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About pace: How variations in method and definition affect quantification of pacing in bears?
Abstract
Repetitive pacing behavior is exhibited by many species in zoos and is particularly prevalent in carnivores with large home ranges, such as bears. Pacing can be a behavioral indicator of poor welfare, however, understanding this behavior can be challenging. As many bears that pace are singly housed, efforts to systematically examine and ameliorate pacing may be strengthened by multi-institutional studies. However, there is currently no standardized method to quantify pacing, which makes cross-institutional analyses of causal factors and intervening measures challenging. The purpose of this study was to compare multiple sampling methods and definitions for quantifying pacing in bears to understand how they affect outcome measures. We analyzed video recordings of two grizzly and two black bears pacing, using three sampling methods (continuous, instantaneous 30-s interval, instantaneous 1-min interval), and three definitions of pacing (AB—two repetitions of the path, ABA—three repetitions, ABAB—four repetitions). A generalized linear mixed model revealed that continuous and instantaneous 30-s interval methods captured more pacing than instantaneous 1-min methods, and definitions captured a decreasing amount of pacing from AB to ABA to ABAB. AB also captured the highest number of pacing bouts. The importance of comparability across institutions is growing, and a standard methodology and definition for recording pacing would be useful. We suggest that the combination of instantaneous sampling and the ABA definition presents a good balance between capturing the right data and being flexible enough for a variety of institutions to implement.
Research Highlights
• We found that different sampling methods and definitions used to observe pacing in bears do affect the amount of pacing behavior recorded.
• We recommend using instantaneous sampling and the ABA definition of pacing for bear behavior studies.
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In natural environments, bear behavior follows seasonal patterns but the zoo environment differs from the natural environment in several ways, including the presence of zoo visitors. Although typically difficult to disentangle, we were able to tease apart the effects of seasonal changes and visitor density on the visibility and behavior of 10 bears representing five species housed at Cleveland Metroparks Zoo due to the disruption caused by COVID-19. We conducted a longitudinal bear behavior monitoring project from June, 2017-November, 2020. Bears were more visible in the spring and in the presence of visitors, locomoted more and were less inactive when large crowds were present, foraged and locomoted more when it was earlier in the day, and locomoted more at higher temperatures. There were limited differences in bear visibility to observers between 2020 (when the zoo was temporarily closed to visitors) and the previous three years. There were no differences in rates of stereotypy or social behavior across seasons, crowds, or daily attendance categories. Based on these limited differences, neither season nor visitor density seemed to have an apparent effect on bear behavior or welfare.
Captive grizzly bears, like their wild counterparts, engage in considerable variability in their seasonal and daily activity. We documented the year-long activity of two grizzly bears located at the Woodland Park Zoo in Seattle, Washington. We found that behaviors emerged in relation to month-to-month, seasonal, and time of day (hour-to-hour) observations, and events that occurred on exhibit, such as daily feedings. Seventeen behaviors split into seven classes of behavior were observed during their on-exhibit time over a 13-month period. Inactivity was the most frequent class of responses recorded, with most inactive behaviors occurring during the winter months. Both stereotypic and non-stereotypic activity emerged during the spring and summer months, with stereotypic activity occurring most frequently in the morning and transitioning to non-stereotypic activity in the latter part of the day. Results are discussed with respect to how captive grizzly bear behaviors relate to their natural seasonal and daily activity, as well as how events, such as feeding times and enrichment deliveries, can be used to optimize overall captive bear welfare.
Breeding and welfare problems confront many conservation breeding programs. Stereotypies—repetitive, unvarying, functionless behaviours —are common abnormal behaviours that often arise in suboptimal conditions. While the role of stereotypies in welfare assessment is well studied, few investigations address the relationship between stereotypic behaviour and reproduction. We examined the correlation between stereotypic behaviour and reproductive performance in 101 giant pandas (Ailuropoda melanoleuca). High stereotyping males copulated more and produced more cubs, suggesting that highly sexually motivated males were prone to stereotypy but also had high reproductive competence. Female stereotypies were negatively associated with all reproductive measures closely tied to behavioural competence: high stereotyping females were less likely to copulate, less likely to mother-rear cubs, and—probably a result of poor maternal care—had lower cub survival. However, females that exhibited stereotypies were more likely to produce a cub, suggesting stereotypies are tied to behavioural but not physiological competence. High stereotyping female pandas also displayed strong and consistent bias toward production of female offspring while paternal relationship to sex allocation was the reverse. These results are consistent with stress-mediated sex allocation theory. Our findings raise concern about differential reproductive success among high and low stereotyping pandas, and possible genetic adaptation to captivity.
Individuals at risk for schizophrenia-spectrum disorders display abnormalities related to motivational salience, or the ability of stimuli to elicit attention due to associations with rewards or punishments. However, the nature of these abnormalities is unclear because most focus on responses to stimuli from broad “pleasant” and “unpleasant” categories and ignore the variation of motivational salience within these categories. In two groups at risk for schizophrenia-spectrum disorders—a Social Anhedonia group and a Psychotic-like Experiences group—and a control group, the current study examined event-related potential components sensitive to motivational salience—the Early Posterior Negativity (EPN), reflecting earlier selective attention, and the Late Positive Potential (LPP), reflecting sustained attention. Compared to controls, the Social Anhedonia group showed smaller increases in the EPN in response to erotica and smaller increases in the LPP as the motivational salience of pleasant images increased (exciting<affiliative<erotica). In contrast, the Psychotic-like Experiences group had larger increases in LPP amplitudes as the motivational salience of pleasant images increased. Also, both at-risk groups showed larger increases in the LPP to threatening images but smaller increases to mutilation images. These findings suggest that examining abnormalities beyond those associated with broad categories may be a way to identify mechanisms of dysfunction.
Count data can be analyzed using generalized linear mixed models when observations are correlated in ways that require random effects. However, count data are often zero-inflated, containing more zeros than would be expected from the typical error distributions. We present a new package, glmmTMB, and compare it to other R packages that fit zero-inflated mixed models. The glmmTMB package fits many types of GLMMs and extensions, including models with continuously distributed responses, but here we focus on count responses. glmmTMB is faster than glmmADMB, MCMCglmm, and brms, and more flexible than INLA and mgcv for zero-inflated modeling. One unique feature of glmmTMB (among packages that fit zero-inflated mixed models) is its ability to estimate the Conway-Maxwell-Poisson distribution parameterized by the mean. Overall, its most appealing features for new users may be the combination of speed, flexibility, and its interface's similarity to lme4.
Three brown bear (Ursus arctos arctos) individuals and two sloth bear (Melursus ursinus inornatus) individuals were observed in captivity to produce behavioural profiles for each individual. Data collected through behavioural observations were used to produce activity budgets, and to identify space usage and certain aspects of social behavior. Behaviour monitoring allowed the researchers to evaluate the welfare of the animals by identifying the occurrence of stereotypic behaviours, which are sometimes associated with stress. Behavioural profiles were created using data obtained through behavioural observations (coding) and keeper questionnaires (rating). The behavioural observations indicated a number of stereotypic behaviours in sloth bears but not in brown bears. The uniformity of zone usage was calculated to investigate if the enclosure size and features were adequate for use, and a social aspect of otherwise solitary animals was also identified. The behavioural profiles generated through coding and rating were compared to determine the reliability between these two methods in Ursids. Profiles were not compared between individuals since this study is not a comparison between different personality types but rather an effort (one of the few ones existing in literature) to select a valid and reproducible methodology capable of assessing personality in bears.
Stereotypies are commonly observed in zoo animals, and it is necessary to better understand whether ambient environmental factors contribute to stereotypy and how to affect animal welfare in zoo settings. This study investigated the relationships between stereotypic behaviors and environmental factors including ambient temperatures, humidity, light intensity, sound intensity and number of visitors. Seven giant pandas were observed in three indoor enclosures and three outdoor enclosures. Environmental factors were measured for both indoor and outdoor enclosures and the effect they had on stereotypical behaviors was investigated. Our research found that light intensity significantly correlated with all stereotypies behaviors. Higher environmental temperature reduced the duration of pacing but increased the frequency of pacing, the duration and frequency of door-directed, meanwhile the duration of head-toss. However, we found no noticeable effect of humidity on stereotypic behaviors except for the frequency of head-toss. We also found that sound intensity was not correlated with stereotypies. Finally, the growth of visitors was negatively associated with the duration of door-directed. These results demonstrated that various environmental factors can have significant effects on stereotypic behaviors causing the expression of various stereotypies. Thus, stereotypies in zoo animals may not simply represent suboptimal welfare, but rather might be adopted as a means of coping with an aversive environment.
Pacing behaviour is complex and identifying the motivational basis for pacing and designing an effective remedial strategy can be challenging. Details of the behaviour may provide insight into the motivational basis of behaviour and should be carefully examined. A long-term observational study of pacing by a female Malayan sun bear (Helarctos malayanus) was conducted to gather detailed information on the pacing behaviour and guide husbandry changes. Full-day behaviour observations were conducted (n=60; mean duration=5.9 hrs/observation). Pacing data were recorded using continuous sampling methodology with all-occurrences recording of events before and after pacing bouts. Solitary behaviour and social interaction between the focal female and a male and female exhibit partner were recorded using instantaneous sampling and all-occurrences methodologies, respectively. All pacing bouts occurred between tunnels to off-exhibit indoor holding areas, bouts were short in duration and variable, and pacing often began after the male bear entered a shift tunnel. Social interactions between the two females were frequently agonistic. Based on these findings, the non-focal female bear was removed from the group and the focal female and male were given access to indoor holding areas on most days. The focal female only paced once when provided access to indoor holding. When the bears did not have off-exhibit access, pacing characteristics appeared similar to bouts before modifications but pacing no longer appear to be influenced by the male’s behaviour. Our detailed analysis of pacing by the female sun bear provided insight regarding motivation, the need for husbandry changes, and evaluation of those changes.
The evaluation of enrichment programs is important to determine their effect on nonhuman animal welfare. The daily activity pattern and use of space of 3 brown bears (Ursus arctos) were used for long-term macroevaluation of enrichment to compare the baseline and enrichment phases. Focal sampling methods were used for data collection, and instantaneous scans were made at 2-min intervals during 15 sessions of 1 hr for each animal during the 2 study periods. The enrichment devices were categorized as feeding, occupational, and sensorial. The long-term macroevaluation in 3 bears showed statistically significant differences in some types of activity but not in others. There were also statistically significant differences for the use of space in 4 of the 8 zones in which the enclosures were divided. A more homogenous pattern in the use of space was only observed during the enrichment phase in the old female. The 3 brown bears followed different patterns concerning the enrichment program.
The welfare of captive bears became a big issue of concern in Poland when a case of a bear being ill-treated became a high-profile case in the media. This case created a challenge to verify, study, and understand the main problems associated with bear keeping so that zoos could significantly improve the conditions in which they keep bears or ensure they keep bears at the minimum required standards. The results presented here are from 1 of the few countrywide studies of captive bear conditions conducted in all the captive institutions in Poland that keep bears. Thirteen institutions kept bears at the time of the study (2007-2009), including 54 individuals of 5 species. Major welfare problems were identified, and the results have been used to challenge zoos to address the changes required and focus the government's attention on areas that require legislative improvement.
Maślak R., Sergiel A., Bowles D., Paśko Ł. (2016): The Welfare of Bears in Zoos: A Case Study of Poland. Journal Of Applied Animal Welfare Science 19/1: 24-36.
A significant challenge for animal care staff in zoos is the prevention or reduction of stereotypic behaviors in the animals they manage. Zoo professionals work to create opportunities for animals to demonstrate species-typical behaviors and to teach visitors about the natural behaviors of the animals on exhibit. Therefore the expression of stereotypic behavior presents a multidisciplinary problem. Behavioral researchers have repeatedly examined stereotypic behavior in zoological settings to determine successful approaches to address this challenge. Three investigations of pacing in two adult male sloth bears (Melursus ursinus) at Smithsonian's National Zoological Park are presented here. In addition, a case report detailing observations of the rapid onset of an intense stereotypy in a young male sloth bear is included. The first study investigates the effects of five different enrichment strategies on pacing behavior in an adult male with a long history of pacing. The second is a two-year study examining seasonal changes and the effects of social companionship on pacing when the same adult male was housed with a breeding female, a non-breeding (contracepted) female, or a young male. In the third study, we present preliminary data on the effects of the selective serotonin re-uptake inhibitor, fluoxetine, as an adjunct pharmacological treatment for pacing. And finally, our case report details the development an intense stereotypy in a young male sloth bear just after he is weaned and separated from his mother. The findings reveal that the causes, degree, and effective management of even a single observed behavior such as pacing within even a single species can vary greatly by individual and circumstance, highlighting the need for individualized assessment and management plans.
Maximum likelihood or restricted maximum likelihood (REML) estimates of the
parameters in linear mixed-effects models can be determined using the lmer
function in the lme4 package for R. As for most model-fitting functions in R,
the model is described in an lmer call by a formula, in this case including
both fixed- and random-effects terms. The formula and data together determine a
numerical representation of the model from which the profiled deviance or the
profiled REML criterion can be evaluated as a function of some of the model
parameters. The appropriate criterion is optimized, using one of the
constrained optimization functions in R, to provide the parameter estimates. We
describe the structure of the model, the steps in evaluating the profiled
deviance or REML criterion, and the structure of classes or types that
represents such a model. Sufficient detail is included to allow specialization
of these structures by users who wish to write functions to fit specialized
linear mixed models, such as models incorporating pedigrees or smoothing
splines, that are not easily expressible in the formula language used by lmer.
Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.
Bears in the wild spend large proportions of time in foraging activities. In zoos their time budgets differ markedly from those of their wild counterparts. Feeding enrichment has been documented to increase foraging behavior and to reduce stereotypies. But in general these procedures have no long-term effects and result in habituation. As can be expected by the predictions of the optimal foraging theory, foraging activities are restricted as long as the availability of food is predictable. To quantify the effect of spatial unpredictability, three feeding methods have been designed to stimulate functional foraging behavior in captive Malayan sun bears in the long-term. In order to examine if habituation occurs, the most effective method was tested for 12 consecutive days. Activities of four adult sun bears at the Cologne Zoo were recorded by focal animal recording of foraging behaviors and time sampling of activities for a total of 360 hr. Implementing unpredictability significantly increased the time the bears spent foraging and led to a higher diversity of foraging behaviors. The effects lasted throughout the entire day and no habituation occurred in the course of 12 consecutive days. The study shows how functional species typical behavior in captive Malayan sun bears can be stimulated in the long-term by simulating natural characteristics of food availability. Zoo Biol. XX:XX-XX, 2014. © 2014 Wiley Periodicals, Inc.
The effect of enclosure design on diurnal activity and stereotypic behaviour was assessed in 17 adult Malayan Sun bears (Helarctos malayanus), kept either in barren indoor enclosures or relatively enriched outdoor enclosures. Locomotion was the most frequent activity observed in the indoor bears, followed by resting. In contrast, conspecifics housed outdoors spent most of the time resting. Eleven forms of stereotypic behaviours were recorded in the bears, with pacing being the most common. The frequency and repertoire of stereotypies were significantly higher in the indoor bears irrespective of enclosure size. Novel forms of locomotor (forward-reverse pacing) and oral (allo-sucking) stereotypies were recorded. Oral stereotypies were predominant in the bears housed indoors, while patrolling was confined to the outdoor bears. Enclosure complexity significantly influences activity budget and occurrence of stereotypic behaviours, highlighting the importance of appropriate enclosure design and enrichment for the welfare of captive bears.
Because of the suppressive effect of stress on reproduction and health, it is important to evaluate potential stressors that may compromise captive breeding programs for endangered species. However, behavioral and physiological measures of stress are sometimes difficult to interpret, and their relationship to stress can be obscured by factors unrelated to stress, such as seasonal and diurnal patterns. Here we present findings for daily and seasonal variation in glucocorticoid (GC) secretion and behavior from a 6-year study of 2 giant pandas (Ailuropoda melanoleuca). In the American black bear (Ursus americanus), seasonal patterns of corticoid secretion are putatively linked to metabolic demands of hibernation. Although pandas do not hibernate, we have found a similar pattern of GC dynamics. Using radioimmunoassay of urinary GC metabolites, we found seasonal variation in GC levels in an adult female and an adult male panda. As in black bears, winter and spring GC levels were significantly higher than summer levels. Additionally, in the female, GC levels during the period of parental care and lactation were higher, regardless of calendar season, than during other periods. Diurnal patterns were also detected in both the female and male panda, with elevated GCs in the morning sample. However, these diurnal patterns were not evident during the fall and summer months. Daily levels of several behaviors potentially indicative of stress also varied significantly with season in both male and female. Additionally seasonal dynamics of feeding behavior were documented. In the female, periods of elevated and diminished appetite were associated with embryonic diapause and post-implantation, respectively. The male had elevated feeding during the fall. Although these patterns are instructive for comparison with other species, we urge caution because our limited sample size does not allow us to extrapolate beyond the individuals studied.
The behavior of giant pandas (Ailuropoda melanoleuca) was studied under captive conditions. Both male and female pandas spent similar amounts of time engaged in eating and locomotion. Males performed anogenital-marking more but rested less than females, which suggests a sexually dimorphic pattern of behavior. Furthermore, females housed in the seminatural environment spent significantly less time engaged in stereotyped behavior than did females housed in the traditional enclosure, indicating that an enclosure environment affects the behavior of giant pandas. These data illustrate the importance of careful management and facility design for captive giant pandas. Zoo Biol 22:77–82, 2003. © 2003 Wiley-Liss, Inc.
The zoo scientific community was among the first to focus attention on captivity-induced stereotypic behaviors, their causes, and methods of eradication. Environmental enrichment has emerged recently as the main husbandry tool for tackling this problem. An increasing number of research publications have attempted to evaluate the effectiveness of enrichment in reducing stereotypic behavior and to develop further concepts to explain how effective enrichment works. A review and meta-analysis of this literature indicates that enrichment is a successful technique for reducing stereotypic behavior in zoo animals. Enrichment was associated with significant reduction in stereotypy performance about 53% of the time. Published enrichment and stereotypy research is lacking for most zoo species, with most studies on large, charismatic, and often endangered species, but it is unclear whether stereotypies are more prevalent in these species. In addition, problems with scientific methods and data presentation, quantitatively detailed in this work, severely limit the conclusions drawn from zoo research. Further understanding of what kinds of enrichment works and what doesn't will require greater attention to experimental design, sample size, statistical analysis, and better descriptions of enrichment properties and the form of stereotypy. We recommend that future studies focus on increasing sample size (e.g., through multi-institutional studies), appropriate repeated measures design (e.g., with multiple baseline and experimental phases), providing full statistical information about the behavioral changes observed (including standard error), and ultimately the development of a predictive science for enrichment, stereotypies, and wellbeing. Zoo Biol 0:1–20, 2005. © 2005 Wiley-Liss, Inc.
Stereotypic behavior is exhibited by a wide range of captive animals. Its association with hormones, especially elevated cortisol level and lack of naturalistic stimuli in the environment, has been little studied. This study hypothesizes that stereotypic behavior is caused by stress due to lack of appropriate, naturalistic stimuli in the environment. Using four adult pandas (Ailuropoda melanoleuca) in the Beijing Zoo from March–July in 2003, we tested the following predictions: 1) stereotypic behavior and fecal cortisol level will not change associated with the progress of reproductive state; 2) there is a positive correlation between the occurrence of stereotypic behavior and fecal cortisol level; and 3) environmental enrichment by adding a naturalistic stimulus will reduce both stereotypic behavior and fecal cortisol level. We did not find any significant differences in the occurrence of stereotypic behavior and fecal cortisol level but did find a significant difference in the total time engaged in displaying the stereotypic behavior among the three estrous periods. The level of stereotypic behavior was correlated with elevated fecal cortisol level. Enrichment simply by adding a naturalistic stimulus did not show significant effects on stereotypic behavior, or on fecal cortisol level. Our results supported the second prediction, but did not completely support the first and the third ones perhaps because of the small sample size. Additionally, our results showed that stereotypic behavior might be a response to a heightened level of cortisol. Zoo Biol 0:1–15, 2006. © 2006 Wiley-Liss, Inc.
Measuring Behaviour has established itself as a standard text. Largely rewritten, updated and reorganised, this third edition is, as before, a guide to the principles and methods of quantitative studies of behaviour, with an emphasis on techniques of observation, recording and analysis. It provides the basic knowledge needed to measure behaviour, doing so in a succinct and easily understood form. The sections on research design and the interpretation and presentation of data have been greatly expanded. Written with brevity and clarity, Measuring Behaviour is, above all, a practical guide book. Aimed primarily at undergraduate and graduate students in biology and psychology who are about to embark upon quantitative studies of animal and human behaviour, this book provides a concise review of methodology that will be of great value to scientists of all disciplines in which behaviour is measured, including biological anthropology, the social sciences and medicine.
Animal keepers at zoos and wildlife rescue centers often possess in‐depth knowledge of the health and behavior of the individuals under their care. While it is often not feasible for keepers to regularly collect behavior data through formal scientific methods, efforts should be made to find alternative means to capture this knowledge. We investigated the use of keeper feedback to study the behavior of sloth bears at the Agra Bear Rescue Facility (ABRF; Agra, India). We prepared a survey with 5 questions focused on behaviors indicative of playfulness, boldness, aggressiveness, and the tendency to express self‐directed behaviors (SDB). We asked keepers to rate bears on a Likert scale from 1 (least likely to exhibit a behavior) to 5 (most likely) for 44 adult female bears (5–21 years of age). We validated this method by comparing keeper ratings of SDB with formal behavior observations, finding that time of day had an influence on the accuracy of keeper assessments. We found a significant negative correlation between housing bears in larger groups (>15) and SDB. In addition, we correlated ratings given by keepers for all study behaviors. Social play had significant negative correlation with aggression toward people. There was no correlation between social play and aggression toward other bears, possibly due to the existence of cohesive social groups in group housing or high dimensionality of the data. We found that keeper feedback is an efficient tool to gather behavior data on captive sloth bears and recommend its use in future studies.
Zoo-housed bears are prone to exhibiting stereotypic behaviors, generally considered indicators of negative welfare. We explored the effects of a variable-time feeding enrichment schedule on behavioral indicators of welfare in four bear species at Cleveland Metroparks Zoo. We distributed the diets of eight bears in one of five enrichment items, for two consecutive days each, and monitored behavior throughout the day. In Experiment 1, we compared variable-time to fixed-time presentation of enrichment over two, 10-day periods. Overall, bears performed more exploratory behavior when enriched (p < 0.0001). Furthermore, variable-time enrichment was associated with a greater increase in exploratory behavior than fixed-time enrichment when compared to baseline (p < 0.001). Both fixed-time (punadjusted <0.05, padjusted = 0.07) and variable-schedule (punadjusted <0.05, padjusted = 0.09) enrichment were also associated with similar decreases in abnormal behavior compared to baseline. For Experiment 2, we tested habituation to enrichment over 30 days using multiple items and a semi-variable presentation schedule. Again during the enrichment period, bears exhibited increased exploratory behavior (p < 0.0001) and decreased abnormal behaviors compared to baseline (punadjusted = 0.05, padjusted = 0.09). We observed no habituation during the 30-day sustained enrichment period for these behaviors. Collectively, these results suggest that daily, variable-schedule feeding enrichment, with intermittent presentation of unique enrichment items, increases behavioral indicators of positive welfare and decreases behavioral indicators of negative welfare.
Captive bears are housed in environments that differ greatly from their natural habitat, restricting their ability to perform normal species-specific behaviours. This may be detrimental to welfare, with disabled individuals at particular risk. The effect of physical disability on behaviour and enclosure utilisation was assessed in 12 adult Malayan sun bears (Helarctos malayanus) using 10minute interval scan sampling. Amputees spent less time performing locomotor behaviours than able-bodied bears, used their enclosures less evenly, but did not exhibit obvious stereotypies. This was possibly due to the increased energy demands of locomotion, or residual pain in amputated limbs. Amputees spent less time grooming, but did not differ in time spent climbing compared with non-amputees. Partially sighted bears did not differ from able-bodied controls in enclosure use or behaviour. Age was positively correlated with stereotypical behaviour, and negatively correlated with maintenance and resting. Medication use was associated with more resting and grooming, and reduced stereotypy. The findings suggest that enclosures for amputees can be smaller than those for able-bodied bears, but should still contain a variety of climbing structures. Partially sighted bears fare well in enclosures designed for able-bodied bears, not requiring any special provision.
When considering methodologies for collecting behavioral data, continuous sampling provides the most complete and accurate data set whereas instantaneous sampling can provide similar results and also increase the efficiency of data collection. However, instantaneous time intervals require validation to ensure accurate estimation of the data. Therefore, the objective of this study was to validate scan sampling intervals for lambs housed in a feedlot environment. Feeding, lying, standing, drinking, locomotion, and oral manipulation were measured on 18 crossbred lambs housed in an indoor feedlot facility for 14 h (0600–2000 h). Data from continuous sampling were compared with data from instantaneous scan sampling intervals of 5, 10, 15, and 20 min using a linear regression analysis. Three criteria determined if a time interval accurately estimated behaviors: 1) R² ≥ 0.90, 2) slope not statistically different from 1 (P > 0.05), and 3) intercept not statistically different from 0 (P > 0.05). Estimations for lying behavior were accurate up to 20-min intervals, whereas feeding and standing behaviors were accurate only at 5-min intervals (i.e., met all 3 regression criteria). Drinking, locomotion, and oral manipulation demonstrated poor associations (R²) for all tested intervals. The results from this study suggest that a 5-min instantaneous sampling interval will accurately estimate lying, feeding, and standing behaviors for lambs housed in a feedlot, whereas continuous sampling is recommended for the remaining behaviors. This methodology will contribute toward the efficiency, accuracy, and transparency of future behavioral data collection in lamb behavior research. © 2017 American Society of Animal Science. All rights reserved.
Beta regression is often used to model the relationship between a dependent variable that assumes values on the open interval (0,1) and a set of predictor variables. An important challenge in beta regression is to find residuals whose distribution is well approximated by the standard normal distribution. Two previous works compared residuals in beta regression, but the authors did not include the quantile residual. Using Monte Carlo simulation techniques, this paper studies the behavior of certain residuals in beta regression in several scenarios. Overall, the results suggest that the distribution of the quantile residual is better approximated by the standard normal distribution than that of the other residuals in most scenarios. Three applications illustrate the effectiveness of the quantile residual.
Recording behavior at fixed intervals (instantaneous sampling) can reduce labor relative to observing continuously. However, instantaneous sampling may inaccurately estimate potentially important responses, such as how frequently cows perform a behavior (i.e., the number of bouts). Our objective was to validate the use of instantaneous sampling for capturing how long and how frequently cows in freestall housing lie down or visit the feed bunk and water trough. We predicted that more frequent sampling would be needed to accurately reflect the behaviors that cows spent less time performing. In addition, we predicted that instantaneous sampling would underestimate how often cows engaged in behaviors that they frequently performed in short bouts or with short intervals between bouts, as some of these events may occur between sample intervals. Continuous video observations of 18 lactating Holstein-Friesian dairy cows were conducted for 48-h periods. Instantaneous samples (1 and 30 s, and 1, 3, 5, 10, 15, and 30 min) were generated from continuous data, with the samples recorded at 1-s intervals representing true values. Estimates from each sample interval ≥30 s were compared pairwise to true values with regression analysis. Sample intervals were considered accurate if they met 3 criteria: coefficient of determination ≥0.9 (i.e., strongly related to true values), slope = 1, and intercept = 0 (i.e., did not over- or underestimate true values). The amount of time cows spent lying (12.1 ± 1.8 h/24 h, mean ± standard deviation) or visiting the water trough (1.1 ± 0.8 h/24 h) and feed bunk (5.6 ± 0.8 h/24 h) were accurately captured using sample intervals ≤30, 10, and 5 min, respectively. In addition, sample intervals ≤3 min accurately estimated the number of lying bouts (10.3 ± 2.4 per 24 h), likely because cows were recumbent for long periods (74.0 ± 17.4 min, on average, with <6% of bouts lasting <5 min) and rarely resumed lying soon after standing up (0.4% of intervals between lying bouts were <30 s). However, shorter sample intervals may be needed in situations where cows more frequently transition between lying and standing. In contrast to lying in this study, cows visited the water trough and feed bunk for shorter periods (3.5 ± 1.7 and 25.6 ± 5.8 min, respectively) and frequently returned to these resources soon after leaving (17 and 7% of intervals between visits were <30 s long). As some of these events likely occurred between sample intervals, all sample intervals ≥30 s underestimated the number of times cows visited the water trough and feed bunk (18.5 ± 6.2 and 14.1 ± 4.4 per 24 h, respectively). Therefore, continuous observation is needed to determine how often cows visit these resources.
Behavioral studies of wild animals kept in captivity provide useful information for conservation programs and animal welfare. These studies can also be time and resource consuming. For this reason, the aim of this study was to develop an ethogram for a semi-imprinted cheetah, during lactation and kept in captivity, and to compare two behavioral sampling methods in order to construct a time budget. During the first 34 days of the study, ad libitum sampling was used for describing observed behaviors, which allowed development of an ethogram. During the following 30 days, focal sampling with continuous recording and focal sampling with time sampling (instantaneous sampling) every 60 seconds, aided by three cameras, was applied in order to determine the behavioral time budget. An ethogram composed of eight categories and 22 behaviors was developed. The cheetah allocated most of her time to resting while lying down with her cubs, the most frequent behavioral category assessed by both methods. Pearson’s correlation was significant (p<0.05) for 11 of the 22 behaviors, but only two presented a moderate correlation according to the r-value (pacing and eating chicken). Allo-coprophagia and pacing with cubs were behaviors described for the first time in cheetahs. These behaviors could be indicative of the inability to perform basic, normal behaviors and may represent a welfare concern. For future studies, the use of cameras located in previously detected areas of use with continuous recording could provide the best method for behavioral studies in captive felids.
This book is comprised of 11 chapters generally discussing different perspectives of stereotypic behaviour in man and animals. The chapters are divided into 3 parts (normal animal and abnormal environment, stereotypic behaviours as pathologies and treating stereotypic behaviours). The first chapter reviews the extent and nature of research into stereotypic behaviour. Chapters 2-4 (part I) focus on the ethological perspective. Behaviour is discussed, including stereotypies, in terms of its motivated basis (stereotyping subjects are normal animals responding in species-typical ways to an abnormal environment). Chapters 5-8 (part II) emphasize clinical psychology, psychiatry and neuroscience. Three assumptions are presented: stereotypies of focus are the products of dysfunction (animal is abnormal); fullest understanding of stereotypies will come from investigating the neurophysiological mechanisms involved; and processes involved at this level have great cross-species generality. Part III (chapter 9 and 10) illustrates how stereotypies can be tackled and reduced by those concerned about their unaesthetic appearance and/or welfare implications. Chapter 11 provides a synthesis of the book and future research and suggestions on how terminology can be improved.
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. Zoo Biol. XX:XX–XX, 2014. © 2014 Wiley Periodicals Inc.
Captive bears are prone to developing dental pathology for reasons including longevity in captivity, inappropriate diet, trauma, and stereotypical bar biting. If not detected, this can cause pain and suffering, with negative welfare consequences. As animals cannot verbally express feelings, objective methods are required to detect pain. Some methods of pain assessment can be invasive and impractical but behavioural observations offer a non-invasive alternative. Behavioural assessment for the detection of pain has been described in some domestic species but little published research has applied this to wild animal species. Eight Malayan sun bears (Helarctos malayanus) required dental extractions under anaesthesia. Their behaviour was observed, alongside a control cohort with no visible disease, pre-operatively and at one, two and four weeks post-operatively, when it was assumed the pain had resolved from the original pathology and surgery performed. Behavioural indices measured included general activity, social behaviours, stereotypies, eating-related behaviours and oro-facial behaviours hypothesised to be affected by dental pain. Bears that had received treatment took significantly longer to eat hard sugarcane pre-operatively compared to four weeks post-operatively, and took longer to eat soft porridge one week post-operatively compared to four weeks post-operatively. Untreated bears tended to be more active outdoors one week post-operatively compared to the treatment cohort. Results suggest that using hard foods and assessing the duration of eating behaviours could be useful to indicate dental pain in sun bears. General behavioural assessment of dental pain in sun bears is unlikely to be effective as a single diagnostic tool, but may be combined with other methods of assessment, and further research into this area is warranted.
Although captive bears are popular zoo attractions, they are known to exhibit high levels of repetitive behaviors (RBs). These behaviors have also made them particularly popular subjects for welfare research. To date, most research on ursid welfare has focused on various feeding methods that seek to increase time spent searching for, extracting, or consuming food. Prior research indicates an average of a 50% reduction in RBs when attempts are successful and, roughly, a 50% success rate across studies. This research focused on decreasing time spent in an RB while increasing the time spent active by increasing time spent searching for, extracting, and consuming food. The utility of timed, automated scatter feeders was examined for use with captive grizzly bears (Ursis arctos horribilis). Findings include a significant decrease in time spent in RB and a significant increase in time spent active while the feeders were in use. Further, the bears exhibited a wider range of behaviors and a greater use of their enclosure.
Polar bears are known to exhibit repetitive pacing behaviors, usually described as stereotypic, in zoo environments. However, little quantitative information exists about the prevalence of pacing in the zoo population. Similarly, large, multi-institutional studies conducted to determine the relationship between stereotypic behavior in zoo polar bears and environmental/husbandry variables using corticoids as a measure of stress are lacking. The study reported here includes data from 55 bears housed in 20 North American zoos. Individual and zoo characteristics were collected and behavior and fecal glucocorticoid metabolites were measured over a one-year period. Using an epidemiological approach, individual and facility level multiple linear regression models were constructed to determine the nature, strength and significance of environmental/husbandry variables and temperament (measured using a standardized novel object behavior test) on stereotypic pacing and corticoids. We found zoo polar bears performed stereotypic pacing behavior during 11% of the day; the rate rose to 23% when expressed as a percentage of time engaged in locomotor behavior. However, considerable variation in rate of stereotypy was observed. Variables associated with reduced pacing at zoos were: enrichment, number of bears in the group, bear’s having a view out of their exhibit, and presence of a positive reinforcement training program. Among individuals, bear’s whose temperament measured high on the “interest” axis (defined in terms of behavior directed toward the novel object) tended to display less stereotypic behavior and those that scored high on the “slow to approach” axis displayed more pacing. We found higher fecal glucocorticoid levels were associated with higher rates of stereotypic pacing and smaller dry land exhibit area. These results support other studies suggesting polar bears are particularly prone to stereotypic pacing behavior in zoos and that there is a link between stress (measured as fecal glucocorticoids) and pacing in zoo polar bears. These findings also suggest that some easily available tools, namely environmental enrichment and positive reinforcement training, can effectively reduce the incidence of these behaviors. Exhibit designers should take note that providing bears with a view out of their exhibit and larger land areas are associated with both behavioral and physiological benefits. Finally, certain temperaments are associated with elevated levels of both stereotypic behavior and corticoids. This information may provide a tool for proactively identifying the individuals most likely to develop pacing behaviors and providing appropriately enhanced care before the behavior becomes established.
A 12-year-old, male, brown bear (Ursus arctos) named Abdi exhibited stereotypical pacing behavior. He was kept as a pet for 10 years by local villagers, then he was rescued and taken to the Karacabey Bear Sanctuary in July 2001. His physical condition was extremely poor. Because he had never lived with other bears, he was terrified and refused to integrate with them. After 6 months he was healthy physically but observations by the keepers indicated that he was pacing all day. He was treated with fluoxetine (0.62 mg/kg orally every 24 hours) for 6 months, and had been observed totally for 18 months. After stereotypy ceased completely, he was transferred to the large naturalistic enclosure and did not show any stereotypical behavior during the subsequent observation period (1 year). He was treated successfully using a combination of fluoxetine, the provisioning of extra space, and the addition of novel stimulation in a naturalistic enclosure. The space and stimulation could be sufficient to mimic the therapeutic effect of the pharmacological therapy in the long term.
This paper summarises recent findings on the causation of stereotypic behaviours and other abnormal repetitive behaviours (ARBs) in captive animals: primarily motivational frustration and/or brain dysfunction, with possible contributory roles also being played by habit-formation and ‘coping’ effects. We then review the extent to which ARBs occur in zoos and similar, estimating that at least 10000 captive wild animals are affected worldwide. We argue for ‘zero tolerance’ of such ARBs, because stress and poor welfare raise ethical issues, while abnormal behavioural phenotypes and possibilities of impaired brain development challenge both the indirect (e.g. educational) and the direct, intrinsic conservation value of affected animals. We then consider five potential means by which ARBs may be tackled: genetic selection; pharmacological treatment; the reinforcement of alternative behaviours; punishment; and environmental enrichment. All except punishment have potentially useful roles to play, but enrichment is the preferred approach: it is most likely to tackle the problems underlying stereotypic behaviours, and thence to improve both welfare and behaviour with few unwanted side-effects. Nevertheless, in zoos, environmental enrichment to date has only had partial success, with no study managing to abolish ARBs in all its subjects—suggesting either that the enrichments currently being used are never quite optimal, or that by the time they are tackled, ARBs have become resistant to change. We suggest some ways in which the effectiveness of enrichments may be enhanced; propose that certain properties of ARBs may usefully help evaluate their likely ‘treatability’; and emphasise that if improving welfare is more important than just reducing ARB, then additional measures are needed in order to first, reliably identify those individuals most at risk from poor welfare, and then, to fully evaluate the welfare impact of enrichments. This paper also emphasises, with examples, the enormous potential value of zoo-derived data for helping understand how taxon, ecological niche, rearing history, and current housing together affect animals’ responses to captivity.
In captivity, some species often seem to thrive, while others are often prone to breeding problems, poor health, and repetitive stereotypic behaviour. Within carnivores, for instance, the brown bear, American mink and snow leopard typically adapt well to captivity and show few signs of poor welfare, while the clouded leopard and polar bear are generally hard to breed successfully and/or to prevent from performing abnormal behaviour. Understanding the fundamental source of such differences could enable reproductive success and behavioural normalcy to be improved in zoos and breeding centres, by increasing the appropriateness of the enclosure designs and environmental enrichments offered particular species, and by allowing these to be offered pre-emptively instead of reactively. Here, we demonstrate that a significant proportion of the variation in apparent welfare between captive carnivore species stems from specific aspects of natural behaviour. We tested pre-existing hypotheses that species-typical welfare is predicted by natural hunting behaviour, general activity levels, ranging, or territorial patrolling (all activities that are constrained in captivity), by collating data on median stereotypy levels and infant mortality for multiple captive species, and then regressing these against median values for the relevant aspects of natural behavioural biology (e.g. hunts per day, proportion of flesh in the diet, home-range size, etc.). Our results revealed that instead of relating to foraging (e.g. hunting), as often assumed, carnivore stereotypy levels are significantly predicted by natural ranging behaviour (e.g. home-range size and typical daily travel distances). Furthermore, naturally wide-ranging lifestyles also predicted relatively high captive infant mortality rates. These results suggest that enclosure designs and enrichments focussing on carnivores’ ranging tendencies (e.g. providing more space, multiple den sites, greater day-to-day environmental variability/novelty, and/or more control over exposure to aversive or rewarding stimuli) could be particularly effective means of improving welfare; and also, that targeting such enrichment programmes on wide-ranging species, before problems even emerge, might effectively pre-empt their development. Alternatively, species with relatively small ranges could instead be made the focus of future collections and breeding programmes, zoos phasing out wide-ranging carnivores in favour of those species inherently more suited to current or readily achievable enclosure sizes and enrichment regimes.
Seven major types of sampling for observational studies of social behavior have been found in the literature. These methods differ considerably in their suitability for providing unbiased data of various kinds. Below is a summary of the major recommended uses of each technique: In this paper, I have tried to point out the major strengths and weaknesses of each sampling method. Some methods are intrinsically biased with respect to many variables, others to fewer. In choosing a sampling method the main question is whether the procedure results in a biased sample of the variables under study. A method can produce a biased sample directly, as a result of intrinsic bias with respect to a study variable, or secondarily due to some degree of dependence (correlation) between the study variable and a directly-biased variable. In order to choose a sampling technique, the observer needs to consider carefully the characteristics of behavior and social interactions that are relevant to the study population and the research questions at hand. In most studies one will not have adequate empirical knowledge of the dependencies between relevant variables. Under the circumstances, the observer should avoid intrinsic biases to whatever extent possible, in particular those that direcly affect the variables under study. Finally, it will often be possible to use more than one sampling method in a study. Such samples can be taken successively or, under favorable conditions, even concurrently. For example, we have found it possible to take Instantaneous Samples of the identities and distances of nearest neighbors of a focal individual at five or ten minute intervals during Focal-Animal (behavior) Samples on that individual. Often during Focal-Animal Sampling one can also record All Occurrences of Some Behaviors, for the whole social group, for categories of conspicuous behavior, such as predation, intergroup contact, drinking, and so on. The extent to which concurrent multiple sampling is feasible will depend very much on the behavior categories and rate of occurrence, the observational conditions, etc. Where feasible, such multiple sampling can greatly aid in the efficient use of research time.
We estimate that stereotypies are currently displayed by over 85 million farm, laboratory and zoo animals worldwide. This paper investigates their reliability as welfare indicators, by surveying studies relating stereotypy to other welfare measures and by analysing the mechanisms underlying this behaviour. Where data exist, most (approximately 68%) situations that cause/increase stereotypies also decrease welfare. Stereotypy-eliciting situations are thus likely to be poor for welfare, although exceptions exist. Within such an environment, however, most (approximately 60%) accounts link individual stereotypy performance with improved welfare (cf approximately 20% linking it with reduced welfare). Thus, in a sub-optimal environment, non-stereotyping or low-stereotyping individuals could well have the poorest welfare, although again exceptions exist. Examining the mechanisms underlying stereotypy performance, we discuss four processes that could account for these complex links between stereotypy and welfare. Beneficial consequences from performing the specific source-behaviour of the stereotypy ('do-it-yourself enrichment'), or arising from repetition per se ('mantra effects'), may ameliorate welfare in poor environments. In addition, stereotypies that have become centrally controlled (habit-like), or that arise from autistic-like changes in the control of all behaviour (perseveration), are likely to be unreliable indicators of current state because they can be elicited by, or persist in, circumstances that improve welfare. To refine the role of stereotypy in welfare assessment, we suggest the collection of specific additional data to reveal when any of these four processes is acting. Until such research increases our understanding, stereotypies should always be taken seriously as a warning sign of potential suffering, but never used as the sole index of welfare; non-stereotyping or low-stereotyping individuals should not be overlooked or assumed to be faring well; simple measures of frequency should not be used to compare stereotypies that differ in age, form, or the biological or experiential characteristics of the performing animal; enrichments that do not immediately reduce stereotypies should not be assumed failures with respect to welfare; and finally, stereotypies should not be reduced by means other than tackling their underlying motivations.
The stereotypies of individually caged Asiatic black bears (Ursus thibetanus) and Malayan sun bears (Helarctos malayanus) were studied in detail. Stereotypies were performed by 27 of the 29 subjects, were primarily locomotory in form (e.g., pacing), and occupied on average 18% (standard error of the mean (SEM)=2.5) of daylight hours. Stereotypy levels during the night were almost negligible and were highly correlated with daytime levels. Total stereotypies peaked prior to food arrival, although oral stereotypies were most frequent after feeding. In general, stereotypies were performed in locations from which food arrival could be viewed, although Asiatic black bears were equally likely to exhibit stereotypy near a neighboring bear. Across individuals, stereotypy frequency was inversely correlated with inactivity and increased with age. Older bears also showed less normal activity and a reduced diversity of normal behavior. Stereotypy levels were unrelated to levels of “compulsive” behavior (e.g., hair plucking) or repetitive self-sucking–a potential deprivation stereotypy. More frequent stereotypies were performed more invariantly (i.e., were more predictable from one repetition to the next) and in more diverse contexts, namely 1) outside the pre-feeding period, and 2) during the night. Contrary to observations reported elsewhere, higher frequencies of stereotypy were not associated with reduced behavioral diversity, or with a more elaborate repertoire of stereotypy forms and sequences. Although the two species did not differ in overall frequency, the stereotypies of sun bears appeared to be more food-motivated than those of Asiatic black bears: the sun bears displayed a higher frequency and diversity of oral stereotypies, and higher levels of pre-feeding stereotypy, and performed significantly more of their total stereotypies in locations from which they could view food arrival. This study demonstrates how analyzing stereotypies in detail can help identify the motivations that underlie these behaviors, and potentially reveal their degree of establishment–both of which are important factors in stereotypy treatment. Zoo Biol 23:409–430, 2004. © 2004 Wiley-Liss, Inc.
Behavioral and hormonal data were compared for four giant pandas in two management conditions: (1) panda confined to exhibit area and (2) panda given choice to move freely between exhibit and off-exhibit bedroom areas. Pandas displayed fewer signs of behavioral agitation and lower urinary cortisol in the free choice condition. Time active did not differ between the two conditions. These results suggest that simply offering pandas free access to alternative locations can improve behavioral and hormonal variables that may be related to well-being. Zoo Biol 0:1–7, 2005. © 2005 Wiley-Liss, Inc.
In the present study we compared 33 enclosures in 28 parks, with a total of 66 bears. We chose direct observation of behaviour rather than surveys. Each enclosure was observed during one day; stereotypies and social relationships were qualitatively noted in types and amount. The connections of behaviour with bears characteristics and types of management were established. Young bears exhibited fewer stereotypies than adult ones, especially if these adults were kept indoor at night. Contrary to stereotyped pacing and circling, head-tossing was more frequent in young subjects. Occurrences of stereotypical behaviour were more numerous during the afternoon, especially if animals received a single main feed in the evening. Whereas circling was observed only in bears kept with related fellows, pacing was more frequent when they were kept with unrelated. Neither social isolation nor sex did influence stereotypies. Keeping more than two bears together was a source of social conflict. These results suggest some recommendations for housing and management of captive brown bears. # 2004 Elsevier B.V. All rights reserved.
Studies of the effects of ambient noise on animals have found variable results. A study was conducted at the Smithsonian's National Zoological Park to determine what effect short-term demolition work would have on the behavior and cortisol excretion of giant pandas. Behavioral and endocrine differences were examined during the presence and absence of demolition work being conducted on an adjacent exhibit complex. High frequency noise was significantly louder on work days compared to non-work days. Panda activity budgets differed significantly between work and post-work periods, although in different ways. The male's use of substrates and locations that might be associated with refuge or shelter changed during the study; the female did not show similar changes. He spent more time in the enclosure adjacent to the work site rather than a more distant enclosure during the demolition period whether work was occurring or not. The behavior of both animals was more often characterized as “restless” during, as opposed to before or after the work period. In general, cortisol excretion increased during the study in both animals but this was likely a seasonal effect in the male. In many cases, significant short-term increases in cortisol were temporally associated with certain kinds of construction noises or specific physiological events. Variability in cortisol secretion fluctuated during the study for both animals but in differing patterns. These results demonstrate that demolition noise was associated with behavioral and some physiological changes in giant pandas, and these changes were individual-specific. Zoo Biol 0:1–18, 2006. © 2006 Wiley-Liss, Inc.
The behaviour of a male American black bear Ursus americanus was observed for over 2400 h across all seasons of the year. Stereotypic pacing was most frequent, oriented away from the exhibit, and performed mainly after feeding during the period May–July; from August–November pacing was oriented towards the exhibit and performed mainly around feeding time. Placing bear odors in the enclosure slightly reduced pacing and increased exploring/foraging in the late spring. Hiding small food items in the exhibit almost completely eliminated pacing in the fall and replaced it with foraging. Comparison with seasonal changes in the behaviour of wild bears suggest that the stereotypy of this bear, and probably zoo bears in general, developed from two main primary behaviours that cannot be performed in a barren zoo environment: mate-seeking behaviour predominating in the late spring and foraging behaviour in the late summer and fall.
The benefits to captive animals of environmental enrichment (EE) are widely recognized. Few studies have, however, studied how to maximise the effect of EE. One issue with EE programs seems to be habituation to the enrichment device. To study the effect of habituation to EE, 14 captive sloth bears (Melursus ursinus) were subjected to two different EE treatments. Treatment one presented EE (logs with honey containing holes) for five consecutive days, whereas treatment two presented EE on intermittent days for five days. Intermittent presentations tended to reduce habituation toward the EE. Both consecutive and intermittent presentations significantly reduced stereotypies; however, the consecutive presentations had a longer-lasting effect. Explorative behaviors increased in both treatments, consistent with earlier findings that EE increase levels of natural behaviors. Other behaviors were unaffected by the EE presentations. The results show that intermittent presentation of EE objects may secure the interest of the animals, but continuous access to enrichment may be more efficient in reducing stereotypies in the long run.
We conducted a brief study of the effectiveness of environmental enrichment for a polar bear at the Bronx Zoo with two objectives in mind. First we wanted to determine if a novel method of collecting data that easily fits into a zookeeper's work routine would produce usable data and if so, we wanted to evaluate the effectiveness of some new items that had been purchased for enriching the polar bear in reducing his pacing behavior. Observations were recorded for 119 days over a period of 5 months from April 2007 through August 2007. Five new items and eight previously used items were rotated and presented to the polar bear in the morning and afternoon. We recorded the bear's behavior five times per day as we passed by his exhibit during our regular work routine. Predictably, we found that the newer enrichment items were more effective at increasing play and decreasing pacing, as well as other more subtle effects on his behavior that helped us to design a better enrichment routine. More importantly, we found that this method of "multi-point scan sampling" was effective at producing ample and reliable data that could be used to analyze the bear's behavior without adding significant work to the keepers' daily routine.
This paper proposes a regression model where the response is beta distributed using a parameterization of the beta law that is indexed by mean and dispersion parameters. The proposed model is useful for situations where the variable of interest is continuous and restricted to the interval (0, 1) and is related to other variables through a regression structure. The regression parameters of the beta regression model are interpretable in terms of the mean of the response and, when the logit link is used, of an odds ratio, unlike the parameters of a linear regression that employs a transformed response. Estimation is performed by maximum likelihood. We provide closed-form expressions for the score function, for Fisher's information matrix and its inverse. Hypothesis testing is performed using approximations obtained from the asymptotic normality of the maximum likelihood estimator. Some diagnostic measures are introduced. Finally, practical applications that employ real data are presented and discussed.