Stereotypic behavior in Asiatic black and Malayan sun bears

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.     

Consequences of long-distance swimming and travel over deep-water pack ice for a female polar bear during a year of extreme sea ice retreat

Polar bears (Ursus maritimus) prefer to live on Arctic sea ice but may swim between ice floes or between sea ice and land. Although anecdotal observations suggest that polar bears are capable of swimming long distances, no data have been available to describe in detail long distance swimming events or the physiological and reproductive consequences of such behavior. Between an initial capture in late August and a recapture in late October 2008, a radio-collared adult female polar bear in the Beaufort Sea made a continuous swim of 687 km over 9 days and then intermittently swam and walked on the sea ice surface an additional 1,800 km. Measures of movement rate, hourly activity, and subcutaneous and external temperature revealed distinct profiles of swimming and walking. Between captures, this polar bear lost 22% of her body mass and her yearling cub. The extraordinary long distance swimming ability of polar bears, which we confirm here, may help them cope with reduced Arctic sea ice. Our observation, however, indicates that long distance swimming in Arctic waters, and travel over deep water pack ice, may result in high energetic costs and compromise reproductive fitness.     

Behavioral development of a polar bear cub (Ursus maritimus) in captivity

The difficulty of observing polar bears (Ursus maritimus) in the wild has prohibited the gathering of behavioral data necessary to develop a baseline set of milestones for monitoring cub development. This study describes and quantifies previously undocumented trends in behavior observed in a captive cub–information that will be useful both in future comparative studies and in the implementation of husbandry improvements. Nearly 400 hr of behavioral data were collected, 100 hr of which were video recordings from the maternity den during the first 3 months of life. Den videos were scored to determine activity budgets and levels of maternal contact. For the remainder of the first year, mother and cub were observed in the outdoor enclosure. The onset and relative frequency of 40 discrete cub behaviors were tracked, as were patterns of mother–cub contact, including nursing and weaning. This study revealed that environmental conditions, habitat enrichment, and conditioning procedures influenced the patterns of developmental behavior exhibited by a polar bear cub. Both climatic and developmental factors had significant effects on the time the bears spent swimming. Management practices, such as environmental enrichment, and a conditioning procedure involving separation of mother and cub caused transient changes in several tracked behaviors. As the cub aged, the longest time between consecutive maternal contacts increased. Nursing bouts recorded per hour of observation decreased, and the duration of individual nursing bouts and pre‐nurse begging periods increased. Zoo Biol 22:507–514, 2003. © 2003 Wiley‐Liss, Inc.     

Issues of choice and control in the behaviour of a pair of captive polar bears (Ursus maritimus)

Stereotyped behaviour occurs in a wide variety of captive animals including ursids. The provision of animal control over aspects of their environment by providing choices is a critical element for improving welfare. The behaviour of two sibling polar bears at a metropolitan zoo was examined to investigate the effect of providing access to their indoor, off-exhibit holding space. Both bears demonstrated behavioural changes when given the choice to access their indoor dens including decreased stereotyped behaviours and increased social play. These results, although based on just two bears, provide additional support for the assertion that choice and control are closely tied to issues of well-being for captive animals.     

Observations of mortality associated with extended open-water swimming by polar bears in the Alaskan Beaufort Sea

During aerial surveys in September 1987–2003, a total of 315 live polar bears were observed with 12 (3.8%) animals in open water, defined for purposes of this analysis as marine waters >2 km north of the Alaska Beaufort Sea coastline or associated barrier islands. No polar bear carcasses were observed. During aerial surveys in early September, 2004, 55 polar bears (Ursus maritimus) were seen, 51 were alive and of those 10 (19.9%) were in open water. In addition, four polar bear carcasses were seen floating in open water and had, presumably, drowned. Average distance from land and pack ice edge for live polar bears swimming in open water in 2004 (n=10) were 8.3±3.0 and 177.4±5.1 km, respectively. We speculate that mortalities due to offshore swimming during late-ice (or mild ice) years may be an important and unaccounted source of natural mortality given energetic demands placed on individual bears engaged in long-distance swimming. We further suggest that drowning-related deaths of polar bears may increase in the future if the observed trend of regression of pack ice and/or longer open water periods continues.     

Stereotypies,aggression and the feeding schedules of tethered sows

Thirty tethered sows were observed for 5 min every half-hour for 9 h spanning the two feeding periods. Activity, consisting largely of food searching behaviour and drinking, was largely restricted to two 2-h periods following each feed. Three categories of stereotyped behaviour were observed and these were closely tied to the feeding periods. Short-duration bouts of rubbing, head-waving and bar-biting occurred during food delivery, while long-duration bouts of highly stereotyped and idiosyncratic sequences of rubbing and drinking were shown by older sows immediately after feeding. Vaccuum chewing tended to occur slightly later. I suggest that frustration of feeding motivation rather than under-stimulation underlies stereotypies in pigs, and that the different forms may represent stereotype of the appetitive and consummatory phases. Aggression was rare and was not closely related to the feeding periods or to stereotypies.     

Kicking,rocking, and waving: Contextual analysis of rhythmical stereotypies in normal human infants

I analysed the triggering contexts of over 14 000 bouts of rhythmical stereotypies of the legs, arms, and whole torso observed in 20 normal infants during their first year. Infant stereotypies were elicited by a wide variety of contexts including non-alert states, interactions with the caregiver and other persons, feeding situations, object interest, and kinaesthetic changes. The frequency of stereotypy in all contexts was a function of age. Non-alert states and interactions with the caregiver were disproportionately associated with leg and torso stereotypies. The relationship between these human stereotypies and the function and control of stereotyped behaviour in other species is discussed.     

The acute physiological response of polar bears to helicopter capture

Many wildlife species are live captured, sampled, and released; for polar bears (Ursus maritimus) capture often requires chemical immobilization via helicopter darting. Polar bears reduce their activity for approximately 4 days after capture, likely reflecting stress recovery. To better understand this stress, we quantified polar bear activity (via collar-mounted accelerometers) and body temperature (via loggers in the body core [T_abd] and periphery [T_per]) during 2–6 months of natural behavior, and during helicopter recapture and immobilization. Recapture induced bouts of peak activity higher than those that occurred during natural behavior for 2 of 5 bears, greater peak T_per for 3 of 6 bears, and greater peak T_abd for 1 of 6 bears. High body temperature (>39.0°C) occurred in T_per for 3 of 6 individuals during recapture and 6 of 6 individuals during natural behavior, and in T_abd for 2 of 6 individuals during recapture and 3 of 6 individuals during natural behavior. Measurements of T_abd and T_per correlated with rectal temperatures measured after immobilization, supporting the use of rectal temperatures for monitoring bear response to capture. Using a larger dataset (n = 66 captures), modeling of blood biochemistry revealed that maximum ambient temperature during recapture was associated with a stress leukogram (7–26% decline in percent lymphocytes, 12–21% increase in percent neutrophils) and maximum duration of helicopter operations had a similar but smaller effect. We conclude that polar bear activity and body temperature during helicopter capture are similar to that which occurs during the most intense events of natural behavior; high body temperature, especially in warm capture conditions, is a key concern; additional study of stress leukograms in polar bears is needed; and additional data collection regarding capture operations would be useful.     

圈养马来熊行为节律和时间分配的季节变化

2009年3－12月,分春、夏、秋、冬4个季节,采用人工观察和红外摄像记录观察2种方式,对上海动物园的圈养马来熊进行行为学研究。建立的行为谱包括休息、走动、踱步、乞食、采食、爬树、探寻、擦痒、玩耍、追逐、嗅闻、示警、打斗、爬跨、舔阴、交配和排泄,将相关行为合并后归纳成6类,即休息、运动、乞食、刻板、社群和其他行为。马来熊用于休息的时间最多,其次是运动和乞食行为。各行为具有不同程度的季节性差异,运动行为（F=62.748,P<0.001）和社群行为（F=26.041,P<0.001）季节性差异极显著,刻板行为（F=4.667,P<0.05）差异显著,休息行为（F=1.857,P>0.05）和乞食行为（F=1.180,P>0.05）差异不显著。圈养马来熊具有明显的日活动节律,00:00－5:00和20:00－24:00是马来熊的休息高峰,6:00开始活动量增大,8:00－9:00是马来熊的正常进食高峰,同时,运动、乞食、社群等行为逐渐增多,乞食行为集中在运动场10:00－15:00游客多的时段。18:00之后运动逐渐减少,进入休息状态。春夏昼间行为比较,运动和刻板行为（P<0.05）差异显著。年龄因素,春季对休息、运动和刻板行为影响特别显著（P<0.001）,社群和乞食行为的影响显著（P<0.05）,夏季对乞食行为影响特别显著（P<0.001）,运动、刻板和社群行为影响显著（P<0.05）。性别因素,春季对社群行为影响极显著（P<0.001）,休息、乞食和其他行为影响显著（P<0.05）,夏季只对社群行为影响显著（P<0.05）。秋冬间各行为差异不显著,室内和运动场的行为对比表明,刻板和休息多在室内,运动行为多在运动场,室内和运动场秋季的运动行为和社群行为差异显著（P<0.05）,冬季的刻板行为差异极显著（P<0.001）。     

The use of infrared thermography to noninvasively measure the surface temperature of polar bears during bouts of social play

Infrared thermography or thermal imagery is a noninvasive tool that can be used to measure the temperature of surfaces. Typically, thermal imagery is used for construction or military purposes but is increasingly used as a noninvasive tool in wildlife studies. We investigated the use of thermal imagery to measure surface temperature changes as a proxy for energetic expenditure. We measured the surface temperature of polar bear (Ursus maritimus) eyes, while immobilized, to determine whether the eye is a thermal window that can accurately indicate internal temperature. We found a significant difference (2.68 ± 0.41°C) between the surface temperature of the eye measured with thermal imagery and the internal rectal temperature. Additionally, we measured surface temperature changes in polar bears after bouts of social play as a proxy for energy expenditure. Mean temperature of the eye increased by 1.34 ± 0.43°C after social play, indicating that this activity increased energy expenditure. During the fasting season, polar bears rely on fat stores, and any energy expenditure beyond what is required to travel may be costly to their survival, particularly in years of low resource availability. We conclude that thermal imagery is a useful tool to noninvasively investigate the energetics of social play.     

Positive feedback loops sustain repeating bursts in neuronal circuits

Voluntary movements in animals are often episodic, with abrupt onset and termination. Elevated neuronal excitation is required to drive the neuronal circuits underlying such movements; however, the mechanisms that sustain this increased excitation are largely unknown. In the medicinal leech, an identified cascade of excitation has been traced from mechanosensory neurons to the swim oscillator circuit. Although this cascade explains the initiation of excitatory drive (and hence swim initiation), it cannot account for the prolonged excitation (10–100 s) that underlies swim episodes. We present results of physiological and theoretical investigations into the mechanisms that maintain swimming activity in the leech. Although intrasegmental mechanisms can prolong stimulus-evoked excitation for more than one second, maintained excitation and sustained swimming activity requires chains of several ganglia. Experimental and modeling studies suggest that mutually excitatory intersegmental interactions can drive bouts of swimming activity in leeches. Our model neuronal circuits, which incorporated mutually excitatory neurons whose activity was limited by impulse adaptation, also replicated the following major experimental findings: (1) swimming can be initiated and terminated by a single neuron, (2) swim duration decreases with experimental reduction in nerve cord length, and (3) swim duration decreases as the interval between swim episodes is reduced.     

Environmental and social influences on enclosure use and activity patterns of captive sloth bears (Ursus ursinus)

Four adult sloth bears (Ursus ursinus) at the Los Angeles Zoo were studied for 13 months to quantify the influence of environmental and social variables on enclosure use and activity. Observations were conducted in 1-hr samples, using 1-min scans, for a total of 150 hr distributed across two seasons and three time periods. Data were then subjected to chi-square and log-linear analyses. These showed that the bears' enclosure use and activity patterns were conditional on variations in the physical and social environments. Individual rearing history also influenced activity, as hand-reared bears showed significantly higher frequencies of self-directed and stereotyped behaviors than did mother-reared animals. Changes in group composition significantly affected the behavior patterns of the two females, which were most social when exhibited with a familiar male. Social behavior and nonsocial activity also decreased in the presence of an unfamiliar male. Further evaluations of exhibit design and management practices are encouraged to identify variables that increase the reproductive success, physical well-being, and educational value of captive sloth bears. © 1992 Wiley-Liss, Inc.     

Stereotyped behaviour,adjunctive drinking and the feeding periods of tethered sows

The behaviour of 25 tethered sows in an intensive piggery was observed for 1 h before and 1 h after the delivery of food to determine if behavioural stereotypies appeared as adjunctive behaviours. The different components of behavioural stereotypies were found to have different associations with the feeding period. Head-waving, bar-biting, and rubbing the snout against the cage were most common before feeding, and were shown particularly by the older sows. Manipulating the drinker and, for some sows, rubbing were most common after. There was some evidence of polydipsia. Vacuum chewing, playing with the chain, and aggressive behaviours, however, did not appear to be associated with the feeding period. The last two behaviours occurred only rarely. Seven sows showed stereotyped sequences of rapid rubbing or rapid drinking after the delivery of food, and these sows showed more excitement before food was delivered. Rooting was common for the full hour after all food had been consumed, and occurred in conjunction with long duration drinking. I suggest that the occurrence of adjunctive drinking by sows results from the persistence of feeding motivation, perhaps because concentrated food does not provide sufficient stomach distension, combined with the knowledge that food will definitely not be forthcoming. Stereotyped sequences of behaviour may be a means of reducing the arousal generated by the expectation of food.     

Effects of inedible, manipulable objects on captive bears

Bears in captivity often show abnormal behaviors such as stereotypies and periods of excessive inactivity. Most of the research aimed at reducing abnormal behaviors in bears has focused on feeding enrichment. However, the effects of feeding enrichment only seem to last as long as it takes a bear to consume the food. This study investigated the effects of inedible, manipulable objects on bears. Two polar bears (Ursus maritimus) received plastic floats. A sloth bear (Melursus ursinus) and a spectacled bear (Treniarctos ornatus) received plastic balls. During a 7-week period, polar bears nearly doubled their activity in the presence of toy floats, and the spectacled bear halved its pacing in the presence of toys. The sloth bear did not respond to the objects. These findings indicate that access to manipulable nonfood objects such as plastic toys can result in prolonged engagement in appetitive behaviors by polar bears.     

Effect of temperature on the walking behaviour of an egg parasitoid: disentangling kinetic response from integrated response

1. This study investigated the effect of temperatures ranging from 10.8 to 34.2 °C on seven walking parameters of an egg parasitoid, Anaphes listronoti. Those responses were compared with a theoretical kinetic model in order to disentangle the kinetic response of the insect from its integrated response. 2. Walking speed increased continuously with temperature, but walking distance and duration were maximised between 25 and 30 °C, and decreased at higher and lower temperatures. At the lowest temperature, females unexpectedly walked a greater distance and for a longer duration in comparison with intermediate temperatures. 3. The number of walking bouts followed the same polynomial trend as walking distance and duration, with a maximum between 30 and 35 °C. The duration of walking bouts was maximised at 20 °C and decreased at lower and higher temperatures, whereas the duration of resting bouts linearly decreased with increasing temperature. There was no effect of temperature on the turning rate of females. 4. For A. listronoti, walking speed and duration of resting bouts followed the kinetic response, but the other behavioural components did not, especially at the lowest and highest temperatures. Walking distance and duration were higher than expected under the kinetic response at 10.8 °C and lower than expected at 34.2 °C. This pattern suggests an integrated response combining behavioural escape from adverse temperature and energy saving. 5. This detailed analysis of the walking behaviour of A. listronoti illustrates the complexity of insect behavioural responses to temperature and the difficulty involved in assessing underlying mechanisms.     

Estimating the energy expenditure of free‐ranging polar bears using tri‐axial accelerometers: A validation with doubly labeled water

Measures of energy expenditure can be used to inform animal conservation and management, but methods for measuring the energy expenditure of free‐ranging animals have a variety of limitations. Advancements in biologging technologies have enabled the use of dynamic body acceleration derived from accelerometers as a proxy for energy expenditure. Although dynamic body acceleration has been shown to strongly correlate with oxygen consumption in captive animals, it has been validated in only a few studies on free‐ranging animals. Here, we use relationships between oxygen consumption and overall dynamic body acceleration in resting and walking polar bears Ursus maritimus and published values for the costs of swimming in polar bears to estimate the total energy expenditure of 6 free‐ranging polar bears that were primarily using the sea ice of the Beaufort Sea. Energetic models based on accelerometry were compared to models of energy expenditure on the same individuals derived from doubly labeled water methods. Accelerometer‐based estimates of energy expenditure on average predicted total energy expenditure to be 30% less than estimates derived from doubly labeled water. Nevertheless, accelerometer‐based measures of energy expenditure strongly correlated (r² = 0.70) with measures derived from doubly labeled water. Our findings highlight the strengths and limitations in dynamic body acceleration as a measure of total energy expenditure while also further supporting its use as a proxy for instantaneous, detailed energy expenditure in free‐ranging animals.     

Behavioral response of polar bears to aircraft activity on the northern coast of Alaska

The rapid loss of arctic sea ice is forcing a larger proportion of the Southern Beaufort Sea polar bear (Ursus maritimus) population to spend more time on land, increasing chances of negative interactions between people and bears. In the United States, the Marine Mammal Protection Act (MMPA) protects polar bears from incidental disturbance from human activities. For the remote and roadless areas of northern Alaska, USA, effective management of small aircraft activity is necessary to limit disturbance, but effects of overflights on polar bear behavior are largely unknown. During 2021 and 2022, we intentionally exposed polar bears (n = 115) to systematic aircraft activity (helicopter, fixed-wing) until we observed a disruption of behavior that qualified as a level B take response (e.g., abrupt change in activity or movement) under the MMPA. We used a Bayesian logistic regression to determine what factors influence and can be used to predict when a polar bear will exhibit a level B take response and estimate the probability of an aircraft eliciting a level B take response at different altitudes above the polar bear. Aircraft type, flight altitude, landscape (barrier islands vs. mainland), and bear behavior (active vs. inactive) upon initial aircraft encounter were all important predictors of take. Probability of take rapidly increased with a decrease in flight altitude starting at 450 m for helicopter and 300 m for fixed-wing aircraft. Active (e.g., standing, walking) polar bears on barrier-island landscapes were more likely to experience take than inactive (e.g., bedded) bears on mainland landscapes. Our findings can help with assessments and management plans by quantifying disturbance to polar bears from current and future human activity that involves aircraft use.     

Increased prey vulnerability as a result of prey-prey interactions

This study examines indirect effects in a trophic system with three levels, consisting of two prey species, a top predator, and an intermediate predator. Qualitative data showed that the activity of both the top predator Aeshna juncea (Odonata) and the active prey Heterocope saliens, (Copepoda) caused bouts of swimming in the sedentary prey Sida crystallina (Cladocera). These swimming bouts caused encounters, reactions, attacks and captures of S. crystallina by the intermediate predator Coenagrion hastulatum (Odonata). Quantitative data showed that C. hastulatum had a higher encounter frequency and a higher attack frequency on the sedentary prey when the active prey was present. This result was an effect of encounters between the two prey which increased swimming activity of the sedentary S. crystallina. The results suggest that interactions between prey 1 and prey 2, and between prey and predators, could influence the structure of natural communities.     

Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity

The effects of declining Arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter‐specifically, spatially, and temporally. Because marine mammals occupy upper trophic levels in Arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. Polar bears (Ursus maritimus) are apex predators that primarily consume benthic and pelagic‐feeding ice‐associated seals. As such, their productivity integrates sea ice conditions and the ecosystem supporting them. Declining sea ice availability has been linked to negative population effects for polar bears but does not fully explain observed population changes. We examined relationships between spring foraging success of polar bears and sea ice conditions, prey productivity, and general patterns of ecosystem productivity in the Beaufort and Chukchi Seas (CSs). Fasting status (≥7 days) was estimated using serum urea and creatinine levels of 1,448 samples collected from 1,177 adult and subadult bears across three subpopulations. Fasting increased in the Beaufort Sea between 1983–1999 and 2000–2016 and was related to an index of ringed seal body condition. This change was concurrent with declines in body condition of polar bears and observed changes in the diet, condition and/or reproduction of four other vertebrate consumers within the food chain. In contrast, fasting declined in CS polar bears between periods and was less common than in the two Beaufort Sea subpopulations consistent with studies demonstrating higher primary productivity and maintenance or improved body condition in polar bears, ringed seals, and bearded seals despite recent sea ice loss in this region. Consistency between regional and temporal variation in spring polar bear fasting and food web productivity suggests that polar bears may be a useful indicator species. Furthermore, our results suggest that spatial and temporal ecological variation is important in affecting upper trophic‐level productivity in these marine ecosystems.     

Observations of a wild polar bear (<Emphasis Type="Italic">Ursus maritimus</Emphasis>) successfully fishing Arctic charr (<Emphasis Type="Italic">Salvelinus alpinus</Emphasis>) and Fourhorn sculpin (<Emphasis Type="Italic">Myoxocephalus quadricornis</Emphasis>)

Polar bears, Ursus maritimus, throughout their range, are nutritionally dependent on ringed (Phoca hispida) and bearded seals (Erignathus barbatus), which are predominantly caught on the sea ice. Other marine prey species are caught and consumed, but less frequently. As the annual sea ice retreats, polar bears throughout their range are forced ashore, where they mostly live off their stored adipose tissue. However, while land-bound they have been observed catching birds and terrestrial mammals. Although polar bears evolved from brown bears (U. arctos), direct observations of polar bears diving for and catching fish have not been reported. Here, we document observations of a young male polar bear catching Arctic charr (Salvelinus alpinus) and Fourhorn sculpin (Myoxocephalus quadricornis) by diving in Creswell Bay, Nunavut. We recorded six search bouts, where six fish were caught during dives, which were preceded by a snorkel. The average dive and snorkel length was (mean ± SD) 13 ± 5 and 6 ± 2 s, respectively.