bluuebunny/crossref_metadata_2025_split huggingface dataset:
How territoriality affects the density of an egg predator: Habitat renovation and reintroduction as a method of conserving two endangered desert spring fish
Authors: Paciorek Timothy , Al-SHAER Layla , Itzkowitz Murray 
Published: February 2016

Abstract
Conservation of endangered sympatric species must be carefully executed to ensure that the protection of one species does not negatively impact the survival of another. Critically endangered Pecos gambusia Gambusia nobilis and Leon Springs pupfish Cyprinodon bovinus, which are endemic to a threatened desert spring habitat, exemplify one such scenario. Recently, this habitat has been expanded, and captively bred C. bovinus were released to repopulate an area historically known to contain this species. A previous study suggested that G. nobilis are detrimental to C. bovinus populations, due to their tendency to congregate near spawning pairs and feed on their eggs. Whether G. nobilis are attracted to territorial C. bovinus, regardless of spawning behavior, remains unclear. To determine this, the number of G. nobilis in occupied and unoccupied breeding territories of both wild and captively bred C. bovinus was measured. Gambusia nobilis densities were similar between unoccupied and occupied territorial sites, suggesting that they do not show a preference for C. bovinus territories. Regardless of habitat location or prior captivity, territorial C. bovinus significantly excluded G. nobilis within their direct vicinity (5 cm), but not from their entire territory. Decreased G. nobilis density within the habitat may allow C. bovinus to defend their breeding territories more readily during the summer spawning season. This study provides empirical evidence of captively raised individuals behaving similarly to wild individuals upon reintroduction to their natural habitat and support for conservation methods that focus on common limiting factors between endangered species [Current Zoology 60 (4): 527–533, 2014].
Effects of environmental variability and offspring growth on the movement ecology of breeding Scopoli’s shearwater Calonectris diomedea
Authors: Cecere Jacopo G. , Gaibani Giorgia , Imperio Simona 
Published: February 2016

Abstract
Most seabird species display colonial behavior during the breeding period which implies that food resources around breeding sites can easily go depleted. Seabirds need to both reach profitable areas, which can be located far from the colony, and return to the colony regularly. In this context, flexibility in movement behavior may be crucial for breeding success. During chick-rearing, Procellariformes species can alternate short trips lasting 1–4 days for chick provisioning with longer trips for self-provisioning in what has been called a dual-foraging strategy. We analyzed foraging trips from 136 Scopoli’s shearwaters from three Mediterranean colonies tracked with GPS during 6 chick-rearing seasons to assess whether the adoption of a dual foraging strategy depends on the quality of habitat surrounding the colony. We found a marked dual-foraging strategy only in birds from the Linosa colony which was the largest colony in terms of breeding pairs and was characterized by having a lower marine habitat quality. Birds from this colony performed foraging trips that extended up to 369 km from the nest and lasted more than 10 days. In general, the decision to perform long lasting trips was triggered by lower values of primary production and higher offspring weight. Contrary to expectation, the decision to feed far from the colony was not related to the parents’ weight. At the same time, despite the higher productivity offered by distant areas, the higher proportion of long trips performed by birds breeding in poor areas was not sufficient to maintain the same body mass as the ones breeding in richer areas.
Individual repeatability in timing and spatial flexibility of migration routes of trans-Saharan migratory raptors
Authors: López-López Pascual , García-Ripollés Clara , Urios Vicente 
Published: February 2016

Abstract
Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level (i.e. repeatability in migratory routes and timing) still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability (or conversely, the flexibility) in migration. To this end, we analysed a dataset of 48 trips (23 springs and 25 autumns) recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration (13 ± 2 days, range = 9–18 d) than in spring migration (19 ± 3 days, range = 13–26 d), which can be explained by differences in environmental conditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration (i.e. strong endogenous control of migration) and high flexibility in routes.
A network of sex and competition: The promiscuous mating system of an invasive weevil
Authors: Inghilesi Alberto Francesco , Mazza Giuseppe , Cervo Rita , Cini Alessandro 
Published: February 2016

Abstract
Invasive alien pest insect species represent a major threat for agriculture and biodiversity. Because chemical treatments employed to contrast such pests elicit serious environmental and human health problems, a great effort is currently directed to develop long term and environmentally friendly biological control strategies. However, the successful application of some promising techniques, such as the Sterile Insect Technique (SIT), requires a deep knowledge of the pest basic biology. Here, we argue that understanding pest sexual biology using a social network approach can significantly improve the performance of control strategies. For example, SIT may benefit from understanding how individuals interact and how males accede to reproduction, in order to target the most reproductively active and polygamic males. In this paper we studied the socio-sexual networks of the Asian red palm weevil (RPW) Rhynchophorus ferrugineus, a worldwide invader which is causing heavy economic impacts on several palm species. We found that the RPW has a highly promiscuous mating system, characterized by forced interruptions of pair copulations by additional males. The social network is highly non-random nor regular: few males almost monopolize reproduction, behaving as key-players in the network of matings. Additionally, males have a stable pattern of sexual behaviour over time. We use RPW social network as a case study to direct the development of management techniques such as SIT strategy.
Environmental factors determining growth of salamander larvae: A field study
Authors: Limongi Laura , Ficetola Gentile Francesco , Romeo Giuseppe , Manenti Raoul 
Published: February 2016

Abstract
Larval growth and survival of organisms are strongly influenced by abiotic and biotic factors, as demonstrated by experimental studies performed under controlled laboratory or semi-natural conditions. Even if they have many advantages, experiments cannot cover the full complexity of natural conditions and field studies are needed for a better understanding of how environmental variation determines growth and development rate. Fire salamander Salamandra salamandra females give birth to larvae in a variety of habitats, both epigean and subterranean. In caves, salamander larvae successfully grow and metamorphose, but their growth is more than three times longer than in epigean streams and factors determining these differences require investigation. We performed a field study to understand the factors related to the growth of fire salamander larvae in different environmental conditions, evaluating the relationship between environmental features and larval growth and differences between caves and epigean spring habitats. Both caves and epigean larvae successfully grew. Capture-mark-recapture allowed to individually track individuals along their whole development, and measure their performance. Growth rate was significantly affected by environmental variables: larvae grew faster in environments with abundant invertebrates and few conspecifics. Taking into account the effect of environmental variables, larval growth was significantly lower in caves. Food availability plays a different effect in the two environments. Larval growth was positively related to the availability of invertebrates in epigean sites only. The development rate of hypogeous populations of salamanders is slower because of multiple parameters, but biotic factors play a much stronger role than the abiotic ones.
Is there evidence of selection in the dopamine receptor D4 gene in Australian invasive starling populations?
Authors: Rollins Lee Ann , Whitehead Michael R. , Woolnough Andrew P. , Sinclair Ron , Sherwin William B. 
Published: February 2016

Abstract
Although population genetic theory is largely based on the premise that loci under study are selectively neutral, it has been acknowledged that the study of DNA sequence data under the influence of selection can be useful. In some circumstances, these loci show increased population differentiation and gene diversity. Highly polymorphic loci may be especially useful when studying populations having low levels of diversity overall, such as is often the case with threatened or newly established invasive populations. Using common starlings Sturnus vulgaris sampled from invasive Australian populations, we investigated sequence data of the dopamine receptor D4 gene (DRD4), a locus suspected to be under selection for novelty-seeking behaviour in a range of taxa including humans and passerine birds. We hypothesised that such behaviour may be advantageous when species encounter novel environments, such as during invasion. In addition to analyses to detect the presence of selection, we also estimated population differentiation and gene diversity using DRD4 data and compared these estimates to those from microsatellite and mitochondrial DNA sequence data, using the same individuals. We found little evidence for selection on DRD4 in starlings. However, we did find elevated levels of within-population gene diversity when compared to microsatellites and mitochondrial DNA sequence, as well as a greater degree of population differentiation. We suggest that sequence data from putatively nonneutral loci are a useful addition to studies of invasive populations, where low genetic variability is expected.
A whiter shade of male: Color background matching as a function of size and sex in the yellow shore crab Hemigrapsus oregonensis (Dana, 1851)
Authors: Jensen Gregory C. , Egnotovich Michael S. 
Published: February 2016

Abstract
Juveniles of the shore crab Hemigrapsus oregonensis are highly variable in color, ranging from the typical yellowishgreen of adults to pure white and myriad patterns of white mottling and other disruptive markings, but large individuals with white coloration appear to be very rare. Using image analysis to quantify the relative “whiteness” of beaches, we sampled crabs from nine locations in Washington State that varied widely in their amount of shell fragments and other light-colored material. The total proportion of white individuals in the different locations was strongly correlated to the proportion of white material on the beaches, but there was a striking difference between sexes. Although white specimens of both sexes declined significantly at sizes above 10 mm carapace width, white females generally persisted throughout the entire female size range on lighter-colored beaches while white males larger than 10 mm were virtually absent from all of the sampled populations. Pure white males held on dark backgrounds in captivity remained white, as they lack the dark chromatophores in their hypodermis needed to change color; off-white males became darker and in some cases lightened up again when transferred back to a white background. Behavioral differences between the sexes may result in differential mortality of white individuals by visual predators.
The impact of ancestral population size and incomplete lineage sorting on Bayesian estimation of species divergence times
Authors: Angelis Konstantinos , Dos Reis Mario 
Published: February 2016

Abstract
Although the effects of the coalescent process on sequence divergence and genealogies are well understood, the virtual majority of studies that use molecular sequences to estimate times of divergence among species have failed to account for the coalescent process. Here we study the impact of ancestral population size and incomplete lineage sorting on Bayesian estimates of species divergence times under the molecular clock when the inference model ignores the coalescent process. Using a combination of mathematical analysis, computer simulations and analysis of real data, we find that the errors on estimates of times and the molecular rate can be substantial when ancestral populations are large and when there is substantial incomplete lineage sorting. For example, in a simple three-species case, we find that if the most precise fossil calibration is placed on the root of the phylogeny, the age of the internal node is overestimated, while if the most precise calibration is placed on the internal node, then the age of the root is underestimated. In both cases, the molecular rate is overestimated. Using simulations on a phylogeny of nine species, we show that substantial errors in time and rate estimates can be obtained even when dating ancient divergence events. We analyse the hominoid phylogeny and show that estimates of the neutral mutation rate obtained while ignoring the coalescent are too high. Using a coalescent-based technique to obtain geological times of divergence, we obtain estimates of the mutation rate that are within experimental estimates and we also obtain substantially older divergence times within the phylogeny.
Statistical measures of genetic differentiation of populations: Rationales, history and current states
Authors: Ma Liang , Ji Ya-Jie , Zhang De-Xing 
Published: February 2016

Abstract
Population differentiation is a fundamental process of evolution, and many evolutionary studies, such as population genetics, phylogeography and conservation biology, all require the inference of population differentiation. Recently, there has been a lot of debate over the validity of FST (and its analogue GST) as a measure for population genetic differentiation, notably since the proposal of the new index D in 2008. Although several papers reviewed or explored specific features of these statistical measures, a succinct account of this bewildering issue with an overall update appears to be desirable. This is the purpose of the present review. The available statistics generally fall into two categories, represented by FST and D, respectively. None of them is perfect in measuring population genetic differentiation. Nevertheless, they each have advantages and are valuable for current research. In practice, both indices should be calculated and a comparison of them can generate useful insights into the evolutionary processes that influence population differentiation. FST (GST) has some unique irreplaceable characteristics assuring its standing as the default measure for the foreseeable near future. Also, it will continue to serve as the standard for any alternative measures to contrast with. Instead of being anxious about making choice between these indices, one should pay due attention to the equilibrium status and the level of diversity (especially HS) of the populations, since they largely sway the power of a given statistic to address a specific question. We provide a multi-faceted comparative summary of the various statistics, which can serve as a basic reference for readers to guide their applications.
The evolution of sexual imprinting in socially monogamous populations
Authors: Invernizzi Edith , Gilman R. Tucker 
Published: February 2016

Abstract
Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual imprinting itself evolves. Theoretical work on polygynous mating systems predicts that females will evolve paternal imprinting, which means they learn to prefer phenotypes expressed by their fathers. In nature however, females of some species learn to prefer phenotypes expressed by their mothers instead. We used a dynamical systems model and tools from adaptive dynamics to study how sexual imprinting evolves in species with socially monogamous mating systems. We considered cases in which the target trait for imprinting is under viability selection but is not a reliable signal of paternal investment. Thus, the target trait signals the genetic benefits rather than the parental care benefits of mate choice. When mating is socially monogamous and there is some extra-pair paternity, we show that maternal imprinting can be favored over paternal imprinting. Counterintuitively, females often become choosier when selecting social partners in systems where extra-pair mating is more frequent. That is, females may be more selective when choosing social partners that will sire a smaller percentage of their offspring. Our results offer new testable hypotheses, and advance our understanding of the mechanisms that drive the evolution of mate choice strategies in nature.
Occurrence data may provide unreliable thermal preferences and breadth of species
Authors: Villén-Pérez Sara , Carrascal Luis M. 
Published: February 2016

Abstract
Accurate information on the thermal preference and specialization of species is needed to understand and predict species geographical range size and vulnerability to climate change. Here we estimate the position and breadth of species within thermal gradients based on the shape of the response curve of species abundance to temperature. The objective of the study is to compare the measurements of this approach based on abundance data with those of the classical approach using species’ occurrence data. The relationship between species’ relative abundance and minimum winter temperature of 106 bird species wintering in the Iberian Peninsula is modeled at 100 Km2 resolution with quadratic logistic regressions. From these models we calculated the preferred temperature of species as the temperature at which the abundance is maximized, and the thermal breadth of species as the relative area under the temperature-abundance curve. We also estimated the thermal preferences and breadth of species as the average temperature and temperature range of the UTM cells in which the species are present. The abundance-temperature response curves reveal that birds prefer higher temperatures to overwinter, and are more thermally selective, than is measured by the classical approach. Moreover, response curves detect a higher inter-specific variability in both thermal preferences and thermal breadth of species. As occurrence data gives the same weight to cells with one or many individuals, the average temperature of the cells in which the species is present roughly reflects the average temperature in the region of study and not the environmental preferences of species.
Ultrasonic frogs call at a higher pitch in noisier ambiance
Authors: Zhang Fang , Chen Pan , Chen Zhuqing , Zhao Juan 
Published: February 2016

Abstract
The ultrasonic communication in Concave-eared torrent frogs Odorrana tormota is believed to be an adaptation to avoid masking by the intense low-frequency noise of the rushing stream in their habitat. The acoustic adaptation hypothesis for ultrasonic origin predicts that some organisms subjecting to persistent acoustic interference from broadband, low-frequency environmental noise, might shift their signal frequency upward into frequency bands with lower noise energy. In other words, low-frequency environmental noise might cause upward shifts of species’ vocalization frequencies making their signals more conspicuous. Presently, it is unclear whether male O. tormota adjust their signal features in response to a change in the ambient noise level. We tested the prediction of the acoustic adaptation hypothesis by recording the vocalizations of male O. tormota inhabiting two streams with different background noise levels in Huangshan in central China and comparing their call features including the fundamental frequency (F0). Results showed that the spectrotemporal characteristics of the vocal signals of males in the two habitats were indifferent, except the duration of the call harmonic segments and three parameters related to the call fundamental frequency (F0). In terms of the F0, the pooled and individual frog data showed that frogs inhabiting the noisier habitat tended to emit calls having higher F0. The higher F0 increases the signal-to-noise ratio, thus benefiting the detection of vocalization. Thus, similar to several anuran species, concave-eared torrent frogs also display noise-dependent adjustment of vocal pitch in their vocalizations for making them more audible.