Amphibian Declines

Amphibian Declines: The Conservation Status of United States Species

Edited by MICHAEL LANNOO
Copyright Date: 2005
Edition: 1
Pages: 1115
https://www.jstor.org/stable/10.1525/j.ctt1pp5xd
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  • Book Info
    Amphibian Declines
    Book Description:

    This benchmark volume documents in comprehensive detail a major environmental crisis: rapidly declining amphibian populations and the disturbing developmental problems that are increasingly prevalent within many amphibian species. Horror stories on this topic have been featured in the scientific and popular press over the past fifteen years, invariably asking what amphibian declines are telling us about the state of the environment. Are declines harbingers of devastated ecosystems or simply weird reflections of a peculiar amphibian world? This compendium—presenting new data, reviews of current literature, and comprehensive species accounts—reinforces what scientists have begun to suspect, that amphibians are a lens through which the state of the environment can be viewed more clearly. And, that the view is alarming and presages serious concerns for all life, including that of our own species. The first part of this work consists of more than fifty essays covering topics from the causes of declines to conservation, surveys and monitoring, and education. The second part consists of species accounts describing the life history and natural history of every known amphibian species in the United States.

    eISBN: 978-0-520-92943-2
    Subjects: Biological Sciences

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. ACKNOWLEDGMENTS
    (pp. ix-x)
  4. ADVISORY BOARD
    (pp. xi-xii)
  5. CONTRIBUTORS
    (pp. xiii-xviii)
  6. PREFACE
    (pp. xix-xxii)
    MICHAEL LANNOO
  7. PART ONE Conservation Essays
    • INTRODUCTION
      • ONE Diverse Phenomena Influencing Amphibian Population Declines
        (pp. 3-6)
        TIM HALLIDAY

        Twelve years after the Declining Amphibian Populations Task Force (DAPTF) was established, those who have to answer queries from other biologists and the media are still unable to say why amphibians are declining. In this chapter, I briefly discuss a number of issues concerning amphibian declines and, in so doing, will attempt to reveal some of the reasons for these declines.

        Scientific and media attention in the last twelve years has been largely focused on the sudden collapses of amphibian faunas in protected areas, notably in Australia, Central America, and the Pacific Northwest of the United States. This attention is...

      • TWO Why Are Some Species in Decline but Others Not?
        (pp. 7-9)
        MARTHA L. CRUMP

        Since residents of Monteverde began to informally monitor the golden toads’(Bufo periglenes)activity in 1972, these toads have emergeden massefrom their underground retreats every year in April and May. During 1988, however, something was definitely wrong. I found only one golden toad in the Monteverde Cloud Forest Reserve in northwestern Costa Rica; in the previous year I had seen over 1,500 individuals. During the following month, I could not find harlequin frogs(Atelopus varius)at my study site along the Río Lagarto near Monteverde—on a single day just the year before, I had found over 700...

      • THREE Philosophy, Value Judgments, and Declining Amphibians
        (pp. 10-14)
        SARAH AUCOIN, ROBERT G. JAEGER and STEVE GIAMBRONE

        As quoted, Shapin’s (1996) view of how the modern natural sciences establish knowledge (based on the historical roots of the Scientific Revolution) provides an interesting framework from which to examine contemporary discourses concerning “declining amphibian populations.” If one believes the paradigm advocated by Shapin, then amphibian population and community ecologists should follow a rigorous philosophy of science in their studies of populations and species, in which “society is kept at bay.” Being trapped by “the problem of induction” (Hume, 1748; Popper, 1959), these ecologists might emphasize rigor by basing research programs on the hypothetico-deductive model (Lakatos, 1970). Such rigor, then,...

      • FOUR Embracing Human Diversity in Conservation
        (pp. 15-16)
        WHIT GIBBONS

        Amphibians are in decline. It is not important whether decline means the number of species, populations, or individuals, or whether amphibians will always be perceived as declining because of varying numbers of offspring, or whether the natural fluctuations in amphibian communities make quantification difficult. Fewer amphibian species, populations, and individuals are on Earth today than were present in the last century, primarily because most species no longer have as much of their requisite natural habitat as they did a century ago, a decade ago, or even a year ago. The formula is simple, and it does not require intense scientific...

      • FIVE Declining Amphibian Populations Task Force
        (pp. 17-21)
        W. RONALD HEYER and JAMES B. MURPHY

        During the 1970s and 1980s, researchers in many parts of the world reported seemingly drastic population declines and disappearances of amphibians. International amphibian and reptile scientific societies held special sessions at annual meetings. In February 1990, the U.S. National Academy of Sciences sponsored an international meeting to determine whether there was cause for alarm.

        From these meetings, researchers reached two conclusions: (1) although most of the evidence for amphibian declines was anecdotal, the number and geographically dispersed nature of the informal reports indicated that the situation should be addressed and treated as a possible environmental emergency and (2) an international...

    • DECLINES
      • SIX Meeting the Challenge of Amphibian Declines with an Interdisciplinary Research Program
        (pp. 23-27)
        JAMES P. COLLINS, NICHOLAS COHEN, ELIZABETH W. DAVIDSON, JOYCE E. LONGCORE and ANDREW STORFER

        Amphibian populations fluctuate in size (Pechmann et al., 1991; Alford and Richards, 1999), but around 1989, herpetologists became alarmed by reports that populations and even species were declining—some to extinction (Blaustein and Wake, 1990; Corn, 1994a; Bury et al., 1995; Pounds et al., 1997). By 1997, this problem led three of us (J.P.C., A.S. and E.W.D.) to organize a workshop. This workshop, “Amphibian population dynamics: Is the threat of extinction increasing for amphibians?” was supported by the National Science Foundation (NSF) and held in May 1998 in Washington, D.C. As a practical matter, we could not invite all researchers...

      • SEVEN Biology of Amphibian Declines
        (pp. 28-33)
        DAVID M. GREEN

        The evident decline of amphibian populations today is worrisome and surprising. Infectious disease (Cunningham et al., 1996; Lips, 1999; Morell, 1999), parasitic infection (Sessions and Ruth, 1990; Johnson et al., 1999), ultraviolet radiation (Blaustein et al., 1994c), chemical pollutants (Berrill et al., 1997b; Bonin et al., 1997b; Hayes et al., 2002a,c), introduced predators (Liss and Larson, 1991; Bradford et al., 1993; Morgan and Buttemer, 1996), habitat destruction (Blaustein et al., 1994a; Green, 1997c; Corn, 2000), and climate change (Pounds et al., 1999) are among the many probable causes touted as explanations for present-day declining amphibian populations. Yet, amphibians are abundant,...

      • EIGHT Declines of Eastern North American Woodland Salamanders (Plethodon)
        (pp. 34-46)
        RICHARD HIGHTON

        Recent declines and extinctions of amphibian populations have been reported in many areas of the world. A majority of the documented declines are in easily detectable anuran species. In eastern North America, flatwoods salamanders(Ambystoma cingulatum)have declined and have recently been added to the threatened species list, and southern dusky salamanders(Desmognathus auriculatus)have disappeared at some sites (Dodd, 1998). A decline has been reported in a small part of the range of green salamanders (Aneides aeneus; Snyder, 1991). However, other published reports indicate little change in eastern salamander populations (e.g., Pechmann et al., 1991; Hairston and Wiley, 1993;...

      • NINE Decline of Northern Cricket Frogs (Acris crepitans)
        (pp. 47-54)
        ROBERT H. GRAY and LAUREN E. BROWN

        At the end of the nineteenth century, there were indications that northern cricket frogs(Acris crepitans)were numerous in the midwestern United States. Garman (1892) found the species was “one of the most abundant members of the family in all parts of Illinois,” and Hay (1892) similarly indicated it was “one of our commonest batrachians” in Indiana. This abundance continued well past the middle of the twentieth century in both of these states (Smith, 1961; Minton, 1972). Campbell (1977) published the first report of a cricket frog decline in the relatively small area occupied by the species in extreme southern...

      • TEN Overwintering in Northern Cricket Frogs (Acris crepitans)
        (pp. 55-58)
        JASON T. IRWIN

        Although winter weather in north-temperate regions may dominate 6–9 months of the year, this season has received relatively little attention in studies of amphibian life history. While some aspects of behavioral and physiological responses to cold have been elucidated, we generally have not applied this understanding to the management and conservation of amphibian populations. To begin to address this concern, I provide a basic description of the various overwintering methods used by amphibians and of the physiological responses that accompany these methods. Then I describe the unique overwintering method of northern cricket frogs(Acris crepitans)and consider how their...

    • CAUSES
      • ELEVEN Repercussions of Global Change
        (pp. 60-63)
        JAMIE K. REASER and ANDREW BLAUSTEIN

        Living organisms must track the climate regimes appropriate for their survival, adapt to new conditions, or go extinct. In the 1970s, climatologists began to warn that Earth would experience rapid changes, induced in part by emissions of “greenhouse” gases resulting from the burning of fossil fuels, intensifying land use, and reduction in forest cover. They projected that global temperatures would rise substantially in the coming decades (e.g., Climate Resources Board, 1979). At approximately the same time, climatologists also became concerned that chloroflourocarborns (CFCs) and other commonly used industrial gases were depleting the earth’s protective ozone layer, thereby increasing the amount...

      • TWELVE Lessons from Europe
        (pp. 64-74)
        K. HENLE

        Amphibians and reptiles are coming to be regarded in Europe as indicator groups for a general decline in species diversity (Thielcke et al., 1983; Blab, 1985, 1986). The decline of these groups has been well documented in Europe and on other continents as a result of numerous surveys (e.g., Lemmel, 1977; Feldmann, 1981; Hayes and Jennings, 1986; Hölzinger, 1987; Osborne, 1990; Carey, 1993; Mahony, 1993). Even in areas little affected by human activity, declines seem to have occurred. However, to date, adequate investigations of the declines and their actual causes are lacking (Pechmann et al., 1991; but see Osborne, 1989)....

      • THIRTEEN Risk Factors and Declines in Northern Cricket Frogs (Acris crepitans)
        (pp. 75-86)
        VAL R. BEASLEY, SANDRA A. FAEH, BRIGIT WIKOFF, CRAIG STAEHLE, JOYCE EISOLD, DONALD NICHOLS, REBECCA COLE, ANNA M. SCHOTTHOEFER, MARTIN GREENWELL and LAUREN E. BROWN

        Reports from around the world have indicated declines in numerous amphibian species (e.g., Wake, 1991; Adler, 1992; K. Phillips, 1994; Stebbins and Cohen, 1995; Green, 1997b; Lannoo, 1998b). There have been many proposed causes for these amphibian declines: habitat destruction, acidification of aquatic environments, pesticides, other toxicants, viral, bacterial, and fungal infections, drought, feral pigs, and excessive ultraviolet (UV-B) irradiation linked to ozone depletion from environmental contamination with chloroflourocarbons (Baker, 1985; Harte and Hoffman, 1989; Pechmann et al., 1991; Blaustein et al., 1994c; Kutka, 1994; Stebbins and Cohen, 1995; Berger et al., 1998). One species that has exhibited a marked...

      • FOURTEEN Ultraviolet Radiation
        (pp. 87-88)
        ANDREW R. BLAUSTEIN and LISA K. BELDEN

        Global climate changes, including changes in atmospheric conditions, may be contributing to amphibian population declines. Thus, a number of recent studies have investigated the effects of the ultraviolet (UV) component of ambient solar radiation on amphibians. Studies of amphibians and UV radiation have concentrated on UV-B (280–315 nm), which is the portion of the spectrum of most biological concern at the earth’s surface. Higher wavelengths are less efficiently absorbed by critical biomolecules; lower wavelengths are absorbed by stratospheric ozone (see Blaustein et al., 1994c). UV-B radiation is known to induce the formation of photoproducts that can cause cell death...

      • FIFTEEN Xenobiotics
        (pp. 89-92)
        CHRISTINE M. BRIDGES and RAYMOND D. SEMLITSCH

        Published in 1962, Rachel Carson’sSilent Springwas an impassioned plea to reduce or eliminate the production and release of xenobiotics into the environment.Silent Springpainted a grim portrait of an earth so polluted with these human-produced chemicals that no birds or frogs were left to sing during the spring. Since that time, the federal government has passed many acts and laws in an effort to protect wildlife from the burgeoning number of chemicals finding their way into the environment (e.g., the most recent amendments of the Federal Insecticide, Fungicide and Rodenticide Act [1976], Clean Water Act [1992], Toxic...

      • SIXTEEN Variation in Pesticide Tolerance
        (pp. 93-95)
        CHRISTINE M. BRIDGES and RAYMOND D. SEMLITSCH

        A growing body of evidence suggests that a number of amphibian populations have declined in recent years (Barinaga, 1990; Blaustein and Wake, 1990; Wake, 1998). The cause of these declines has been difficult to establish because in some instances only a single species is declining while sympatric species are thriving (e.g., K.R. McAllister et al., 1993). Similar variation can be observed within a single species at the population level—there are often instances when some populations of a particular species are declining while others remain unaffected (e.g., northern leopard frogs[Rana pipiens], Corn and Fogleman, 1984; mountain yellow-legged frogs[R....

      • SEVENTEEN Lucké Renal Adenocarcinoma
        (pp. 96-102)
        ROBERT G. MCKINNELL and DEBRA L. CARLSON

        The Lucké renal adenocarcinoma of northern leopard frogs(Rana pipiens)was originally described by Balduin Lucké during the 1930s (Lucké, 1934a,b, 1938a). Lucké’s contribution to this era in medical history is important for several reasons. At the time, Lucké, a pathologist at the University of Pennsylvania, was treading on dangerous terrain when he suggested that the frog renal adenocarcinoma was caused by a virus—in this case, a herpesvirus (Lucké, 1952). A few years earlier, Rockefeller Institute’s Peyton Rous had identified a virus as the etiological agent of a chicken tumor. Rous was castigated by the medical establishment for daring...

      • EIGHTEEN Malformed Frogs in Minnesota: History and Interspecific Differences
        (pp. 103-108)
        DAVID M. HOPPE

        Sporadic reports of malformed amphibians are abundant in the literature, and these reports have been thoroughly reviewed prior to the recent “outbreak” of malformations (Van Valen, 1974) as well as in papers related to the current malformation phenomenon (Ouellet, 2000; Lannoo et al., 2003). Merrell (1969) reported finding limb malformations in northern leopard frogs(Rana pipiens)from a Minnesota site at a frequency of 14.8% during late July 1965. There were no subsequent Minnesota reports until 1993, when residents near Granite Falls, Minnesota, reported “large numbers” of abnormal leopard frogs exhibiting extra limbs, missing limbs, and a missing eye (Helgen,...

      • NINETEEN Parasites of North American Frogs
        (pp. 109-123)
        DANIEL SUTHERLAND

        Every species of vertebrate has co-evolved with its own diverse parasite fauna. Harboring huge numbers of parasitic worms of several different species might seem to imply that the host’s health is severely compromised and may even be fatal. After all, malaria and hookworms annually kill millions of people worldwide. Fortunately for most wild animal populations, especially those inhabiting relatively natural environments that have not been severely altered by humans, heavy parasite burdens are usually not detrimental to an individual host or host population. During co-evolution, parasite and host have “learned,” through natural selection, to tolerate each other relatively well. Many...

      • TWENTY Parasite Infection and Limb Malformations: A Growing Problem in Amphibian Conservation
        (pp. 124-138)
        PIETER T. J. JOHNSON and KEVIN B. LUNDE

        Over the last two decades, scientists have become increasingly concerned about ongoing trends of amphibian population decline and extinction (Blaustein and Wake, 1990, 1995; Phillips, 1990; Pechmann et al., 1991; Wake, 1998). Parasitic pathogens, including certain bacteria, fungi, viruses, and helminths (see also Sutherland, this volume), have frequently been implicated as causes of gross pathology and mass die-offs, often in synergism with environmental stressors (Dusi, 1949; Elkan, 1960; Elkan and Reichenbach-Klinke, 1974; Nyman, 1986; Worthylake and Hovingh, 1989; Carey, 1993; Blaustein et al., 1994b; Faeh et al., 1998; Berger et al., 1998; Morell, 1999; Kiesecker, 2002; Lannoo et al., 2003)....

      • TWENTY-ONE Pine Silviculture
        (pp. 139-145)
        D. BRUCE MEANS

        The Coastal Plain of the southeastern United States is a vast natural area that has gone largely unheralded. Geographically, it fringes the southeastern corner of the continent, stretching 3,200 km from Long Island, New York, to the Mexican border, and including all of Florida. Geologically, it is a region composed entirely of sedimentary deposits of limestone, clay, sand, a small amount of gravel, and peat. Biologically, it is one of the country’s richest centers of biodiversity and endemism, yet basic studies and even surveys of its biota are often wanting (Dodd, 1997; Means, 2000).

        The Coastal Plain contains the highest...

      • TWENTY-TWO Commercial Trade
        (pp. 146-148)
        ANTHONY B. WILSON

        The international and interstate trade in amphibians is enormous and legally complex. There are also ramifications to this trade. In addition to posing a threat to native populations from overcollecting, the herpetofauna trade (including the bait industry) imports native animals that may be diseased or of different genetic stock and exotic species that may be invasive.

        The U.S. Federal Animal Welfare Act of 1966 regulates the use of animals for research and exhibition, as well as for the pet trade. Many state regulators misunderstand this law, believing that it totally regulates the pet industry. In fact, this law defines animals...

    • CONSERVATION
      • TWENTY-THREE Houston Toads and Texas Politics
        (pp. 150-167)
        LAUREN E. BROWN and ANN MESROBIAN

        Media hype has inaccurately portrayed amphibian declines as cataclysmic events of recent origin. It is more probable that declines in the United States began in earnest at least as far back as the mid-nineteenth century, shortly after the invention of the steel moldboard plow. Repeated use of this agricultural implement results in a 5–8 cm thick compacted layer of hardpan 5–30 cm beneath the surface, which is probably impenetrable to many animals including amphibians (Bromfield, 1955; Brown and Morris, 1990). The moldboard plow continues to be widely used in agricultural areas across the United States to the present...

      • TWENTY-FOUR Amphibian Conservation Needs
        (pp. 168-176)
        EDWARD D. KOCH and CHARLES R. PETERSON

        We have experienced many scientific and management challenges and opportunities through our 15 years working together to understand and conserve amphibians in the northern Rocky Mountain and Pacific Northwest regions of the United States. We have observed that many herpetologists are unaware of or poorly informed on management needs and opportunities for conserving amphibian species. Because of this lack of awareness and a relative lack of attention paid by herpetologists to serving specific research and management needs, many natural resource managers lack the sound scientific information and experience needed to conserve amphibians and their habitats.

        Citizens have created many tools...

      • TWENTY-FIVE Amphibian Population Cycles and Long-Term Data Sets
        (pp. 177-184)
        HOWARD H. WHITEMAN and SCOTT A. WISSINGER

        The loss of biodiversity throughout the world is increasing at an alarming rate, with habitat destruction and fragmentation as the leading causes for extinction rates that are 100 to 1,000 times greater than pre-human levels (Pimm et al., 1995; Global Biodiversity Assessment, 1996; Chapin et al., 1998). Such losses are particularly evident among amphibian populations, which have disappeared or are declining in a wide range of environments (Wyman, 1990; Carey, 1993; Pounds and Crump, 1994; Blaustein and Wake, 1995; Vertucci and Corn, 1996; Lannoo, 1998b; Wake, 1998; Houlahan et al., 2000). Although most researchers agree that many amphibian populations are...

      • TWENTY-SIX Landscape Ecology
        (pp. 185-192)
        DAVID E. NAUGLE, KENNETH F. HIGGINS, REX R. JOHNSON, TATE D. FISCHER and FRANK R. QUAMEN

        The increased public interest in amphibian conservation and the growing evidence of detrimental effects of habitat fragmentation on biological diversity (see Saunders et al., 1991 for a review) has prompted land managers to seek ways of managing amphibian populations at landscape scales. For example, principles of landscape ecology are now being used by avian ecologists to direct conservation efforts and design nature reserve systems (e.g., Robbins et al., 1989; Pearson, 1993; Flather and Sauer, 1996).

        Landscape ecology emphasizes landscape patterning, species interactions across landscape mosaics, and the change in these patterns and interactions over time (e.g., Gardner et al., 1987;...

      • TWENTY-SEVEN Conservation of Texas Spring and Cave Salamanders (Eurycea)
        (pp. 193-197)
        PAUL T. CHIPPINDALE and ANDREW H. PRICE

        Many species of endemic aquatic organisms inhabit the springs and water-filled caves of the Edwards Plateau region of central Texas. Most have limited distributions, and their existence is dependent upon the availability of clean water from subterranean sources (the Edwards Aquifer and associated aquifers). The Edwards Plateau is composed of uplifted karst limestone; water percolates through the limestone, recharges the underground reservoirs, and re-emerges from a large number of springs. The biggest and most well known of these springs are located along the southern and eastern margins of the Edwards Plateau (the Balcones Escarpment) and include Barton Springs in the...

      • TWENTY-EIGHT Lessons from the Tropics
        (pp. 198-205)
        KAREN R. LIPS and MAUREEN A. DONNELLY

        Abrupt declines in amphibian populations have been reported in the media and the scientific literature for more than a decade. Scientists have detected declines in amphibian populations in North America (Corn and Fogleman, 1984; Blaustein and Wake, 1990; Bishop and Pettit, 1992; Carey, 1993; Kagarise-Sherman and Morton, 1993; Scott, 1993; Drost and Fellers, 1996; Green, 1997b; Lannoo, 1998b), Central America (Crump et al., 1992; Pounds et al., 1997; Lips, 1998, 1999; Wilson and McCranie, 1998), and South America (Heyer et al., 1988; Weygoldt, 1989; LaMarca and Reinthaler, 1991; Lynch and Grant, 1998), as well as in Australia (Richards et al.,...

      • TWENTY-NINE Taxonomy and Amphibian Declines
        (pp. 206-209)
        SHERMAN A. MINTON

        Any attempt to describe the extent and significance of biodiversity requires a clear and workable system of classification. This is especially true of conservation efforts with a goal of the recognition and protection of threatened populations. However, the past decade has seen a major revision in systematics with some authorities going so far as to state that the Linneaen system of classification and nomenclature has outlived its usefulness.

        The species concept is a particular point of controversy in the taxonomy of higher organisms. For much of this century, the genetic or biological species concept using the touchstone of reproductive isolation...

      • THIRTY Conservation Systematics: The Bufo boreas Species Group
        (pp. 210-221)
        ANNA M. GOEBEL

        Systematics and taxonomy play critical roles in conservation (May, 1990; Eldredge, 1992; Systematics Agenda, 2000, 1994a,b; Wheeler, 1995; Koch and Peterson, this volume; Minton, this volume). Taxonomic names are important for recognition and clear communication about the units to be conserved; conservation efforts have been compromised when taxonomy did not accurately reflect systematic relationships (e.g., Greig, 1979; Avise and Nelson, 1989; Daugherty et al., 1990; O’Brien and Mayr, 1991; Mishler, 1995; but see Zink and Kale, 1995). However, new developments in systematics and taxonomy that recognize, describe, and quantify organismic diversity have not been adequately incorporated into conservation programs. Extinction...

      • THIRTY-ONE Factors Limiting the Recovery of Boreal Toads (Bufo b. boreas)
        (pp. 222-236)
        CYNTHIA CAREY, PAUL STEPHEN CORN, MARK S. JONES, LAUREN J. LIVO, ERIN MUTHS and CHARLES W. LOEFFLER

        Boreal toads(Bufo b. boreas)are widely distributed over much of the mountainous western United States. Populations in the Southern Rocky Mountains suffered extensive declines in the late 1970s through early 1980s (Carey, 1993). At the time, these mass mortalities were thought to be associated with a bacterial infection (Carey, 1993). Although the few populations that survived the mass die-offs were not systematically monitored until at least 1993, no mass mortalities had been observed until 1996 when die-offs were observed. A mycotic skin infection associated with a chytrid fungus is now causing mortality of toads in at least two of...

      • THIRTY-TWO Southwestern Desert Bufonids
        (pp. 237-240)
        BRIAN K. SULLIVAN

        The anuran family Bufonidae is a large, cosmopolitan group comprising of almost 400 species that inhabit a great variety of environments. Three bufonids with relatively limited distribution in the United States are federally listed as “endangered:” Wyoming toads(Bufo baxteri), arroyo toads(B. californicus), and Houston toads(B. houstonensis); golden toads(B. periglenes)from Central America are perhaps the best known example of an anuran that has recently declined. By contrast, marine toads(B. marinus)are one of the most successful anuran introductions, having spread throughout much of the Southern Hemisphere. In spite of the attention these forms have received,...

      • THIRTY-THREE Amphibian Ecotoxicology
        (pp. 241-243)
        RAYMOND D. SEMLITSCH and CHRISTINE M. BRIDGES

        The imperiled status of numerous amphibian species worldwide suggests that current research efforts need to take new, biologically relevant directions in order to understand the influence of chemical contamination. A recent summary of the current state of understanding concerning declining amphibians indicates that airborne contaminants are important but that “existing test protocols might be inappropriate” to evaluate their influence (Wake, 1998). We advocate adopting several approaches, experimental designs, and analyses that will promote a better understanding of the effects that chemicals can have on individuals, populations, and communities. We also provide examples of these approaches and the types of hypotheses...

      • THIRTY-FOUR Museum Collections
        (pp. 244-246)
        JOHN W. FERNER, JEFFREY G. DAVIS and PAUL J. KRUSLING

        Most professional herpetologists have had a course in college or graduate school that required some form of field collection. Perhaps it was a class in vertebrate natural history, where we were expected to collect, preserve, document, and catalog one or more specimens from each of the major vertebrate classes. These specimens were often expected to be of “museum quality” and handed in to the professor as part of our evaluation for the course. The resulting collections were then routinely retained at the institution (or in some cases in the personal collection of the professor) as a teaching resource and record...

      • THIRTY-FIVE Critical Areas
        (pp. 247-259)
        HUGH R. QUINN and COLLEEN SCOTT

        The global decline of amphibians has received a great deal of attention (Wake, 1991; Wake and Morwitz, 1991; K. Phillips, 1994) and serves as an indicator of a larger problem involving the decline of overall biodiversity associated with uncontrolled human population growth. In North America, amphibians have declined due to environmental alteration associated with timber harvesting, agriculture, wetland drainage, urbanization, stream pollution and siltation, and the introduction of exotic predators (Orser and Shure, 1972; Bury, 1983; Gore, 1983; Hayes and Jennings, 1986; Pierce and Harvey, 1987; Ash, 1988; Welsh and Lind, 1988; Blaustein and Wake, 1990, 1995; Pechmann et al.,...

      • THIRTY-SIX Creating Habitat Reserves for Migratory Salamanders
        (pp. 260-264)
        SUZANNE C. FOWLE and SCOTT M. MELVIN

        Habitat loss and fragmentation results in the reduction and isolation of amphibian populations (Reh and Seitz, 1990; Gulve, 1994) and the subsequent increased risk of local extinction (Saccheri et al., 1998). While local extinctions are often part of amphibian population dynamics, amphibian populations persist because such extirpations are compensated for by recolonization and the resulting rescue effect (Skelly et al., 1999). However, the fragmentation of amphibian habitats inhibits dispersal and thereby hinders or prevents the rescue effect (Reh and Seitz, 1990; Gulve, 1994).

        Massachusetts provides a prime example of this conservation challenge and of the need to protect connected habitat...

      • THIRTY-SEVEN Population Manipulations
        (pp. 265-270)
        C. KENNETH DODD JR.

        In recent years in North America and in other locales, there has been a surge of interest in the status and conservation of amphibian populations. Concern centers on the disappearance or decline of individual populations, species, and even geographic assemblages of amphibians, particularly anurans. The declines are real, despite much initial skepticism that downward trends in numbers might result from natural population fluctuations. That skepticism has been valuable, however, in that it forced researchers to double efforts to ensure that they were not crying wolf over a phenomenon that could be of natural occurrence. Although there is likely no one...

      • THIRTY-EIGHT Exotic Species
        (pp. 271-274)
        WALTER E. MESHAKA JR.

        Within the framework of species conservation resides the increasingly relevant and disconcerting topic of exotic species. A conservative definition of exotic amphibian species includes only those species that have colonized the United States by human-mediated dispersal. This definition covers six anuran species (Table 38-1): green and black dart-poison frogs(Dendrobates auratus); Cuban treefrogs(Osteopilus septentrionalis); coquis(Eleutherodactylus coqui), greenhouse frogs(E. planirostris); African clawed frogs(Xenopus laevis); and wrinkled frogs(Rana rugosa). By including any extralimital populations of species otherwise native within the continental United States and whose dispersal to extralimital sites was human-mediated, I expand this list to include...

      • THIRTY-NINE Protecting Amphibians While Restoring Fish Populations
        (pp. 275-276)
        DEBRA PATLA

        Park and wildlife managers are facing an ironic dilemma as they work to restore and protect aquatic ecosystems—must amphibians be sacrificed if native fish are to return?

        Over the past century throughout the United States, resource managers sought to enhance the recreational value of lakes and streams by stocking non-native (exotic) game fish. The “success” of this effort is now recognized as a serious impediment to conserving natural aquatic biodiversity. Introduced fish endanger and replace native fish species through predation, competition, hybridization, and disease transmission. In many cases, bringing back the natives is doomed unless the introduced fish are...

      • FORTY Reflections Upon Amphibian Conservation
        (pp. 277-281)
        THOMAS K. PAULEY

        I began my fieldwork with amphibians in West Virginia in 1963 at the age of 23, and I have spent most of my time (when not teaching) walking the mountains of West Virginia searching for amphibians and reptiles. My major study sites include the New River Gorge National River, the Bluestone National Scenic River, the Gauley River National Recreational Area, and the high Alleghenies. Animals of particular interest include Cheat Mountain salamanders(Plethodon nettingi)and Cow Knob salamanders(P. punctatus). I draw from these years of experience to present the following information on amphibian conservation.

        The New River Gorge National...

    • SURVEYS AND MONITORING
      • FORTY-ONE Distribution of South Dakota Anurans
        (pp. 283-291)
        DAVID E. NAUGLE, TATE D. FISCHER, KENNETH F. HIGGINS and DOUGLAS C. BACKLUND

        In a little over a century, the prairie pothole region of the northern Great Plains has been transformed from a contiguous expanse of wetlands and grasslands into a highly fragmented agricultural landscape. Regional wetland losses due to agricultural activities and urbanization have been extensive and widespread, exceeding 90% in northwestern Iowa and western Minnesota (Tiner, 1984; Dahl, 1990; Leja, 1998). Declines in amphibian numbers coinciding with the habitat loss have heightened concerns over the future of amphibian populations (e.g., Barinaga, 1990; Blaustein and Wake, 1990, 1995; Wake, 1991; Lannoo, 1998b).

        South Dakota (199,500 km² in area), a state that lies...

      • FORTY-TWO Nebraska’s Declining Amphibians
        (pp. 292-294)
        DAVID S. MCLEOD

        During the 1970s, John D. Lynch and his students conducted extensive fieldwork in Nebraska to complete a herpetological survey begun by George E. Hudson nearly three decades earlier (Hudson, 1942; Lynch, 1985). In the wake of alarm calls concerning the status of amphibians around the globe since the late 1980s and early 1990s numerous studies have been conducted to determine whether or not amphibians are in fact declining and if changes are the results of local or global phenomena. During the late 1990s, I revisited the work done by Lynch to address questions of amphibian population declines at the state...

      • FORTY-THREE Museum Collections Can Assess Population Trends
        (pp. 295-299)
        JEFF BOUNDY

        Early warnings of amphibian declines have been realized as species have vanished, or disappeared from large portions of their ranges (Blaustein et al., 1994a; Pechmann and Wilbur, 1994; Lannoo, 1998b,c). These declines have alerted biologists and conservation agencies to the need to combine proactive evaluation of status and trends with retroactive research on causes of disappearances (Heyer et al., 1994; Fellers and Freel, 1995; Green, 1997b; Lannoo, 1998a). An initial step in detecting population declines in seemingly stable species can be accomplished by comparing current population levels with historical data. However, detecting shallow declines is difficult in the absence of...

      • FORTY-FOUR Monitoring Salamander Populations in Great Smoky Mountains National Park
        (pp. 300-306)
        ERIN J. HYDE and THEODORE R. SIMONS

        Recent evidence of worldwide amphibian population declines has highlighted the need for a better understanding of both species-specific habitat associations and methodologies for monitoring long-term population trends (Barinaga, 1990; Blaustein and Wake, 1990; Wake, 1991; Lannoo, 1998b). For decades, studies have relied on relative abundance indices to evaluate salamander populations across space and time. However, little effort has been made to evaluate the underlying assumptions of these indices or their relationship to the true population. Heatwole (1962) has shown that eastern red-backed salamanders(Plethodon cinereus)change their micro-habitat use in response to precipitation events, differentially using cover objects and leaf...

      • FORTY-FIVE North American Amphibian Monitoring Program (NAAMP)
        (pp. 307-313)
        LINDA A. WEIR and MICHAEL J. MOSSMAN

        Declines in amphibian populations have been noted since at least the 1970s (Gibbs et al., 1971; Hayes and Jennings, 1986; Tyler, 1991; Pounds and Crump, 1994; Bradford et al., 1994a; Drost and Fellers, 1996; Green, 1997b; Lannoo, 1998b; Bury, 1999; Campbell, 1999). In 1989 at the World Congress of Herpetology, informal conversations among scientists led to a concern that amphibian declines were more than local phenomena and may be a global issue (Wake and Morowitz, 1991; see also K. Phillips, 1994). In 1991, out of this concern, scientists and resource managers established the Declining Amphibian Populations Task Force (DAPTF) and...

      • FORTY-SIX Evaluating Calling Surveys
        (pp. 314-319)
        SAM DROEGE and PAIGE EAGLE

        In North America, approximately 55 of the 103 species of anurans can be surveyed readily by using counts of vocalizing males as an index to their presence or population size. Such surveys are most applicable to eastern and northern parts of the continent, where almost all species regularly vocalize and breeding seasons extend over several weeks. In the West, members of the chorus frog(Pseudacris)complex and American bullfrogs(Rana catesbeiana)consistently call during their breeding seasons, but many of the other species call either infrequently, quietly, or sporadically only following heavy rains and are thus unsuited to be surveyed...

      • FORTY-SEVEN Geographical Information Systems and Survey Designs
        (pp. 320-325)
        CHARLES R. PETERSON, STEPHEN R. BURTON and DEBRA A. PATLA

        The availability and utility of Geographical Information Systems (GIS) has increased greatly within the past 20 years. For general descriptions of GIS, see Clarke (1997), Heywood et al. (1998), and Krzysik (1998a). In the past, GIS required expensive workstations, software that was difficult to use, expert technicians, and considerable resources for acquiring spatial data in a digital format. Now, systems using relatively inexpensive desktop computers and programs (e.g., ArcView) have the ability to perform many workstation GIS functions. The software is easier to use, training is widely available, and large amounts of spatial data in digital format can be obtained...

      • FORTY-EIGHT Impacts of Forest Management on Amphibians
        (pp. 326-327)
        ROCHELLE B. RENKEN

        Researchers with the Missouri Department of Conservation, the Missouri Department of Natural Resources, the U.S. Forest Service, and cooperating universities (University of Missouri–Columbia, University of Missouri–St. Louis, Michigan Technological University, and University of Tennessee–Chattanooga) are conducting a bold experiment to examine the long-term, large-scale impacts of forest management practices on the biotic and abiotic components of the oakhickory forests of southern Missouri. Entitled the Missouri Ozark Forest Ecosystem Project (MOFEP), the project’s purpose is to conduct a controlled experiment to document the effects of typical forest management practices on the numbers and types of forest plants and...

      • FORTY-NINE Monitoring Pigment Pattern Morphs of Northern Leopard Frogs
        (pp. 328-337)
        ROBERT G. MCKINNELL, DAVID M. HOPPE and BEVERLY K. MCKINNELL

        This study has emerged from the coupling of exceedingly rare events. Here we report on the progeny of northern leopard frogs(Rana pipiens)that have undergone mutations affecting their pigment patterns. These extraordinarily uncommon pattern mutations have increased to polymorphic frequencies in populations of frogs in the upper Midwest. The vast majority of mutations are lost, and the success of mutant genes (i.e., their increase and retention in a population) is in itself a rare event (Crow and Kimura, 1970). However, the rare burnsi and kandiyohi mutations have indeed become polymorphic in Minnesota and its contiguous states. We cannot address...

    • EDUCATION
      • FIFTY The National Amphibian Conservation Center
        (pp. 339-340)
        ANDREW T. SNIDER and ELIZABETH ARBAUGH

        Zoos are evolving, becoming more than just a place to take children on a warm summer day. The best zoos provide not only the recreational opportunities but the educational and science-based conservation opportunities as well. Most zoos must rely upon the charismatic megafauna (elephants, rhinos, lions, etc.) to bring the public through the gates—it is a simple matter of economics. This does not mean, however, that the smaller, lesser-known species, such as amphibians, should be excluded. In fact, amphibians have become big business. With the overwhelming number of frog-related items currently in the marketplace (including Kermit©and ads with...

      • FIFTY-ONE A Thousand Friends of Frogs: Its Origins
        (pp. 341-342)
        TONY P. MURPHY

        What do malformed frogs in Minnesota and Japan have in common? Students on field trips discovered them. The problem of malformed frogs drew national attention in 1995 when Cindy Reinitz and her students at the Minnesota New Country School in Henderson, Minnesota, found large numbers of malformed frogs. Images of frogs with gross abnormalities were broadcast on national news programs and printed in newspapers across the country. Minnesota scientists were already studying the phenomenon, but the large number of malformed frogs found by these students created intense interest, both in the public and in politicians.

        Following this, Cindy Reinitz, Judy...

    • A PERSPECTIVE
      • FIFTY-TWO Of Men and Deformed Frogs: A Journalist’s Lament
        (pp. 344-348)
        WILLIAM SOUDER

        In August 1995, a group of middle school students on a field trip in south-central Minnesota made an odd and, to their minds, alarming discovery while exploring a bean field surrounding a large wetland. A year later I started writing about what they had found, and once I started writing I learned that it was hard to stop. A mystery in biology is a mystery without end, for inside every question are the seeds of a thousand more questions. The book of life is a narrative running in two directions—into the past and toward the future. For a biologist,...

  8. PART TWO Species Accounts
    • Introduction
      (pp. 351-380)
      MICHAEL LANNOO, ALISA L. GALLANT, PRIYA NANJAPPA, LAURA BLACKBURN and RUSSELL HENDRICKS

      Worldwide reports of amphibian population declines and malformations prompt concern about species protection. At this point in time in the United States, we recognize 289 extant amphibian species: 103 species of frogs and 186 species of salamanders (Appendix IN-A), although the identity and relationships of species in several genera remain unresolved. Amphibians occur in nearly all habitats, and they exhibit variations in life history and natural history features that enable them to accommodate a wide range of environmental conditions (Duellman, 1999; Zug et al., 2001; Pough et al., 2004). Some species are entirely aquatic, while others spend their complete life...

    • ANURA
      (pp. 381-600)

      Nielson et al. (2001) recommended that the genusAscaphusbe split into two species: tailed frogs(A. truei)and Montana tailed frogs(A. montanus). Their analysis was based on divergence of mitochondrial DNA and was consistent with previous allozyme work (Daugherty, 1979). The following account highlights references that are specific to the new species. Refer to theAscaphus trueiaccount for a complete review of the genusAscaphus.

      Montana tailed frogs occur in the Blue Mountains of southeast Washington (Metter, 1964a), central Idaho and the panhandle (Linsdale, 1933a; Corbit, 1960; Maughan et al., 1980), and western Montana (Smith, 1932; Franz...

    • CAUDATA
      (pp. 601-914)

      Ringed salamanders(Ambystoma annulatum)are endemic to the Interior Highlands (Ozark and Ouachita mountains) in Arkansas, Missouri, and Oklahoma (Anderson, 1950; Smith, 1950; Dowling, 1956, 1957; Anderson, 1965; McDaniel, 1975; Funk, 1979; Minter, 1979; Schuette, 1980; Trauth, 1980; Johnson, 1987; Turnipseed and Altig, 1991). No specimens have been reported from the Ozark Plateau of Kansas (Collins, 1993). There are no data to suggest that the current distribution differs from the pre-settlement distribution. Phillips et al. (2000) note that populations in the northeastern portion of the range (central Missouri) have less variable mitochondrial DNA components than populations to the southwest (southern...

  9. EPILOGUE Factors Implicated in Amphibian Population Declines in the United States
    (pp. 915-925)
    DAVID F. BRADFORD

    Many species of amphibians have declined substantially in distribution or number of populations in the United States and globally, and a variety of anthropogenic and natural factors have been suggested as causal agents in these declines (e.g., Green, 1997a,b; Lannoo, 1998, 2003; Alford and Richards, 1999; Houlahan et al., 2000, 2001; Semlitsch, 2000; Alford et al., 2001; Lannoo et al., Introduction, Part One this volume). Evidence for the causal action of these agents derives from many types of sources, all of which are important in seeking to understand amphibian population declines. Clear cause-and-effect relationships have been demonstrated in some cases,...

  10. CONCLUSION
    (pp. 926-926)
    MICHAEL LANNOO

    This work synthesizes and offers direction. In Part One we have attempted to present what we know about the extent and causes of amphibian declines and what we can do about them. In Part Two we present the life history and natural history features needed to manage for amphibians, with a current assessment of their distribution. In assembling the literature for this project, and with a quick look at the species accounts, what immediately is noticeable is that a few species are well known and have a large literature, some species are better known and have a modest literature, and...

  11. LITERATURE CITED
    (pp. 927-1076)
  12. INDEX
    (pp. 1077-1094)