Uninhibited chickens: ranging behaviour impacts motor self-regulation in free-range broiler chickens (Gallus gallus domesticus).
Abstract Inhibiting impulsive, less flexible behaviours is of utmost importance for individual adaptation in an ever-changing environment. However, problem-solving tasks may be greatly impacted by individual differences in behaviour, since animals with distinct behavioural types perceive and interact with their environment differently, resulting in variable responses to the same stimuli. Here, we tested whether and how differences in ranging behaviour of free-range chickens affect motor self-regulation performance during a cylinder task. For this task, subjects must refrain from trying to reach a food reward throu...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Ferreira VHB, Reiter L, Germain K, Calandreau L, Guesdon V Tags: Biol Lett Source Type: research

Experimental translocations to low predation lead to non-parallel increases in relative brain size.
Abstract Predation is a near ubiquitous factor of nature and a powerful selective force on prey. Moreover, it has recently emerged as an important driver in the evolution of brain anatomy, though population comparisons show ambiguous results with considerable unexplained variation. Here, we test the reproducibility of reduced predation on evolutionary trajectories of brain evolution. We make use of an introduction experiment, whereby guppies (Poecilia reticulata) from a single high predation stream were introduced to four low predation streams. After 8-9 years of natural selection in the wild and two generations o...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Mitchell DJ, Vega-Trejo R, Kotrschal A Tags: Biol Lett Source Type: research

Dynamics of the energy seascape can explain intra-specific variations in sea-crossing behaviour of soaring birds.
Abstract Thermal soaring birds extract energy from the atmosphere to achieve energetically low-cost movement. When encountering regions that are energetically costly to fly over, such as open seas, they should attempt to adjust the spatio-temporal pattern of their passage to maximize energy extraction from the atmosphere over these ecological barriers. We applied the concept of energy landscapes to investigate the spatio-temporal dynamics of energy availability over the open sea for soaring flight. We specifically investigated how the 'energy seascape' may shape age-specific sea-crossing behaviour of European hone...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Nourani E, Vansteelant WMG, Byholm P, Safi K Tags: Biol Lett Source Type: research

Winter is coming: harsh environments limit independent reproduction of cooperative-breeding queens in a socially polymorphic ant.
Abstract Cooperative breeding animals frequently inhabit harsh environments. It is widely accepted that harsh environments hinder independent reproduction, and this constraint maintains individuals in family groups. Yet the assumption that harsh ecological conditions reduce the success of members of cooperative breeding groups when breeding independently has not been experimentally tested. We addressed this shortcoming using the socially polymorphic Alpine silver ant, Formica selysi. This species has single-queen (independent breeders) and multiple-queen (cooperative breeders) colonies coexisting within population...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: De Gasperin O, Blacher P, Grasso G, Chapuisat M Tags: Biol Lett Source Type: research

Environmental factors explain spawning day deviation from full moon in the scleractinian coral Acropora.
In this study, we analysed environmental factors that are potentially correlated with spawning day deviation, in relation to the full moon phase, in Acropora corals inhabiting seven reefs in Australia and Japan. We accordingly found that sea surface temperature and wind speed within one to two months prior to the full moon of the spawning month were strongly correlated with spawning day deviations. In addition, solar flux had a weak effect on the night of spawning. These findings indicate that Acropora have the capacity to adjust their development and physiology in response to environmental factors for fine-tuning the timi...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Sakai Y, Hatta M, Furukawa S, Kawata M, Ueno N, Maruyama S Tags: Biol Lett Source Type: research

Resilience: nitrogen limitation, mycorrhiza and long-term palaeoecological plant-nutrient dynamics.
Abstract Ecosystem dynamics are driven by both biotic and abiotic processes, and perturbations can push ecosystems into novel dynamical regimes. Plant-plant, plant-soil and mycorrhizal associations all affect plant ecosystem dynamics; however, the direction and magnitude of these effects vary by context and their contribution to ecosystem resilience over long time periods remains unknown. Here, using a mathematical framework, we investigate the effects of plant feedbacks and mycorrhiza on plant-nutrient interactions. We show evidence for strong nutrient controlled feedbacks, moderation by mycorrhiza and influence ...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Bonsall MB, Froyd CA, Jeffers ES Tags: Biol Lett Source Type: research

Fracture mechanics, enamel thickness and the evolution of molar form in hominins.
Abstract As the tissue most directly responsible for breaking down food in the oral cavity, the form and function of enamel is obviously of evolutionary significance in humans, non-human primates and other vertebrates. Accordingly, a standard metric, relative enamel thickness (RET), has been used for many decades to provide insights into vertebrate and human palaeobiology. Relatively thick enamel has evolved many times in vertebrates including hominoids (the group to which living humans and fossil hominins belong), and this pattern is thought to provide information about taxonomy, phylogeny, functional anatomy and...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Schwartz GT, McGrosky A, Strait DS Tags: Biol Lett Source Type: research

Demographic expansion of an African opportunistic carnivore during the Neolithic revolution.
Abstract The diffusion of Neolithic technology together with the Holocene Climatic Optimum fostered the spread of human settlements and pastoral activities in North Africa, resulting in profound and enduring consequences for the dynamics of species, communities and landscapes. Here, we investigate the demographic history of the African wolf (Canis lupaster), a recently recognized canid species, to understand if demographic trends of this generalist and opportunistic carnivore reflect the increase in food availability that emerged after the arrival of the Neolithic economy in North Africa. We screened nuclear and m...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Eddine A, Rocha RG, Mostefai N, Karssene Y, De Smet K, Brito JC, Klees D, Nowak C, Cocchiararo B, Lopes S, van der Leer P, Godinho R Tags: Biol Lett Source Type: research

Success, competition and opportunities.
PMID: 31964263 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Beerling D Tags: Biol Lett Source Type: research

Partitioning colony size variation into growth and partial mortality.
In this study, we develop a generalizable model of partitioned growth and partial mortality and apply it to data from 11 species of reef-building coral. We show that corals generally grow at constant radial increments that are size independent, and that partial mortality acts more strongly on small colonies. We also show a clear life-history trade-off between growth and partial mortality that is governed by growth form. This decomposition of net growth can provide mechanistic insights into the relative demographic effects of the intrinsic factors (e.g. acquisition of food and life-history strategy), which tend to affect gr...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Madin JS, Baird AH, Baskett ML, Connolly SR, Dornelas MA Tags: Biol Lett Source Type: research

Predator type influences the frequency of functional responses to prey in marine habitats.
Abstract The functional response of a consumer to a gradient of resource density is a widespread and consistent framework used to quantify the importance of consumption to population dynamics and stability. Within benthic marine ecosystems, both crustaceans and fishes can provide strong top-down pressure on prey populations. Taxon-specific differences in biomechanics or habitat use, among other factors, may lead to variable functional response forms or parameter values (attack rate, handling time). Based on a review of 189 individual functional response fits, we find that these predator guilds differ in their freq...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Dunn RP, Hovel KA Tags: Biol Lett Source Type: research

Pre- and post-copulatory traits working in concert: sexual dichromatism in passerines is associated with sperm morphology.
Abstract Passerine birds produce costly traits under intense sexual selection, including elaborate sexually dichromatic plumage and sperm morphologies, to compete for fertilizations. Plumage and sperm traits vary markedly among species, but it is unknown if this reflects a trade-off between pre- and post-copulatory investment under strong sexual selection producing negative trait covariance, or variation in the strength of sexual selection among species producing positive covariance. Using phylogenetic regression, we analysed datasets describing plumage and sperm morphological traits for 278 passerine species. We ...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Durrant KL, Reader T, Symonds MRE Tags: Biol Lett Source Type: research

When do older birds better resist stress? A study of the corticosterone stress response in snow petrels.
Abstract Life-history theory predicts that, to optimize their fitness, individuals should increase their reproductive effort as their residual reproductive value decreases. Accordingly, several studies have shown that individuals downregulate their glucocorticoid stress response (a proxy of reproductive investment in vertebrates) as they age, and as the subsequent reproductive value decreases. However, and surprisingly, results appear inconsistent, suggesting that the environmental context or the individual state may affect the relationship between age and reproductive effort. Here, we tested for the first time th...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Angelier F, Chastel O, Lendvai AZ, Parenteau C, Weimerskirch H, Wingfield JC Tags: Biol Lett Source Type: research

Correction to 'Obligately silent males sire more offspring than singers in a rapidly evolving cricket population'.
PMID: 31937215 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Heinen-Kay JL, Urquhart EM, Zuk M Tags: Biol Lett Source Type: research

Egg incubation temperature does not influence adult heat tolerance in the lizard Anolis sagrei.
Abstract Extreme heat events are becoming more common as a result of anthropogenic global change. Developmental plasticity in physiological thermal limits could help mitigate the consequences of thermal extremes, but data on the effects of early temperature exposure on thermal limits later in life are rare, especially for vertebrate ectotherms. We conducted an experiment that to our knowledge is the first to isolate the effect of egg (i.e. embryonic) thermal conditions on adult heat tolerance in a reptile. Eggs of the lizard Anolis sagrei were incubated under one of three fluctuating thermal regimes that mimicked ...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Gunderson AR, Fargevieille A, Warner DA Tags: Biol Lett Source Type: research

Increased summer food supply decreases non-breeding movement in black-legged kittiwakes.
Abstract Individual condition at one stage of the annual cycle is expected to influence behaviour during subsequent stages, yet experimental evidence of food-mediated carry-over effects is scarce. We used a food supplementation experiment to test the effects of food supply during the breeding season on migration phenology and non-breeding behaviour. We provided an unlimited supply of fish to black-legged kittiwakes (Rissa tridactyla) during their breeding season on Middleton Island, Alaska, monitored reproductive phenology and breeding success, and used light-level geolocation to observe non-breeding behaviour. Am...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Whelan S, Hatch SA, Irons DB, McKnight A, Elliott KH Tags: Biol Lett Source Type: research

Unhatched eggs represent the invisible fraction in two wild bird populations.
Abstract Prenatal mortality is typically overlooked in population studies, which biases evolutionary inference by confounding selection and inheritance. Birds represent an opportunity to include this 'invisible fraction' if each egg contains a zygote, but whether hatching failure is caused by fertilization failure versus prenatal mortality is largely unknown. We quantified fertilization failure rates in two bird species that are popular systems for studying evolutionary dynamics and found that overwhelming majorities (99.9%) of laid eggs were fertilized. These systems thus present opportunities to eliminate the in...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Hemmings N, Evans S Tags: Biol Lett Source Type: research

Correction to 'Blue Carbon stocks of Great Barrier Reef deep-water seagrasses'.
PMID: 31910733 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - January 1, 2020 Category: Biology Authors: York PH, Macreadie PI, Rasheed MA Tags: Biol Lett Source Type: research

Evolutionary rates are correlated between cockroach symbionts and mitochondrial genomes.
Abstract Bacterial endosymbionts evolve under strong host-driven selection. Factors influencing host evolution might affect symbionts in similar ways, potentially leading to correlations between the molecular evolutionary rates of hosts and symbionts. Although there is evidence of rate correlations between mitochondrial and nuclear genes, similar investigations of hosts and symbionts are lacking. Here, we demonstrate a correlation in molecular rates between the genomes of an endosymbiont (Blattabacterium cuenoti) and the mitochondrial genomes of their hosts (cockroaches). We used partial genome data for multiple s...
Source: Biology Letters - January 1, 2020 Category: Biology Authors: Arab DA, Bourguignon T, Wang Z, Ho SYW, Lo N Tags: Biol Lett Source Type: research

Flight, symmetry and barb angle evolution in the feathers of birds and other dinosaurs.
Abstract There has been much discussion over whether basal birds (e.g. Archaeopteryx and Confuciusornis) exhibited active flight. A recent study of barb angles has suggested they likely could not but instead may have exhibited a gliding phase. Pennaceous primary flight feathers were proposed to show significant shifts in barb angle values of relevance to the inference of flight in these extinct taxa. However, evolutionary trends in the evolution of these barb angle traits in extant volant taxa were not analysed in a phylogenetic frame. Neither the ancestral crown avian condition nor the condition in outgroup dinos...
Source: Biology Letters - December 6, 2019 Category: Biology Authors: Wang X, Tang HK, Clarke JA Tags: Biol Lett Source Type: research

Dogs perceive and spontaneously normalize formant-related speaker and vowel differences in human speech sounds.
Abstract Domesticated animals have been shown to recognize basic phonemic information from human speech sounds and to recognize familiar speakers from their voices. However, whether animals can spontaneously identify words across unfamiliar speakers (speaker normalization) or spontaneously discriminate between unfamiliar speakers across words remains to be investigated. Here, we assessed these abilities in domestic dogs using the habituation-dishabituation paradigm. We found that while dogs habituated to the presentation of a series of different short words from the same unfamiliar speaker, they significantly dish...
Source: Biology Letters - December 6, 2019 Category: Biology Authors: Root-Gutteridge H, Ratcliffe VF, Korzeniowska AT, Reby D Tags: Biol Lett Source Type: research

Inquiline predator increases nutrient-cycling efficiency of Nepenthes rafflesiana pitchers.
Abstract The modified-leaf pitchers of Nepenthes rafflesiana pitcher plants are aquatic, allochthonous ecosystems that are inhabited by specialist inquilines and sustained by the input of invertebrate prey. Detritivorous inquilines are known to increase the nutrient-cycling efficiency (NCE) of pitchers but it is unclear whether predatory inquilines that prey on these detritivores decrease the NCE of pitchers by reducing detritivore populations or increase the NCE of pitchers by processing nutrients that may otherwise be locked up in detritivore biomass. Nepenthosyrphus is a small and poorly studied genus of hoverf...
Source: Biology Letters - December 6, 2019 Category: Biology Authors: Lam WN, Chou YY, Leong FWS, Tan HTW Tags: Biol Lett Source Type: research

The past, present and future of cleaner fish cognitive performance as a function of CO2 levels.
Abstract Ocean acidification is one of the many consequences of climate change. Various studies suggest that marine organisms' behaviour will be impaired under high CO2. Here, we show that the cognitive performance of the cleaner wrasse, Labroides dimidiatus, has not suffered from the increase of CO2 from pre-industrial levels to today, and that the standing variation in CO2 tolerance offers potential for adaptation to at least 750 µatm. We acclimated cleaners over 30 days to five levels of pCO2, from pre-industrial to high future CO2 scenarios, before testing them in an ecologically relevant task-the abilit...
Source: Biology Letters - December 6, 2019 Category: Biology Authors: Paula JR, Baptista M, Carvalho F, Repolho T, Bshary R, Rosa R Tags: Biol Lett Source Type: research

Spontaneous abortion as a response to reproductive conflict in the banded mongoose.
Abstract When breeding females compete for limited resources, the intensity of this reproductive conflict can determine whether the fitness benefits of current reproductive effort exceed the potential costs to survival and future fertility. In group-living species, reproductive competition can occur through post-natal competition among the offspring of co-breeding females. Spontaneous abortion could be a response to such competition, allowing females to curtail reproductive expenditure on offspring that are unlikely to survive and to conserve resources for future breeding opportunities. We tested this hypothesis u...
Source: Biology Letters - December 6, 2019 Category: Biology Authors: Inzani E, Marshall HH, Thompson FJ, Kalema-Zikusoka G, Cant MA, Vitikainen EIK Tags: Biol Lett Source Type: research

Cardiac metabolomic profile of the naked mole-rat-glycogen to the rescue.
Abstract The African naked mole-rat (Heterocephalus glaber) is unique among mammals, displaying extreme longevity, resistance to cardiovascular disease and an ability to survive long periods of extreme hypoxia. The metabolic adaptations required for resistance to hypoxia are hotly debated and a recent report provides evidence that they are able to switch from glucose to fructose driven glycolysis in the brain. However, other systemic alterations in their metabolism are largely unknown. In the current study, a semi-targeted high resolution 1H magnetic resonance spectroscopy (MRS) metabolomics investigation was perf...
Source: Biology Letters - November 28, 2019 Category: Biology Authors: Faulkes CG, Eykyn TR, Aksentijevic D Tags: Biol Lett Source Type: research

Late Cretaceous domatia reveal the antiquity of plant-mite mutualisms in flowering plants.
Abstract Mite houses, or acarodomatia, are found on the leaves of over 2000 living species of flowering plants today. These structures facilitate tri-trophic interactions between the host plant, its fungi or herbivore adversaries, and fungivorous or predaceous mites by providing shelter for the mite consumers. Previously, the oldest acarodomatia were described on a Cenozoic Era fossil leaf dating to 49 Myr in age. Here, we report the first occurrence of Mesozoic Era acarodomatia in the fossil record from leaves discovered in the Upper Cretaceous Kaiparowits Formation (76.6-74.5 Ma) in southern UT, USA. This discov...
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Maccracken SA, Miller IM, Labandeira CC Tags: Biol Lett Source Type: research

Parasite-induced plasticity in host social behaviour depends on sex and susceptibility.
Abstract Understanding the effects of parasites on host behaviour, of host behaviour on parasite infection, and the reciprocal interactions between these processes is vital to improving our understanding of animal behaviour and disease dynamics. However, behaviour and parasite infection are both highly variable within and between individual hosts, and how this variation affects behaviour-parasite feedbacks is poorly understood. For example, it is unclear how an individual's behaviour before infection might change once it becomes infected, or as the infection progresses, and how these changes depend on the host's p...
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Stephenson JF Tags: Biol Lett Source Type: research

Oxygen supply limits the heat tolerance of avian embryos.
We report experiments confirming the two conditions of the oxygen-supply model in Japanese quail embryos, Coturnix coturnix. Hypoxia (12% O2) greatly reduced the chance of survival at 47.5°C, and hyperoxia greatly improved the chance of survival at 48.5°C. This finding expands the scope of the oxygen-supply model to a terrestrial, endothermic species, suggesting that oxygen supply generally limits the heat tolerance of embryos. PMID: 31744411 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Vimmerstedt JC, Padilla Pérez DJ, Angilletta MJ, VandenBrooks JM Tags: Biol Lett Source Type: research

Flight capacity increases then declines from the core to the margins of an invasive species' range.
Abstract Individuals that disperse farther than other individuals are more likely to be on the frontlines of spreading populations and may be more likely to mate with one another as a consequence of their spatial proximity. Over generations, this process-known as spatial sorting-can produce patterns of increasing dispersal ability from a population's core towards the spreading front. By contrast, when the spread of a population is limited by the availability of suitable habitat, theory predicts that range boundaries can select against more dispersive phenotypes and produce patterns of decreasing dispersal capacity...
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Merwin AC Tags: Biol Lett Source Type: research

The effects of anthropogenic noise on animals: a meta-analysis.
Abstract Anthropogenic noise has become a major global pollutant and studies have shown that noise can affect animals. However, such single studies cannot provide holistic quantitative assessments on the potential effects of noise across species. Using a multi-level phylogenetically controlled meta-analysis, we provide the first holistic quantitative analysis on the effects of anthropogenic noise. We found that noise affects many species of amphibians, arthropods, birds, fish mammals, molluscs and reptilians. Interestingly, phylogeny contributes only little to the variation in response to noise. Thus, the effects ...
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Kunc HP, Schmidt R Tags: Biol Lett Source Type: research

Species diversity and composition drive the aesthetic value of coral reef fish assemblages.
uet N Abstract Cultural and recreational values of biodiversity are considered as important dimensions of nature's contribution to people. Among these values, the aesthetics can be of major importance as the appreciation of beauty is one of the simplest forms of human emotional response. Using an online survey, we disentangled the effects of different facets of biodiversity on aesthetic preferences of coral reef fish assemblages that are among the most emblematic assemblages on Earth. While we found a positive saturating effect of species' richness on human preference, we found a net negative effect of species abu...
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Tribot AS, Deter J, Claverie T, Guillhaumon F, Villéger S, Mouquet N Tags: Biol Lett Source Type: research

Eco-evolutionary feedbacks link prey adaptation to predator performance.
Abstract Eco-evolutionary feedbacks may determine the outcome of predator-prey interactions in nature, but little work has been done to quantify the feedback effect of short-term prey adaptation on predator performance. We tested the effects of prey availability and recent (less than 100 years) prey adaptation on the feeding and growth rate of largemouth bass (Micropterus salmoides), foraging on western mosquitofish (Gambusia affinis). Field surveys showed higher densities and larger average body sizes of mosquitofish in recently introduced populations without bass. Over a six-week mesocosm experiment, bass were p...
Source: Biology Letters - November 21, 2019 Category: Biology Authors: Fryxell DC, Wood ZT, Robinson R, Kinnison MT, Palkovacs EP Tags: Biol Lett Source Type: research

Plastic but repeatable: rapid adjustments of mitochondrial function and density during reproduction in a wild bird species.
Abstract Most of the energy fluxes supporting animal performance flow through mitochondria. Hence, inter-individual differences in performance might be rooted in inter-individual variations in mitochondrial function and density. Furthermore, because the energy required by an individual often changes across life stages, mitochondrial function and density are also expected to show within-individual variation (i.e. plasticity). No study so far has repeatedly measured mitochondrial function and density in the same individuals to simultaneously test for within-individual repeatability and plasticity of mitochondrial tr...
Source: Biology Letters - November 14, 2019 Category: Biology Authors: Stier A, Bize P, Hsu BY, Ruuskanen S Tags: Biol Lett Source Type: research

Osmotic 'cost' of reproduction in breeding male toads.
In this study, we investigated osmotic consequences of reproduction in a context where reproduction induces a shift from terrestrial habitats to freshwater environments. During reproduction, toads migrate to breeding ponds where males remain for several weeks, while females leave shortly after egg-laying. We assessed plasma osmolality of male spined toads during the whole reproductive period (approx. 30 days) in conjunction with markers of individual condition. We found that osmolality decreases during the protracted period of immersion in freshwater during reproduction, presumably through water influx as indicated by body...
Source: Biology Letters - November 14, 2019 Category: Biology Authors: Brischoux F, Cheron M Tags: Biol Lett Source Type: research

Audio-visual crossmodal correspondences in domestic dogs (Canis familiaris).
Abstract Crossmodal correspondences are intuitively held relationships between non-redundant features of a stimulus, such as auditory pitch and visual illumination. While a number of correspondences have been identified in humans to date (e.g. high pitch is intuitively felt to be luminant, angular and elevated in space), their evolutionary and developmental origins remain unclear. Here, we investigated the existence of audio-visual crossmodal correspondences in domestic dogs, and specifically, the known human correspondence in which high auditory pitch is associated with elevated spatial position. In an audio-visu...
Source: Biology Letters - November 14, 2019 Category: Biology Authors: Korzeniowska AT, Root-Gutteridge H, Simner J, Reby D Tags: Biol Lett Source Type: research

Why intergroup variation matters for understanding behaviour.
Abstract Intergroup variation (IGV) refers to variation between different groups of the same species. While its existence in the behavioural realm has been expected and evidenced, the potential effects of IGV are rarely considered in studies that aim to shed light on the evolutionary origins of human socio-cognition, especially in our closest living relatives-the great apes. Here, by taking chimpanzees as a point of reference, we argue that (i) IGV could plausibly explain inconsistent research findings across numerous topics of inquiry (experimental/behavioural studies on chimpanzees), (ii) understanding the evolu...
Source: Biology Letters - November 14, 2019 Category: Biology Authors: Kaufhold SP, van Leeuwen EJC Tags: Biol Lett Source Type: research

Field-realistic antidepressant exposure disrupts group foraging dynamics in mosquitofish.
Abstract Psychoactive pollutants, such as antidepressants, are increasingly detected in the environment. Mounting evidence suggests that such pollutants can disrupt the behaviour of non-target species. Despite this, few studies have considered how the response of exposed organisms might be mediated by social context. To redress this, we investigated the impacts of two environmentally realistic concentrations of a pervasive antidepressant pollutant, fluoxetine, on foraging behaviour in fish (Gambusia holbrooki), tested individually or in a group. Fluoxetine did not alter behaviour of solitary fish. However, in a gr...
Source: Biology Letters - November 14, 2019 Category: Biology Authors: Martin JM, Saaristo M, Tan H, Bertram MG, Nagarajan-Radha V, Dowling DK, Wong BBM Tags: Biol Lett Source Type: research

A palaeolimnological perspective to understand regime-shift dynamics in two Yangtze-basin lakes.
In this study, two typical lakes (Chaohu and Zhangdu) from the LYB were selected to determine the trajectories of ecological regime shifts, both of which transitioned from vegetation- to plankton-dominated states several decades ago. Ecological trajectories since the 1900s in both lakes were reconstructed using palaeolimnological proxies, mainly diatom assemblages. Although results show that regime shifts occurred in both lakes in the 1970s and the 1950s, respectively, their inherent mechanisms were different. In Lake Zhangdu, altered hydrological conditions pushed the ecosystem across an ecological threshold, providing an...
Source: Biology Letters - November 8, 2019 Category: Biology Authors: Xu M, Wang R, Dong X, Yang X Tags: Biol Lett Source Type: research

Correction to 'Lionfish predators use flared fin displays to initiate cooperative hunting'.
PMID: 31690209 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - November 8, 2019 Category: Biology Authors: Biology Letters Editorial Team Tags: Biol Lett Source Type: research

Correction to 'Evidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)'.
PMID: 31690210 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - November 8, 2019 Category: Biology Authors: Coomes JR, McIvor GE, Thornton A Tags: Biol Lett Source Type: research

How moles walk; it's all thumbs.
Abstract A recurring theme in the evolution of tetrapods is the shift from sprawling posture with laterally orientated limbs to erect posture with the limbs extending below the body. However, in order to invade particular locomotor niches, some tetrapods secondarily evolved a sprawled posture. This includes moles, some of the most specialized digging tetrapods. Although their forelimb anatomy and posture facilitates burrowing, moles also walk long distances to forage for and transport food. Here, we use X-ray Reconstruction Of Moving Morphology (XROMM) to determine if the mole humerus rotates around its long axis ...
Source: Biology Letters - October 31, 2019 Category: Biology Authors: Lin YF, Konow N, Dumont ER Tags: Biol Lett Source Type: research

Multi-modal communication: song sparrows increase signal redundancy in noise.
We presented male song sparrows with song playback and a taxidermic mount with or without a low-frequency acoustic noise from a nearby speaker. We found that males did not switch their signalling effort to visual modality (i.e. wing waves) in response to the noise. However, the correlation between warbled soft songs and wing waves increased in the noise treatment, i.e. signals became more redundant. These results suggest that when faced with anthropogenic noise, song sparrows can increase the redundancy of their multi-modal signals, which may aid in the robustness of the communication system. PMID: 31662064 [PubMed - ...
Source: Biology Letters - October 31, 2019 Category: Biology Authors: Akçay Ç, Beecher MD Tags: Biol Lett Source Type: research

Pollinator effectiveness and importance between female and male mining bee (Andrena).
Abstract Bees are often considered to be effective pollinators in both agricultural and natural ecosystems but could be ineffective pollinators in that they collect large quantities of pollen for food provision but deliver little to stigmas. Male bees do not collect pollen to feed larvae, and their pollination role has been underappreciated. Here we compare pollination effectiveness, visit frequency and pollen foraging behaviour between female and male individuals of a mining bee, Andrena emeishanica, visiting a nectariferous spring flower (Epimedium pubescens). Female bees were observed to forage for both pollen ...
Source: Biology Letters - October 31, 2019 Category: Biology Authors: Tang J, Quan QM, Chen JZ, Wu T, Huang SQ Tags: Biol Lett Source Type: research

Assessing the affective component of pain, and the efficacy of pain control, using conditioned place aversion in calves.
Abstract Pain in animals is typically assessed using reflexive and physiological responses. These measures allow inferences regarding nociception but provide little basis for conclusions about the affective component of pain (i.e. how negatively the experience is perceived). Calves routinely undergo painful procedures on commercial farms, including hot-iron disbudding, providing a convenient model to study pain in animals. The aim of this study was to investigate the affective component of post-procedural pain due to hot-iron disbudding, using conditioned place aversion. Calves (n = 31) were subjected to two proce...
Source: Biology Letters - October 31, 2019 Category: Biology Authors: Ede T, von Keyserlingk MAG, Weary DM Tags: Biol Lett Source Type: research

Testing biodiversity theory using species richness of reef-building corals across a depth gradient.
Abstract Natural environmental gradients encompass systematic variation in abiotic factors that can be exploited to test competing explanations of biodiversity patterns. The species-energy (SE) hypothesis attempts to explain species richness gradients as a function of energy availability. However, limited empirical support for SE is often attributed to idiosyncratic, local-scale processes distorting the underlying SE relationship. Meanwhile, studies are also often confounded by factors such as sampling biases, dispersal boundaries and unclear definitions of energy availability. Here, we used spatially structured o...
Source: Biology Letters - October 31, 2019 Category: Biology Authors: Roberts TE, Keith SA, Rahbek C, Bridge TCL, Caley MJ, Baird AH Tags: Biol Lett Source Type: research

Earlier colony arrival but no trend in hatching timing in two congeneric seabirds (Uria spp.) across the North Atlantic.
, Wanless S, Strøm H Abstract A global analysis recently showed that seabird breeding phenology (as the timing of egg-laying and hatching) does not, on average, respond to temperature changes or advance with time (Keogan et al. 2018 Nat. Clim. Change 8, 313-318). This group, the most threatened of all birds, is therefore prone to spatio-temporal mismatches with their food resources. Yet, other aspects of the breeding phenology may also have a marked influence on breeding success, such as the arrival date of adults at the breeding site following winter migration. Here, we used a large tracking dataset of two...
Source: Biology Letters - October 25, 2019 Category: Biology Authors: Merkel B, Descamps S, Yoccoz NG, Danielsen J, Daunt F, Erikstad KE, Ezhov AV, Grémillet D, Gavrilo M, Lorentsen SH, Reiertsen TK, Steen H, Systad GH, Þórarinsson ÞL, Wanless S, Strøm H Tags: Biol Lett Source Type: research

Expression analyses of cave mollies (Poecilia mexicana) reveal key genes involved in the early evolution of eye regression.
Abstract Eye regression occurs across cave-dwelling populations of many species and is often coupled with a decrease or loss in eye function. Teleost fishes are among the few vertebrates to undergo widespread colonization of caves and often exhibit eye regression with blindness. Cave populations of the poeciliid fish Poecilia mexicana (cave molly) exhibit reduced-albeit functional-eyes, offering the opportunity to investigate partial eye regression. We sequenced eye transcriptomes of cave and surface populations of P. mexicana to identify differentially expressed genes that potentially underlie eye regression in c...
Source: Biology Letters - October 25, 2019 Category: Biology Authors: McGowan KL, Passow CN, Arias-Rodriguez L, Tobler M, Kelley JL Tags: Biol Lett Source Type: research

Maze learning and memory in a decapod crustacean.
This study provides an initial description of spatial learning in a benthic decapod; a better appreciation of this adaptive trait in these animals will develop our understanding of resource exploitation by benthic crustaceans and their ecological roles. PMID: 31640528 [PubMed - in process] (Source: Biology Letters)
Source: Biology Letters - October 25, 2019 Category: Biology Authors: Davies R, Gagen MH, Bull JC, Pope EC Tags: Biol Lett Source Type: research

The two oxpecker species reveal the role of movement rates and foraging intensity in species coexistence.
ka CT Abstract The two Buphagus oxpecker species are specialized passerines that forage for ticks and other food particles on the body of ungulates in the African savannahs. One of their intriguing features is their ability to coexist despite sharing the same, specialized diet. Using co-occurrence data (photographs of giraffes with oxpeckers on them) and approximate Bayesian computing, we demonstrate that yellow-billed oxpeckers changed host faster than red-billed oxpeckers and appeared to displace red-billed oxpeckers from preferred giraffe body parts. Conversely, red-billed oxpeckers exhibited a fuller use of ea...
Source: Biology Letters - October 25, 2019 Category: Biology Authors: Péron G, Bonenfant C, Gagnon R, Mabika CT Tags: Biol Lett Source Type: research

Complex factors shape phenotypic variation in deep-sea limpets.
Abstract Pectinodontid limpets are important members of deep-sea hot vents and cold seeps as can be seen by their conspicuous presence in both extant and extinct systems. They have traditionally been classified into different genera and species based on shell and radula characteristics; the reliability of these characters has been questioned but not tested thoroughly. Here, for the first time in taxa endemic to deep-sea chemosynthetic ecosystems, we combine substrate translocation with molecular data to assess the plasticity and variability of key phenotypic characters. Molecular data revealed that several 'specie...
Source: Biology Letters - October 25, 2019 Category: Biology Authors: Chen C, Watanabe HK, Nagai Y, Toyofuku T, Xu T, Sun J, Qiu JW, Sasaki T Tags: Biol Lett Source Type: research