Abnormal Repetitive Behaviors (ARBs) are commonly observed in many species of wild animals who are forced to live in captive environments such as zoos. These behaviors are largely studied and well understood by observing these animals in their domestic habitat and comparing their behavior with the ones held in zoos. Many experiments and studies have been carried out, some said that these newly acquired behavior patterns are not useful nor do they have a function whatsoever it can be argued that these changes can serve as a coping mechanism for the animal and as a new way to alleviate the stressful housing environment. Regardless of high-quality cares, ARBs will still present, which poses a huge question about animal welfare to the managers. The aim of this assignment is to review the issues that affect the lives of these captured animals and in particular the prevalence of these abnormal behaviors in different types of primates
How different species of animals respond to this new stress that is present in their life and most importantly what can zoo administration do in order to decline the frequency of these ARB in their captive animals? This can be achieved only by studying the ARB in-depth understanding how and why these abnormal behaviors manifest and most importantly informing zoos about the species that are predisposed to develop these behaviors when stripped away from their natural habitat and what ways can be used to reduce and eliminate these abnormal behaviors.
For instance, in chimpanzees and Old World Monkeys seem to be affected by changes quite frequently. There are 37 abnormal behaviors noted in captured chimpanzees such as self-groom with an object, rub hands, pluck hair, bounce twirl and head toss which are also repetitive behaviors. The patterns of these behaviors were studied in an experiment held in industry accredited zoos and involved forty group-living individuals. It was clearly noted that these animals manifested changes in their normal behaviors with rock and pat genitalia being the most prevalent ones. On the contrary, other species of primates develop violent behaviors towards themselves such as hair plucking, (93% of the captured Pan Bonobos engage in this self-harming behavior.
Teeth clenching, rocking and spinning are frequently seen in zoo housed-gorillas while changes in motor patterns such as bouncing, somersaulting, rocking and swaying are most widespread in Old World Monkeys. Some of the reasons why these behaviors are more common in primates are shown in Table 1 along with some possible solutions suggested by the animal behaviorists that studied these ARB in these species.
As noted in the table it is obvious that small remote areas where these animals are housed in zoos, away from their natural habitat and in some cases separation from their mother are among the main factors that contribute in the triggering of these ARB. Most common ARB’s include motor abnormalities such as Pacing, head rolling and sometimes even both of them, violent behaviors such as hair Pulling are also Present in these species.
Most animal behaviorists who studied these ARB also suggested solutions on how these behaviors can be reduced and most of them include housing of these animals in bigger environment where they can have more freedom to Perform the same habits they would do in their natural habitat and also adapting zoos in order to make them a more comfortable environment for these animals.
Much like primates, bears are also to this kind of behaviors when held captive in zoos. In zoo houses, polar bears pacing is the most prevalent abnormal behavior and they spend a tremendous amount of time pacing which is (approximately 11-13% of their time ) This is caused by the remote area where they are forced to live when held captive, which is one millionth of the size that they would normally inhabit in their native habitat. To improve the major effect that space has in these animals an extreme study was performed in two spectacled bears that were housed in a basic enclosure in a European zoo.
The outcome of this experiment was disturbing, since it was stated that these bears would spend a median of 57 minutes per hour performing abnormal behaviors. To provide with a solution about this problem these bears were transferred into a more spacious environment and also provided with dental care which resulted in the decrease in the intensity of their abnormal behaviors.
Larger carnivore species tend to be more affected by these behaviors when being captured because when they inhabit their natural habitat they send more time haunting for food, pacing for hours and most importantly not being in the sight of the public eyes which sometimes causes distress in these animals. Moreover having a larger body size and longer daily travel makes large carnivores more predisposed to develop these repetitive behaviors.
However, are there any cases in which these changes in behavioral patterns are beneficial to the animals? In comparison of captive and free-living waterfowls activities, two species of ducks were studied: one represents the diving duck, Common Eider (Somateria mollissima) and one representative for dabbling duck species, Garganey (Anas querquedula). Birds were fed daily with poultry corn, poultry grower’s pellets on ground, in the water and in feeding trays. Eiders were kept outdoor with an approximately minimum 3 meter-deep lake, grass and concrete areas. Garganey’s enclosure was 15 × 8 m in size with a shallow, reed-fringed lake, and open areas of grass and hedgerow. In total, birds were observed for approximately 36 h during molting period (July–August), and 26 h during non-molting period(January). Observations were made daily in five-minute sampling sessions in both sexes, alternatively. Their behaviors were observed and categorized into six contents: foraging, resting, maintenance, locomotion, social and alert. Data were analyzed by a statistic.
After the experiment, both species showed significant increase in resting and maintenance, decrease in foraging and locomotion, while no obvious change was recorded in social and alert. This can be explained by the higher demand in energy for feather regrowth. The increasing in molt intensity and potential shortened molting time resulted from the saved energy would be beneficial because flightless birds are in higher risk of being predated. Previous studies showed that other diving ducks switch to nocturnal feeding to avoid predators rather than energy saving; and some others spent more time foraging during molting period. The behavioral change occurred in experimented birds in spite of their being flightless year-round in captivity, with constant supply of food and no risk of predation. The author suggested that this increase in resting during a vulnerable period (molting) is mostly endogenous and beneficial to the animal.
We can see that when moved to living conditions that were more suitable about their way of life these animals were performing less repetitive behaviors, and their health improved notably. It is clear that to have healthy, stress-free animals living in our zoos the actual conditions, where they live should be changed and replaced with wider paces, better health care and greater day-to-day environmental complexity, increased privacy, hiding opportunity/multiple daily feeds.
Sometimes some animal species fail to adapt to the captive conditions, and they engage intensively in these abnormal behaviors and this might just give us an insight that not all animal can be held captive and live under these new restrictions. Studying these abnormal behaviors that captive animals perform would help zoo administration to take better care of the animals who live their zoos and might also help them find ways to provide the most suitable environment for their animals.