of apparent stability two populations of wood turtles declined, (2) the declines were more or less synchronous in both populations, (3) the beginning of each decline corresponded to the opening of the habitat for recreation, (4) an increase in mean turtle age suggests a failure of recruitment, and (5) a simultaneous reduction in numbers of adult females suggests that the failure of recruitment alone is not sufficient to explain the declines.
Throughout our study the size of the forest remained the same, road building was restricted, and the quality of the air and water were constant. The wood turtle populations remained stable when people were denied access to the property. When the area was opened to human recreation (hiking, fishing), the two discrete wood turtle populations declined steadily; the total number of turtles in both populations declined by 100% in ten years. As wilderness areas become mixed-use recreation areas, wood turtle populations may suffer. We conclude that without proper management, the increasing recreational use of parks, reservoirs, and wildlife reserves will adversely affect the long-term survival of the North American wood turtle.
Information is presented on egg production in five species of Graptemys.
G. flavimaculata: Twenty clutches were produced in six seasons (19821987) by a non-growing female (148 mm CL) of unknown age. Clutch size ranged from 2 to 5 with a mean of 3.40 and a mean clutch frequency (CF) of 3.33, egg mass ranged from 10.0 to 17.2 g with a mean of 14.49 g. Twenty-two additional clutches were produced by three young females in the years 19881992. These animals grew from a mean CL of 117 mm to 138 mm during that time and produced 22 clutches ranging from 1 to 5 eggs with a mean CS of 2.41 and egg mass ranging from 10.6 to 16.1 g with a mean of 13.25 g. Clutch frequency ranged from 1 to 5. Mean CF was not calculated as all females did not reproduce in each of the seasons. Nesting seasons (n = 10) ranged from 11 December through 28 June, with oviposition date of first clutch ranging from 11 December through 28 May with a mean date of 26 February, and date of last oviposition ranging from 11 April through 28 June with a mean date of 5 June. Mean length of the nesting season for the group was 98 days.
G. nigrinoda delticola: A group of 55 females of mean CL 141.8 mm, and in which growth was negligible, produced 91 clutches in the six seasons 19861992. Clutch frequency ranged from 1 to 5 with a mean of 3.57; CS ranged from 1 to 7 with a mean of 3.15; and egg mass ranged from 9.8 to 18.2 g with a mean of 14.2 g. Nesting seasons of the group had a mean length of 176 days, with date of oviposition of first clutch ranging from 2 October through 1 February with a mean of 31 November and dates of last clutch ranging from 15 April through 17 June with a mean of 29 May.
G. barbouri: In eight seasons, 25 clutches were produced with individual CF ranging from 1 to 4, CS ranged from 1 to 6 with a mean of 3.38 and egg mass ranged from 10.9 to 20.1 g with a mean of 15.13 g. Nesting seasons ranged from 13 March through 25 July.
G. pulchra: In five seasons, 13 clutches were produced with individual CF ranging from 1 to 2; CS ranged from 1 to 5 with a mean of 3.54 and egg mass ranged from 11.4 to 20.0 g with a mean of 16.38 g. Nesting seasons ranged from 21 December through 22 June.
G. versa: In five seasons, 19 clutches were produced. Individual CF ranged from 1 to 5, CS ranged from 1 to 6 with a mean of 4.63, and egg mass ranged from 8.0 to 14.0 g with a mean of 10.68 g. Nesting season ranged from 19 February through 28 June. Laying dates of first clutches of seasons were much more variable than laying date of last clutch of seasons (e.g., variance of those dates of G. flavimaculata: 63.7617.72; variance of those dates of G. n. delticola: 60.510.94 ). In the series of the non-growing female G. flavimaculata, investment in egg production increased significantly through the first three seasons and remained high in subsequent seasons as represented by increased CF and egg mass and decreased CS (means for first three seasons: CF 2.33, CS 3.86, egg mass 13.96 g, mean annual clutch mass 125.5 g; those for subsequent seasons: CF 4.33, CS 3.15, egg mass 15.16 g, mean annual clutch mass 206.8 g). In the series of G. n. delticola clutches, investment in egg production was uniform in the first three as opposed to subsequent seasons as represented by higher CF and lower CS and egg mass (means for first three seasons: CF 3.40, CS 3.48, egg mass 14.66 g, mean annual clutch mass 179.4 g; those for subsequent seasons: CF 4.40, CS 2.79, egg mass 14.08 g, mean annual clutch mass 172.9 g).
Information is presented concerning egg production in a 15-season period (19781993) for a mature animal of unknown age (old), and of six progeny females, producing in an aggregate of 14 seasons. Clutch frequency (CF) for the old female was 2 in 13 seasons and 1 in the remaining two seasons. CF of progeny females, in their 5th through 12th year of age, was 2 in five seasons and 1 in nine seasons. Laying dates ranged from 25 October through 11 March in the entire series and did not differ significantly in the old and progeny series (P >.2 in each paired comparison of dates of CF1 and of 1st clutch or 2nd clutch of CF2). Mean date of clutches laid as CF1 and as 1st clutch of CF2 did not differ (23 December10 December, P >.1), while dates of 1st and 2nd clutches of CF2 differed significantly (15 December1 February, P <.001). Clutch size (CS) was larger in progeny females (mean 6.475.68 ). Mean size of clutches laid as CF1 were larger than those laid as CF2 in both series, and clutches laid as 2nd of CF2 were larger than those laid as 1st of CF2 in both series (mean for old and progeny: CF1 = 6.00, 6.77; CF2 = 5.65, 6.20; 1st of CF2 = 4.85, 5.80; 2nd of CF2 = 5.69, 6.60). None of these differences was significant at P =.05. Egg mass for the old female was consistent (with records kept only in the last ten seasons) and ranged from 32.8 to 58.3 g (mean 49.92 g, n = 69 eggs ). Eggs laid as CF1 were significantly larger than those laid as CF2 (means 54.17 and 48.82 g, P <.01), and those laid as 1st of CF2 were larger than those laid as 2nd of CF2 (means 52.68 and 48.18 g, P <.001). Progeny females began egg production at similar sizes (276291 mm CL ) but at differing ages (5 years, 9 months9 years, 8 months) with faster growing animals producing at younger ages. The first, second, and third reproductive seasons of progeny females was characterized by low CF, high CS, and small egg mass (1st year means CS 6.00, CF 1.17; egg mass 35.21; n = 7 clutches; 2nd + 3rd year means CS 7.20, CF 1.25; egg mass 35.59; n = 5 clutches). Mean annual clutch mass for these years was 246.5 g in the 1st year and 320.9 g in the 2nd + 3rd years. Mean annual clutch mass increased to 471.3 g in the fourth season (mean CS 7.20, CF 1.6; egg mass 39.29 g; n = 5 clutches). Egg production in the fifth season of the progeny females did not differ from that of the old female (progeny and old: mean CS 6.00, 5.68; CF 2.00, 1.86; egg mass 48.02, 49.92 g; annual clutch mass 576.2, 527.4 g; n = 2 clutches of progeny series ).Return to List
Knowledge of tortoise food habits can provide insights into tortoise dietary and habitat requirements, and it is therefore important in management of tortoise populations. The purpose of this paper is to present a methodology that was successful in elucidating desert tortoise, Gopherus agassizii, food habits in the western Mojave Desert. These methods are also applicable to studies of other tortoise species living in arid regions.
The methodology is useful in estimating tortoise diet and plant abundance, both of which are needed to quantitatively assess whether tortoises are selective foragers. To determine whether tortoises are selective foragers, a null model incorporating diet and plant abundance (i.e., Ho : plant abundance = food choice) can be statistically evaluated. Moreover, other questions can be addressed such as whether tortoises prefer succulent to dried forage, and whether tortoises prefer native to exotic plant species.
Diet is estimated by direct observation of tortoises while plant abundance is estimated by following a stratified random sampling methodology. Estimating plant abundance in deserts is complicated because the investigator must make many subjective choices when formulating a sampling scheme. One must choose the number of unique vegetational/topographical strata; sample size; allocation of samples among habitat strata; quadrant size, shape, and number; when and how often to sample; whether herbaceous perennials are considered annuals or perennials; etc. The approach to each of these choices to achieve a satisfactory sampling methodology is discussed and results are presented.
From 1990 to 1992 extensive field survey and collection of tortoises in southern Nevada has documented a pattern of occurrence of desert tortoises symptomatic for Upper Respiratory Tract Disease (URTD). Symptomatic tortoises were found throughout southern Nevada, but the highest occurrence was in habitat adjacent to urbanized areas and adjacent to highways and roads. In a sample of 841 tortoises removed from land in the Las Vegas Valley scheduled for development, 7.8% were obviously escaped or released captives, and 14.5% were symptomatic for URTD. Outside the Las Vegas Valley, the distribution of symptomatic tortoises closely corresponded to proximity to major highway access from Las Vegas. It is well known that captive tortoises (including those symptomatic for URTD) escape and are purposely released into the wild and that the disease may be spread in this manner. It is hypothesized that the pattern of distribution of symptomatic tortoises can be explained by the escape and release of captive tortoises into the wild. Management of wild tortoise populations has probably already been compromised by the existence of a large captive tortoise population and can be significantly complicated by future uncontrolled adoption programs.Return to List
Historically the spotted turtle, Clemmys guttata, was considered the most abundant turtle in Massachusetts. In the past century spotted turtle populations have declined substantially. Presently the spotted turtle is listed as a Species of Special Concern by the Massachusetts Division of Fisheries and Wildlife because of its scarcity, habitat loss, habitat fragmentation, road mortality, and collection for the pet trade. Using radiotelemetry techniques, we are intensively studying the demographics and habitat use of spotted turtle populations in central Massachusetts. The goal of this study is to provide necessary ecological information for the establishment and management of reptile and amphibian reserves.Return to List
Chelonian Research Foundation (CRF) was established in May 1992 as a nonprofit 501(c)(3) tax-exempt private operating foundation organized for the production, publication, and support of worldwide turtle and tortoise research, with an emphasis on systematic relationships, geographic distribution, natural history, morphology, and the scientific basis of chelonian diversity and conservation biology. Our goal is the increased scientific understanding and conservation of the diverse species of turtles and tortoises of the world. We hope to accomplish these aims through a combination of CRF turtle research and scientific publications, as well as through donations of CRF support for a wide range of scientific and conservation- oriented turtle research projects by other investigators.
In our capacity as a nonprofit organization we solicit support from the public at large and interested individuals and organizations for the on-going expenses of carrying out our goals. We are especially grateful for donations to our special research endowment, The Linnaeus Fund, which grants annual awards for turtle research projects carried out by scientists around the world. In our first year of operation, The Linnaeus Fund provided partial support of $500 each to four separate turtle research projects on endangered, threatened, and rare turtle species. Two of these projects concerned native New England species: a study on the seasonal movements and habitat preferences of spotted turtles in Connecticut, and a study on the ecology and natural history of the wood turtle in New Hampshire. Other supported projects included a study on the molecular systematics and evolution of sex-determining mechanisms in American marsh turtles, and a study on the taxonomic relationships of the giant Asian softshell turtle. Our awards will continue to be made annually, hopefully with steadily increasing support through the growth of our endowment fund. Linnaeus Fund Awards for 1992 were $500 each, as follows:
Chelonian Research Foundation is also undertaking the publication of a new journal of turtle and tortoise studies entitled Chelonian Conservation and Biology, Journal of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group and International Bulletin of Chelonian Research. This journal is published by CRF with support from Conservation International (Washington, D.C.), Chelonia Institute (Arlington, Virginia), Wildlife Conservation Society (Bronx, New York), Florida Audubon Society (Casselberry, Florida), and IUCN (The World Conservation Union)Species Survival Commission. The journal will be under the joint co-editorship of John L. Behler, Peter C. H. Pritchard, and Anders G. J. Rhodin, and will be a peer-reviewed professional scientific journal with an Editorial Board of world-renowned turtle biologists and conservationists, including Indraneil Das, C. Kenneth Dodd, Jr., Arthur Georges, J. Whitfield Gibbons, John B. Iverson, Michael W. Klemens, Jeffrey E. Lovich, Russell A. Mittermeier, Edward O. Moll, David J. Morafka, Ian R. Swingland, Bern W. Tryon, and George R. Zug. The first issue of the journal is scheduled for November, 1993. The journal will be available by subscription and will not be limited to Specialist Group members. In addition, Chelonian Research Foundation is planning to publish a Monograph Series (not yet named) for longer chelonian research contributions, with the first issues planned for sometime in the near future. Works already in progress are: (1) a synoptic bibliographic database of all scientific turtle literature ever published, currently totaling over 24,000 scientific references; (2) a monograph by Peter C. H. Pritchard on the Galapagos tortoises, with special reference to their nomenclature and conservation status; (3) a synoptic nomenclator of all scientific names used for turtles at all systematic levels, currently numbering over 4800 names; and (4) a database of vernacular and common turtle names from around the world.
Interested individuals and scientists around the world will be encouraged to consider the CRF journal Chelonian Conservation and Biology and the planned Monograph Series as potential publication outlets for their turtle research. Anyone interested in making a donation to CRF, subscribing to the journal, or receiving more information about any of our activities, including applications for turtle research funding through The Linnaeus Fund (annual application deadline November 15), or information about our publications, please contact us at the address above.
Since the presentation of the above poster in July 1993, CRF has continued its programs of chelonian research support and scientific publications. Our grants program has made awards on an annual basis through both the Linnaeus Fund and general CRF support of other worthwhile turtle research and conservation projects, with 32 proposals receiving a total of $26,500. Our two research publications have met with resounding success. Our journal has expanded rapidly to fill a needed publication niche for all chelonian studies and our monograph series has been initiated.
Chelonian Conservation and BiologyInternational Journal of Turtle and Tortoise Research. This is the only international scientific peer-reviewed journal of cosmopolitan and broad-based coverage of all aspects of conservation and biology of all chelonians, including freshwater turtles, marine turtles, and tortoises. We have produced seven issues to date (April, 1997) publishing 126 scientific papers and over 800 pages of text. Since our initial issue in November 1993, our worldwide distribution has grown steadily, and we currently have a circulation of over 1,000 to more than 60 nations. The depth and breadth of our coverage of turtle research has also increased; included in the contents are the formal descriptions of three new genera and four new species of turtles, as well as articles on ecology, systematics, conservation, distribution, reproduction, sex determination, breeding and husbandry, pathology, physiology, morphology, and wildlife management. We publish about two issues a year with the subscription price a very modest $25 per volume of four issues (over two years) for individuals, and $50 for institutions.
Chelonian Research MonographsContributions in Turtle and Tortoise Research. The first issue in this series, The Galapagos Tortoises: Nomenclatural and Survival Status, by Peter C. H. Pritchard (85 pages, 53 color plates, hard or soft cover available), was published in July 1996. The second issue, a two-volume set, The Conservation Biology of Freshwater Turtles, is due out relatively soon.
In addition to these existing publications, CRF is also developing a series of more popular works on turtles entitled Cheloniana
Nepals extensive wetlands lie in a vast and varied riverine floodplain formed by the four major rivers (the Gandaki, the Koshi, the Karnali, and the Mahakali) that emerge from the Himalayas. This riverine floodplain is among the first few areas where both agriculture and human civilization had their beginning. Historically, the wetlands of the Koshi River in eastern Nepal were renowned for their abundance and diversity of turtles and fish, but it is now greatly impacted by human activity (damming, diversion, and channelization) and is the most highly vulnerable of the four river systems. Most of the rivers upper reaches remain in a pristine condition, but the lower reaches have been altered by the Koshi Dam, which has blocked all migration of fish and turtles. Because of changes in the river channel and sediment management activities, restoration of turtle habitat represents a significant environmental challenge and substantial cost. Nevertheless, restoration of the Koshi River wetlands ecosystem is vital to the management of the many remaining turtle populations of such species as Indotestudo elongata, Hardella thurjii, and Kachuga tecta. The present exhibit provides an overview of the ecosystem, biota, and endangered flora and fauna in the wetland at the bend of the Koshi River, at the religious temple there, and of the surrounding area. A conservation and management plan is presented for the threatened species in the wetlands of Nepal.Return to List
Highway and road traffic have been associated with significant decreases in the density of tortoise populations. Those decreases are most noticeable immediately adjacent to the roadway, but have now been documented to extend beyond 3.5 km from the road. Tortoise movement patterns suggest that highway and road traffic removes tortoises from a population faster than new tortoises can be recruited from adjacent habitat. Recently a tortoise preserve of approximately 584 km² was established in Piute Valley, Nevada, as partial mitigation for the take of 88 km² of tortoise habitat in Las Vegas Valley. This preserve is bounded and transected by approximately 80 km of federal and state highways and county roads that experience moderate to heavy traffic. A detectable decrement in tortoise sign extends at least 3.5 km perpendicular to and in both directions from these roads, indicating that 498 km² or 85% of this preserve is negatively impacted by roads. Unlike many other causes of mortality, highway impacts can be effectively managed and virtually eliminated by constructing tortoise barriers along highway shoulders. In addition to direct mortality, highways and roads fragment habitat and populations, support inflated predator populations, and provide for human access. Despite the obvious negative impacts of highways and roads on tortoise populations, no management agency in Nevada has yet required that highway and road impacts be effectively mitigated either through their management plans or through the permitting procedures associated with new roads or road expansion.Return to List
Captive Breeding Program
The Trachemys decorata captive breeding program was developed under the umbrella of the AZAs Chelonian Advisory Group by a consortium of eight zoological institutions, Beardsley Zoological Gardens, Bermuda Aquarium Museum and Zoo, Columbus Zoo, Institute for Herpetological Research, Jersey Wildlife Preservation Trust, Lowry Park Zoological Garden, Zoo Atlanta, and ZooDom (the National Zoo of the Dominican Republic). The breeding stock (founders) was collected in the southwestern region of the Dominican Republic in June 1991, as a cooperative effort between James Conyers of the Bermuda Aquarium Museum and Zoo and ZooDom staff. The project had a successful start the same year, and an informal studbook was maintained to effectively manage the captive population.
José Ottenwalder (National Coordinator, GEF-UNDP Dominican Republic Biodiversity Project, United Nations Development Program) has coordinated both field and education aspects of the program in the Dominican Republic and has provided information on translocation, monitoring, and wild status.
Translocation and Monitoring
Under a cooperative research and conservation effort, a reintroduction program for captive-bred T. decorata is being implemented by ZooDom with the financial support of the Columbus Zoo. In addition, both the Toledo Zoo and Cleveland Metroparks Zoo have contributed a Trovan reader, 245 transponders, 3 radio transmitters, and funds to monitor the reintroduced turtles. The protocol and methodology for the translocation have been drafted. Turtles hatched in 1992 and 1993 were released in fall 1994. An additional 20 turtles produced by U.S. institutions will be returned for release in May 1997. Released turtles will be monitored for at least 610 years. The reintroduction site is located within the boundaries of the Jaragua National Park, southwestern Dominican Republic. Jaragua is the largest protected area (1,400 km²) in the Dominican Republic and the insular Caribbean. The specific site, known as Laguana de los Chupaderos, was selected in January 1993 based on previous field experience, remoteness, and existing protective infrastructure. In May 1993 the site was surveyed in anticipation of the release. During this visit, areas of the habitat utilized by young turtles in the lagoon were located; several adult females were captured, marked, and released; and park wardens were briefed on the project.
Despite their full legal protection and threatened status, the species is heavily exploited for food in the Dominican Republic and Haiti. While illegal hunting for commercialization and subsistence use take place throughout the year, most animals are taken during the nesting season, directly reducing the fraction of the population with the highest reproductive value.
Currently there are 18.24.107 captive T. decorata distributed among seven institutions and two private parties. Overall, the population looks very good, with a healthy founder population that probably has a minimal inbreeding coefficient (based on capture records and personal observation of their habitat by J. Conyers). A formal studbook was approved for the species in February 1995 by the AZA Wildlife Conservation and Management Committee. Approval was based primarily on the following factors: