bluuebunny/crossref_metadata_2025_split huggingface dataset:
The sex ratio of wild Chinese alligators Alligator sinensis
Authors: Zhao Lan , Yang Hai-Qiong , Fang Li-Ming , Pan Guo-Liang , Zou Wei-Qiang , Ren Da-Bin , Wan Qiu-Hong , Fang Sheng-Guo 
Published: February 2016

Abstract
The Chinese alligator Alligator sinensis is one of the most endangered crocodilian species, and typically exhibits temperature-dependent sex determination. It is extremely important to clarify the sex structure of Chinese alligators to implement recovery projects successfully. However, the sex ratio of wild Chinese alligators remains unknown. In this study, we collected 28 years of sex ratio data from Chinese alligators residing in the natural and artificial habitats of Changxing Nature Reserve, China, and examined the differences in the sex ratio dynamics between these two populations. We observed that the sex ratio of wild Chinese alligators is 1 male to 4.507 females, which was significantly lower compared to that of the captive population (1 to 2.040; P &lt; 0.001), and is significantly different to previously documented sex ratios for this species (all P &lt; 0.01). Furthermore, we documented an annually stable (P = 1.000) female-biased sex ratio for wild alligators at hatching [1 male to 4.747 females; 0.174 (0.167–0.182)], in contrast to a dramatically fluctuating sex ratio (P &lt; 0.001) in captivity [1 male to 1.674 females; 0.374 (0.246–0.593)], showing a potential mechanism for adjusting the sex structure. Finally, we found that the hatchling sex ratios were similar to that of the population sex ratio (P = 0.748), with little correlation to air temperature values in the 60–70 day incubation period during the breeding season (July and August; both P &gt; 0.05). Overall, this study indicates that the stabilized female-biased sex ratio of Changxing Chinese alligators might result from selection pressure caused by local mate competition and major inbreeding.
Evolutionary consequences of deception: Complexity and informational content of colony signature are favored by social parasitism
Authors: Lorenzi Maria Cristina , Azzani Laura , Bagnéres Anne-Geneviève 
Published: February 2016

Abstract
Nestmate recognition codes show remarkable chemical complexity, involving multiple biochemical pathways. This complexity provides the opportunity to evaluate the ecological and social conditions that favor the evolution of complex signaling. We investigated how the chemical signatures of three populations of the social paper wasp Polistes biglumis differed in terms of concentration of hydrocarbons, proportions of branched hydrocarbons and overall variation. We tested whether the variation in chemical signatures among populations could be explained by the prevalence of social parasites or whether this was just an effect of local abiotic conditions which influenced the composition of the hydrocarbon cuticular layer. We studied the chemical signature in three populations in which obligate social parasites differed in the selection pressures they imposed on host populations. Within each population, we restricted our analyses to non-parasitized hosts, to avoid potential short-term effects of parasite presence on the host chemical signatures. We found that host colonies in parasitized populations had more diverse profiles than the parasite-free population. Moreover, the overall concentration of hydrocarbons and the relative proportion of branched hydrocarbons were larger in the parasitized populations, relative to the non-parasitized one. This is to our knowledge the first evidence in favour of the hypothesis that different traits in the host chemical signatures as a whole undergo evolutionary changes resulting from directional or balancing selection imposed by social parasites. We conclude that obligate social parasites act as ‘engines of diversity’ on host chemical signatures and operate in favor of a geographic mosaic of diverging communication codes.
Sexual conflict and deception in poison frogs
Authors: Summers Kyle 
Published: February 2016

Abstract
I review evidence that females deceive males in the context of sexual selection and sexual conflict in the green poison frog, Dendrobates auratus. In this species, males mate polygynously when they have the opportunity, but polygyny imposes a cost on female reproductive success. Some females attempt to guard their mates when those males are approached by other females. This behavior involves both aggression toward other females and active “pseudo-courtship” of the male. This courtship is hypothesized to be a deceptive signal that functions to prevent the male from mating with other females. Observational and comparative evidence is presented in support of the predictions of this hypothesis. This form of deception is compared to similar behaviors that occur in other species, and the possibility that other forms of deception occur in poison frogs is discussed.
Sexual deception: Coevolution or inescapable exploitation?
Authors: Lehtonen Jussi , Whitehead Michael R. 
Published: February 2016

Abstract
Sexual deception involves the mimicry of another species’ sexual signals in order to exploit behavioural routines linked to those signals. Known sexually deceptive systems use visual, acoustic or olfactory mimicry to exploit insects for prédation, cleptoparasitism and pollination. It is predicted that where sexual deception inflicts a cost on the receiver, a coevolutìonary arms race could result in the evolution of discriminating receivers and increasingly refined mimicry. We constructed a conceptual model to understand the importance of trade-offs in the coevolution of sexually deceptive mimic and receiver. Four components examined were: the cost of mimicry, the cost to receiver for being fooled, the density of mimics and the relative magnitude of a mimicry-independent component of fitness. The model predicts that the exploitation of non-discriminating receivers by accurate signal mimicry will evolve as an evolutionary stable strategy under a wide range of the parameter space explored. This is due to the difficulty in minimising the costs of being fooled without incurring the cost of falsely rejecting real mating opportunities. In the model, the evolution of deception is impeded when mimicry imposes substantial costs for both sides of the arms race. Olfactory signals that are potentially cheap to produce are therefore likely to be more vulnerable to exploitation than expensive visual ornaments.
Sex differences in anogenital distances and digit ratios in wild David’s rock squirrels Sciurotamias davidianus
Authors: Zhao Dapeng , Chen Zhuoyue , Li Baoguo 
Published: February 2016

Abstract
The prenatal hormonal environment plays an important role in organizing sex differences in the morphology, physiology and behavior of humans as well as other vertebrates. Currently, all related research on rodents has been focused on Myo-morpha. This study presents data on sex differences in the anogenital distance (AGD) and the ratio of the second to the fourth digit length (2D:4D) from 44 wild David’s rock squirrels Sciurotamias davidianus captured from the Qinling Mountains, China. This was the first study of a species from Sciuromorpha. The AGD as well as body mass are sexually dimorphic. There are no sex differences or lateral asymmetry in 2D:4D. Significant correlation was not found between AGD and 2D:4D for any paw. The findings indicate that 2D:4D may not be fixed or influenced by the prenatal steroidal environment in David’s rock squirrels.
Genotoxicity testing for radon exposure: Dolichopoda (Orthoptera, Rhaphidophoridae) as potential bio-indicator of confined environments
Authors: Gustavino Bianca , Meschini Roberta , Franzetti Giulia , Gratton Paolo , Allegrucci Giuliana , Sbordoni Valerio 
Published: February 2016

Abstract
Radon represents the major source of natural radioactivity in confined environments. Despite the clear evidence of a direct association between residential exposure and human lung cancer provided by case-control studies, results relating indoor exposure and genotoxic/mutagenic effect induction are still contradictory. The present study attempts to estimate the genotoxic effects induced by exposure to radioactive radon in wild cricket populations sampled from caves where varying concentrations of radon are present. Cave crickets are also tested as possible bio-indicator organisms of genotoxic potential of contaminated residential and confined environments. Six caves in Central Italy are considered covering a broad spectrum of radon radioactivity concentration (221–26, 000 Bq/m3). Dolichopoda specimens were sampled from each cave; both haemocytes and brain cells taken from individuals were tested for responsiveness to DNA damage induced by radon through the Comet assay. Specimens from the least radioactive cave, housed in controlled conditions for 60 days before analysis, were used as control group. Statistically significant increase of DNA damage was found in all groups of individuals from each cave, for both cell types. Very low values of all Comet parameters were found in control group individuals, which gave indications of a good responsiveness of the organism to the variable environmental levels of radioactive contamination. Results indicate that cave crickets represent a reliable tool for the detection of genotoxic potential induced by radioactive contamination of confined environments and can be proposed as a possible bio-indicator system for air (-radioactive) pollution related to indoor exposure.
Boldness is related to the development of the cephalic crest in the male of the river blenny Salaria fluviatilis (Asso, 1801)
Authors: Fabre Noëlle , GarcÍa-Galea Eduardo , Vinyoles Dolors 
Published: February 2016

Abstract
Boldness is defined as the tendency of an individual to take risks when exposed to novel objects or situations. The main aim of this work was to dilucidate if boldness was related to the development of the secondary sexual traits (SSTs) in the male of the river blenny Salaria fluviatilis, a freshwater fish which takes care of eggs. As a second objective SSTs effect on parental status adoption was also be explored. Wild young fish were caught in the Segre River (Ebro basin) in November 2010. Fish were kept in five aquaria in groups of eight males and eight females with artificial nests. Boldness (boldness score and hesitancy) of males (initially with little SSTs development) was tested as the time required to exit a refuge when exposed to a new environment. Fish were mantained in the same aquaria for several months, and males’ SSTs development and reproductive behaviour were monitored. Boldness score was negatively associated to cephalic crest development. Hesitancy was negatively related to male length and was also influenced by the interaction between male length and cephalic crest. Parental status acquisition was positively related to the male’s length, marginally related to anal gland development, and non-related to cephalic crest. These results suggest an intrasexual role of the crest as an informative trait of boldness (honest signal) which might not necessarily be chosen by the females. It is also discussed that correlational selection could be responsible for linking boldness and growth rate in this species. Sexual selection, in addition to having directed the evolution of secondary sexual traits, might have favored certain personality traits (e.g. boldness) associated with the achievement of a larger body length.
The impact of attractants on pocket gopher trapping
Authors: Baldwin Roger A. , Meinerz Ryan , Orloff Steve B. 
Published: February 2016

Abstract
Pocket gophers (Geomyidae) have an extensive impact on both natural and agricultural systems. Trapping is a technique often used to sample and manage these populations. The identification of an attractant that increases capture rates of pocket gophers would greatly assist researchers and pest management professionals alike. Therefore, we tested the attractiveness of four attractants (peanut butter, anise, grapefruit attractant, and carrot) plus a control (no attractant) using uncovered and covered trap sets to determine what impact they have on visitation and capture rates of pocket gophers. We also determined how the impact of cover status and attractants differ across varying weights and gender of pocket gophers. We found no direct effect of any attractant on visitation and capture rates of pocket gophers, nor on the gender of captured individuals. However, when no attractant was used, the number of pocket gophers captured per 100 trap nights was greater when trap sets were uncovered vs. when covered, and capture rates were generally high and consistent when using peanut butter as an attractant. Additionally, we noted that covered trap sets that were baited with peanut butter yielded heavier pocket gopher captures than uncovered trap sets using this same attractant. This is key, given the difficulty associated with capturing older, more experienced individuals. Combined with data from a previous investigation, this suggests that there is no advantage to using any attractant when utilizing uncovered trap sets, but there is likely some benefit to using peanut butter in covered trap sets [Current Zoology 60 (4): 472–478, 2014].
Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size
Authors: Namgail Tsewang , Takekawa John Y. , Bala-Chandran Sivananinthaperumal , Sathiyaselvam Ponnusamy , Mundkur Taej , Newman Scott H. 
Published: February 2016

Abstract
Relationship between species’ home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.
To forage or hide? Threat-sensitive foraging behaviour in wild, non-reproductive passerine birds
Authors: Turney Shaun , Godin Jean-Guy J. 
Published: February 2016

Abstract
Because antipredator behaviours are costly, the threat-sensitive predator avoidance hypothesis predicts that individual animals should express predator-avoidance behaviour proportionally to the perceived threat posed by the predator. Here, we experimentally tested this hypothesis by providing wild passerine birds supplemental food (on a raised feeding platform) at either 1 or 4 m from the edge of forest cover (potential refuge), in either the presence or absence of a nearby simulated predation threat (a sharp-shinned hawk Accipiter striatus model). Compared with the control treatment, we observed proportionally fewer bird visits to the food patch, and the birds took longer to re-emerge from forest refuge and return to feed at the food patch, after the hawk presentation than before it. The observed threat-sensitive latency-to-return response was stronger when the food patch was further away from the nearest refuge. Overall, our results are consistent with the predictions of the threat-sensitive predator avoidance hypothesis in that wild passerine birds (primarily black-capped chickadees Poecile atricapillus) exhibited more intense antipredator behavioural responses with increasing level of apparent threat. The birds were thus sensitive to their local perceived threat of predation and traded-off safety from predation (by refuging) and foraging gains in open habitat in a graded, threat-sensitive manner.
Behavioral effects of social challenges and genomic mechanisms of social priming: What’s testosterone got to do with it?
Authors: Rosvall Kimberly A. , Peterson Mark P. 
Published: February 2016

Abstract
Social challenges from rival conspecifics are common in the lives of animals, and changes in an animal’s social environment can influence physiology and behavior in ways that appear to be adaptive in the face of continued social instability (i.e. social priming). Recently, it has become clear that testosterone, long thought to be the primary mediator of these effects, may not always change in response to social challenges, an observation that highlights gaps in our understanding of the proximate mechanisms by which animals respond to their social environment. Here, our goal is to address the degree to which testosterone mediates organismal responses to social cues. To this end, we review the behavioral and physiological consequences of social challenges, as well as their underlying hormonal and gene regulatory mechanisms. We also present a new case study from a wild songbird, the dark-eyed junco Junco hyemalis, in which we find largely divergent genome-wide transcriptional changes induced by social challenges and testosterone, respectively, in muscle and liver tissue. Our review underscores the diversity of mechanisms that link the dynamic social environment with an organisms’ genomic, hormonal, and behavioral state. This diversity among species, and even among tissues within an organism, reveals new insights into the pattern and process by which evolution may alter proximate mechanisms of social priming.
Are we really seeing the big picture? Some reflections on the current debates in evolutionary biology
Authors: Zhang De-Xing 
Published: February 2016

Abstract
After more than one hundred fifty years of the publication of On the Origin of Species by Darwin, scientists are still arguing on the relative importance of mutation and natural selection, on the driving force of organismal evolution, on microevo-lution and macroevolution, etc. Such periodically repeated debates appeared to have introduced more chaos than musings. What happened and why? Have we really considered our views, opinions and arguments under the big picture of evolution before posing the questions? Or are we talking past each other? We do need some reflections. While we believe that the current evolutionary theory is doing fine, perhaps a refinement or re-encapsulation of its knowledge framework can help promote a better understanding of the evolutionary science as a whole and blow off the mist over the big picture.
Exploration behaviour and behavioural flexibility in orb-web spiders: A review
Authors: Hesselberg Thomas 
Published: February 2016

Abstract
Orb-web spiders and their webs constitute an ideal model system in which to study behavioural flexibility and spatial cognition in invertebrates due to the easily quantifiable nature of the orb web. A large number of studies demonstrate how spiders are able to modify the geometry of their webs in response to a range of different conditions including the ability to adapt their webs to spatial constraints. However, the mechanisms behind this impressive web-building flexibility in these cognitively limited animals remain poorly explored. One possible mechanism though may be spatial learning during the spiders’ exploration of their immediate surroundings. This review discusses the importance of exploration behaviour, the reliance on simple behavioural rules, and the use of already laid threads as guidelines for web-building in orb-web spiders. The focus is on the spiders’ ability to detect and adapt their webs to space limitations and other spatial disruptions. I will also review the few published studies on how spatial information is gathered during the exploration phase and discuss the possibility of the use of ‘cognitive map’-like processes in spiders. Finally, the review provides suggestions for designing experimental studies to shed light on whether spiders gather metric information during the site exploration (cognitive map hypothesis) or rely on more simple binary information in combination with previously laid threads to build their webs (stigmergy hypothesis).
Evolved to adapt: A computational approach to animal innovation and creativity
Authors: Kolodny Oren , Edelman Shimon , Lotem Arnon 
Published: February 2016

Abstract
The production of novel behavioral sequences that gives rise to animal innovation and creativity is one of the most intriguing aspects of behavioral evolution. Numerous studies have recently documented the abundance and diversity of innovative and creative behaviors between and within species, yet the ability to innovate or to act creatively has mainly been described and quantified as a measure of animals’ cognitive abilitywithout explicit reference to cognitive mechanismsthat may account for these behaviors. Here we discuss the creative process from a computational point of view and suggest such a mechanistic framework. In light of recent research on human creativity, animal learning, and animal problem solving, we suggest that animal creativity is best understood as the production of context-appropriate novel behavioral sequences, which may be facilitated by the ability to learn the regularities in the environment and to represent them hierarchically, allowing for generalization. We present a cognitive framework that we recently developed, which employs domain-general mechanisms and has been used in the modeling of a range of sequential behaviors, from animal foraging to language acquisition, and apply it to behavioral innovation. In a series of simulations, we show how innovation and creative behavior can be produced by this learning mechanism, as it constructs a network representing the statistical regularities of the environment. We use the simulations to demonstrate the role of particular cognitive parameters in this process and to highlight the effects of the learning dynamics and individual experience on creativity.
Invasion genetics: Lessons from a ubiquitous bird, the house sparrow Passer domesticus
Authors: Liebl Andrea L. , Schrey Aaron W. , Andrew Samuel C. , Sheldon Elizabeth L. , Griffith Simon C. 
Published: February 2016

Abstract
Following an introduction, non-native species are exposed to environments that differ from those found in their native range; further, as these non-native species expand beyond the site of introduction, they must constantly adapt to novel environments. Although introduced species are present across most ecosystems, few species have successfully established themselves on a truly global scale. One such species, the house sparrow Passer domesticus, is now one of the world’s most broadly distributed vertebrate species and has been introduced to a great part of its current range. To date, work on four continents suggests both genetic and phenotypic variation exists between native and introduced ranges. As such, house sparrows represent an excellent opportunity to study adaptations to novel environments and how these adaptations are derived. The global distribution of this species and the multiple independent introductions to geographically isolated sites allow researchers to ask questions regarding genetic variation and adaptation on a global scale. Here, we summarize the molecular studies of invasive house sparrows from the earliest work using allozymes through more recent work on epigenetics; using these studies, we discuss patterns of dispersal of this species. We then discuss future directions in techniques (e.g. next generation sequencing) and how they will provide new insight into questions that are fundamental to invasion biology. Finally, we discuss how continued research on the house sparrow in light of these genetic changes and adaptations will elucidate answers of adaptation, invasion biology, range expansion, and resilience in vertebrate systems generally.