Contrafreeloading in grizzly bears: implications for captive foraging enrichment

Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non‐nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced “chow” diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food‐restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife. Zoo Biol 29:484–502, 2010. © 2009 Wiley‐Liss, Inc.     

Tongue twisters: feeding enrichment to reduce oral stereotypy in giraffe

Stereotypic behavior has been well‐studied and documented in a variety of animals including primates, carnivores, and domesticated ungulates. However, very little information is known about stereotypic behavior of captive exotic ungulates. Giraffe have been found to perform a wide range of stereotypic behaviors. According to a survey of zoological institutions, oral stereotypies, specifically the licking of nonfood objects are the most prevalent stereotypic behaviors observed in giraffe. Their performance appears to be related to feeding and rumination and may be a result of the inability of a highly motivated feeding behavior pattern, tongue manipulation, to be successfully completed. To test this hypothesis, the indoor and outdoor feeders for three giraffe housed at Zoo Atlanta were modified to require the giraffe to perform more naturalistic and complex foraging behaviors. Data were collected using instantaneous scan sampling in both exhibit and holding areas. Our results showed that, for the giraffe that engaged in the highest rates of oral stereotypic behavior in the baseline, more complex feeders that required tongue use to access grain or alfalfa had the greatest effect on behavior. For the giraffe that performed low baseline rates of oral stereotypic behavior, adding slatted tops to the alfalfa feeders indoors virtually eliminated the behavior. Although some changes in ruminating and feeding behavior were observed, the decreases in stereotypic behavior were not associated with the changes in ruminating or feeding behavior. These results provide evidence for the hypothesis that oral stereotypy in herbivores can be reduced by encouraging giraffe to engage in more naturalistic foraging behavior. Zoo Biol 27:200–212, 2008. © 2008 Wiley‐Liss, Inc.     

A survey assessment of variables related to stereotypy in captive giraffe and okapi

Stereotypic behavior has been investigated in a wide variety of animals, but little published information is available on this problem in captive exotic ungulates. A survey was used to gather information on the prevalence of stereotypic behavior in giraffe and okapi and to identify variables associated with these behaviors. Of the 71 institutions that received a survey, 69.0% responded. Data were reported for 257 individuals, including 214 giraffe (representing five subspecies) and 29 okapi. Of the animals included in the survey, 79.7% performed at least one type of stereotypic behavior. Licking of non-food objects (72.4%) and pacing (29.2%) were the most prevalent stereotypic behaviors, though other stereotypies were reported in 3.2% of the animals. The results of a logistic regression performed on the data indicated that sub species, number of hours the individuals spent indoors, access at night to conspecifics, feeding frequency, method of feeding, and type of food provided were predictors of stereotypic licking. Sub species, birth history, size of the indoor enclosure, environmental change, and type of food provided were found to be significant predictors of stereotypic pacing. In general, feeding motivation appears to be related to an oral stereotypy, whereas other environmental factors appear to be associated with a locomotor stereotypy. The results of this study suggest changes in management strategies that may be empirically studied and applied to improve the well-being of captive populations of giraffe and okapi.     

An “orientation sphere” visualization for examining animal head movements

1. Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.
2. Animal heads often move during specific behaviors and, additionally, typically have sensory systems (notably vision, smell, and hearing) sampling in defined arcs (normally to the front of their heads). As such, head‐mounted electronic sensors consisting of accelerometers and magnetometers, which can be used to determine the movement and directionality of animal heads (where head “movement” is defined here as changes in heading [azimuth] and/or pitch [elevation angle]), can potentially provide information both on behaviors in general and also clarify which parts of the environment the animals might be prioritizing (“environmental framing”).
3. We propose a new approach to visualize the data of such head‐mounted tags that combines the instantaneous outputs of head heading and pitch in a single intuitive spherical plot. This sphere has magnetic heading denoted by “longitude” position and head pitch by “latitude” on this “orientation sphere” (O‐sphere).
4. We construct the O‐sphere for the head rotations of a number of vertebrates with contrasting body shape and ecology (oryx, sheep, tortoises, and turtles), illustrating various behaviors, including foraging, walking, and environmental scanning. We also propose correcting head orientations for body orientations to highlight specific heading‐independent head rotation, and propose the derivation of O‐sphere‐metrics, such as angular speed across the sphere. This should help identify the functions of various head behaviors.
5. Visualizations of the O‐sphere provide an intuitive representation of animal behavior manifest via head orientation and rotation. This has ramifications for quantifying and understanding behaviors ranging from navigation through vigilance to feeding and, when used in tandem with body movement, should provide an important link between perception of the environment and response to it in free‐ranging animals.

     

“Contrafreeloading” et localisation de l'agent renforcateur

Since Jensen (1963), the phenomenon of “contrafreeloading” corresponds to the fact that animals which have been conditioned to perform a task (by skinnerian conditioning for instance) continue to behave as they have been taught to even when a more simple and effortless solution is made available to them (for instance free access to abundant food in skinnerian situation). This behaviour has been considered as an exception to the “law of the least effort” (Tolman, 1955). To explain it, two types of theories have been put forward. The first one assumes the existence of positive reinforcers connected with the acquired activity, the other one of aversive stimulus connected with the most effortless solution (such as neophobia in the case of cup of abundant food). A reconsideration of the analysis of operant behaviour has led us to take into account the localisation of reinforcing agents and to integrate it in our experiments. The results that have been obtained cannot be accounted for by the theories mentioned above.     

Consistency of captive giraffe behavior under two different management regimes

Long‐term animal behavior studies are sometimes conducted at a single site, leading to questions about whether effects are limited to animals in the same environment. Our ability to make general conclusions about behavior is improved when we can identify behaviors that are consistent across a range of environments. To extend Veasey and colleagues' ([1996b] Anim Welf 5:139–153) study, I compared not only activity budgets but also social behavior of an all‐female group of giraffe at The Maryland Zoo in Baltimore (MZiB) to those previously observed in breeding groups at The San Diego Zoo's Wild Animal Park (SDZWAP; Bashaw et al. [2007] J Comp Psychol 121:46–53). Morning activity budgets and the maintenance of social relationships were consistent across groups. MZiB female giraffe interacted more frequently and the identity of animals that formed the strongest relationships was less predictable than at SDZWAP. Results support earlier findings that captive giraffe maintain social relationships and suggest that studies of giraffe social relationships and activity are generalizable across a range of captive conditions. Zoo Biol 30:371–378, 2011. © 2010 Wiley‐Liss, Inc.     

Assessing antixenosis of soybean entries against Piezodorus guildinii (Hemiptera: Pentatomidae)

Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae) is a major soybean (Glycine max (L.) Merrill) pest and reduces grain quality and yield worldwide. In the context of integrated pest management strategies, plant resistance stands out as an extremely valuable tool for the management of pest populations. Here, we evaluated the resistance of several soybean entries to P. guildinii using tests of attractiveness and feeding preference. We also evaluated trichome number and length as well as pod hardness to evaluate the relationships between these parameters and the resistance to stink bug. D 75-10169, PI 171451, PI 229358, PI 227687, “IAC 100,” IAC 78-2318, PI 274454, PI 274453 and “IAC 19” were less attractive and less consumed by stink bugs. D 75-10169, PI 227687 and PI 274454 received low probe numbers and a short consumption duration per probe; “IAC 100” and PI 274453 received low probe numbers; PI 171451 and PI 229358 received short probe durations; and “IAC 19” received the highest number of probes. There was no correlation between trichome density and length with the attractiveness and feeding preference of the adult insects; however, pod hardness results suggested that this morphological factor may influence the number of probes performed by the insect. PI’s entries, D 75-10169, “IAC 100” and “IAC 19” expressed antixenosis resistance and should be appropriate for use in soybean breeding programs aimed at developing entries with higher resistance to pest insects.     

The weaker sex: Is being male a legally cognizable defect,impairment, or disability?

Compared with women, men die from cancer and coronary artery disease in disproportionately higher numbers and are more susceptible to a host of emotional and developmental disorders. The authors of this article consider what scientific proof or evidence would be required to legally recognize “being male” as a disability, based on the overwhelming number of physical deficiencies to which males are genetically predisposed. The article summarizes major scientific findings on male health problems and explores various laws and policies that might be implicated by treatment of males as a special category recognized by the law. How the law creates categories of individuals and the reasons why these categories are created for legal classification are reviewed. In addition, the potential for a “maleness” defense in the context of criminal law and procedure is assessed. Lastly, the authors examine the policy implications of treating men as a disabled class, and consider how judges, juries, and legislators would view a scientifically based approach to the creation of a class. Given the many false starts in the past, in which the law had embraced what later was shown to be bad science, substantial historical baggage will have to be overcome to convince judges, juries, and legislators that science has now got it in the sense of having established a valid, causal, genetic or biological determinant for behavior. The consideration of a “male deficiency” theory under the law would have to rely on a more inclusive view of legal “disability” and a willingness to allow technologic advances in genetics to inform our understanding of criminal behavior.     

Does a homogeneous population of elementary movement detectors activate the landing response of blowflies,Calliphora erythrocephala?

The landing response of tethered flying blowflies, Calliphora erythrocephala, was elicited by moving periodic gratings, and by stripes moving apart. The influence of binocular interactions on the landing response was investigated by comparing the responses of intact (“binocular”) animals to the response of flies which had one eye covered with black paint (“monocular” flies) effectively eliminating the input from this eye. Directions of motion eliciting a maximal response (preference direction) were determined in intact animals, and in “molecular” flies for different regions of the visual field. Preference directions determined in “monocular” flies follow the orientation of Z-axes (Fig. 4). Preference directions determined in intact animals and in “monocular” flies differ in the binocular eye region: in intact animals, the preference directions corresponds to vertical directions of motion; whereas the preference direction determined for the same area in “monocular” flies are inclined obliquely against the vertical plane. Sex-specific differences were found for the ventral binocular eye region in which the shift of preference directions is more pronounced in male than in female flies. The experimental data support the hypothesis that elementary movement detectors are aligned along the Z-axes of the eye, and that preference directions deviating from the orientation of elementary movement detectors are caused by binocular interactions.     

Social and Individual Components of Animal Contact in Preschool Children

ABSTRACT

Humans are generally biophilic. Still, for unknown reasons, interest in animals varies substantially among individuals. Our goal was to investigate how differential interest of children towards animals might be related to social competence and personality. We proposed two alternatives: 1) Children may compensate for potential deficits in social competence by resorting to animals, and 2) Socially well-connected children may show a particular interest in animals. We focused on relationships between age, gender, family background, play behavior, personality components, and contact with rabbits in 50 children (22 boys/28 girls; 3 to 7 years of age) at a preschool in Krems/Austria. Data were analyzed using GLM. We found that each one of these variables had significant impact on intensity of engagement with the rabbits. In general, girls, children with siblings, and children without pets were more oriented towards the rabbits than were boys, children without siblings, or pet-owning children. The older the children, the less frequently they occupied themselves with the rabbits but the longer they remained when they did engage them. Furthermore, we found that the more “Confident/Respected” (PCA factor 1) and less “Patient/Calm,” “Cheerful/Sociable,” and “Solitary” (PCA factors 2–4) the children, the more time they spent in direct occupation with rabbits. Most effects of the investigated variables varied between boys and girls. By and large, our findings support the hypothesis that the “socially competent” children were particularly interested in the animals. Also, children's social styles, as evinced in interactions with peers, were generally reflected in how they interacted with the rabbits.     

On the logic of Fisherian sexual selection*

In Fisher's model of sexual selection, a female preference for a male trait spreads together with the trait because their genetic bases become correlated. This can be interpreted as a “greenbeard” system: a preference gene, by inducing a female to mate with a trait-bearing male, favors itself because the male is disproportionately likely also to carry the preference gene. Here, we use this logic to argue that Fisherian sexual selection in diploids proceeds via two channels: (i) trait-bearing males are disproportionately the product of matings between preference-bearing mothers and trait-bearing fathers, and thus trait and preference genes are correlated “in trans”; (ii) trait and preference genes come into gametic phase disequilibrium, and thus are correlated “in cis.” Gametic phase disequilibrium is generated by three distinct mechanisms that we identify. The trans channel does not operate when sexual selection is restricted to the haploid phase, and therefore represents a fundamental difference between haploid and diploid models of sexual selection. We show that the cis and trans channels contribute equally to the spread of the preference when recombination between the preference and trait loci is free, but that the trans channel is substantially more important when linkage is tight.     

Laterality of Hand Function in Tufted Capuchin Monkeys (Cebus apella): Comparison between Tool Use Actions and Spontaneous Non-tool Actions

This study examined hand preference for tool use and spontaneous non-tool actions in tufted capuchin monkeys (Cebus apella). We noted a lack of lateral bias across measures, and greater strength of hand preference for tool use than for self-directed or feeding activities. Animals that used tools exhibited a population-level right-hand bias for self-touching whereas animals that did not use tools exhibited a lack of lateral bias for this measure. Our findings are consistent with views that hand preference is expressed more strongly for tool use than for non-tool activities, and that lateral bias for self-directed behavior is related to problem-solving skills in primates.     

Fine‐scale habitat heterogeneity influences browsing damage by elephant and giraffe

Effects of large mammalian herbivores on woody vegetation tend to be heterogeneous in space and time, but the factors that drive such heterogeneity are poorly understood. We examined the influence of fine‐scale habitat heterogeneity on the distribution and browsing effects of two of the largest African terrestrial mammals, the elephant and giraffe. We conducted this study within a 120‐ha (500 x 2,400 m) ForestGEO long‐term vegetation monitoring plot located at Mpala Research Center, Kenya. The plot traverses three distinct topographic habitats (“plateau,” “steep slopes,” and “valley”) with contrasting elevation, slope, soil properties, and vegetation composition. To quantify browsing damage, we focused on Acacia mellifera, a palatable tree species that occurs across the three habitat categories. Overall tree density, species richness, and diversity were highest on the steep slopes and lowest on the plateau. Acacia mellifera trees were tallest and had the lowest number of stems per tree on the steep slopes. Both elephant and giraffe avoided the steep slopes, and their activity was higher during the wet season than during the dry season. Browsing damage on Acacia mellifera was lowest on the steep slopes. Elephant browsing damage was highest in the valley, whereas giraffe browsing damage was highest on the plateau. Our findings suggest that fine‐scale habitat heterogeneity is an important factor in predicting the distribution of large herbivores and their effects on vegetation and may interact with other drivers such as edaphic variations to influence local variation in vegetation structure and composition.     

Interactive effects between diet and genotypes of host and pathogen define the severity of infection

Host resistance and parasite virulence are influenced by multiple interacting factors in complex natural communities. Yet, these interactive effects are seldom studied concurrently, resulting in poor understanding of host‐pathogen‐environment dynamics. Here, we investigated how the level of opportunist pathogen virulence, strength of host immunity and the host condition manipulated via diet affect the survival of wood tiger moth Parasemia plantaginis (Arctidae). Larvae from “low cuticular melanin” and “high cuticular melanin” (considered as low and high pathogen resistance, respectively) selection lines were infected with moderately and highly virulent bacteria strains of Serratia marcescens, while simultaneously manipulating host diet (with or without antibacterial compounds). We measured host survival and food preference before and after infection to test whether the larvae “self‐medicate” by choosing an anti‐infection diet (Plantago major, i.e., plantain leaf) over lettuce (Lactuca sativa). “High melanin” larvae were more resistant than “low melanin” larvae to the less virulent strain that had slower growth and colonization rate compared with the more virulent strain. Cuticular melanin did not enhance survival when the larvae were infected with the highly virulent strain. Anti‐infection diet enhanced survival of the “high melanin” but not the “low melanin” hosts. Survival was dependent on family origin even within the melanin selection lines. Despite the intrinsic preference for lettuce, no evidence of self‐medication was found. These results demonstrate that the relative benefit of host cuticular melanin depends on both diet and pathogen virulence: plantain diet only boosted the immunity of already resistant “high melanin” hosts, and cuticular melanin increased host survival only when infected with moderately virulent pathogen. Moreover, there was considerable variation in host survival between families within both melanin lines suggesting genetic basis for resistance. These results indicate that although melanin is an important predictor of insect immunity, its effect on disease outcomes greatly depends on other interacting factors.     

Innate preference or opportunism: mosquitoes feeding on birds of prey at the Southeastern Raptor Center

The amplification of mosquito‐borne pathogens is driven by patterns of host use by vectors. While each mosquito species is innately adapted to feed upon a particular group of hosts, this “preference” is difficult to assess in field‐based studies, because factors such as host defenses and spatial and temporal overlap of mosquitoes and hosts affect which host animals actually get bitten. Here we examined patterns of host use by mosquitoes feeding on caged raptors at a rehabilitation and education center for birds of prey in Alabama, U.S.A. PCR‐based techniques were used to determine the host species fed upon. Of 19 raptor species at the facility, seven were found to be fed upon by mosquitoes. Feeding indices and linear regression indicated that no species or family of raptor were significantly preferred over another (R²=0.46). Relative abundance adjusted for bird size explained a statistically significant amount of the variation in relative host use (R²=0.71), suggesting that bird size is an important component of host selection by mosquitoes. These findings support the hypothesis that traits of host animals drive patterns of host use by mosquitoes in nature, an interaction that leads to amplification of mosquito‐borne viruses.     

The Power of Association: Its Impact on Willingness to Buy GM Food

Affect, associations, and images associated with food technologies may be important factors influencing consumers’ perception of and willingness to accept new food technologies. The aim of the present study was to investigate free associations evoked by the term “biotechnology” and how they influence behavior. Therefore, participants (N = 632) were asked to name three associations they had in mind when confronted with the term “biotechnology.” After that, respondents indicated how positive or how negative these associations were. Additionally, an equivalent gain task was used to measure participants’ behavioral intentions related to genetically modified (GM) chocolate. Results of a log-linear analysis and a correspondence analysis suggest that attitudes toward biotechnology result in a wide range of associations. Participants having negative attitudes mentioned images related to the environment and industry more often compared with participants having positive attitudes. Results of the equivalent gain task show that willingness to buy GM chocolate can be predicted by the subjects’ three reported associations (p < .001), as well as by their gender (p = .003). The model explains 33.5% of the variance. Affect related to people's associations with gene technology strongly influenced their acceptance of GM foods.     

The scanning behavior of juncos: A game-theoretical approach

Flocking birds frequently look up or “scan” while they are feeding on the ground. High scanning rates increase the probability that the birds in a flock will see an approaching predator in time to avoid predation; however, high scanning rates also decrease the feeding rates of the scanning individuals. Since the scanning rate that maximizes the survival probability of one individual depends on how frequently other birds in the same flock are scanning, the optimal scanning behavior must be modeled as a game. We develop a realistic model of scanning behavior and use it to find two game theoretical solutions—the “co-operative” or Pareto optimum and the “selfish” or Nash optimum. The observed scanning rates do not differ significantly from the co-operative optimal scanning rate. We argue that in a game where players meet again and again such apparent co-operation may be an evolutionarily stable strategy.     

利益相关者视角下的濒危物种价值评估与生态补偿——以翅果油树为例

濒危物种价值评估可为生物多样性保护提供重要的政策支撑。本文以国家二级重点保护植物翅果油树为例,从利益相关者视角作为切入点,基于选择实验法评价其偏好和支付意愿(WTP),进而探讨生态补偿机制。基于管理部门、企业和农户三方利益相关者的利益诉求,分析确定了5个翅果油树的物种属性,即种植面积、产品分类、树苗品种、保护投入和农户收益。运用随机参数Logit模型分析了利益相关者对不同物种属性变量的偏好和支付意愿。结果表明: 受访者对“保护增加投入”偏好最强和支付意愿最高,每户为331.00 yuan·a^-1;对产品开发的“高低端产品同时开发”和“高端产品开发为主”变量偏好次之,WTP分别为每户242.71和227.57 yuan·a^-1;对“农户收益”、“保护投入不变”、“树苗品种”和“种植面积”由强到弱依次表现出一定的偏好及支付意愿;而对“保护不投入”和“低端产品开发为主”偏好最弱且WTP为负值。通过直接和间接补偿方式对补偿客体(翅果油树及其生境)实施生态补偿,得到的补偿剩余价值为每户每年285.62元。