ABSTRACTS FROM THE 25th ANNIVERSARY MEETING OF THE
INTERNATIONAL HERPETOLOGICAL SYMPOSIUMMr. Patrick J. Baker III Department of Zoology, Miami University Oxford, OH 45056 Phone: (513) 523-3167 bakerpj@muohio.edu Dr. William P. McCord DVM c/o East Fishkill Animal Hospital Rte. 82 Hopewell Junction, NY 12533
In response to the global decline in turtle populations, the importance
of captive breeding by zoos and private breeders cannot be overstated. Unsustainable human
consumption and habitat destruction have pushed many species, especially those from Asian
countries, to the brink of extinction. The future survival of many affected species depends
upon the establishment of successful captive breeding groups both inside and outside range
countries, as well as in situ conservation efforts. In this talk and in an informal workshop
session, we will discuss our methods for the care and captive breeding of a wide variety of
turtles with diverse habitat requirements and other special needs. |
Eugene Bessette Ophiological Services, 13916 SW Archer Road, Archer, Florida 32618 Telephone: 352-495-3075 Fax: 352-495-2952 Email: ophiosvc@quixnet.net "The Dream" in my mind's eye is a worthy goal or process that adds value to other peoples' lives. The thin thread of "The Serpent" has interwoven so many relationships and opportunities to enable a select few who are willing to accept a life of passionate pursuit in this so often misunderstood fascinating world of the reptile. An overview of the process of events, which many people, will either like or dislike, regarding how society is embracing reptiles as a "main stream" part of the family unit. Where is it heading? How can we further continue to be a significant part of establishing what future generations to come will be able to observe or posses? Change is constant, so we must be also. Many questions to be asked but, together those interested people of like mindedness can ensure a viable world for the "Living Reptiles". |
KELLY BRADLEY Research Technician, Dallas Zoo, Reptile Department, 650 R L Thornton Frwy, Dallas, TX 75203 USA Phone: (214) 670-7573 Email: kabradley13@hotmail.com Cuba is home to over 90 species of lizards, including the Genus Chamaeleolis. This distinctive genus of anoline lizards is comprised of five taxa. Chamaeleolis chamaeleonides has one of the widest distributions among this group. Until recent years, this species was not represented in US collections due to political constraints, hence captive management techniques were unknown. In an effort to establish general husbandry protocols for large anoline lizards, the Fort Worth Zoo received a single pair of captive hatched adults in 1992 from the Czech Republic. This program has proven to be very successful, and to date the Fort Worth Zoo has produced more than 30 specimens, including second generation offspring. All aspects of this group's husbandry will be discussed, especially environmental requirements, diet, propagation, and neonate husbandry. |
KURT A. BUHLMANN Coordinator for Amphibian and Chelonian Conservation (Conservation International) and Deputy Chair of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group Conservation International Center for Applied Biodiversity Science 1919 M Street, NW, Suite 600, Washington DC 20036 At this point in time, there are few sectors of the conservation and herpetological communities that have not heard of the crisis facing Asian freshwater turtles and tortoises. The documentation of the unsustainable commercial exploitation of chelonians for the food and traditional medicine is convincing and undeniably real. Feelings of hopelessness have at times been nearly overwhelming. However, over the past year, substantial progress has been made towards achieving action on the behalf of beleaguered turtle species. International conservation organizations, zoos and aquariums, private turtle hobbyists, government authorities, and university research scientists have begun to work together on this problem. Fund-raising efforts are beginning to bear fruit. Long-range efforts are being launched on several fronts including support for education programs and law enforcement efforts in the range countries, identification of proposed and "protected" natural areas within range countries, field research and surveys to identify original distributions, habitats, and life histories of Asian turtle species, and the establishment of range country rescue centers. Of perhaps greatest immediate importance is the progress being made to establish genetically viable populations (Assurance Colonies) of every species of exploited chelonian and to house them in long term captive or semi-wild conservation programs. The Turtle Survival Alliance (TSA), a new working group of the IUCN, has been formed to facilitate action in this direction. Through collaborative efforts with the institutions and individuals referred to above, many of these "Assurance Colonies" will be established in the United States and hopefully in range countries through collaboration with international government authorities. They will be stocked primarily through the confiscations of illegally traded turtles. Should the combined education and enforcement efforts prove not effective in time to prevent the extinctions of turtle species in the wild in Asia, Assurance Colonies will "keep the pieces" and provide future reintroduction options. |
JON COOTE Director of Research T-Rex, Units 1 & 2 Belton Road West, Loughborough, Leicestershire, England LEII OTR Phone: 1509-610-310, Fax: 1509-610-304 Email: Jgcoote@aol.com Although the world's first reptile keepers may have been Mexican, historical data suggests that the beginnings of herpetoculture were primarily a British endeavor during the nineteenth century. This is indicated by the world's first chelonian building around 1820; the first zoo reptile house in 1849; and the first book, in English, on herpetoculture, 'The Vivarium', published in1897. The huge increase of individual's wealth, as a result of the British industrial revolution, provided the means, and the leisure, for many individuals to indulge themselves in the increasingly fashionable study of natural history, including herpetology. Increasing knowledge, higher expectations, and improved technology, contributed to the success of their captive care. The data available outlines some of the pioneering attempts of these, mostly forgotten, early herpetoculturalists to provide us with the foundations of the knowledge and skills that we enjoy today. Early captive breeding successes were more frequent than generally supposed. For at least one snake species it's captive breeding still remains to be repeated to this day. It is also possible to speculate, from available data, on the exchange of information between at least one of these early British pioneers and his colleagues in North America. |
EDWARD A. DeGRAUW, Ph.D. Biology Department, University of Puget Sound, 1500 N. Warner St., Tacoma, Washington, USA Phone: (253) 879-2744 Email:edegrauw@ups.edu The lizard genus, Abronia , is currently comprised of twenty-eight recognized species, more than half the species of the gerrhonotine anguid lizard diversity. This genus is found within a geographic region extending from southern Tamaulipas, Mexico to northeastern El Salvador and southern Honduras. Within this area the distribution of Abronia is restricted to the pine-oak and cloud forests of the highland regions (from 800->2,800 meters). Abronia are omnivorous, ovoviviparous, arboreal lizards with strongly prehensile tails. Like other anguids the tail is easily autonomized, which affects their suitability for arboreal existence and the ability of being allowed to copulate. They are active thermoregulators with preferred body temperatures ranging from 22-28șC and an upper thermal limit of 33-35șC. They have a well developed chemosensory ability that they use in tracking of prey, which consists of a wide variety of vertebrates and invertebrates. Chemosensory ability allows recognition of conspecifics by sex and reproductive status. The lizards are somewhat solitary and intraspecific aggression is common, particularly between males. With the exception of females and their own offspring, adults have been known to eat neonates. Breeding within this genus generally occurs in September-October with birth of young in May-June. Litter sizes range from 1-17. Neonates are 30-40 mm SVL with weights ranging from 2.5-5.0 g. They are hardy in captivity, but successful breeding of this genus requires high UVB radiation and active management of temperature on a daily and annual basis. |
EDWARD A. DeGRAUW, Ph.D. Biology Department, University of Puget Sound, 1500 N. Warner St., Tacoma, Washington, USA Phone: (253) 879-2744 Email:edegrauw@ups.edu The lizard genus Xenosaurus consists of at least six species of crevice-dwelling lizards found from Tamaulipas, Mexico south to Alta Verapaz, Guatemala. The species within this genus are found in a variety of habitats ranging from tropical to nearly xeric. Most of the species are thermoconformers (22-25ș C)that exhibit no basking behaviors with an upper thermal limit of approximately 37șC. They are suited to a crevice-dwelling lifestyle with varying degrees of flattened body and head morphology and choose crevices with a height approximately 0.75 times the length of their head. The skin of these lizards allows water to be drawn by capillary action anterior along their body to the corners of their mouth for drinking. Food consists primarily of Orthopterans and Lepidopteran larvae, which are found within the crevices the lizards inhabit. The species within this genus are solitary, with varying degrees of aggression displayed toward conspecifics and the degree of aggression changing with reproductive status. Some members of the genus demonstrate parental-neonate associations lasting up to 55 days which are adaptive to the offspring, while in other species the young disperse immediately to avoid the cannibalistic behavior of the adults. The lizards are hardy in captivity and captive husbandry and breeding requirements are minimal. Care must be taken with groupings of some species to avoid potentially damaging aggressive encounters. |
NATHAN DUNSTAN (1) , TIM NIAS (1), JAMES BEATON (2) and PETER MIRTSCHIN (1) (1) Venom Supplies Pty Ltd, PO Box 547, Tanunda, South Australia 5352, (2) PO Box 1940, Humpty Do, Northern Territory, Australia 0836 The taipan, Oxyuranus scutellatus, is a large elapid with highly toxic venom, which occurs in the northern coastal regions of Australia and is used widely for venom production for antivenom and medical research. Venom Supplies currently has 38 taipans ranging from juvenile to adults for the purpose of venom extraction. Here we report the care and maintenance required to manage taipans to a Good Manufacturing Practice (GMP) venom production over a period of 2 years from 1999 to 2001. In the study period we there were 44 records of milkings and achieved an average yield of 868 mg per milking. We found that a minimum fortnightly milking frequency was adequate recovery time for the snakes with an average of 20 milkings per year. The snakes are kept between a minimum of 31 deg C and a maximum of 32 deg C. Special attention to heating has had a positive effect on the temperament. Minimal health problems were experienced with the snakes. Some of the problems were an infected fang sheath, protozoan infection and there was 1 death due to a lesion of the liver. Particular consideration to hygiene, minimized health problems. Despite their deadly potential, generally these snakes were easy to handle, good natured and are good venom producers. |
JIM HARRISON Kentucky Reptile Zoo/Captive Born Venoms 200 L & E Railroad, Slade, KY 40376 tel: 606-663-9160 fax: 606-663-6917 Email: kyreptil@mailhost.mis.net Over the past several years there has been an increase in the captive breeding and keeping of venomous reptiles, and an increase in envenomations by exotic snakes has been observed. Several case histories of exotic envenomations by Elapidae and Viperidae in the U.S. will be discussed, including observations of systemic and local effects of venoms, and reactions to antisera. Post-bite consequences of necrosis, surgery, and rehabilitation will be addressed. |
RICK HUDSON Deputy-chair IUCN Iguana Specialist Group, Conservation Biologist Fort Worth Zoo,1989 Colonial Parkway Fort Worth, TX 76110 Telephone: 817-759-7177 Fax: 817-759-7501 Email: Iguanhudso@aol.com The iguanas of the West Indies comprise two genera, Cyclura (eight species) and Iguana (two species), with 18 recognized taxa. These large herbivorous lizards inhabit fragile island ecosystems and most populations have suffered substantial declines largely due to the activities of man. Their tropical dry forest habitats have been eliminated or altered by human development and they are particularly sensitive to the negative effects of introduced mammalian species (feral exotics). As a group these iguanas represent the most highly endangered lizards in the world and recent IUCN Red List assessments rank nine taxa as Critically Endangered, four as Endangered, and four as Vulnerable. Several species are at high risk of extinction and are not predicted to survive without conservation intervention. This paper will review the natural history and conservation status of Caribbean iguanas, and discuss some of the research and recovery programs that have been initiated to prevent their extinction. Zoos have played a leading role in the implementation of these programs and these efforts will be highlighted. |
BOB MYERS American International Rattlesnake Museum, 202 San Felipe NW.,Albuquerque, NM 87104 Telephone:(505) 242-6569, www.rattlesnakes.com Private reptile exhibits come and go. What makes one succeed and the next dwindle from existence? Is the formula for success measured in well planned and researched details, or is it just a matter of common sense? Are there other characteristics to the equation that may be a bit more elusive? In this presentation you will learn the path taken by a former biology teacher, Bob Myers of the American International Rattlesnake Museum in Albuquerque, New Mexico. The Rattlesnake Museum just concluded its tenth year and doesn't seem to be losing steam. The Museum has been featured on National Geographic Explorer, the Discovery Channel, Good Morning America, Good Morning Television (in Europe), Reptile Magazine, Amphibian and Reptile Hobbyist Magazine, and scores of additional local, regional, national and international television shows, radio programs, magazines, newspapers and travel guides. And, while the Museum's logo T-shirts don't quite rival the numbers of Planet Hollywood's or Tommy Hilfiger's, they are increasingly recognized by reptile enthusiasts around the world. And yet, with all the hype, the Museum's primary concept remains, education. Visitors are willing students in this Crotalid classroom. Myths are explored, phobias cured, mysteries revealed and respect gained for these curious reptiles, and surviving students to this"striking" exhibit leave with a diploma, their "Certificate of Bravery!" |
TIM NIAS (1), BRADLEY OLIVER (3), JAMES BEATON (2), PETER MIRTSCHIN (1) (1) Venom Supplies Pty Ltd, PO Box 547, Tanunda, South Australia (2) PO Box 1940, Humpty Do, Northern Territory, Australia 0836 (3) PO Box 559, Two Wells, South Australia 5501 Inland taipans inhabit a very arid part of Australia and little is known about the ecologies. This paper reports on breeding this species in captivity over a period of 5 years at Venom Supplies Pty Ltd. There were 11 clutches with a total of 120 eggs produced in this period from which there were 57 males, 58 females and 5 unsexed offspring. Mean egg widths for both male and female were 34mm and mean lengths for males were 67mm and 69mm for females. The mean egg weights were 47gm for males and 49gm for females. For both egg weights and egg widths, most of the eggs were in the lower half of the range whereas the egg lengths were evenly distributed through the range. There were a higher number of females with mid range snout vent lengths (SVL) than males with the mean SVL for males 400mm and 397 for females. Tail lengths were evenly distributed through their ranges for both males and female with means of 67 for males and 63 for females. Copulations varied between early September through to mid January. Ovipositions varied between late November to end of March. The mean gestation period was 67 days. Hatching varied between late January to early June. The mean incubation time was 73 days. The mean copulation plus incubation was 140 days. |
GREG LIPPS and R. ANDREW ODUM Department of Herpetology, Toledo Zoological Society, P.O. Box 140130, Toledo, OH 43614 The Wyoming toad, Bufo baxteri, is perhaps the most endangered amphibian in the North America. It became extinct at its last remaining wild refuge in the early 1990s and its recovery has been entirely based on captive reproduction and repatriation from a small captive nucleus. Unfortunately the captive population has been plagued with challenges and sporadic breeding, which has hindered repatriation efforts. Many husbandry protocols at different institutions were tested with different successes. What factors were important for successful reproduction were not readily apparent so a program was established to quantify relationships between numerous husbandry variables and reproduction. Factors that were examined included length of hibernation period, age of animal, mass of animal, temperature of hibernation, length of time between hibernation and breeding, inbreeding coefficient of resulting offspring, and number of hormonal injections. Factors that showed significant relationships to successful reproduction included: number of injections of hormones, length of hibernation period, mass of females, and age of animal. This presentation will discuss the history and challenges of the Wyoming toad conservation efforts, as well as efforts to quantify husbandry parameters necessary for successful reproduction. |
CHARLIE PAINTER New Mexico Department of Game and Fish, Santa Fe, New Mexico USA Phone: (505) 476-8106 Email: CPainter@state.nm.us On 24 January 1975, the New Mexico ridgenose rattlesnake, Crotalus willardi obscurus, was listed as Endangered by the New Mexico Department of Game and Fish. On 4 August 1978, the species became the first rattlesnake listed as Threatened under authority of the federal Endangered Species Act. Limited habitat and the potential for overcollecting were given as the primary reasons for these listings. Since that time numerous investigators: Klauber, Degenhardt, Altenbach, Applegarth, Painter, Barker, and Holycross have explored the Animas and Peloncillo mountains of southwest New Mexico and southeast Arizona and the Sierra San Luis of northern Sonoran andChihuahua, Mexico and have added considerably to the understanding of this unique montane rattlesnake. The earliest studies concentrated on the distribution and habitat use, while an emphasis on systematics, ecology, natural history, and conservation have dominated the later studies. Most of the data in this presentation were collected by Painter and Holycross. We worked in the Animas Mountains (New Mexico) from 1994 - 1999, the Peloncillo Mountains (Arizona and New Mexico) from 1995 - 1998, and in the Sierra San Luis (Sonora and Chihuahua) in 1998. Field teams dedicated 1,355 "person-days" searching for C. w. obscurus over the course of the study. 206 individual C. w. obscurus (160, Animas Mountains; 17, Peloncillo Mountains; 29, Sierra San Luis) were marked during these studies. |
JIM PETHER Centro de Investigaciones Herpetologicas. PO: BOX 101 Galdár 35460. Gran Canaria. Spain. Tel. (34) 928-551269 Fax.(34) 928-551242 Mobil. 669-478130 E-mail jim.pether@wanadoo.es The Canary Island archipelago situated close to the coast of Morocco, although poor in herpetofauna is rich in endemisms. Of the 17 species of reptiles and amphibians in the Canary Islands 14 are endemic, the other three being introduced species. In the last 25 years three new species have been rediscovered, two in the last 5 years including Gallotia gomerana from the island of Gomera. G. gomerana was first described in 1985 by a German mamalogist (Hutterer), also ancient documents from the 16th century mention a large lizard on Gomera. A team of biologist rediscovered a relict population of these lizards in 1999 on the cliffs of La Merica in the municipality of Valle Gran Rey. A total of six lizards, three males and three females, were captures over a period of six months. The lizards are to be the founder group for a captive breeding program run by the Department of the Environment of the Canarian Government. Captive breeding may be the only salvation for these extremely rare lizards. A provisional census has shown a wild population of only five lizards and it is calculated that a maximum population of only twenty may exist. This makes G. gomerana among the most endangered vertebrate in the world. |
LOUIS W. PORRAS 7705 North Wyatt Earp Avenue, Eagle Mountain, UT 84043 wildlife@sisna.com The Colorado Plateau is a physiographic region of southwestern North America that encompasses most of northern Arizona and eastern Utah, parts of western Colorado, and extreme southwestern Wyoming. The area is drained primarily by the Green and Colorado rivers, and is characterized by broad plateaus, ancient volcanic mountains, and deeply dissected canyons. The Colorado Plateau is one of the most scenic regions in the world. The western rattlesnake (Crotalus viridis) has long been recognized as the most widespread and phenotypically variable rattlesnake in North America and has been partitioned into nine subspecies based on scalation, size, color, pattern, and geographic distribution. The Colorado Plateau is pivotal to our understanding of the evolution of the C. viridis group, as six members potentially contact one another at or near the Grand Canyon. Recent molecular studies investigating specific regions of mtDNA do not support monotypic status for the group but rather indicate two major lineages (Douglas et al., in press). An overview of the rattlesnakes of this region is presented, and aspects of their natural history and evolutionary relationships are discussed. |
ALLEN REPASHY Sandfire Dragon Ranch, 8440 Production Ave San Diego, Ca. Telephone: 760-726-4878 Email: allen@sandfiredragonranch.com Sandfire Dragon Ranch became the name associated with Bob Mailloux in 1992, after he developed the beautiful red color morph of the Inland Bearded Dragon Pogona vitticeps. Bob had been working extensively with Reptiles and Amphibians for approximately 35 years at that point, with his primary emphasis on amphibians. Bob and I became friends in the early nineties when our paths crossed through the trade. We quickly became friends and exchanged ideas, shared techniques, and discussed our long term goals. We soon began discussing ways to combine Bobs years of knowledge, and my strong business background, to create a new facility directed at large scale propagation of Herps for the pet trade. In about 1996, we began pooling our resources, and developed methods and refined techniques to successfully produce select species of frogs and lizards on a commercial scale for the pet trade. A brief over view of our lizard propagation techniques will be presented. I will mainly focus on our amphibian propagation. The methodology to reproduce frogs began as a "green house style" style set up with manipulation of environmental cues at the appropriate time of year. This type of production has remained fairly constant, only the scale had to be changed. Rearing methods to achieve the large numbers of specimens for commercial production has changed significantly. Details on the development of an intensive aquaculture system to optimize this production will be discussed. Observations on the effects of water quality, pheromones, nutrition, temperature and density on the survival and growth rates will be provided. In developing these methods my opinion on health problems and deformities such as "spindle leg" syndrome will be provided. These methods were primarily developed for several species of Old World tree frogs in the genus Litoria. The process has been a learning experience, it has answered many questions and generated many more. |
GERARD T. SALMON 30 Appletree Drive Rhinebeck, New York 12572 gtstexmex@aol.com Confusion regarding natural history and taxonomy has plagued this group of kingsnakes since the discovery of each of the species (currently recognized as Lampropeltis alterna, L. mexicana and L. ruthveni). Due to their secretive nature and difficulty in collecting specimens, captive breeding of specific locality founders has shed light on the colors and patterns possible in these often polymorphic snakes. Recent work in Mexico has yielded new information on their geographic distribution and microhabitat preferences. Gerry has been working on this species group for more than 15 years and has done extensive research in museum collections and in the field. This talk will highlight some of the information that is a work in progress and several papers are due to be published in the near future. |
SCOTT J. STAHL, DVM, DABVP-AVIAN Eastern Exotic Veterinary Center Fairfax, Virginia USA Complications with laying eggs or giving birth to young are common sequelae of breeding reptiles. Veterinarians treating reptiles in practice will often be presented with reptiles with dystocia. Dystocia in reptiles can be multifactorial and may be the result of inappropriate nesting sites, stress, dehydration, malnutrition, obesity, salpingitis, obesity, malformed eggs and abnormal reproductive anatomy. This presentation will discuss the general clinical presentation and commonly used medical and surgical options for the treatment of dystocia in snakes, lizards and chelonians. |
BRYAN L. STARRETT South Carolina Aquarium, 100 Aquarium Wharf, Charleston, SC 29401 While the geographic distribution of herpetofauna throughout most of North America is well understood and extensively represented in the literature, the biogeography of Grand Canyon amphibians and reptiles (particularly viperids) remains poorly known, and published indices are scarce. The Grand Canyon lies within the Colorado Plateau region and extends nearly 278 miles from Lake Powell at the Utah border to Lake Mead, Nevada encompassing 1900 square miles. The dearth of knowledge regarding occurrence and distribution of herpetofauna is due largely to the enormity and remoteness of habitat. Miller et al (1981) identified 39 reptile and 7 amphibian species in Checklist of the Reptiles and Amphibians of the Grand Canyon Area, and in Amphibians and Reptiles of the Grand Canyon (1982). Eleven taxa were identified as "Problematical Species", some of which are unlikely to occur naturally in the vicinity of the Grand Canyon. The author and other individuals participated in a series of river trips through most of the Inner Gorge of the Grand Canyon from 1991 to 1999. The occurrence of some species previously considered rare is frequently documented. Of particular interest is Crotalus mitchelli and C. viridis occurring sympatrically and syntopically. Much confusion exists regarding identification, and hence, distribution of these species in the Canyon. Herein we elucidate the distribution of these and other viperids in the Grand Canyon. |
PETER TAYLOR Department of Herpetology, Saint Louis Zoological Park One Government Drive, St Louis, MO 63110 Telephone:(314) 781-0900 ext. 255 Email: petetaylor@stlzoo.org This paper will accomplish several objectives. First, it will give a description of Cuvier's Dwarf Caiman Paleosuchus palpebrosus and its place within the Crocodilia relative to other species. Notes on its congener, Schneider's Dwarf Caiman P. trigonatus, and on an ecological analog, the West African Dwarf Crocodile, Osteolaemus tetraspis will further define its ecological niche and taxonomic position. Because of the paucity of wild observations of such basic events as nesting and feeding, much captive information will be brought to bear. Mastery of captive management is a desirable goal in itself. Additionally, some details of zoo husbandry and reproduction can complement and support that which has currently been observed in nature. The comparatively robust status of this species from a population and conservation standpoint, should create a reasonable time buffer for these investigations to take place in the future. A life history problem that has been addressed by other investigators is the lack of environmentally available heat for nest incubation in forest crocodilian species. It has been demonstrated that P. trigonatus will exploit ground termite species and their heat generating mounds for warming nests. This has not been seen in wild P. palpebrosus. Captive data points toward P. palpebrosus having at least lower end thresholds for hatching young and concomitantly reducing temperatures required to produce gender modes. Implications are that the tolerance fr less sunny pastures of "cool crocs" broadens ecological space the order. |
DR. ROBERT WILKINSON Southwest Missouri State University, Department of Biology, Springfield Missouri 65804 Email: ktwilkinson@worldnet.att.net Missouri populations of the long-lived hellbender, Cryptobranchus alleganiensis, were censuses in 1998-1999. These data were compared to data from previous studies from the 1970's and 1980's. The hellbender populations appear to have declined in all rivers sampled. This decline is characterized by an increase in average body size, due to an apparent lack of recruitment of young into the population. Hellbenders from all rivers, except the Niangua, tended to be in better body condition in the 1998-1999 sample than they were in the past. It is not known whether the population decline for hellbenders has a single cause of whether each population has experienced independent declines. |
ROBERT T. ZAPPALORTI Herpetological Associates, Inc., 575 Toms River Road, Jackson, New Jersey 08527, USA E-mail: RZappalorti@aol.com Herpetological Associates, Inc. conducted surveys for corn snakes (Elaphe guttata) and pine snakes (Pituophis melanoleucus) from 1977 - 1997 for the New Jersey Department of Environmental Protection, Division of fish and Wildlife, Endangered and Nongame Species Program (NJDEP), the Trust for Public Land, the New Jersey Conservation Foundation, and The Nature Conservancy. Evaluations of potential suitable habitats were made within the historic know range in southern New Jersey. Critical habitat for corn snakes (e.g., such as winter dens and nesting areas) were confirmed at 14 sites in Burlington County, 2 sites in Cumberland County, and 5 sites in Ocean County. Critical habitat for the northern pine snake was also found 9 sites in Atlantic County, 16 sites in Burlington County, 1 in Camden County, 1 in Cape May County, 3 sites in Cumberland County, 1 in Gloucester County, 1 in Monmouth County, and 10 in Ocean County. Methods to capture and observe these snakes is provided in order to determine presence or absence along with the biology and important life history notes. Radio-telemetry was used to determine habitat selection, activity range size, seasonal movements, nesting sites, and winter hibernation sites. The average home range of 21 northern pine snakes was 50. 10 hectares (125.29 acres), whereas the average home range of 5 corn snakes was 18.30 hectares (45.23 acres). Likewise, between 1984 and 1986, radiotelemetry was used to monitor the movements, foraging strategy, and habitat use of the timber rattlesnake (Crotalus horridus) in southern New Jersey. Movement patterns of males and non-gravid females consisted of constantly shifting, non-overlapping activity areas. In most cases these snakes moved in a looping pattern during the active season and returned to the same hibernation site from which they departed. Males generally exhibited the largest activity ranges (N =7, mean 48.6 hectares, range 3.5 to 123.5 hectares), and the sizes of their ranges were positively correlated with the number of days the snakes were monitored. This was not true for gravid or non-gravid females. Gravid females exhibited more static, overlapping activity areas and shorter migratory distances (N= 7, mean 9.9 hectares, range 1.8 to 20.4 hectares) from hibernacula. Whereas non-gravid females moved farther from overwintering sites (N = 6, mean 17.3, range 5.4 to 46.4 hectares)then gravid females, but not as far as males. Typical habitat consisted of pitch pine and Virginia pine mixed with black, post, scarlet, scrub, and white oaks. These upland forests often have intermittent stream corridors, Sphagnum bogs, or grassy savannahs interspersed within them. Pine Barrens rattlesnakes used underground rodent burrows and natural spaces under the root-systems of cedar, sour gum, and red maple trees along stream edges for winter refuge. The ground surface at hibernacula is often covered with a thick carpet of Sphagnum moss, in densely vegetated Atlantic white cedar stands. Early in April 1995, an extensive forest fire burned an estimated 20,000 acres (8,094 hectares)of Pinelands. Approximately 90% of the forest area used by rattlesnakes during the previous study was burned. In an attempt to learn about changes in habitat selection, activity range size, or behavioral shifts following a major forest fire, follow-up radio telemetry studies to Reinert and Zappalorti's (1988a) earlier studies have been initiated. This included foraging sites, gestation sites, and hibernating sites. Fortunately, at the time of the fire, the rattlesnakes were stillunderground. When they emerged from hibernation, only two individuals had minor facial burns which subsequently healed after shedding. This massive fire-induced alteration of the structural environment surrounding the overwintering habitat of rattlesnakes provided an opportunity to examine responses of snakes to infrequent natural disaster. Data collected after the fire provided a direct comparison for pre-burn and post-burn habitat disturbance. Preliminary results of this investigation include the first observation of two neonate C. horridus hibernating in an artificial den, similar to the type described in Zappalorti and Reinert (1994). This was the first time Pine Barrens rattlesnakes were observed hibernating in an upland situation. One of the two individuals was radio-tracked for two successive years. In the fall of 1995, it shifted to a more typical situation at the stream-edge of the cedar swamp, and returned to the same location in the winter of 1996. Another first-time observation involves the shift from one overwintering stream to another by a postpartum female in the winter of 1996. After emerging from her overwintering burrow in the spring of 1995, she moved south through the burnt forest about 1.6 km to a trash-pile on the edge of a sand road. She remained there for about one month, then moved 25 meters east to a field-edge mound. After giving birth to 12 young, the female moved 0.5 km, towards a stream where she overwintered in 1995. This was the first time we observed a Pine Barrens rattlesnake shifting stream corridors to hibernate. Such behavior has important implications because it demonstrates non-fidelity to a particular stream corridor and suggests that Pine Barrens timbers may be more pioneering in surrounding available habitat than previously thought. In 1995 the snake's hibernaculum was engulfed by the fire, whereas her location on the new stream had not been burned. Several other radio-monitored rattlesnakes moved to unburned sections of the den-stream, while a few returned to partially burned sections. Shifting ovenvintering sites may be beneficial to the survival of a population, especially if the habitat becomes radically altered by natural or human causes. Thanks to funding provided by The Nature Conservancy and the Trust for Public Lands, we have completed 5 years of this comparative radio-tracking study in the burned acreage of the Pine Barrens. The information obtained will not only provide answers to basic ecological questions, but it will also generate invaluable insight useful to the NJDEP and other wildlife conservation groups who are interested in the management of these 3 declining species. |
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