No abstract

A current focus of zoo-based research aims to identify indicators of animal welfare. Reliable behavioral indicators of welfare are highly desirable as behavioral observation is non invasive and requires little in the way of specialized equipment and other costly resources-save for observer time. Anticipatory behavior is an indicator of an animal's sensitivity to reward and as such, it is a real-time indicator of animals' own perceptions of their well-being. In fact, anticipatory behavior may generate a positive affective state and thus be at least a brief manifestation of good welfare itself. The husbandry conditions of most captive animals are such that food acquisition and other positive outcomes are highly scheduled and easily signaled. These conditions promote the development of anticipatory behavior, yet little research has either documented or interpreted this behavior in zoo and aquarium animals. This commentary suggests that anticipatory behavior could be a useful tool for assessing welfare and calls upon zoo and aquarium researchers to begin to develop this tool by describing the behavior and the circumstances that lead to its modulation.

The concept that animals have personalities is gaining traction in the scientific community and is well established in zoos and aquariums. Applying knowledge of animal personalities has occurred more slowly and is most often only considered informally. However, animal personalities are likely to affect the welfare animals experience in captivity and thus should be of primary concern to zoo managers. In addition, animal personality likely affects the outcomes of zoo guest experiences and potentially guests' conservation-related behavior. With over 1,000,000 animals in the care of zoos internationally and hundreds of millions of visitors annually, it would be prudent and beneficial to maximize our use of animal personality data in zoos to effect positive conservation outcomes. Understanding how to broaden population planning techniques to include measures of animal personality and the important outcomes of welfare and education value is of prime importance to the zoo industry. In order to succeed, it is necessary to employ techniques that reliably assess animal personalities and provide measures that can easily be used in population planning models. We discuss the outcomes of recent workshops designed to determine the best techniques for measuring animal personalities in the zoo setting with the goal of incorporating personality into population planning.

The effect of an individual's behavioral type (e.g., its boldness or aggressiveness) on fitness likely depends on the environmental context. In many species, an important component of an individual's environment is its social environment-the mix of individuals in its social group. Accordingly, much of game theory assumes that the mix of behavioral types (BTs) in a social group influences individual fitness and group dynamics. Few experimental studies, however, have directly investigated how the group's mix of BTs influences individual and group outcomes. Here we manipulated social group composition in the water strider Aquarius remigis and evaluated the effects of our manipulation on individual behavior and various group outcomes (overall group activity, aggression, mating success). We formed 12 groups that differed substantially in average male BT (activity and aggression level), each with a low variance in BT. That is, one group had only the most active and aggressive males, a second group was made up of the next most active and aggressive males, and on down to a group of all very inactive and unaggressive males. All groups also had females. We found that, on average, groups made up of more active-aggressive males continued to be more active than other groups, but that contrary to predictions, these groups did not tend to enjoy higher mating success. Instead, a major factor affecting group mating activity was the presence of hyper-aggressive males. Hyper-aggressive males drove females out of the group and thereby decreased the group's overall mating activity. We discuss these findings in terms of their importance to the study of behavioral plasticity in social groups and the potential role of keystone individuals in determining group dynamics.

The goal of habitat restoration is to provide environmental conditions that promote the maintenance and growth of target populations. But rarely is it considered how the allocation of resources influences the diversity of phenotypes in these populations. Here we present a framework for considering how habitat restoration can shape the development and expression of phenotypes. We call this approach phenotype management as it entails restoring the resources in a habitat to manage phenotypic diversity. Pheno type management is achieved by manipulating the spatial and temporal distribution of resources to alter the degree of competition among individuals. Differences in competition, in turn, lead to changes in phenotypic and life history expression that affect popu lation parameters including demography and effective population size (N e). To illustrate how phenotype management can be applied, we explore how resource distributions shape variation in phenotypes in two imperiled fishes, Pacific salmon and desert pupfish. In both examples, modulating male reproductive phenotypes changes the allocation of reproductive success among popu lation members to subsequently affect N e. These examples further demonstrate that whether to increase or decrease phenotypic diversity depends on the primary conservation pressures faced by the species.