bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spring peepers Pseudacris crucifer modify their call structure in response to noise
Authors: Hanna Dalal E. L. , Wilson David R. , Blouin-Demers Gabriel , Mennill Daniel J. 
Published: February 2016

Abstract
Acoustic interference can impede effective communication that is important for survival and reproduction of animals. In response to acoustic interference, some animals can improve signalling efficacy by altering the structure of their signals. In this study, we played artificial noise to 46 male spring peepers Pseudacris crucifer, on their breeding grounds, and tested whether the noise affected the duration, call rate, and peak frequency of their advertisement calls. We used two experimental noise treatments that masked either the high- or low-frequency components of an average advertisement call; this allowed us to evaluate whether frogs adaptively shift the peak frequency of their calls away from both types of interference. Our playback treatments caused spring peepers to produce shorter calls, and the high-frequency noise treatment caused them to lower the frequency of their calls immediately after the noise ceased. Call rate did not change in response to playback. Consistent with previous studies, ambient temperature was inversely related to call duration and positively related to call rate. We conclude that noise affects the structure of spring peeper advertisement calls, and that spring peepers therefore have a mechanism for altering signal structure in response to noise. Future studies should test if other types of noise, such as biotic or anthropogenic noise, have similar effects on call structure, and if the observed changes to call structure enhance or impair communication in noisy environments [Current Zoology 60 (4): 438–448, 2014].
Genetic variation in birds in relation to predation risk by hawks: A comparative analysis
Authors: Møller Anders P. , Nielsen Jan T. 
Published: February 2016

Abstract
The level of genetic variation among individuals may affect performance by reducing the ability of prey to detect and escape from predators if lack of genetic variation reduces flight ability directly or indirectly through reduced parasite resistance. We investigated vulnerability of common avian prey species to predation by the sparrowhawk Accipiter nisus and the goshawk A. gentilis in relation to an index of genetic similarity among adults of potential prey species. We estimated a prey vulnerability index that reflects the abundance of prey relative to the expected abundance according to local population density, and related this index to band sharing coefficients based on analyses of minisatellites for adults in local breeding populations. The prey vulnerability index was positively correlated with the band sharing coefficient in both predators, even when controlling for potentially confounding variables. These findings indicate that prey species with high band sharing coefficients, and hence low levels of genetic variation, are more readily caught by avian predators. Therefore, predation may constitute a major cost of low levels of genetic variation in extant populations of prey.
Knockouts of high-ranking males have limited impact on baboon social networks
Authors: Franz Mathias , Altmann Jeanne , Alberts Susan C. 
Published: February 2016

Abstract
Social network structures can crucially impact complex social processes such as collective behaviour or the transmission of information and diseases. However, currently it is poorly understood how social networks change over time. Previous studies on primates suggest that ‘knockouts’ (due to death or dispersal) of high-ranking individuals might be important drivers for structural changes in animal social networks. Here we test this hypothesis using long-term data on a natural population of baboons, examining the effects of 29 natural knockouts of alpha or beta males on adult female social networks. We investigated whether and how knockouts affected (1) changes in grooming and association rates among adult females, and (2) changes in mean degree and global clustering coefficient in these networks. The only significant effect that we found was a decrease in mean degree in grooming networks in the first month after knockouts, but this decrease was rather small, and grooming networks rebounded to baseline levels by the second month after knockouts. Taken together our results indicate that the removal of high-ranking males has only limited or no lasting effects on social networks of adult female baboons. This finding calls into question the hypothesis that the removal of high-ranking individuals has a destabilizing effect on social network structures in social animals.
Hybridisation on coral reefs and the conservation of evolutionary novelty
Authors: Richards Zoe T. , Hobbs Jean-Paul A. 
Published: February 2016

Abstract
Hybridisation was traditionally considered rare on coral reefs. However, a rapid increase in hybrid studies over the last 20 years has revealed that hybridisation on coral reefs is common and widespread. In this review, we summarise the growing body of evidence arising from studies on stony corals and reef fishes to verify the occurrence of hybridisation, and we examine the influence hybridisation has had on the enormous level of biodiversity present on coral reefs. We discuss the challenges of distinguishing hybridisation from alternative hypotheses (e.g. incomplete lineage sorting). This review also explores the evolutionary consequences of hybridisation, which range from increasing genetic diversity and the production of novel lineages that may outperform the parent species, to reverse speciation and extinction by genetic swamping. Instances of hybridisation can be natural or occur as a result of human impacts (e.g. habitat degradation) and distinguishing between these two very different causal mechanisms is important for management. Currently, the legislative status of hybrids is unclear and hybrids are rarely protected in conservation programs. Failing to adequately manage hybridisation and hybrid lineages may lead to potential losses of evolutionary novelty, declines in phylogenetic diversity or species extinctions. To conserve existing coral reef biodiversity, and the processes that generate biodiversity, conservation policies must be re-defined and instances of hybridisation must be assessed and managed on a case-by-case basis.
Managing hybridization of a recovering endangered species: The red wolf Canis rufus as a case study
Authors: Gese Eric M. , Knowlton Fred F. , Adams Jennifer R. , Beck Karen , Fuller Todd K. , Murray Dennis L. , Steury Todd D. , Stoskopf Michael K. , Waddell Will T. , Waits Lisette P. 
Published: February 2016

Abstract
Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered species recovery effort for the red wolf Canis rufus is a classic system for understanding and addressing the challenges of hybridization. From 1987?1993, 63 red wolves were released from captivity in eastern North Carolina, USA, to establish a free-ranging, non-essential experimental population. By 1999, managers recognized hybridization with invasive coyotes Canis latrans was the single greatest threat to successful recovery, and an adaptive management plan was adopted with innovative approaches for managing the threat of hybridization. Here we review the application and results of the adaptive management efforts from 1993 to 2013 by comparing: (1) the numbers of wolves, coyotes, and hybrids captured, (2) the numbers of territorial social groups with presumed breeding capabilities, (3) the number of red wolf and hybrid litters documented each year and (4) the degree of coyote introgression into the wild red wolf gene pool. We documented substantial increases in the number of known red wolves and red wolf social groups from 1987–2004 followed by a plateau and slight decline by 2013.The number of red wolf litters exceeded hybrid litters each year and the proportion of hybrid litters per year averaged 21%. The genetic composition of the wild red wolf population is estimated to include &lt; 4% coyote ancestry from recent introgression since reintroduction. We conclude that the adaptive management plan was effective at reducing the introgression of coyote genes into the red wolf population, but population recovery of red wolves will require continuation of the current management plan, or alternative approaches, for the foreseeable future. More broadly, we discuss the lessons learned from red wolf adaptive management that could assist other endangered species recovery efforts facing the challenge of minimizing hybridization.
Detection of social group instability among captive rhesus macaques using joint network modeling
Authors: Beisner Brianne A. , Jin Jian , Fushing Hsieh , Mccowan Brenda 
Published: February 2016

Abstract
Social stability in group-living animals is an emergent property which arises from the interaction amongst multiple behavioral networks. However, pinpointing when a social group is at risk of collapse is difficult. We used a joint network modeling approach to examine the interdependencies between two behavioral networks, aggression and status signaling, from four stable and three unstable groups of rhesus macaques in order to identify characteristic patterns of network interdependence in stable groups that are readily distinguishable from unstable groups. Our results showed that the most prominent source of aggression-status network interdependence in stable social groups came from more frequent dyads than expected with opposite direction status-aggression (i.e. A threatens B and B signals acceptance of subordinate status). In contrast, unstable groups showed a decrease in opposite direction aggression-status dyads (but remained higher than expected) as well as more frequent than expected dyads with bidirectional aggression. These results demonstrate that not only was the stable joint relationship between aggression and status networks readily distinguishable from unstable time points, social instability manifested in at least two different ways. In sum, our joint modeling approach may prove useful in quantifying and monitoring the complex social dynamics of any wild or captive social system, as all social systems are composed of multiple interconnected networks.
No association between brain size and male sexual behavior in the guppy
Authors: Corral-López Alberto , Eckerström-Liedholm Simon , Der Bijl Wouter VAN , Kotrschal Alexander , Kolm Niclas 
Published: February 2016

Abstract
Animal behavior is remarkably variable at all taxonomic levels. Over the last decades, research on animal behavior has focused on understanding ultimate processes. Yet, it has progressively become more evident that to fully understand behavioral variation, ultimate explanations need to be complemented with proximate ones. In particular, the mechanisms generating variation in sexual behavior remain an open question. Variation in aspects of brain morphology has been suggested as a plausible mechanism underlying this variation. However, our knowledge of this potential association is based almost exclusively on comparative analyses. Experimental studies are needed to establish causality and bridge the gap between microand macroevolutionary mechanisms concerning the link between brain and sexual behavior. We used male guppies that had been artificially selected for large or small relative brain size to study this association. We paired males with females and scored the full known set of male and female sexual behaviors described in guppies. We found several previously demonstrated associations between male traits, male behavior and female behavior. Females responded more strongly towards males that courted more and males with more orange coloration. Also, larger males and males with less conspicuous coloration attempted more coerced copulations. However, courting, frequency of coerced copulation attempts, total intensity of sexual behavior, and female response did not differ between largeand small-brained males. Our data suggest that relative brain size is an unlikely mechanism underlying variation in sexual behavior of the male guppy. We discuss these findings in the context of the conditions under which relative brain size might affect male sexual behavior.
From the lab to the world: The paradigmatic assumption and the functional cognition of avian foraging
Authors: Sulikowski Danielle , Burke Darren 
Published: February 2016

Abstract
Mechanisms of animal learning and memory were traditionally studied without reference to niche-specific functional considerations. More recently, ecological demands have informed such investigations, most notably with respect to foraging in birds. In parallel, behavioural ecologists, primarily concerned with functional optimization, have begun to consider the role of mechanistic factors, including cognition, to explain apparent deviations from optimal predictions. In the present paper we discuss the application of laboratory-based constructs and paradigms of cognition to the real-world challenges faced by avian foragers. We argue that such applications have been handicapped by what we term the ‘paradigmatic assumption’ – the assumption that a given laboratory paradigm maps well enough onto a congruent cognitive mechanism (or cognitive ability) to justify conflation of the two. We present evidence against the paradigmatic assumption and suggest that to achieve a profitable integration between function and mechanism, with respect to animal cognition, a new conceptualization of cognitive mechanisms functional cognition – is required. This new conceptualization should define cognitive mechanisms based on the informational properties of the animal’s environment and the adaptive challenges faced. Cognitive mechanisms must be examined in settings that mimic the important aspects of the natural environment, using customized tasks designed to probe defined aspects of the mechanisms’ operation. We suggest that this approach will facilitate investigations of the functional and evolutionary relevance of cognitive mechanisms, as well as the patterns of divergence, convergence and specialization of cognitive mechanisms within and between species.
A matter of time: Temporal variation in the introduction history and population genetic structuring of an invasive lizard
Authors: Moule Hannah , Chaplin Kirilee , Bray Rebecca D. , Miller Kimberly A. , Thompson Michael B. , Chapple David G. 
Published: February 2016

Abstract
Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and fragmentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the biology and genetics of the invader. We investigated the invasion of Lord Howe Island by the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic structure (whether new haplotypes had been introduced to the island, and shifts in haplotype frequencies) of the species on the island between these two time points. No new haplotypes were introduced to the island between 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enable us to better manage their impacts.
Behavioral dependent dispersal in the invasive round goby Neogobius melanostomus depends on population age
Authors: Thorlacius Magnus , Hellström Gustav , Brodin Tomas 
Published: February 2016

Abstract
Biological invasions cause major ecological and economic costs in invaded habitats. The round goby Neogobius melanostomus is a successful invasive species and a major threat to the biodiversity and ecological function of the Baltic Sea. It is native to the Ponto-Caspian region and has, via ballast water transport of ships, invaded the Gulf of Gdansk in Poland. Since 1990, it has spread as far north as Raahe in Northern Finland (64°41′04”N, 24°28′44”E). Over the past decade, consistent individual differences of behavioral expressions have been shown to explain various ecological processes such as dispersal, survival or reproduction. We have previously shown that new and old populations differ in personality trait expression. Individuals in new populations are bolder, less sociable and more active than in old populations. Here we investigate if the behavioral differentiation can be explained by phenotype-dependent dispersal. This was investigated by measuring activity, boldness and sociability of individually marked gobies, and subsequently allowing them to disperse in a system composed of five consecutive tanks connected by tubes. Individual dispersal tendency and distance was measured. Our results revealed that in newly established populations, more active individuals disperse sooner and that latency of a group to disperse depends on the mean sociability of the group. This indicates the presence of personality dependent dispersal in this species and that it is maintained at the invasion front but lost as the populations get older.
Does disruptive camouflage conceal edges and features?
Authors: Webster Richard J. 
Published: February 2016

Abstract
Camouflage is ubiquitous in the natural world and benefits both predators and prey. Amongst the range of concealment strategies, disruptive coloration is thought to visually fragment an animal’s’ outline, thereby reducing its rate of discovery. Here, I propose two non-mutually exclusive hypotheses for how disruptive camouflage functions, and describe the visual mechanisms that might underlie them. (1) The local edge disruption hypothesis states that camouflage is achieved by breaking up edge information. (2) The global feature disruption hypothesis states camouflage is achieved by breaking up the characteristic features of an animal (e.g., overall shape or facial features). Research clearly shows that putatively disruptive edge markings do increase concealment; however, few tests have been undertaken to determine whether this survival advantage is attributable to the distortion of features, so the global feature disruption hypothesis is under studied. In this review the evidence for global feature disruption is evaluated. Further, I address if object recognition processing provides a feasible mechanism for animals’ features to influence concealment. This review concludes that additional studies are needed to test if disruptive camouflage operates through the global feature disruption and proposes future research directions.
Frequency-dependent flight activity in the colour polymorphic wood tiger moth
Authors: Rojas Bibiana , Luis-MartÍnez Armando , Mappes Johanna 
Published: February 2016

Abstract
Predators efficiently learn to avoid one type of warning signal rather than several, making colour polymorphisms unexpected. Aposematic wood tiger moth males Parasemia plantaginis have either white or yellow hindwing coloration across Europe. Previous studies indicate that yellow males are better defended from predators, while white males have a positively frequency-dependent mating advantage. However, the potential frequency-dependent behavioural differences in flight between the morphs, as well as the role of male-male interactions in inducing flying activity, have not been previously considered. We ran an outdoor cage experiment where proportions of both male morphs were manipulated to test whether flying activity was frequencydependent and differed between morphs. The white morph was significantly more active than the yellow one across all treatments, and sustained activity for longer. Overall activity for both morphs was considerably lower in the yellow-biased environment, suggesting that higher proportions of yellow males in a population may lead to overall reduced flying activity. The activity of the yellow morph also followed a steeper, narrower curve than that of the white morph during peak female calling activity. We suggest that white males, with their presumably less costly defences, have more resources to invest in flight for predator escape and finding mates. Yellow males, which are better protected but less sexually selected, may instead compensate their lower flight activity by ‘flying smart’ during the peak female-calling periods. Thus, both morphs may be able to behaviourally balance the trade-off between warning signal selection and sexual selection. Our results emphasize the greater need to investigate animal behaviour and colour polymorphisms in natural or semi-natural environments.
Changes in Mediterranean mesocarnivore communities along urban and ex-urban gradients
Authors: Recio Mariano R. , Arija Carmen M. , Cabezas-Díaz Sara , Virgós Emilio 
Published: February 2016

Abstract
Urbanization causes wildlife habitat loss, fragmentation, and the replacement of specialist species by generalists and/or exotic taxa. Because mesocarnivores are particularly vulnerable to habitat modifications, the rapid expansion of urban areas and the increasing trend for ex-urban development occurring in Mediterranean ecosystems may be major drivers of change in mesocarnivore communities. We combined camera trapping and sign surveys to quantify the richness and relative abundance of a set of wild and domestic mesocarnivores. We quantified these variables controlling for the gradient of urbanism, ex-urbanism, and other environmental variables in patches of natural vegetation in the region of Madrid (central Spain), and a non-urbanized control area ~220 km south of Madrid city. Using conditional autoregressive models (CAR) and model selection procedures, we found that urbanization influenced mesocarnivore community composition but this influence was not detrimental for all the species tested. Generalist carnivores such as the red fox Vulpes vulpes were more abundant in urban and ex-urban areas. Ex-urban development creates overlapping areas between wild and domestic species (such as the domestic cat Felis catus and the wildcat Felis silvestris) but contact between wild and domestic carnivores in natural areas is unlikely. Detection of species in the control area was very low. Therefore, the impact of urbanization in causing changes in mesocarnivore communities may be less than other factors such as illegal predator culling.