Behavioral Ecology最新文献

Supply and demand affect the values of goods exchanged in cooperative trades where high demand typically leads to a higher cost. An exception has been described in the marine cleaning mutualism involving the cleaner fish Labroides dimidiatus and its variety of "client" coral reef fishes. Cleaner fish feed on clients' ectoparasites (ie gnathiid isopods) but prefer eating clients' mucus instead, which constitutes cheating. Here, we provide field observations, followed by a set of laboratory experiments with real client fish and Plexiglas feeding plates as surrogates for clients. In the field and in three experiments with real clients, we found that satiated cleaner fish were more cooperative, even though low hunger levels should make them less dependent on cleaning interactions. Similarly, the more abstract version of the cleaner-client experiments using Plexiglas plates offering two food types as stand-ins for client ectoparasites and mucus showed that satiation led cleaner fish to feed more against their preferences-an indicator of cooperative behaviour. However, this outcome occurred only if the temptation to eat the preferred food was low. When temptation to cheat was high, cleaner fish did so. We provide a further general support to these findings with a game-theoretic model. Many mutualisms involve food as a commodity. Thus, identifying foraging decision rules will enhance our understanding of how individuals adjust to variations in market conditions in real-time rather than playing a fixed strategy based on average market conditions.

The backgrounds that cryptic animals choose will affect the efficacy of their camouflage. Most animals use a range of microhabitats consisting of a variety of substrates, vegetation and lighting conditions. As some of these will be better suited to facilitating camouflage than others, we expect cryptic animals to consider their conspicuousness when choosing a background to occupy. If the availability of backgrounds varies between populations of cryptic animals, then selective pressure on their coloration may also vary, resulting in intraspecific variation and presumably animals being better suited to the backgrounds locally available to them than those at other locations. In this study we investigate how backgrounds available to Jacky dragons (Amphibolurus muricatus) vary across their range, whether these lizards are occupying backgrounds that match well to their dorsal patterns, and how backgrounds compare to their dorsal patterns. Wild lizards were located and photographed along with the background they were found on, and other options available nearby. We compared lizards and backgrounds within their microhabitat as well as all backgrounds across all microhabitats. We found that lizards were not occupying the backgrounds that best matched their own patterns, that background options varied between locations, and that lizards from certain locations were occupying backgrounds closer matching to their own pattern than those from other locations. These outcomes provide interesting insight into the variance of local factors that influence the pattern phenotype, as well as how the relative need for camouflage might vary and be balanced with other needs.

Long-term social monogamy, a prevalent mating system in avian species, is often associated with increased cooperation and coordination as well as reduced sexual conflict. Although many studies have highlighted the benefits of long-term partnerships for individuals, there remains a lack of insight into how closely partners associate with one another behaviorally. To date, studies investigating pair cohesion in seasonal and long-term partnerships are typically restricted to arrivals at the nest or feeding sites during the breeding season. Using fine-scale automated tracking data on chirruping wedgebills (Psopodes cristatus), a territorial socially monogamous species, we characterized how partners coordinate their movement during and after the breeding season. We used 12 pair-bonded individuals with consistently high localization rates that were tracked for a period between 32 and 69 days, with an average of 260,000 localizations per individual. We demonstrate that pairs (1) had extremely similar home ranges with a similarity index of 0.93 versus 0.18 for non-pairs, (2) maintained consistently closer proximity than expected from movement without paying attention to a partner, and (3) followed each other as they moved, with individuals following their moving partner in 42% of cases during and in 47% of cases after breeding. Our findings show that pair cohesion in socially monogamous territorial species can be very high in both a breeding and non-breeding context, illustrating that strong coordination among partners has important functions beyond reproduction and parental care.

Recent theoretical integration of the spatiotemporal and cultural elements of animal behavior has led to increasing calls to incorporate animal culture into conservation. Implementation of this idea remains sparse due to disconnects between the theoretical concept of considering culture in animal conservation and the spatiotemporal approaches typically employed in conservation practice. Here we propose that this gap can be bridged by (1) clarifying that spatiotemporal conservation interventions inherently interact with culture regardless of whether this connection is acknowledged; and (2) strategically considering feasible "entry points" for considering animal culture in conservation practice. Recent advances in dynamic management strategies indicate the capacity for modern conservation approaches to integrate additional dimensions of animal behavior, and could serve as a particularly fruitful space for considering culture. Drawing on instructive examples from cetaceans, we examine instances where protection in space and time can facilitate the conservation of culture, and where focusing on conserving culturally distinct groups can yield protection in space and time. Human interventions that explicitly consider these interwoven dimensions in practice are achievable and can enable more holistic protections for diverse taxa.

Parasitic infections often alter host behavior, including foraging and the consumption of bioactive substances. In honeybees (Apis mellifera), infection with the common gut parasite Nosema ceranae causes metabolic disruption and increased mortality. Ethanol is a naturally occurring bioactive compound found in nectar, and honeybees exhibit high tolerance and resilience to chronic exposure. However, whether honeybees actively use ethanol during infection remains unclear. Here, we investigated whether N. ceranae-infected honeybees alter their ethanol consumption. In a feeding experiment, infected and uninfected honeybees were given a choice between plain sucrose solution and ethanol-spiked food (0.5% or 1% ethanol). We measured food consumption, survival, and spore load. Although overall food intake did not differ between groups, infected honeybees consumed a significantly higher proportion of ethanol-spiked food. Survival analysis showed that a diet containing 1% ethanol caused higher mortality than a diet containing 0.5% ethanol; however, among honeybees on a 1% ethanol diet, this negative effect was less pronounced in infected individuals than in controls. Spore load did not differ between treatments. These results suggest that N. ceranae infection induces a shift in feeding behavior toward increased ethanol intake, which may benefit infected honeybees by reducing mortality. This may reflect a self-medication response, although alternative explanations remain possible. Further research into ethanol's effects on Nosema spores is needed. Nonetheless, our findings provide insights into honeybee interactions with bioactive compounds and suggest that ethanol may be a behaviorally relevant dietary substance.

Phenotypic plasticity allows organisms to adapt to changing environments within their lifetimes. However, environmentally induced changes in the plastic trait of interest may influence a range of fitness-related traits due to trade-offs, pleiotropy, linkage, or epistasis of genes regulating the plastic trait. These correlated responses may constrain or facilitate the evolution of plasticity, but their evolutionary implications are often poorly understood due to a lack of data on their direction and magnitude. Males in the African cichlid Astatotilapia burtoni are blue or yellow, and males are able to adjust their body coloration to the color of the background, presumably to increase crypsis. To test whether background color influences fitness-related traits, we raised mix-sex groups of juvenile A. burtoni to adulthood in yellow or blue tanks. We found that more males adopted the blue phenotype in blue tanks while more males adopted the yellow phenotype in the yellow tank, though the degree of background color matching decreased with age. Males, but not females, from blue tanks showed earlier sexual maturation than those held in yellow tanks. However, across the duration of the experiment, there was a higher occurrence of breeding in females housed in yellow tanks than those that were housed in blue tanks. In addition, fish in blue tanks exhibited reduced growth rate but higher survivorship relative to their yellow-reared counterparts. Our data suggest that background color affects important fitness-related traits in a color polymorphic cichlid, which may influence the evolution of phenotypic plasticity.

Aposematic species signal to potential predators with salient and recognizable coloration. Predators learn to associate these warning signals with secondary defenses (eg toxins) and will subsequently avoid attacking aposematic prey. Warning signals can therefore reduce the need to hide and/or flee and alleviate some of the energetic/opportunity costs of predator avoidance. Consequently, aposematic species are frequently active and bold in behavior. Batesian mimics replicate the colors, and often the behavior, of aposematic species and may benefit from a similar reduction in predation risk and energetic/opportunity costs. Allobates zaparo (Aromobatidae) is a nontoxic Batesian mimic of the chemically defended poison frog Ameerega bilinguis (Dendrobatidae). However, the efficacy of mimicry appears to change throughout ontogeny as Al. zaparo develops from a seemingly cryptic juvenile to the mimetic adult. We examined how morphological mimicry (ie color) and the propensity to explore a novel environment (ie boldness) changed throughout ontogeny. We predicted that mimicry would improve with increasing size and that better mimics would engage in more exploratory behavior. We found that larger mimics more closely matched their model however they were less likely to be active than were smaller frogs. These data suggest that larger size, and more accurate mimicry, do not necessarily correspond to increases in behavioral boldness. This result may arise from limitations in Batesian mimicry but factors including foraging requirements or social/reproductive behavior cannot be discounted. More research is needed to understand the relationship between behavior, color, body size, and maturity in these frogs and across Batesian mimics more widely.

Parental care can improve early offspring survival against predators by providing protection and resources. However, we have little knowledge of how its effects shape predator-prey interactions later in life. We investigated this with the burying beetle Nicrophorus vespilloides which provides care for offspring and carries warning coloration to advertise its chemical defenses to predators. Warning displays by prey are selected by predators for uniformity and to reliably advertise the extent to which individuals are chemically defended. We investigated whether the strength of the correlation between the conspicuousness of the warning display and the potency of the chemical defenses depends on levels of care received during development by manipulating the level of maternal care received by larvae and tracking the effects into adulthood. We found that individuals that received limited care, developed into smaller adults with less conspicuous warning displays. The correlation between the visual display and the chemical defense was also weaker when broods received little care as larvae. We conclude that maternal care received by burying beetles modulates the information content of aposematic defense: less care makes signals less reliable. Our results further suggest that the prey's social environment could constrain the response to selection from predators on warning signal reliability.

Animal social systems are remarkably diverse, ranging from solitary individuals to well-connected cooperative groups. Understanding the drivers of this variation is a key question in behavioral ecology and has been the focus of numerous studies linking social structure to ecological, demographic, and life history patterns within groups, population, and species. Equipped with this information, researchers are now turning to investigations that are comparative in nature. However, comparing social networks remains a considerable logistical and analytical challenge. Here, we present the latent layers framework, which outlines how observed social networks are linked to the 2 underlying latent networks that are of interest for most research questions: the realised social network (the actual pattern of social interactions), and the social preference network driving these interactions. This conceptual framework provides a clear and unified approach to understand when and why differences in network properties and sampling protocols can introduce discrepancies between observed and latent networks, potentially biasing or confounding statistical inference. We then use this conceptual framework to outline some of the central challenges to comparing animal social networks, describe why and how they create challenges for comparative analyses, and suggest potential directions for solutions. The latent layers framework can help researchers to identify networks they can (or cannot) compare. In doing so, this framework facilitates advances in comparative social network studies with the potential to generate new and important insights into the ecological and evolutionary drivers of variation in social structure across the animal kingdom.

Persistent noise pollution produced by boat traffic is reshaping marine soundscapes globally. Despite growing ecological concern, most studies to date have focused on individual-level effects under laboratory conditions, leaving major gaps in our understanding of how boat noise shapes species interactions in the wild. Using field-based behavioral assays, we investigate how boat noise from different engine types (4-stroke and 2-stroke) affects the mutualistic partnership between Steinitz's goby (Amblyeleotris steinitzi) and snapping shrimp (Alpheus spp.). Across 123 partnerships, we recorded behavioral responses before, during, and after noise exposure. Gobies increased burrow use during 4-stroke boat noise exposure, while shrimp responded stronger to 2-stroke noise-reflecting taxon-specific sensitivities to different noise spectra. Despite these shifts, tactile partner communication was not affected by boat noise. These findings highlight divergent vulnerabilities between species tied to different engine acoustics and emphasize the need for targeted research to inform strategies for mitigating marine noise pollution.