Jay M. Savage

Amphibian and reptile declines over 35 years at La Selva, Costa Rica

Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these “enigmatic” declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by ≈75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks.

The Origins and History of the Central American Herpetofauna

1943a. Comments on the herpetofauna of the Sierra de los Cuchumatanes of Guatemala. Occ. Pap. Mus. Zool., Univ. Mich. No. 471, 28 pp. . 1943b. Taxonomic and geographic comments on Guatemalan salamanders of the genus Oedipus. Misc. Pub. Mus. Zool., Univ. Mich. No. 56, 33 pp. 1948. The amphibians and reptiles of Alta Verapaz, Guatemala. Ibid. No. 69, 109 pp. . 1950. A geographic study of the herpetofauna of Alta Verapaz, Guatemala. Contrib. Lab. Vert. Biol. Univ. Mich. No. 45, 77 PP. 1951. The herpetofauna of the Guatemalan Plateau, with special reference to its distribution on the southwestern highlands. Ibid. No. 49, 71 pp. . 1954a. A description of a subhumid 943a. Com ents on the herpetofauna corridor across northern Central America, with comments on its herpetofaunal indicators. Ibid. No. 65, 26 pp. . 1954b. Herpetofauna of the southeastern highlands of Guatemala. Ibid. No. 68, 65 pp. 1957. Herpetofaunal dispersal routes through northern Central America. Copeia 1957(2):89-94. 1966. The environment of the Central American cold-blooded vertebrate fauna. Copeia 1966(4):684-699. WAGNER, P. L. 1964. Natural vegetation of Middle America. In Handbook of Middle American Indians, vol. 1. R. Wauchope and R. C. West, eds., pp. 216-264. Univ. Texas Press, Austin, Texas.

The Dendrobatid Frogs of Central America

BENTLEY, P. J. 1966. Adaptations of Amphibia to arid environments. Science 152:619-623. , A. K. LEE, AND A. R. MAIN. 1958. Comparison of dehydration and hydration of two genera of frogs (Heleioporus and Neobatrachus) that live in areas of varying aridity. J. Exp. Biol. 35:677-684. LEE, A. K. 1967. Studies in Australian Amphibia. II. Taxonomy, ecology and evolution of the genus Heleioporus Gray (Anura: Leptodactylidae). Austral. J. Zool. 15:367-439. MAIN, A. R., M. J. LITTLEJOHN, AND A. K. LEE. 1959. Ecology of Australian frogs. In: Biogeography and ecology in Australia. A. Keast, R. L. Crocker, and C. S. Christian, eds., pp. 396-411. W. Junk, The Hague. MCCLANAHAN, L. 1967. Adaptations of the spadefoot toad, Scaphiopus couchi, to desert environments. Comp. Biochem. Physiol. 20: 73-99. PACKER, W. C. 1963. Dehydration, hydration, and burrowing behavior in Heleioporus eyrei (Gray) (Leptodactylidae). Ecology 44:643-651. RUIBAL, R. 1962. The adaptive value of bladder water in the toad, Bufo cognatus. Physiol. Zool. 35:218-233. SHOEMAKER, V. H. 1964. The effects of dehydration on electrolyte concentrations in a toad, Bufo marinus. Comp. Biochem. Physiol. 13: 261-271. WIGGLESWORTH, V. B. 1965. The principles of insect physiology. 6th ed. Methuen, London.

Variation and distribution in the tree-frog genus Phyllomedusa in Costa Rica, central America

Resume The frog genus Phyllomedusa is represented in Costa Rica by six species. Analysis of variation in coloration, webbing, and measurements delineates features that distinguish the various forms. The characteristics of the flank pattern in the nominal species P. callidryas and P. helenae, utilized by previous authors to separate them, are shown to be subject to individual and geographic variation. The two forms represent two of many populations within a single species, P. callidryas. Reasons for not using the term subspecies for geographic segments of callidryas are presented. The diagnostic features and the geographic and ecologic distribution of the Costa Rican species, P. annae, P. calcarifer, P. callidryas, P. lemur, P. saltator and P. spurrelli, based on the entire species ranges, are discussed.

Variation and distribution in the tree‐frog genus Phyllomedusa in Costa Rica, central America: With 6 figures

Resume The frog genus Phyllomedusa is represented in Costa Rica by six species. Analysis of variation in coloration, webbing, and measurements delineates features that distinguish the various forms. The characteristics of the flank pattern in the nominal species P. callidryas and P. helenae, utilized by previous authors to separate them, are shown to be subject to individual and geographic variation. The two forms represent two of many populations within a single species, P. callidryas. Reasons for not using the term subspecies for geographic segments of callidryas are presented. The diagnostic features and the geographic and ecologic distribution of the Costa Rican species, P. annae, P. calcarifer, P. callidryas, P. lemur, P. saltator and P. spurrelli, based on the entire species ranges, are discussed.

Systematics and the biodiversity crisis

This article discusses the importance of systematics in evaluating the global biodiversity crisis. Topics covered include the following: what systematic biology is; the diversity of species and higher taxa; biodiversity undersiege; systematics and conservation; systematics and global climatic change. 28 refs., 2 figs., 1 tab.

Systematics and distribution of the Mexican and Central American stream frogs related to Eleutherodactylus rugulosus

The ubiquitous Mexican and Central American stream frogs allied to Eleutherodactylus rugulosus form a confusing spectrum of distinctive to subtly different populations. The condition of the male secondary sexual features: presence or absence of vocal slits and presence or absence of nuptial pads on the thumb, combined with the geographically consistent color (white, pale yellow, gold, orange, red or chestnut) of the venter of adults in life, provide the key to untangling the species problem in this group. For purposes of analysis the populations were grouped by the male secondary sexual features and compared in detail on the basis of 15 other characters of morphology and coloration. Twelve species are recognized within the rugulosus group, and may be placed in four series based on the presence (+) or absence (-) of vocal slits and nuptial pads in adult males. + +: Eleutherodactylus milesi of northern Honduras; E. merendonensis of northwestern Honduras; E. punctariolus of southern Costa Rica and western Panama; E. fleischmanni of Costa Rica; and E. escoces (sp. nov.) a bright red-bellied new species from the slopes (1100-2100 m) of Volcan Barba, Volcan Irazu and Volcan Turrialba of Costa Rica; +-: E. vocalis of northwestern Mexico; a new species, E. azueroensis (sp. nov.) from the Peninsula Azuero of western Panama; and E. taurus of the Golfo Dulce lowlands of southwestern Costa Rica and adjacent Panama; +: E. matudai from the Pacific slopes of extreme southern Mexico and adjacent Guatemala; and a new species, E. angelicus, from the Cordillera de Tilaran and Volcan Poas in Costa Rica; --: E. brocchi of Alta and Baja Verapaz, Guatemala; and the wideranging lowland and slope species known from Mexico to western Panama, E. rugulosus. The Atlantic versant Mexican populations of this species are distinctive and have been variously recognized as a subspecies of E. rugulosus or as a separate species by previous authors. The earliest name for this population is Hylodes berkenbuschii Peters and E. natator Taylor and E. vulcani Shannon and Werler are strict synonyms. The seemingly allopatrically isolated southern populations of E. rugulosus in eastern and southwestern Nicaragua, Costa Rica and Panama are slightly distinct from the main population system of E. rugulosus. The earliest name for the southern stock is Lithodytes ranoides Cope with Liohyla pittieri Guinther a strict synonym. Neither of these populations is recognized as separate from E. rugulosus. E. chiquito Lynch placed by its describer in the rugulosus group is a synonym of E. greggi of extreme southern Pacific slope Mexico and Guatemala, which is a member of the distantly related mexicanus group. Members of the rugulosus group fall into four geographic and ecologic distribution patterns: a) lowland and slope species, centered on the distribution of the wide-ranging E. rugulosus population system, with the allopatric E. vocalis on the northwest Mexican periphery, E. azueroensis on the southwest Panama periphery, the small population of E. merendonensis in northwestern Honduras and E. taurus occupying the Golfo Dulce lowlands of Costa Rica and western Panama, where E. rugulosus occurs only along the Pacific slope (600-1200 m) of the Talamanca-Chiriqui massif; b) E. brocchi and E. matudai in the highlands of southern Mexico and Guatemala; c) E. milesi in the uplands of

Infrageneric classification and species composition of the anole genera, Anolis, Ctenonotus, Dactyloa, Norops and Semiurus (Sauria: Iguanidae)

All valid species of Anolis, Ctenonotus, Dactyloa, Norops and Semiurus are listed by genus and where possible by the infrageneric categories (from most to least inclusive): series, subseries and species groups. An alphabetical index cross-referencing the species names to genus and series is also included.

Central American Frogs Allied to Eleutherodactylus bransfordii (Cope): A Problem of Polymorphism

Analysis of color and structural variation in Costa Rican populations of the frog Eleutherodactylus bransfordii delineates three basic dorsal patterns, four distinct types of ridging patterns, and ten modifying color characters, that may be superimposed at random on the back patterns. The animals can be grouped into four distinct morphs based upon the color and ridging characters. Morph I includes frogs with uniform back color and scattered ridging, Morph II with mottled back color and scattered ridging, Morph III with uniform back color and V-shaped or hourglass ridging, and Morph IV with dorsolateral stripes, and dorsolateral, parallel ridging. The morphs are not expressions of sexual dimorphism. Frequencies of morphs are significantly different between nine populations with large samples. No obvious correlation with bioclimate, altitude, or vegetation is suggested by morph frequency differences. It appears that uniform-mottled-dorsolateral stripes are probably allelic expressions of one gene, with uniform representing the heterozygous condition. Ridging appears to be controlled by three allelic expressions of one gene, with parallel ridging a homozygous recessive, V-shaped and hourglass another homozygous recessive, and scattered ridging dominant over the other alleles.

Frogs of the Eleutherodactylus biporcatus Group (Leptodactylidae) of Central America and Northern South America, Including Rediscovered, Resurrected, and New Taxa

Abstract A revision of the broad-headed frogs of the biporcatus species group of Eleutherodactylus s.l. has a wholly unexpected nomenclatural consequence. Eleutherodactylus biporcatus (W. Peters, 1863) is not from “Veragua” (western Panama) as originally thought, but is the proper name for the Venezuelan frog heretofore known as E. maussi (Boettger, 1893). Three names are resurrected from synonymy for Central American species currently masquerading under the misapplied name biporcatus, and a fourth species is described as new: (1) The rediscovery of Eleutherodactylus gulosus (Cope, 1875) shows it to be a large montane frog occupying an apparently small range in the borderland of Costa Rica and Panama. (2) Eleutherodactylus rugosus (W. Peters, 1863) is a smaller species occurring on the Pacific versant of southwestern Costa Rica and western Panama; Lithodytes pelviculus Cope and L. florulentus Cope are synonyms of E. rugosus. (3) Eleutherodactylus megacephalus (Cope, 1875), an intermediate-sized frog ranging from Honduras to central Panama, is the more common species to which the name biporcatus has usually been applied. Available material from the western half of the Isthmus of Panama was too sparse to decide if another (unnamed) species is being included under the name megacephalus. (4) The name biporcatus also has been used for Eleutherodactylus opimus, new species, which occurs from central Panama to western Colombia. Based on the condition of the m. adductor mandibulae, the Venezuelan Eleutherodactylus biporcatus s.s. (E. maussi, auctorum) belongs to the Middle American clade of Eleutherodactylus (subgenus Craugaster). However, preliminary data on karyotypes, as well as morphological differences, cast doubt on the closeness of E. biporcatus to the other species studied. The monophyly of the “biporcatus group” therefore remains to be tested. RESUMEN La revisión de las ranas de cabeza ancha del grupo biporcatus de Eleutherodactylus tiene una consecuencia nomenclatural completamente inesperada. Eleutherodactylus biporcatus (W. Peters, 1863) no es de “Veragua” (Panamá occidental) como se creía previamente, sino que es el nombre propio de la rana venezolana conocida hasta ahora como E. maussi (Boettger, 1893). Se resucitan tres nombres de la sinonimia para especies centroamericanas previamente ocultos bajo el nombre incorrecto de biporcatus, y se describe una cuarta especie nueva: (1) El redescubrimiento de Eleutherodactylus gulosus (Cope, 1875) indica que es una rana grande, de montaña, que tiene una distribución geográfica pequeña en la frontera entre Costa Rica y Panamá. (2) Eleutherodactylus rugosus (W. Peters, 1863) es una especie más pequeña que ocurre en las tierras más bajas del Pacífico del suroccidente de Costa Rica y del occidente de Panamá; Lithodytes pelviculus Cope y L. florulentus Cope son sinónimos de E. rugosus. (3) Eleutherodactylus megacephalus (Cope, 1875), una rana de tamaño intermedio y distribuida desde Honduras hasta Panamá central, es la especie que más comunmente se ha llamado biporcatus. El material disponible de la mitad occidental del Istmo de Panamá no es adecuado para decidir si hay alguna otra especie (sin nombre) incluida bajo el nombre megacephalus. (4) El nombre biporcatus también se ha usado para Eleutherodactylus opimus, especie nueva, que ocurre desde Panamá central hasta Colombia occidental. Basándose en la condición del m. adductor mandibulae, Eleutherodactylus biporcatus s.s. (E. maussi auctorum) de Venezuela pertenece al clado mesoamericano de Eleutherodactylus (subgenero Craugaster). Sin embargo, información preliminar sobre cariotipos, así como diferencias morfológicas, hacer dudar del parentesco de E. biporcatus con las otras especies estudiadas. La monofilia del “grupo biporcatus” debe ser corroborada.