17 research outputs found

    Does disappearance mean extirpation? The case of right whales off Namibia

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    Right whales off Namibia were severely depleted by early 19th century whaling, and rarely featured in modern whaling catches in the 1920s. Aerial surveys of the Namibian coastline from 1978 and onwards revealed increasing numbers of right whales, but few cow-calf pairs. Aerial surveys off South Africa since 2009 showed a major decline in the availability of animals without calves. Twenty individual matches were made between 94 whales photographed off Namibia/Northern Cape in 2003–2012 and 1,677 photographed off South Africa in 1979–2012. Eight were adult females that calved in South African waters, but only one was also seen with a calf off Namibia. Twelve out of 13 individuals off Namibia with distinctive dorsal pigmentation were first seen as calves off South Africa. These results strongly indicate connectivity between the two regions, while the presence off Namibia of three adult females from the South African population in the season in which they are believed to conceive suggests that there is unlikely to be any genetic differentiation between the two areas. We conclude that the reappearance of right whales off Namibia represents range expansion from South Africa rather than the survival of a few remnants of an originally separate stock.Benguela Environment Fisheries Interaction & Training Programme (BENEFIT), Namibian Coast Conservation and Management Project (NACOMA), and The Namibia Nature Foundation (NNF).Department of Industries (and its successors), Department of Transport (through the SA National Antarctic Programme), South African Marine Corporation, World Wide Fund for Nature (SA), The Green Trust, Moby Dick Rum, Exclusive Touch, International Whaling Commission, the Island Foundation, and National Research Foundation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-76922016-07-31hb201

    Resource dispersion, territory size and group size of black-backed jackals on a desert coast

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    We studied the relationship between resource— food patch—richness and dispersion on group and territory size of black-backed jackals Canis mesomelas in the Namib Desert. Along beaches where food patches are mostly small, widely separated jackal group sizes are small, and territories are narrow and extremely elongated. Where food patches are rich, fairly clumped and also heterogeneous, group sizes are large and territory sizes small. At a superabundant and highly clumped food source—a large seal rookery—group sizes are large, and territoriality is absent. Although jackals feed at the coast and den nearby, individuals move linearly far inland along well-defined footpaths. The marked climatic gradient from the cold coast inland—a drop in wind speed and rise in effective temperature Te – and use of particular paths by different groups—strongly suggests that these movements are for thermoregulatory reasons only.Universities of Stellenbosch and Pretoria and the National Research Foundationhttp://link.springer.com/journal/13364hb2014mn201

    Setback distances as a conservation tool in wildlife-human interactions : testing their efficacy for birds affected by vehicles on open-coast sandy beaches

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    In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviou

    Setback distances as a conservation tool in wildlife-human interactions : testing their efficacy for birds affected by vehicles on open-coast sandy beaches

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    In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviou

    A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

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    Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin similar to 100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants

    Revised taxonomic status of Pseudalmenus barringtonensis Waterhouse, 1928 stat. rev. (Lepidoptera: Lycaenidae): uncovering Australia’s greatest taxonomic fraud

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    The Australian endemic lycaenid Pseudalmenus H.H. Druce, 1902 occupies a unique phylogenetic position within the Theclinae–Polyommatinae assemblage. Although the genus exhibits complex geographic variation, it has long been considered to be monotypic. However, evidence from adult phenotype (colour pattern), immature stages (final instar larva) and ecology (ant specificity) (total of 10 unique character states) as well as limited genetic data (mitochondrial COI) suggest that there are two species, namely, P. chlorinda (Blanchard, 1848) from Tasmania and the mainland of south-eastern Australia and P. barringtonensis Waterhouse, 1928 stat. rev., which is allopatric and narrowly restricted to montane areas in northern New South Wales. Examination of the ‘holotype’ male of P. barringtonensis in the Australian Museum showed that it is a fake, although the data label is genuine; the specimen is actually P. chlorinda chloris Waterhouse & Lyell, 1914 that has been modified with red paint to resemble P. barringtonensis. The true holotype is currently missing, but a specimen in the Australian Museum (registration No. K199026) that is part of the Colin W. Wyatt Theft Collection with a fictitious label is almost certainly the true holotype of P. barringtonensis. We discuss the history of this most unusual and bizarre circumstance and conclude that Wyatt stole the holotype sometime in 1946 before he returned to England (∼72 years ago) and fabricated the fake holotype as a replacement specimen. Such a fraudulent and unprecedented act surely ranks as Australia’s greatest taxonomic fraud

    The subspecies concept in butterflies: has its application in taxonomy and conservation biology outlived its usefulness?

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    Subspecies lie at the interface between systematics and population genetics, and represent a unit of biological organization in zoology that is widely used in the disciplines of taxonomy and conservation biology. In this review, we explore the utility o

    When and where did troidine butterflies (Lepidoptera: Papilionidae) evolve? Phylogenetic and biogeographic evidence suggests an origin in remnant Gondwana in the Late Cretaceous

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    The age, geographic origin and time of major radiation of the butterflies (Hesperioidea + Papilionoidea + Hedyloidea) are largely unknown. The general modern view is that butterflies arose during the Late Jurassic/Cretaceous in the southern hemisphere (southern Pangea/Gondwana before continental breakup), but this is not universally accepted, and is a best guess based largely on circumstantial evidence. The extreme paucity of fossils and lack of modern, higher-level phylogenies of extant monophyletic groups have been major impediments towards determining reliable estimates of either their age or geographic origin. Here we present a phylogenetic and historical biogeographic analysis of a higher butterfly taxon, the swallowtail tribe Troidini. We analysed molecular data for three protein-encoding genes, mitochondrial ND5 and COI-COII, and nuclear EF-1α, both separately and in combination using maximum parsimony (with and without character weighting and transition/ transversion weighting), maximum likelihood and Bayesian methods. Our sample included representatives of all 10 genera of Troidini and distant ingroup taxa (Baroniinae, Parnassiinae, Graphiini, Papilionini), with Pieridae as outgroup. Analysis of the combined dataset (4326 bp; 1012 parsimony informative characters) recovered the Troidini as a well supported monophyletic group and the monophyly of its two subtribes, Battina and Troidina. The most parsimonious biogeographic hypothesis suggests a southern origin of the tribe in remnant Gondwana (Madagascar-Greater India-Australia-Antarctica-South America) sometime after the rifting and final separation of Africa in the Late Cretaceous (<90 Mya). Although an ancient vicariance pattern is proposed, at least four relatively recent dispersal/extinction events are needed to reconcile anomalies in distribution, most of which can be explained by geological and climatic events in South-east Asia and Australia during the late Tertiary. Application of a molecular clock based on a rate smoothing programme to estimate various divergence times based on vicariance events, revealed two peculiarities in our biogeographic vicariance model that do not strictly accord with current understanding of the temporal breakup of Gondwana: (7) the troidine fauna of Greater India did not become isolated from Gondwana (Antarctica) until the end of the Cretaceous (c. 65 Mya), well after Madagascar separated from Greater India (84 Mya); and (2) the faunas of Greater India, Australia and South America diverged simultaneously, also at the K/T boundary. A recent published estimate of the time (31 Mya) of divergence between Cressida Swainson (Australia) and Euryades Felder & Felder (South America) is shown to be in error

    New ant-Lycaenid associations and biological data for some Australian butterflies (Lepidoptera: Lycaenidae)

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    Records of 61 ant-lycaenid associations and other ecological data are tabulated for 27 Australian species of Lycaenidae. Thirty-one of the ant-lycaenid associations and four larval food plant records are new. Ant-lycaenid records are discussed in furthe

    Taxonomy, ecology, genetics and conservation status of the pale imperial hairstreak ( Jalmenus eubulus ) (Lepidoptera:Lycaenidae): a threatened butterfly from the Brigalow Belt, Australia

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    The taxonomic status of Jalmenus eubulus Miskin stat. rev. is revised and considered to be specifically distinct from J. evagoras (Donovan) based on fundamental differences in morphology, ecology and genetics. Miskin's holotype is fixed by monotypy and illustrated, with type locality Rockhampton, Queensland. Fixed differences in the mitochondrial genomes of J. eubulus and J. evagoras in which the mean pairwise divergence is only 0.85% indicate absence of matrilineal gene flow, whereas allozyme data show significant structure within and between populations of both species consistent with recent diversification. Underlying causes for the observed genetic patterns are investigated. The two species are parapatric, with a narrow range of overlap along the Great Escarpment in south-eastern Queensland. Jalmenus eubulus is restricted to vegetation communities comprising brigalow-dominated old-growth open-forests and woodlands in the Brigalow Belt (with larvae monophagous on Acacia harpophylla F. Muell. Ex Benth), whereas J. evagoras occurs in a range of disturbed eucalypt woodlands/open-forests predominantly in montane and coastal areas east of this bioregion (with larvae polyphagous on Acacia species other than A. harpophylla). The conservation status of J. eubulus is considered to be vulnerable nationally and critically endangered in New South Wales according to International Union for Conservation of Nature (IUCN) criteria. Nationally, the geographic range has an estimated area of occupancy of less than 2000km2, is severely fragmented, and the extent or quality of its habitat, which is poorly conserved, continues to decline. It is recommended that the taxon be used as an indicator for identification of remnant old-growth forest for conservation planning, as well as a flagship for the conservation of invertebrate biodiversity associated with this threatened ecological community
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