Zeigler, S. L., De Vleeschouwer, K. M. and Raboy, B. E. (2013), Assessing Extinction Risk in Small Metapopulations of Golden-headed Lion Tamarins (Leontopithecus chrysomelas) in Bahia State, Brazil. Biotropica. doi: 10.1111/btp.12037
Golden-headed lion tamarins (GHLTs; Leontopithecus chrysomelas) are endangered primates endemic to the Brazilian Atlantic Forest, where loss of forest and its connectivity threaten species survival. Understanding the role of habitat availability and configuration on population declines is critical for guiding proactive conservation for this, and other, endangered species. We conducted population viability analysis to assess vulnerability of ten GHLT metapopulations to habitat loss and small population size. Seven metapopulations had a low risk of extirpation (or local extinction) over the next 100 years assuming no further forest loss, and even small populations could persist with immediate protection. Three metapopulations had a moderate/high risk of extirpation, suggesting extinction debt may be evident in parts of the species’ range. When deforestation was assumed to continue at current rates, extirpation risk significantly increased while abundance and genetic diversity decreased for all metapopulations. Extirpation risk was significantly negatively correlated with the size of the largest patch available to metapopulations, underscoring the importance of large habitat patches for species persistence. Finally, we conducted sensitivity analysis using logistic regression, and our results showed that local extinction risk was sensitive to percentage of females breeding, adult female mortality, and dispersal rate and survival; conservation or research programs that target these aspects of the species’ biology/ecology could have a disproportionately important impact on species survival. We stress that efforts to protect populations and tracts of habitat of sufficient size throughout the species’ distribution will be important in the near-term to protect the species from continuing decline and extinction.
Duckett, P. E., Wilson, P. D., Stow, A. J. (2013), Keeping up with the neighbours: using a genetic measurement of dispersal and species distribution modelling to assess the impact of climate change on an Australian arid zone gecko (Gehyra variegata). Diversity and Distributions. doi: 10.1111/ddi.12071
During this century rapid climate change will have a profound effect on global biodiversity, and species survival will be contingent on their ability to adapt or disperse. Species distribution models are a popular tool for gauging how the distribution of favourable climate may change over space and time. Evaluating the level of dispersal between the current distribution and potential future distribution of a species is a key to predicting their survival, but rarely estimated. Here we applied species distribution models and a genetic estimate of dispersal to quantitatively assess dispersal to new distributions in the timescale imposed by future climate change.
We sampled 635 adult Gehyra variegata (2n = 40a/38b) throughout central and eastern Australia, encompassing much of the recorded distribution for this gecko. We genotyped all individuals at 16 microsatellite loci, from which we estimated mean annual dispersal distance using Wright’s neighbourhood size. Species distribution modelling predicted the current and future distribution of the species, and we used annual dispersal distances to evaluate whether the species could keep up with shifts in the range of their favourable climatic conditions.
Our estimates of mean dispersal showed that 17–41% of the current G. variegata (2n = 40a/38b) distribution was unlikely to contribute to their future distribution given the timescale imposed by future global climate change.
Our approach can make further use of molecular and occurrence record datasets to answer whether a species has the capacity to reach future areas of favourable climate and the extent to which the current distribution will contribute to this process.
Conserving large carnivores: dollars and fence
C. Packer, A. Loveridge, S. Canney, T. Caro, S.T. Garnett, M. Pfeifer, K.K. Zander, A. Swanson, D. MacNulty, G. Balme, H. Bauer, C.M. Begg, K.S. Begg, S. Bhalla, C. Bissett, T. Bodasing, H. Brink, A. Burger, A.C. Burton, B. Clegg, S. Dell, A. Delsink, T. Dickerson, S.M. Dloniak, D. Druce, L. Frank, P. Funston, N. Gichohi, R. Groom, C. Hanekom, B. Heath, L. Hunter, H.H. DeIongh, C.J. Joubert, S.M. Kasiki, B. Kissui, W. Knocker, B. Leathem, P.A. Lindsey, S.D. Maclennan, J.W. McNutt, S.M. Miller, S. Naylor, P. Nel, C. Ng’weno, K. Nicholls, J.O. Ogutu, E. Okot-Omoya, B.D. Patterson, A. Plumptre, J. Salerno, K. Skinner, R. Slotow, E.A. Sogbohossou, K.J. Stratford, C. Winterbach, H. Winterbach, S. Polasky
Ecology Letters (2013)
Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km−2, unfenced populations require budgets in excess of $2000 km−2 to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density-independent factors. Nearly half the unfenced lion populations may decline to near extinction over the next 20–40 years.
Sexual size dimorphism in anurans fails to obey Rensch’s rule
Liao WB, Zeng Y, Zhou CQ, Jehle R
Frontiers in Zoology 2013, doi:10.1186/1742-9994-10-10
Sexual size dimorphism (SSD) is related to ecology, behaviour and life history of organisms. Rensch’s rule states that SSD increases with overall body size in species where males are the larger sex, while decreasing with body size when females are larger. To test this rule, we analysed literature as well as own data on male and female body size in anurans (39 species and 17 genera). We also tested the hypothesis that SSD is largely a function of age difference between the sexes.
Our data set encompassed 36 species with female-biased SSD, and three species with male-biased SSD. All considered species failed to support Rensch’s rule, also when the analyses were phylogenetically corrected. However, SSD was significantly correlated with Sexual Age Difference (SAD) across species. We also found a significant correlation between SSD contrasts and SAD contrasts.
Our study suggests that Rensch’s rule does not accurately describe macroevolutionary patterns of SSD in anurans. That SAD can explain most of the variation in SSD among species when controlling for phylogenetic effects suggests that phylogeny is not responsible for the broad relationship between age and size across the sexes.
Song, G., Yu, L., Gao, B., Zhang, R., Qu, Y., Lambert, D. M., Li, S., Zhou, T., Lei, F. (2013), Gene flow maintains genetic diversity and colonization potential in recently range-expanded populations of an Oriental bird, the Light-vented Bulbul (Pycnonotus sinensis, Aves: Pycnonotidae). Diversity and Distributions. doi: 10.1111/ddi.12067
Two alternative genetic patterns are typical in recently established populations. One is reduced genetic diversity but significant population structuring compared with original populations. The other is the persistence of genetic polymorphisms and the lack of differentiation in frontier populations. This study aims to test for these patterns by examining population genetics of the Light-vented Bulbul (Pycnonotus sinensis), an Oriental bird that has been undergoing rapid range expansion.
Molecular analyses were conducted on mitochondrial DNA and microsatellite datasets from 256 individuals. Intraspecific phylogeny was reconstructed by Bayesian inference and network analysis. Analysis of molecular variance (AMOVA) and Bayesian clustering were applied to determine population structure. Genetic diversity was tested to determine whether there were significant differences between frontier and source populations. Population expansions were tested in mtDNA and microsatellites. Gene flow and recent migrants were estimated by Bayesian methods.
Both high- and low-nucleotide diversities were recorded in frontier populations, and differences in genetic diversity between frontier and source populations were not statistically significant. Population differentiation was recorded in some source but not in frontier populations. Population size expansion was detected both in frontier and in source populations, and for the whole dataset, commencing before the Last Glacial Maximum.
Genetic diversity can be maintained in expanding populations of the Light-vented Bulbul, and genetic differentiation can be avoided, where substantial genetic exchanges are occurring. This study also discusses the potential effects of evolutionary properties such as historical population growth on recently recorded range expansion.
Renfrew, R. B., Kim, D., Perlut, N., Smith, J., Fox, J., Marra, P. P. (2013), Phenological matching across hemispheres in a long-distance migratory bird. Diversity and Distributions. doi: 10.1111/ddi.12080
In the Northern Hemisphere, bird migration from the tropic to the temperate zone in spring is thought to proceed at a rate determined in large part by local phenology. In contrast, little is understood about where birds go or the factors that determine why they move or where they stop during the post-breeding period.
Study sites were in Oregon, Nebraska and Vermont, and location data we collected extend south to Argentina.
We deployed light-level geolocators on individual Bobolinks from three populations across the breeding range and compare their southbound movement phenology to austral greening as indicated by the Normalized Difference Vegetation Index.
Bobolinks from all breeding populations synchronously arrived and remained for up to several weeks in two sequential, small non-breeding areas that were separated by thousands of kilometres, before staging for pre-alternate moult. Similar to the migration patterns of birds to northern breeding areas, movements into the Southern Hemisphere corresponded to increasing primary productivity.
Our findings suggest that the Bobolink’s southbound migration is broadly constrained by resource availability, and its non-breeding distribution has been shaped by the seasonal phenology of grasslands in both time and space. This is the first documentation of individual birds from across a continental breeding range exhibiting phenological matching during their post-breeding southward migration. Known conservation threats overlap temporally and spatially with large concentrations of Bobolinks, and should be closely examined. We emphasize the need to consider how individuals move and interact with their environment throughout their annual cycle and over hemispheric scales.
Zootaxa 3626 (1): 1–54 (12 Mar. 2013)
Distribution and variation of the giant alpha anoles (Squamata: Dactyloidae) of the genus Dactyloa in the highlands of western Panama, with the description of a new species formerly referred to as D. microtus
SEBASTIAN LOTZKAT, ANDREAS HERTZ, JOE-FELIX BIENENTREU & GUNTHER KÖHLER
Six species of giant alpha anoles of the genus Dactyloa are known to occur in western Panama: Dactyloa casildae, D. frenata, D. ibanezi, D. insignis, D. kunayalae, and D. microtus. Based on own material collected along the highlands in Bocas del Toro, Chiriquí, and Veraguas provinces and the Comarca Ngöbe-Buglé of western Panama, we review their variation in morphological characters and the 16S rRNA mitochondrial gene. Our results support all six nominal taxa, but reveal considerable genetic differentiation between populations of the two highland species, D. casildae and D. microtus,
respectively, from different localities. Correlated morphological differences confirm the existence of a cryptic species among populations currently assigned to D. microtus, which we describe as Dactyloa ginaelisae sp. nov. We provide point distribution maps, morphology and color descriptions, photographs in life, conservation status assessments, and an identification key for all seven species.
Zootaxa 3626 (1): 77–93 (12 Mar. 2013)
Molecular phylogenetic reconstruction of the endemic Asian salamander family Hynobiidae (Amphibia, Caudata)
DAVID W. WEISROCK, J. ROBERT MACEY, MASAFUMI MATSUI, DANIEL G. MULCAHY, & THEODORE J. PAPENFUSS
The salamander family Hynobiidae contains over 50 species and has been the subject of a number of molecular phylogenetic investigations aimed at reconstructing branches across the entire family. In general, studies using the greatest amount of sequence data have used reduced taxon sampling, while the study with the greatest taxon sampling has used a limited sequence data set. Here, we provide insights into the phylogenetic history of the Hynobiidae using both dense taxon sampling and a large mitochondrial DNA sequence data set. We report exclusive new mitochondrial DNA data of 2566 aligned bases (with 151 excluded sites, of included sites 1157 are variable with 957 parsimony informative).
This is sampled from two genic regions encoding a 12S–16S region (the 3’ end of 12S rRNA, tRNAVAl, and the 5’ end of 16S rRNA), and a ND2–COI region (ND2, tRNATrp, tRNAAla, tRNAAsn, the origin for light strand replication—OL, tRNACys, tRNATyr, and the 5’ end of COI). Analyses using parsimony, Bayesian, and maximum likelihood optimality criteria produce similar phylogenetic trees, with discordant branches generally receiving low levels of branch support. Monophyly of the Hynobiidae is strongly supported across all analyses, as is the sister relationship and deep divergence between the genus Onychodactylus with all remaining hynobiids. Within this latter grouping our phylogenetic results identify six clades that are relatively divergent from one another, but for which there is minimal support for their phylogenetic placement. This includes the genus Batrachuperus, the genus Hynobius, the genus Pachyhynobius, the genus Salamandrella, a clade containing the genera Ranodon and Paradactylodon, and a clade containing the genera Liua and Pseudohynobius. This latter clade receives low bootstrap support in the parsimony analysis, but is consistent across all three analytical methods. Our results also clarify a number of well-supported relationships within the larger Batrachuperus and Hynobius clades. While the relationships identified in this study do much to clarify the phylogenetic history of the Hynobiidae, the poor resolution among major hynobiid clades, and the contrast of mtDNA-derived relationships
with recent phylogenetic results from a small number of nuclear genes, highlights the need for continued phylogenetic study with larger numbers of nuclear loci.
Zootaxa 3626 (1): 188–200 (12 Mar. 2013)
Revision of batfishes (Lophiiformes: Ogcocephalidae) of New Zealand and adjacent waters, with description of two new species of the genus Malthopsis
HSUAN-CHING HO, CLIVE D. ROBERTS & KWANG-TSAO SHAO
Examination and taxonomic review of the batfishes collected from New Zealand and adjacent waters reveals five nominal species: Halieutopsis bathyoreos and Malthopsis mitrigera are recorded from New Zealand for the first time; the synonymyof Halieutaea maoria with H. stellata is confirmed, and two new species are described. Malthopsis asparata sp. nov. is unique in having stout principal bucklers with prominent spines. Malthopsis parva sp. nov. differs from congeners in having a naked abdomen, a short rostral spine directed upward, and all principal bucklers blunt.
Endemic or exotic: the phylogenetic position of the Martinique Volcano Frog Allobates chalcopis (Anura: Dendrobatidae) sheds light on its origin and challenges current conservation strategies
Antoine Fouquet, Kévin Pineau, Miguel Trefaut Rodrigues, Julien Mailles, Jean-Baptiste Schneider, Raffael Ernst, Maël Dewynter
Systematics and Biodiversity
Amphibian faunas of the Lesser Antilles are depauperate, with only a few species being endemic and generally threatened. Allobates chalcopis from the island of Martinique is a particularly enigmatic case being the only known dendrobatid endemic to an oceanic island. This species has previously been suggested as being introduced to Martinique. The question of its true origin remained unresolved because no individuals were found since its formal description in the 1990s. Twenty years after the last observation of the species, we succeeded in finding an isolated population of Allobates chalcopis in Martinique. The rediscovery allowed us to investigate the species’ phylogenetic position, confirming that it is nested within a clade of lowland Amazonian Allobates but nonetheless distantly related to any known species of the group. The arrival of the species in Martinique likely corresponds to an overseas dispersal from South America during the late Miocene, as previously hypothesized for Bothrops lanceolatus and Leptodactylus fallax; two other species endemic to Martinique and surrounding islands. However, the species was not found in its type locality 500 m a.s.l. but 300 m higher in altitude, in herbaceous areas of the summit of Montagne Pelée. The possible range reduction and population decline in combination with the evidence of endemicity of the species highlights the need for a reassignment of the current Red List status. Furthermore, a refined conservation strategy is needed to guarantee the long-term viability of Allobates chalcopis in its native range.
Selman, W., Qualls, C. and Owen, J. C. (2013), Effects of human disturbance on the behavior and physiology of an imperiled freshwater turtle. The Journal of Wildlife Management. doi: 10.1002/jwmg.538
The effect of human disturbance on wildlife is of increasing interest because of the growing use of wildlands by humans for recreation. Few studies have documented the effect of human disturbance on behavior and physiology simultaneously, with no studies existing for any turtle species. Turtles are one of the most endangered taxonomic groups and many are of conservation concern, including the yellow-blotched sawback (Graptemys flavimaculata), a freshwater turtle of the Pascagoula River system, Mississippi, USA. We studied G. flavimaculata individual- and population-level basking behavior, while also documenting the effects of human disturbance on basking behavior at recreationally disturbed and control sites. We also assessed the physiological response of turtles to human disturbance by measuring heterophil/lymphocyte levels (H:L; higher levels indicate increased stress) and shell condition of captured turtles at the 2 sites. At the individual level, disturbed turtles at the recreationally disturbed site basked for significantly shorter durations than undisturbed turtles at the same site and undisturbed turtles at the control site; disturbed turtles at the control site basked longer than all groups possibly because the few instances of disturbances all occurred during a time of year when basking durations were longest. At the population level, we detected significantly lesser basking percentages at the recreationally disturbed site relative to the control site, possibly because of natural differences among the sites (i.e., a more stable thermal environment) or because of the higher level of human disturbance. At the recreationally disturbed site, more disturbances occurred on weekend and weekend bordering days relative to weekdays, and larger and slower boats disturbed significantly greater percentages of basking turtles compared to smaller and faster watercraft. Further, turtles from the disturbed site had significantly higher H:L levels relative to the undisturbed site, and an index of shell condition was significantly poorer at the disturbed site. Boating records indicate that the impact of recreational boating at the disturbed site likely has grown over the last 22 years because of an increase in the number and size of boats using the river; this trend will likely continue unless restrictions are enacted by managers and/or state entities to limit the number and size of boats that access the river.
Dickson, D. L. and Smith, P. A. (2013), Habitat used by common and king eiders in spring in the southeast Beaufort Sea and overlap with resource exploration. The Journal of Wildlife Management. doi: 10.1002/jwmg.529
The southeast Beaufort Sea is a critical spring staging area for common and king eiders (Somateria mollissima v-nigrum, S. spectabilis), and is for many the final stop before they reach their breeding grounds throughout the western Canadian Arctic. The region also has significant oil and gas potential, and the recent approval of a pipeline through the Mackenzie Valley may make development of these resources economically viable. We used satellite telemetry to determine the distribution and habitat use of eiders staging in the southeast Beaufort Sea in spring, and the overlap of eiders with oil and gas exploration. From 2004 to 2009, we monitored 51 eiders equipped with platform terminal transmitters (PTTs) throughout spring migration (May–June). We compared the marine habitats used by each species, and evaluated habitat preferences using resource selection functions. The location and extent of the flaw lead (open water along the interface between mobile pack ice and stationary landfast ice) at the time when eiders were staging varied among years, but both species showed a strong preference for use of flaw lead habitats. This preference was stronger for common eiders than for king eiders, which also used pack ice extensively. Common eiders generally occurred near the landfast ice edge, whereas king eiders were just as often nearer to the pack ice edge of the flaw lead. Average water depth (±SE) for common eiders was 22 ± 2 m compared to 30 ± 1 m for king eiders. Kernel density estimators showed that eiders generally occurred in lower densities in areas of otherwise suitable habitat off the Mackenzie River delta. We suggest that this is a result of the highly turbid water discharged by the Mackenzie River, which limits visibility. Oil and gas exploration overlapped significantly with the areas used by eiders. The high density of birds using the restricted and ice-rich flaw lead habitats indicates that an accidental spill in the region could be catastrophic for Canada’s western Arctic eider populations.
Varner, D. M., Bielefeld, R. R. and Hepp, G. R. (2013), Nesting ecology of Florida mottled ducks using altered habitats. The Journal of Wildlife Management. doi: 10.1002/jwmg.536
Habitat loss has negatively affected many species of upland-nesting waterfowl. Very few areas contain pristine nesting habitat in Florida because of conversion to agriculture and urban development. Although some species have acclimated to nesting in an altered landscape, little is known about the nesting ecology of Florida mottled ducks (Anas fulvigula fulvigula) that use altered habitats. We located and monitored 77 nests of radio-marked Florida mottled ducks in the Upper St. Johns River Basin (1999–2002) and in south Florida (2009–2011) and tested the effects of nest vegetation characteristics, human disturbance, and temporal variables on estimates of daily nest survival. We also calculated the percent of females that nested each year as a measure of breeding propensity. Nest age at discovery had a positive relationship with daily nest survival. Daily nest survival rates did not vary within or among years and were unaffected by density and height of vegetation at the nest and human disturbance parameters we measured. Breeding propensity ranged from 25% to 56%. Breeding propensities were less than those of other duck species, but our nest success estimate of 28% was greater than most estimates for ducks and is not likely to limit population growth of Florida mottled ducks.
Davis, S. K., Fisher, R. J., Skinner, S. L., Shaffer, T. L. and Brigham, R. M. (2013), Songbird abundance in native and planted grassland varies with type and amount of grassland in the surrounding landscape. The Journal of Wildlife Management. doi: 10.1002/jwmg.537
Agriculture and wildlife conservation programs have converted vast amounts of cropland into grasslands planted with exotic species. Understanding how landscape context influences avian use of native and planted grasslands is essential for developing effective conservation strategies in agricultural landscapes. Our primary objective was to determine the extent to which the amount and type of grassland in the surrounding landscape influences the abundance of grassland songbird species on native and planted grassland parcels in southern Saskatchewan and Alberta, Canada. Bird abundance was more strongly influenced by the amount and type of grassland within 400 m of breeding parcels than at larger spatial scales. Grassland specialists responded similarly to habitat and landscape type over both years and provinces. Sprague’s pipit (Anthus spragueii) and Baird’s sparrow (Ammodramus bairdii) were most common in native grassland parcels surrounded by native grassland and were more likely to occur in planted grasslands surrounded by native grassland. Bobolinks (Dolichonyx oryzivorus) were most common in planted grassland parcels, but their abundance increased with the amount of native grassland surrounding these parcels. Our findings indicate that the suitability of planted grasslands for these species is influenced by their proximity to native grassland. Grassland generalists showed mixed responses to habitat and landscape type over the 2 years (Le Conte’s sparrow [Ammodramus leconteii]) and between provinces (Savannah sparrow [Passerculus sandwichensis] and western meadowlark [Sturnella neglecta]). Management to benefit grassland specialists should therefore consider the landscape context when seeding cultivated land to non-native grassland and conserve extant native grassland.
Elizabeth N. Fairhurst, Andrew G. Horn, Marty L. Leonard, Nest acoustics and begging call structure in nestling tree swallows, Animal Behaviour, Available online 11 March 2013, ISSN 0003-3472, 10.1016/j.anbehav.2013.02.007.
Acoustic signals are altered by the environment during transmission, and, as a result, many show features that overcome this constraint. This phenomenon is well documented for long-distance signals used for mate attraction and territorial defence, but is relatively unexplored for short-distance signals such as the begging calls of young animals. We used the cavity-nesting tree swallow, Tachycineta bicolor, to examine whether the acoustic environment of the nest affected the structure and transmission of begging calls. We found that begging calls were longer and minimum call frequency was lower in smooth-walled than rough-walled nests, and that minimum call frequency decreased with increasing cavity diameter. Begging call features did not, however, vary with reverberation and frequency response within nests, even though calls were more degraded in nests with a more variable frequency response. Our results show that begging call structure varies with the structure of nest cavities and that the acoustic environment of nest cavities affects call transmission. Thus, some of the variation in begging calls currently attributed to factors such as evolutionary conflicts of interest or predation might be partially attributable to the acoustic environment of the nest. More generally, selection for effective transmission deserves more attention as a factor affecting the structure of short-range acoustic signals.