FROGLOG Newsletter of the Declining Amphibian Populations Task Force
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Heleophryne hewitti by Tim Halliday ISSN 1026-0269 FROGLOG Newsletter of the Declining Amphibian Populations Task Force December 2001, Number 48. monitoring will hopefully provide an establishing optimal future monitoring Project opportunity for future reflection on programs of these populations. potential indirect human perturbations Collection of data on habitat Anuran as possible culprits for apparently requirements and community mysterious amphibian declines in such structure, over and above simple areas (sensu the golden toad of Costa measures of diversity and abundance, By Emily Fitzherbert Rica). allows a more multidimensional & Toby Gardner The focus of our efforts was on approach to monitoring to be taken. It vocalizing species, predominantly of is hoped that a more detailed picture Project Anuran is a research the family Hylidae. Eight breeding will provide an enhanced ability to expedition founded as a joint initiative sites, representing a range of sub- identify changes in assemblage between students from the University habitat types from large, open structure and the potential onset of of Edinburgh and the University of permanent ponds to small ephemeral any future population declines. Belize (formerly University College forest pools, were assessed over a A second direction of our work Belize). The project’s main research total of 25 survey nights. Surveillance during Phase I was to conduct a aim is to establish an intensive of each site ran from 1900 to 0300 (or preliminary assessment of ground monitoring program of frogs and toads earlier if calling ceased), and data dwelling species, predominantly of the in the region around the research were collected at hourly intervals. genus Eleutherodactylus. Over one station of the Natural History Museum, Recordings were made on a nominal hundred man-hours of visual Las Cuevas, in the Chiquibul Forest scale of the audible abundance of encounter surveys, in addition to five Reserve, Belize. During the summer each species present following permanent drift-fence arrays, of 2000, the initial field phase of the MAYAMON protocol, and an produced an initially disappointing project collected baseline data on the additional measure of calling intensity result with four species, and less than diversity and relative abundance of (calls per minute) was taken to allow a 30 individuals recorded in total. This anurans, alongside basic ecological more detailed consideration of calling work serves to highlight both the low information such as habitat behavior and reproductive effort. In local abundance of these species and associations, community patterns and addition to these biotic data, the notorious difficulty of fairly calling behavior. The output of the measurements were made to record representing such a cryptic group. project is able to contribute directly to the abiotic environment on each Interestingly, during a week’s the monitoring efforts of the DAPTF in survey night, and each site was surveillance of a region of Caribbean the Yucatan region, under the Mayan mapped in detail to describe its floral pine (Pinus carribea), a much higher Forest Anuran Monitoring Project community. This intensive abundance was found, including an as (MAYAMON), coordinated by Dr. Jack methodology allowed a relatively yet unidentified ranid specimen. Eight Meyer. comprehensive assessment of specimens collected were deposited in Fieldwork is conducted in the vocalizing anurans around Las the Natural History Museum (London), immediate vicinity of the research Cuevas, with 12 species being where they will form an important part station, in an area of broadleaf recorded in particular detail. As well as of the ongoing revision of this little subtropical wet forest interspersed by a photographic record, digital known but highly diverse genus. evergreen forest. Standing at 500 m recordings were made of each species The standard survey methods elevation, Las Cuevas is within the which will form a valuable contribution used were effective in identifying and northern foothills of the Maya to the work of future monitoring groups describing the activity of the majority Mountains of Belize, which form part (see www.projectanuran.org). A of anuran species found. However, it of one of the largest expanses of number of pleasant surprises were is important to recognize, as noted continuous forest in Central America. uncovered, including evidence of a above, that some species are Although the area was extensively high local abundance of the regionally consistently misrepresented using cleared during the peak of the Maya rare Morelet’s tree frog, Agalychnis traditional techniques. One such group civilization (ca. 800 AD), apart from moreletti. Aside from an improved is what can perhaps be termed the selective logging for mahogany and understanding of diversity and relative ‘explosive’ breeders, such as the cedar, and harvesting of latex from the population abundance, an insight was burrowing toad (Rhinophrynus sapodilla tree, it has seen little further gained into the habitat preferences of dorsalis), and Mexican tree frog human disturbance. In this regard it each species, their calling patterns (Smilisca baudinii), whose true represents an excellent location from and the extent of temporal separation numbers are revealed only after which to monitor the dynamics of of each species in an assemblage. intense rains and in suitable clearings. anuran populations in relatively Such information is highly valuable in It is crucial that such considerations pristine tropical environments. Such The World Conservation Union (IUCN)/Species Survival Commission (SSC) The Open University ● The World Congress of Herpetology ● Harvard University are incorporated into future monitoring History Museum (London). twice with cell culture medium in TM programs in order to obtain a more Contact: Emily Fitzherbert & Toby NANOSEP centrifugal concentrator representative picture of amphibian Gardner, Project Anuran, Institute of tubes (molecular weight cutoff 300K, communities (even if it means Ecology and Resource Management, Pall Gelman) before being used to impromptu surveys in the middle of a Kings Buildings, University of inoculate the monolayers. Sterile storm at night!). Edinburgh, UK. water was used in place of the bleach Following the success of www.projectanuran.org to control for these manipulations. Phase I of Project Anuran, a second [email protected] After ten days we scored inoculated field phase is due to be conducted in cells for virus. the summer of 2001, with the intention Not surprisingly, simply of developing a long-term monitoring Disinfection of spraying several million virions with a program. The dearth of long-term, and Ambystoma disinfectant was not very effective. A adequately quantitative, studies of tigrinum spray of bleach reduced titers over a amphibian populations has all too Virus (ATV) thousand-fold, but fell short of frequently been identified as the major complete inactivation. The alcohol- shackle to improving our sprayed samples were still highly understanding of global declines and By Jesse Brunner & Tim active. Soaking samples in 70% their potential causes. Such Sesterhenn isopropyl alcohol and 10% bleach, information is critical in order to Ambystoma tigrinum Virus (ATV) and however, completely inactivated the distinguish between natural inter- related ranaviruses from North virus. One virion remained viable after annual variation in populations and the America, Europe and Australia 45 minutes of exposure to 70% progression of true, long-term trends. (Daszak et al. 1999) are highly lethal ethanol, not complete inactivation, but Ecosystems are dauntingly complex to amphibians, and are frequently over a million-fold reduction in active phenomena, and few more so than associated with epizootics of virus. tropical rainforests, where a seemingly amphibian populations. Researchers Ethanol, isopropyl alcohol, and infinite number of dimensions of have recognized that they may bleach are all adequate disinfectants variability, both spatial and temporal, inadvertently play a role in spreading for viral contamination, but must be serve to confound the naïve ecologist. these and other pathogens and have used methodically. It is not enough to Survey schemes of sufficient duration been urged to implement common simply spray surfaces. Instead, and breadth, so as to allow a high sense disinfection protocols to avoid liberally pour the disinfectant on spills degree of confidence in the spreading disease. Common methods and soak or scrub waders and other predictions of declines and include washing waders, boots, and equipment. Also, it is essential to keep assessment of decline rates, are a nets with a 10% bleach solution or disinfectants fresh: in an initial trial we pivotal step towards the vital with Quat-128. Our lab uses 70% found that the 70% ethanol we had unraveling of this complexity. While ethanol or isopropyl alcohol to been using in the lab was ineffective, little can be done to rectify the lack of disinfect surgical equipment when PIT presumably because it had degraded. historical records, it is in our hands to tagging or taking tail clips in the lab Heat, ultraviolet light and organic ensure the continued provision of new, and field. Ethanol is a standard matter degrade chlorine compounds accurate data sets. It is here that we disinfectant in most laboratories. quickly (Springthorpe and Sattar consider undergraduate contributions, Given that ranaviruses can survive up 1990). Each of these disinfectants