70 research outputs found
Integrative taxonomic reassessment of Odontophrynus populations in Argentina and phylogenetic relationships within Odontophrynidae (Anura)
Amphibians are the most vulnerable vertebrates to biodiversity loss mediated by habitat destruction, climate change and diseases. Informed conservation management requires improving the taxonomy of anurans to assess reliably the species’ geographic range. The genus Odontophrynus that is geographically refined to Argentina, Bolivia, Brazil, Uruguay and Paraguay includes currently 12 nominal species with many populations of uncertain taxonomic assignment and subsequently unclear geographic ranges. In this study, we applied integrative taxonomic methods combining molecular (mitochondrial 16S gene), allozyme, morphological and bioacoustic data to delimit species of the genus Odontophrynus sampled from throughout Argentina where most species occur. The combined evidence demonstrates one case of cryptic diversity and another of overestimation of species richness. The populations referred to as O. americanus comprise at least three species. In contrast, O. achalensis and O. barrioi represent junior synonyms of the phenotypically plastic species O. occidentalis. We conclude that each of the four species occurring in Argentina inhabits medium to large areas. The Red List classification is currently “Least Concern”. We also propose a phylogenetic hypothesis for the genus and associated genera Macrogenioglottus and Proceratophrys (Odontophrynidae)
Description of three Rhacophorus tadpoles (Lissamphibia: Anura: Rhacophoridae) from Sarawak, Malaysia (Borneo)
This communication reports the discovery of the hitherto unknown larval forms of Rhacophorus rufipes and R. penanorum, and
re-describes the tadpole of R. dulitensis. Tadpoles of all three species were discovered at Gunung Mulu National Park, Sarawak
(Borneo), Malaysia. The identity of the larvae was determined by DNA barcoding techniques using partial 16S rRNA mitochondrial
gene sequences. Larval DNA sequences matched those of syntopic adults of respective species. Detailed descriptions
of external morphology and colouration in life are provided along with ecological notes. The tadpole of R. rufipes and R.
dulitensis can be classified as generalized, benthic-nectonic type, whereas tadpoles of R. penanorum show adaptations typical
for a lotic, rheophilous lifestyle
Global and regional ecological boundaries explain abrupt spatial discontinuities in avian frugivory interactions
Species interactions can propagate disturbances across space via direct and indirect effects, potentially connecting species at a global scale. However, ecological and biogeographic boundaries may mitigate this spread by demarcating the limits of ecological networks. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among plant-frugivore networks, while accounting for background spatial and elevational gradients and differences in network sampling. We assessed network dissimilarity patterns over a broad spatial scale, using 196 quantitative avian frugivory networks (encompassing 1496 plant and 1004 bird species) distributed across 67 ecoregions, 11 biomes, and 6 continents. We show that dissimilarities in species and interaction composition, but not network structure, are greater across ecoregion and biome boundaries and along different levels of human disturbance. Our findings indicate that biogeographic boundaries delineate the world’s biodiversity of interactions and likely contribute to mitigating the propagation of disturbances at large spatial scales.The authors acknowledge the following funding: University of Canterbury Doctoral Scholarship (L.P.M.); The Marsden Fund grant UOC1705 (J.M.T., L.P.M.); The SĂŁo Paulo Research Foundation - FAPESP 2014/01986-0 (M.G., C.E.), 2015/15172-7 and 2016/18355-8 (C.E.), 2004/00810-3 and 2008/10154-7 (C.I.D., M.G., M.A.P.); Earthwatch Institute and Conservation International for financial support (C.I.D., M.G., M.A.P.); Carlos Chagas Filho Foundation for Supporting Research in the Rio de Janeiro State – FAPERJ grant E-26/200.610/2022 (C.E.); Brazilian Research Council grants 540481/01-7 and 304742/2019-8 (M.A.P.) and 300970/2015-3 (M.G.); Rufford Small Grants for Nature Conservation No. 22426–1 (J.C.M., I.M.), No. 9163-1 (G.B.J.) and No. 11042-1 (MCM); Universidade Estadual de Santa Cruz (Propp-UESC; No. 00220.1100.1644/10-2018) (J.C.M., I.M.); Fundação de Amparo Ă Pesquisa do Estado da Bahia - FAPESB (No. 0525/2016) (J.C.M., I.M.); European Research Council under the European Union’s Horizon 2020 research and innovation program (grant 787638) and The Swiss National Science Foundation (grant 173342), both awarded to C. Graham (D.M.D.); ARC SRIEAS grant SR200100005 Securing Antarctica’s Environmental Future (D.M.D.); German Science Foundation—Deutsche Forschungsgemeinschaft PAK 825/1 and FOR 2730 (K.B.G., E.L.N., M.Q., V.S., M.S.), FOR 1246 (K.B.G., M.S., M.G.R.V.) and HE2041/20-1 (F.S., M.S.); Portuguese Foundation for Science and Technology - FCT/MCTES contract CEECIND/00135/2017 and grant UID/BIA/04004/2020 (S.T.) and contract CEECIND/02064/2017 (L.P.S.); National Scientific and Technical Research Council, PIP 592 (P.G.B.); Instituto Venezolano de Investigaciones CientĂficas - Project 898 (V.S.D.)
Multimodal Communication in a Noisy Environment: A Case Study of the Bornean Rock Frog Staurois parvus
High background noise is an impediment to signal detection and perception. We report the use of multiple solutions to improve signal perception in the acoustic and visual modality by the Bornean rock frog, Staurois parvus. We discovered that vocal communication was not impaired by continuous abiotic background noise characterised by fast-flowing water. Males modified amplitude, pitch, repetition rate and duration of notes within their advertisement call. The difference in sound pressure between advertisement calls and background noise at the call dominant frequency of 5578 Hz was 8 dB, a difference sufficient for receiver detection. In addition, males used several visual signals to communicate with conspecifics with foot flagging and foot flashing being the most common and conspicuous visual displays, followed by arm waving, upright posture, crouching, and an open-mouth display. We used acoustic playback experiments to test the efficacy-based alerting signal hypothesis of multimodal communication. In support of the alerting hypothesis, we found that acoustic signals and foot flagging are functionally linked with advertisement calling preceding foot flagging. We conclude that S. parvus has solved the problem of continuous broadband low-frequency noise by both modifying its advertisement call in multiple ways and by using numerous visual signals. This is the first example of a frog using multiple acoustic and visual solutions to communicate in an environment characterised by continuous noise
Range extension of Rhacophorus dulitensis Boulenger, 1892 (Amphibia: Anura: Rhacophoridae) in western Borneo
We report on a record of Rhacophorus dulitensis from Kubah National Park in western Sarawak. The new record extends the known geographical range of the species 300 km to the west
Leptolalax gracilis
Leptolalax gracilis (Günther, 1872) Slender Litter Frog (Figures 1–4) Leptobrachium gracile — Günther 1872, Boulenger 1882 Megalophrys gracilis — Boulenger 1908 b, Boulenger 1912 (partim) Megophrys gracilis — Smith 1930 (partim) Leptobrachium gracilis — Inger 1966 Leptobrachium (Leptolalax) gracile — Dubois 1980 Leptolalax gracilis — Dubois 1983 Holotype: BMNH 72.2. 19.35 = 1947.2. 25, an adult female, collected by Alfred A. Everett at Matang, Sarawak, Borneo. Referred material: NMBE 1059912, an adult female, NMBE 1056599, 1056602, 1056604, 1059903 – 1059911, twelve adult males; all from Kubah National Park, Matang Range, Sarawak, Borneo, collected by J. M. Dehling in April and September 2009. Diagnosis: The type species of the genus Leptolalax (Dubois 1980), distinguishable from its congeners by the combination of the following characters: (1) size large, SVL of males 34.3 –39.0 mm, of females 42.4 –49.0 mm, (2) interorbital distance less than or subequal to width of upper eyelid, (3) pectoral glands small and low, hardly discernible, (4) ventrolateral, supra-axillary, and femoral glands absent, (5) venter speckled with large, irregularly shaped spots, (6) snout acuminate in ventral view, rounded in lateral view, (7) webbing between toes basal, (8) advertisement call consisting of long series of notes with 3–4 pulses, dominant frequency at 2600–2800 Hz, without frequency-modulation. Description of the holotype (Figure 1): Habitus slender; head broad (HW/SVL 0.36), wider than long (HW/ HL 1.12) and wider than trunk; snout acuminate in ventral view, rounded in lateral view, slightly protruding, its length two-fifths the head length (SL/HL 0.41) and shorter than eye diameter (SL/ED 0.93); canthus rostralis distinct, almost straight-lined in both dorsal and lateral view; loreal region oblique, moderately concave; nostrils rounded, directed laterally; distance between eye and nostril slightly larger than internarial distance (EN/NN 1.06) and smaller than eye diameter (EN/ED 0.63); pupil vertical; tympanum distinct, rounded, its diameter two-fifths the eye diameter (TD/ED 0.42); interorbital distance subequal to eyelid width (IO/EW 0.99); pineal ocellus absent; symphysial knob on anteriormost part of mandible; vomerine ridge and teeth absent; tongue large, broad, bifid, free for about half its length; median lingual process absent. Fore limbs slender, moderately long (ELB/SVL 0.76, ARM/SVL 0.56); hand about as long as forearm (HND/ ARM 0.49); fingers long and slender, without webbing or lateral fringes of skin (Figure 2); relative length of fingers IV<II<I<III; finger tips rounded and thickened; subarticular tubercles indistinct; large, rounded, prominent tubercle in metacarpal region of fingers I and II; much smaller tubercle in metacarpal region of fingers III and IV. Hind limbs moderately long (LEG/SVL 1.66); tibiofibula long (TFL/SVL 0.53), much longer than foot (TFL/ FOT 1.34) and longer than thigh (TFL/THL 1.08); heels overlapping each other considerably when knees are flexed and thighs are held laterally at right angle to body; toe tips rounded and thickened, smaller than finger tips; toes webbed at bases only (Figure 2); very narrow fringes of skin on lateral sides of toes except preaxial side of toe I and postaxial side of toe V; relative length of toes I<II<V<III<IV; subarticular tubercle on toes I and II, and indistinct proximal one on toe V, replaced on toes III and IV with longitudinal ridge of thickened skin on the plantar side of phalanges except the distal ones; inner metatarsal tubercle oval, large, about half the length of toe I; outer metatarsal tubercle absent. Skin on dorsum mostly smooth in preservative, weakly wrinkled on dorsal surfaces of the extremities; wrinkles forming indistinct, reticulated, predominantly longitudinal, low ridges; supratympanic fold distinct, curved, running from posterior margin of eye to just behind the corner of the mouth; ventral skin smooth; pectoral glands small, very low, hardly discernible, at the insertion of the forelimbs; supraaxillary glands and ventrolateral glandular ridges absent. Variation: Measurements of holotype and topotypes are given in Table 1. A female topotype is larger than the holotype but generally similar in proportions (Table 2). Males are smaller than females but similar in proportions (Tables 1, 2). Males have single, median, subgular vocal sacs. The skin of the dorsum is granular with many small tubercles in life but smooth in preservative. The wrinkles on the dorsal surfaces of the extremities are more discernible in life than in preservative. Colouration in life (based on topotypes): Basal colouration of the dorsum variable between individuals and also within a single individual at different times of the day; from light grey, cream-coloured, or yellowish to dark grey or almost black (Figure 3). Basal colouration of the venter is white. Several colour pattern elements present on body. Their colouration is darker than the sourrounding areas and varies from grey to brown or black. Dark dorsal pattern variable but often consisting of a broad, interrupted line running from tympanum to groin on both sides of the body. Another line runs above the spine in some individuals; in others, this line is reduced to a series of irregularly shaped spots. Some individuals lack a dorsal pattern. The lateral sides of the body have large dark spots in most individuals. In some, there are also small, cream-coloured dots. Dark spots are also present on the lateral sides of the thigh and tibia, above the tympanum and in the loreal region. A large, Y-shaped blotch is present between the eyelids in most individuals, as are two oval, anterolaterally directed spots on the snout, one of each side posterior to the nostrils. These spots can be fused with each other partially or completely, forming V-shaped or triangular blotches. The lips are irregularly barred light and dark, with pattern in the supralabial area being continued in the infralabial area. Legs and lower arms are banded. In most individuals, the bands are darker than the surrounding areas; in some individuals, however, they can become light grey during the night and then are about as light as or even lighter than the surrounding areas (Figure 3). The upper arm and the proximal one-fourth of the lower arm are cream-coloured in most individuals without any pattern or with only small dots. In few individuals the upper arm is dark-banded like the lower arm. The ventral sides of foot, tarsus, and lower arm are dark grey or black. Venter, chest and chin are spotted with large dark spots (Figure 4). In some individuals, the ventral pattern can become quite weak during the night, and is more apparent during the day. The iris is bright red in the upper two-fifths and dull greyish red, with a narrow ring of bright red along the pupil in the lower three-fifths. Colouration in preservative: Similar to that in life but colours are generally paler. Dorsal and ventral patterns are clearly visible. Ecological notes: The species is abundant at the lower elevations (<500 m) of Gunung Serapi in the Matang Range. Individuals can be found in the leaf litter of the forest floor from only a few to several dozens of meters from the next stream. They are seldom found on leaves in the vegetation. Males call from the forest floor but sometimes can be found perched on elevated calling sites like a fallen tree, a tree root, or a rock, up to 2 m above the ground. Characteristics of the advertisement call of topotypic specimens have been reported by Matsui (1997). Etymology: From Latin gracilis, meaning “slender”. In allusion of the slender limbs of the species in comparison to those of Leptobrachium hasseltii, according to the original publication.Published as part of Dehling, Maximilian, 2012, Redescription of Leptolalax gracilis (Günther, 1872) from Borneo and taxonomic status of two populations of Leptolalax (Anura: Megophryidae) from Peninsular Malaysia, pp. 20-34 in Zootaxa 3328 on pages 21-28, DOI: 10.11646/zootaxa.3328.1.2, http://zenodo.org/record/20882
Elevated alpha diversity in disturbed sites obscures regional decline and homogenization of amphibian taxonomic, functional and phylogenetic diversity
Abstract Loss of natural habitat due to land-use change is one of the major threats to biodiversity worldwide. It not only affects the diversity of local species communities (alpha diversity) but can also lead to large-scale homogenization of community composition (reduced beta diversity) and loss of regional diversity (gamma diversity), but these effects are still rarely investigated. We assessed the impact of land-use change on taxonomic, functional and phylogenetic diversity of amphibians in Rwanda, both on the local (community-level) and regional scale (country-wide). Alpha diversity in local communities was higher in farmland than in natural habitats; however, species turnover among farmland sites was much lower than among natural sites, resulting in highly homogenized communities and reduced taxonomic, functional and phylogenetic gamma diversity in farmland across Rwanda. Amphibians found in farmland were mostly disturbance-tolerant species that are widespread in eastern Africa and beyond. In contrast, most of the regionally endemic frog species that make this region a continent-wide hotspot of amphibian diversity were found only in the natural habitats. Ongoing habitat conversion might result in further homogenization of amphibian communities across sub-Saharan Africa and the loss of regional endemism, unique evolutionary lineages, and multifunctionality
How lizards fly: A novel type of wing in animals
<div><p>Flying lizards of the genus <i>Draco</i> are renowned for their gliding ability, using an aerofoil formed by winglike patagial membranes and supported by elongated thoracic ribs. It remains unknown, however, how these lizards manoeuvre during flight. Here, I present the results of a study on the aerial behaviour of Dussumier's Flying Lizard (<i>Draco dussumieri</i>) and show that <i>Draco</i> attaches the forelimbs to the leading edge of the patagium while airborne, forming a hitherto unknown type of composite wing. The attachment of the forelimbs to the patagium suggests that that aerofoil is controlled through movements of the forelimbs. One major advantage for the lizards is that the forelimbs retain their complete range of movement and functionality for climbing and running when not used as a part of the wing. These findings not only shed a new light on the flight of <i>Draco</i> but also have implications for the interpretation of gliding performance in fossil species.</p></div
Diversity of Ptychadena in Rwanda and taxonomic status of P. chrysogaster Laurent, 1954 (Amphibia, Anura, Ptychadenidae)
We assess the diversity of Ptychadena species in Rwanda based on re-examination of voucher specimens in museum collections and our own data from recent assessment of the species composition of amphibian communities in Rwanda. We recognize five species which we allocate to the following available names: P. anchietae, P. chrysogaster, P. nilotica, P. porosissima, and P. uzungwensis. We did not find evidence for the presence of P. grandisonae and P. oxyrhynchus which have been listed for the country. The five species can be distinguished by quantitative morphometrics (discriminant analysis, success rate: 100 %) and a number of qualitative characters of external morphology. We provide an identification key to the Rwandan species and describe the morphology of each species in detail. The taxonomic status and the phylogenetic position of Ptychadena chrysogaster are further assessed based on the partial sequence of the mitochondrial 16S rRNA. The species differs genetically from available homologous sequences from congeners by an uncorrected p distance of at least 4.2 % and appears to be most closely related to specimens assigned to P. porosissima, P. mahnerti, “P. aff. uzungwensis” and “P. aff. bibroni”
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