bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human exploitation of male fiddler crab claws: behavioural consequences and implications for conservation
Authors: Oliveira Rui F. , Machado José L. , Jordão Joana M. , Burford Fiona L. , Latruffe Claire , Mcgregor Peter K. 
Published: February 2006

AbstractMale fiddler crabs have one of their feeding claws greatly enlarged, which may comprise up to 40% of their weight. In southern Portugal (Ria Formosa) the major claw of the fiddler crab Uca tangeri is a local delicacy. Fishermen break off the male major claw and throw the crab back into the mudflat to regenerate a new one. Approximately 38 % of the males sampled had a missing or a regenerating claw. Although individuals are not removed from the population the operational sex ratio is biased towards females since other males and females behave towards clawless males as if they were females. Moreover, removing the major claw from males prevents them from signalling (waving display) to females to attract them to their breeding burrows and it also places them at a disadvantage if they have to defend their burrows from males with intact claws. Thus, the harvesting of male fiddler crab claws has potential consequences at the population level. In this paper we investigated these potential consequences by comparing an exploited population of fiddler crabs at Ria Formosa with a remote population at the Mira estuary that is not under human exploitation. The unexploited population has significantly larger males and a significantly higher density of burrows. The operational sex ratio is also significantly different between the two populations with a female‐biased sex ratio in the exploited population. These preliminary results suggest that claw harvesting in fiddler crabs has a measurable effect at the population level. The consequences of this type of fishery in which the individuals are not removed from the population but the population structure is potentially affected need further investigation.
Housing developments in rural New England: effects on forest birds
Authors: Kluza Daniel A. , Griffin Curtice R. , Degraaf Richard M. 
Published: February 2006

AbstractIn rural New England, forest fragmentation is caused by housing developments in forested areas. To evaluate the effects of these changes on forest birds, we compared bird assemblages between forests with different housing densities in western Massachusetts. Species occurrences and relative abundances were determined from systematic point count surveys and mist‐netting at three plots in forest of low housing density (0–0.05 houses/ha) and of moderate housing density (0.60–6.70 houses/ha) in 1993 and 1994. Among guilds, Neotropical migrants and forest‐interior species had significantly lower abundances in forests of moderate housing density. Abundances of ground/shrub nesting birds as a group, and of individual species such as veery (Catharus fuscescens), ovenbird (Seiurus aurocapillus) and wood thrush (Hylocichla mustelina), were greater in forest of low housing density, but blue jays (Cyanocitta cristata) were more abundant in forest of moderate housing density. Although the abundances of ground/shrub nesting birds were positively related to ground cover, this vegetation structure did not differ between forest types. Avian and mammalian nest predators may be responsible for the trends in bird abundance. Avian nest predators may recognize forest of moderate housing density as edge habitat, and this rural development may also support relatively high densities of mammalian nest predators. These trends suggest that birds of New England's relatively extensive forests may be subject to greater fragmentation effects than generally thought, as a result of increasing rural housing development within forests.
Winter habitat and distribution of the endangered golden‐cheeked warbler (Dendroica chrysoparia)
Authors: Rappole John H. , King David I. , Leimgruber Peter 
Published: February 2006

AbstractThe golden‐cheeked warbler (Dendroica chrysoparia) is an endangered Neotropical migrant that breeds in oak (Quercus)/juniper (Juniperus) habitat of the Edwards Plateau in central Texas. Recently work has been done on the factors affecting breeding populations of this species, but little is known about winter habitat use or distribution. We used extensive field surveys in Honduras and Guatemala to obtain locational information, which was used with topographical and remote sensing data, to identify and calculate the amount of suitable habitat available, and to map the species' distribution in the region. Most individuals were found in pine–oak from 1100–2400 m (
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= 1651 (± 246) m) in elevation, a habitat type that occupied 29.8% of the total land area above 914 m in the region investigated. Based on this information and existing locational data from the literature, we present a map of the winter range for the golden‐cheeked warbler. Threats to the species during this period of the life cycle include logging, burning and clearing for pasture and agriculture.
The mock turtle syndrome: genetic identification of turtle meat purchased in the south‐eastern United States of America
Authors: Roman Joseph , Bowen Brian W. 
Published: February 2006

AbstractMuch of the demand for turtle meat in North America and Europe during the past four centuries has been met using green turtle (Chelonia mydas) and other marine turtles. As stocks of marine turtles dwindled, harvest of the alligator snapping turtle (Macroclemys temminckii), the largest freshwater turtle in North America, increased in the south‐eastern USA. As a result, this species has declined and is now protected in every state of the USA except Louisiana. There is concern that the remaining legal trade in turtle products may serve as a cover for illegally harvested species. To assess the composition of species in commerce, we purchased 36 putative turtle meat products in Louisiana and Florida. Using cytochrome b and control region sequences of the mitochondrial genome, we identified 19 samples as common snapping turtle (Chelydra serpentina), three as Florida softshell (Apalone ferox), one provisionally as softshell turtle (Apalone sp.), one as alligator snapping turtle, and eight as American alligator (Alligator mississippiensis). It appears that M. temminckii is no longer the predominant species in markets of Louisiana. The presence of alligator meat in a quarter of the samples indicates that the trade in turtle products is not entirely legitimate. As is often the case for unsustainable wildlife harvests, large, esteemed species, such as green turtle and alligator snapper, have been replaced by smaller, more‐abundant or mislabelled species, a phenomenon we refer to as the mock turtle syndrome.
The threatened status of restricted‐range coral reef fish species
Authors: Hawkins Julie P. , Roberts Callum M. , Clark Victoria 
Published: February 2006

AbstractCoral reefs are the most diverse ecosystem in the sea. Throughout the world they are being over‐fished, polluted and destroyed, placing biodiversity at risk. To date, much of the concern over biodiversity loss has centred on local losses and the possibility of global extinction has largely been discounted. However, recent research has shown that 24% of reef fish species have restricted ranges (< 800 000 km2), with 9% highly restricted (< 50 000 km2). Restricted‐range species are thought to face a greater risk of extinction than more widespread species since local impacts could cause global loss. We searched for information on status in the wild and characteristics of 397 restricted‐range reef fish species. Fish body size, habitat requirements and usefulness to people were compared with those of a taxonomically‐matched sample of more widespread species. We found that on average species with restricted ranges were significantly smaller (mean total length 19.1 cm versus 24.4 cm), tended to have narrower habitat requirements and were less used by people. Greater habitat specificity will tend to increase extinction risk while, if real, more limited usefulness (equivalent to exploitation) may reduce risk. Fifty‐eight percent of restricted‐range species were considered common/abundant in the wild and 42% uncommon/rare. Population status and threats to 319 species for which data were available were assessed according to the categories and criteria of the IUCN red list of threatened animals. A number of species were found to be rare, were exploited and had highly restricted ranges overlapping areas where reef degradation is particularly severe, placing them at a high risk of extinction. Five species were listed as Critically Endangered, two of them possibly already extinct in the wild, one as Endangered and 172 as Vulnerable. A further 126 species fell into Lower Risk categories and 11 were considered Data Deficient. Given the intensity of impacts to reefs, the broad geographical areas affected and the large numbers of restricted‐range species, global extinctions seem likely. Urgent management action is now crucial for the survival of several species of reef fishes.
Grey squirrels have high seroprevalence to a parapoxvirus associated with deaths in red squirrels
Authors: Sainsbury Anthony W. , Nettleton Peter , Gilray Janice , Gurnell John 
Published: February 2006

AbstractThe population of red squirrels (Sciurus vulgaris) in the British Isles is in decline and is being supplanted by the grey squirrel (Sciurus carolinensis). It has been suggested that parapoxvirus‐associated disease has caused significant mortality in red squirrels and that grey squirrels are the source of the virus. A direct enzyme‐linked immunosorbent assay (ELISA) was developed for the measurement of antibody to squirrel parapoxvirus. We tested 140 sera from red squirrels and 223 from grey squirrels from different populations in the UK. A high percentage (61%) of apparently healthy grey squirrels, were found to have been exposed to the parapoxvirus. Only 2.86% (4/140) of red squirrels had antibody and three of these animals had parapoxvirus‐associated disease. We postulate that the grey squirrel may act as a reservoir host for the virus.
Simultaneous inbreeding and outbreeding depression in reintroduced Arabian oryx
Authors: Marshall T. C. , Spalton J. A. 
Published: February 2006

AbstractIn most species the offspring of closely related parents have reduced fitness compared with the offspring of unrelated parents, a phenomenon known as inbreeding depression. However if parents are very distantly related, their offspring may also have reduced fitness. This pattern, outbreeding depression, has been most commonly observed in plants and only rarely in animals. Here we examine the consequences of inbreeding and outbreeding on juvenile survival of reintroduced Arabian oryx (Oryx leucoryx) in Oman, a population with a small number of founders drawn from a number of sources. Using microsatellite‐based measures of inbreeding and outbreeding, there was no apparent relationship between inbreeding or outbreeding and survival when inbreeding and outbreeding were tested in separate statistical models. However when inbreeding and outbreeding were tested in the same statistical model, we found simultaneous inbreeding depression and outbreeding depression acting on juvenile survival. Outbreeding depression may be more common in vertebrates than previously supposed, and conservation strategies that seek to maximize the genetic diversity of managed populations may risk mixing lineages that are sufficiently differentiated to cause outbreeding depression among descendants.
Flagship species, ecological complementarity and conserving the diversity of mammals and birds in sub‐Saharan Africa
Authors: Williams Paul H. , Burgess Neil D. , Rahbek Carsten 
Published: February 2006

AbstractMore biodiversity could be protected in situ if the few species that attract the most popular support (the ‘flagship’ species) had distributions that also covered the broader diversity of organisms. We studied how well different groups of mammals performed for representing the diversity of mammals and breeding birds among 1° areas of sub‐Saharan Africa. We demonstrate that choosing areas of sub‐Saharan Africa using either conservationists' six primary flagship mammals, or the six ‘Big Five’ mammals popular with wildlife tourists, is not significantly better for representing the diversity of mammals and birds than choosing areas at random. Furthermore, neither of these groups is significantly better for representing the diversity of mammals and birds than groups of the same number of species chosen at random. We show that in order to succeed in representing many mammals and birds in area selection, it is not sufficient for the groups used for selection to occur in many different eco‐regions, they must also have low overlaps in distribution, so as to provide high ecological complementarity (a similar pattern of ecological complementarity must be shared by the larger group of species to be represented). Therefore there may be a need for an explicit policy to balance the requirements of flagship conservation and broader biodiversity conservation, which will have implications for the distribution of resources.
Is one migrant per generation sufficient for the genetic management of fluctuating populations?
Authors: Vucetich John A. , Waite Thomas A. 
Published: February 2006

AbstractSmall isolated populations may face an increasing risk of extinction due to the loss of genetic diversity. This increasing risk, though, may be offset by gene flow, provided the population receives an adequate number of migrants per generation. We show that as temporal fluctuation in population size (FPS) increases, so too does the required number of immigrants. This increase in the requisite number of immigrants arises because the ratio of census size to effective population size decreases with increasing FPS. Because all populations fluctuate, our work extends a recent challenge to the widely adopted one migrant per generation rule, which refers to the supposedly requisite number of immigrants. In a sample of 44 animal populations, ˜60% of the populations fluctuated enough to require >10 immigrants per generation to avoid a substantial loss of genetic diversity, and ˜25% fluctuated enough to require >20 immigrants per generation. We thus recommend that estimation of the requisite number of immigrants take into account fluctuation in population size.
Dynamics of reintroduction in an indigenous large ungulate: the wood bison of northern Canada
Authors: Larter N. C. , Sinclair A. R. E. , Ellsworth T. , Nishi J. , Gates C. C. 
Published: February 2006

AbstractWe document the recolonization of an indigenous large herbivore into its historic range. Eighteen wood bison (Bison bison athabascae) were reintroduced into the Mackenzie Bison Sanctuary of the Northwest Territories, Canada, in 1963. The population subsequently increased in number and range, peaking at about 2400 in 1989; numbers were estimated at about 1900 in 1998. Recolonization occurred through a series of increases in local areas followed by pulses of dispersal and range expansion. This pattern was originally described for exotic species' introductions. Differences in diet and overwinter survival of calves over the bison's range suggest that intraspecific competition for food provided the stimulus for range expansion. For a conservation strategy, the reintroduction of animals into several independent sites in their historic range would facilitate recolonization and achieve a faster spread than a reintroduction into one site followed by waiting for the population to spread as a result of its own density dependent responses.
Mitochondrial DNA and palaeontological evidence for the origins of endangered European mink, Mustela lutreola
Authors: Davison Angus , Griffiths Huw I. , Brookes Rachael C. , Maran Tiit , Macdonald David W. , Sidorovich Vadim E. , Kitchener Andrew C. , Irizar Iñaki , Villate Idoia , González‐esteban Jorge , Ceña Juan Carlos , Ceña Alfonso , Moya Ivan , Miñano Santiago Palazón 
Published: February 2006

AbstractThe European mink Mustela lutreola is one of Europe's most endangered carnivores, with few vulnerable populations remaining. Surprisingly, a recent phylogeny placed a single mink specimen within the polecat (M. putorius, M. eversmannii) group, suggesting a recent speciation and/or the effects of hybridization. The analysis has now been extended to a further 51 mink and polecats. As before, phylogenetic methods failed to resolve the relationships between the species. One haplotype (C11) was found in both species, and predominated in European mink from Spain and eastern Europe. The known M. lutreola fossils are of very young date, so either mink arose recently, or else the situation is confused by hybridization and a biased fossil recovery. The study highlights the dangers of using a single genetic marker in defining Evolutionarily Significant Units (ESUs). Polecats and European mink are clearly distinct in their morphology and ecology, and should still be considered as separate ESUs, but without further data it is difficult to define Management Units. Following the precautionary principle, we recommend that for the moment European mink in eastern Europe (Belarus, Estonia and Russia) and Spain should be managed separately.
Does equalization of family sizes reduce genetic adaptation to captivity?
Authors: Frankham Richard , Manning Heidi , Margan Sienna H , Briscoe David A. 
Published: February 2006

AbstractGenetic adaptation to captive environments is likely to reduce the reproductive fitness of endangered species when they are reintroduced into natural environments. Equalization of family sizes is predicted to halve genetic adaptation to captivity as it removes selection among families and is recommended in captive management of threatened species. This prediction was evaluated by comparing the reproductive fitnesses of replicate populations of Drosophila maintained using either equal (EFS) or variable family sizes (VFS) for 25 generations in captivity under uncrowded conditions on a medium containing CuSO4. After 25 generations, EFS populations produced 8.8% more offspring per pair than their outbred base population on CuSO4 medium, while VFS produced 17.5% more. Consequently, the rate of genetic adaptation to captivity in EFS was about half that in VFS, as predicted. In simulated ‘wild’ conditions (crowded, competitive conditions on medium lacking CuSO4), both treatments showed much lower reproductive fitness than their outbred base population, the reductions being 38% in EFS populations and 43% in VFS populations. Surprisingly, reproductive fitness of the two treatments did not differ significantly under these conditions. These results raise doubts about the ability of equalization of family sizes to reduce genetic deterioration that adversely affects reintroduction success for captive populations of endangered species.
Comparative analyses of correlates ofRed data bookstatus: a case study using European hoverflies (Diptera: Syrphidae)
Authors: Sullivan Matthew S. , Gilbert Francis , Rotheray Graham , Croasdale Stevan , Jones Martin 
Published: February 2006

AbstractWe present a comparative analysis of correlates ofRed data bookstatus that controls for phylogeny. As a model system we use 244 species of hoverfly (Diptera: Syrphidae) from the British fauna, with theirRed data bookstatuses in Britain and three regions of Germany. The analysis is confined to four adult characters, withRed data bookstatus as the dependent variable. Associated with an increase in risk of extinction were a decrease in flight period and an increase in wing length (in two regions). Variables representing the number of habitats occupied and whether species were single‐ or multi‐brooded were not associated with an increase in risk of extinction. At this stage we restrict our analysis to the identification of patterns rather than speculation as to causal mechanisms, but the patterns themselves are of value to conservation biologists, provided the methods used to identify them control for the possible confounding effects of phylogeny.
Genetic management of chondrodystrophy in California condors
Authors: Ralls Katherine , Ballou Jonathan D. , Rideout Bruce A. , Frankham Richard 
Published: February 2006

AbstractFive out of 169 fertile California condor (Gymnogyps californianus) eggs laid in captivity have exhibited chondrodystrophy, a lethal form of dwarfism. Pedigree records indicate that this chondrodystrophy, like similar conditions in chickens, turkeys and quail, is probably inherited as an autosomal, recessive allele. We estimate that the frequency of this putative allele is about 9%. This high frequency is probably due to a founder effect. We consider three management options for the allele: ignoring it, eliminating it by selection and minimizing its phenotypic manifestation by avoiding matings between possible carriers. We recommend minimizing its phenotypic expression because an unacceptably large proportion of condors (up to 78 out of 146) would be prevented from breeding under a selection strategy designed to eliminate the allele. We predict that many captive populations will prove similar to the California condor population in that it will prove inadvisable or impractical to select against one or more deleterious alleles detected in the population.
Biogeographic regionalization of Australia: assigning conservation priorities based on endemic freshwater crayfish phylogenetics
Authors: Whiting Alison S. , Lawler Susan H. , Horwitz Pierre , Crandall Keith A. 
Published: February 2006

AbstractThere are many methods available for evaluating conservation priorities. Traditional methods of species richness, genus richness and critical species counts were compared with newer methods of phylogenetic and genetic diversity. Conservation priorities for areas designated by theInterim biogeographic regionalisation for Australia(Thackway & Cresswell, 1995) were assessed on the basis of the freshwater crayfish fauna of Australia. Distributions for all crayfish species were taken from the literature, and plotted in the IBRA areas. Species and genus richness, as well as the number of rare or endangered species were calculated for each area. A phylogeny of 35 representative crayfish based on 16 S rDNA sequence data was used to assess phylogenetic and genetic diversity of species and genera. Methods of species richness and phylogenetic diversity agreed to a large extent in their ranking of areas, both methods agreed that the north‐west coast of Tasmania and the south‐eastern portion of the continent were of highest priority for conserving the greatest amount of diversity. These results differ greatly from high priority areas based on other taxonomic groups, emphasizing the importance of broad taxonomic and ecological sampling in making conservation decisions.