Effect of feeding boxes on the behavior of stereotyping amur tigers (Panthera tigris altaica) in the Zurich Zoo,Zurich, Switzerland

The stereotyped pacing shown by the two Amur tigers in the Zurich Zoo was hypothesized as being caused by permanently frustrated appetitive foraging behavior. Several electrically controlled feeding boxes were installed and access to each box was possible only twice a day for 15 min at semi‐random times. The boxes had to be opened actively by the tigers. Two trials were carried out: one with solitary confinement, and one with paired confinement. During box feeding, the female's stereotyped pacing was significantly reduced from 16% (solitary confinement, conventional feeding) and 7% (paired confinement, conventional feeding) to 1% (solitary confinement) and less than 0.01% (paired confinement) of the daily observed time. The female's sleeping increased significantly in both solitary and paired confinement. The male only showed a significant reduction in stereotyped pacing behavior when kept with the female (conventional feeding: 10%; box feeding: <0.01% of the daily observed time). On days with a box‐feeding regime in paired confinement, the male spent 25% (83 min) of the observed time with active behavior at the feeding boxes. The results support the hypothesis that permanently frustrated appetitive foraging behavior causes stereotyped pacing in adult tigers. Zoo Biol 21:573–584, 2002. © 2002 Wiley‐Liss, Inc.     

Environmental influences on stereotypy and the activity budget of Indian leopards (Panthera pardus) in four zoos in Southern India

To eliminate abnormal behaviors in leopards (Panthera pardus), such as stereotypic pacing, by utilizing environmental enrichment techniques, a proper understanding of their behavior in captive environments is required. Hence there is a need for animal welfare studies in Indian zoos. The activity budgets of 16 leopards were recorded across four southern Indian zoos: Thiruvananthapuram Zoo, Arignar Anna Zoological Park, Shri Chamarajendra Zoological Gardens, and the Guindy Children's Park. Of the 16 study animals, 14 were studied on‐exhibit on zoo holidays as well as on days with visitors present, and all 16 individuals were studied off‐exhibit on other days with visitors present. The 11 behaviors recorded were categorized into active, resting, and stereotypic behaviors. Leopards exhibited higher levels of activity in the on‐exhibit enclosures on days with no visitors. Feeding time influenced the behavioral repertoire of all 14 leopards studied on‐exhibit. Lower proportions of resting were exhibited during the hours before feeding. The proportion of active behaviors differed significantly across zoos. Stereotypic pacing levels were not influenced by the presence of visitors or by feeding time, but was significantly influenced by enclosure features. Higher levels of stereotypic pacing were exhibited in off‐exhibit than on‐exhibit enclosures. Our study shows that the behavior of captive leopards is influenced by enclosure type, feeding regime, and the presence of visitors. Zoo Biol 21:585–595, 2002. © 2002 Wiley‐Liss, Inc.     

Test multipler Hypothesen zum Auftreten von stereotypen Verhaltensweisen bei Großkatzen im Zoo Leipzig

We tested multiple hypotheses on the occurrence of stereotypic behaviour in leopards (Panthera pardus), snow leopards (Uncia uncia) and tigers (Panthera tigris) at Leipzig Zoo. Stereotypies in all three species occurred exclusively as pacing. Stereotypic pacing was observed in 79% of the 14 animals and occupied on average 19% of the time spent active. Stereotypies were unaffected by species, age, sex and social housing, respectively. Animals showed significantly more stereotypic pacing before feeding. Stereotypic pacing was performed significantly more often in locations from which food arrival could be first viewed. Older animals tended to show more stereotypic pacing after feeding. Animals that generally exhibited more stereotypic behaviour paced significantly more often after feeding. Our results suggest that stereotypies may represent an exaggerated response of food reward. Furthermore, stereotypies may become emancipated from their original motivation over the course of an individual's development. Stereotypies thus could possibly be remedied by increasing the feeding (i.e. reward) frequency, if applied from an animal's early age.     

Foraging across a variable landscape: behavioral decisions made by woodland caribou at multiple spatial scales

We examined the foraging behavior of woodland caribou (Rangifer tarandus caribou) relative to the spatial and temporal heterogeneity of their environment. We assessed (1) whether caribou altered their behavior over time while making trade-offs between forage abundance and accessibility; and (2) whether foraging decisions were consistent across spatial scales (i.e., as scale increased, similar decision criteria were used at each scale). We discuss whether caribou adjusted their behavior to take advantage of changing forage availability through time and space. At the scale of the feeding site (as revealed by discriminant function analyses), caribou in both forested and alpine (above tree-line) environments selected sites where the biomass of particular lichen species was greatest and snow the least deep. Caribou did not select those species with the highest nutritional value (i.e., digestible protein and energy) in either area. Where snow depth, density, and hardness limited access to terrestrial lichens in the forest, caribou foraged instead at those trees with the greatest amount of arboreal lichen. Selection of lichen species and the influence of snow differed across time, indicating that in this system the abundance or accessibility of forage temporally influenced foraging behavior. A path analysis of forest data and multiple regression analysis of alpine data were used to test the hypothesis that variables important at the scale of the feeding site explained foraging effort at the scale of the patch. For forest patches, our hypothesized model reliably explained foraging effort, but not all variables that were statistically important at the scale of the feeding site were significant predictors at the scale of the patch. For alpine patches, our hypothesized model did not explain a statistically significant portion of the variation in the number of feeding sites within the patch, and none of the individual variables from the feeding site remained statistically significant at the patch scale. The incongruity between those variables important at the scale of the feeding site and those important at the patch showed that spatial scale affects the foraging decisions of woodland caribou. At the scale of the landscape, there was a trade-off between forage abundance and accessibility. Relative to the alpine environment, caribou in the forest foraged at feeding sites and patches with greater amounts of less variably distributed lichen, but deeper less variable snow depths. Considering the behavioral plasticity of woodland caribou, there may be no distinct advantage to foraging in one landscape over the other.     

Behavior in adult pairs of captive snow leopards (Panthera uncia)

Eight adult pairs of snow leopards (Panthera uncia) were observed for one to three years in the months December through March to determine the species' social and reproductive characteristics in captivity. To statistically examine the occurrence of behaviors as a function of estrus, the observation weeks were divided into three time blocks: before estrus, estrus, and after estrus. Using percentage of scan samples as an estimate of time spent in various behaviors, 16 behaviors and combined behavior categories were examined for (1) behaviors that differentiated successfully from unsuccessfully breeding pairs, (2) sex differences in behavior, (3) significant correlations between pair members, and (4) behaviors that showed time block effects. The rationale for identifying a behavioral profile of successful breeders in snow leopards was to aid zoos in their captive management programs by increasing their knowledge of the social behavior of this species. By finding correlates to breeding success, informed decisions on whether to change partners after a certain period of time, how to group the cats, and the optimum strategy for a survival plan can be made.     

Peripheral ghrelin injections stimulate food intake, foraging, and food hoarding in Siberian hamsters

Fasting triggers many effects, including increases in circulating concentrations of ghrelin, a primarily stomach-derived orexigenic hormone. Exogenous ghrelin treatment stimulates food intake, implicating it in fasting-induced increases in feeding, a consummatory ingestive behavior. In Siberian hamsters, fasting also stimulates appetitive ingestive behaviors such as foraging and food hoarding. Therefore, we tested whether systemic ghrelin injections (3, 30, and 200 mg/kg) would stimulate these appetitive behaviors using a running wheel-based food delivery system coupled with simulated burrow housing. We also measured active ghrelin plasma concentrations after exogenous ghrelin treatment and compared them to those associated with fasting. Hamsters had the following: 1) no running wheel access, free food; 2) running wheel access, free food; or 3) foraging requirement (10 revolutions/pellet), no free food. Ghrelin stimulated foraging at 0-1, 2-4, and 4-24 h postinjection but failed to affect wheel running activity not coupled to food. Ghrelin stimulated food intake initially (200-350%, first 4 h) across all groups; however, in hamsters with a foraging requirement, ghrelin also stimulated food intake 4-24 h postinjection (200-250%). Ghrelin stimulated food hoarding 2-72 h postinjection (100-300%), most markedly 2-4 h postinjection in animals lacking a foraging requirement (635%). Fasting increased plasma active ghrelin concentrations in a time-dependent fashion, with the 3- and 30-mg/kg dose creating concentrations of the peptide comparable to those induced by 24-48 h of fasting. Collectively, these data suggest that exogenous ghrelin, similar to fasting, increases appetitive behaviors (foraging, hoarding) by Siberian hamsters, but dissimilar to fasting in this species, stimulates food intake.     

Behavioral and adrenocortical responses to environmental changes in leopard cats (Felis bengalensis)

Indicators of environmental adequacy relevant to the well-being of small felids are developed by examining, in 4 captive leopard cats, interrelationships between behavioral and adrenocortical responses to changes in housing conditions. Singly housed cats were moved from their barren home cage (Cage 1, baseline) sequentially to 2 new, barren housing situations (Cages 2 and 3; ≈ 10 weeks/cage). Urinary cortisol concentrations, stereotypic pacing, and hiding frequencies were transiently increased for 1 week after translocation to Cage 2. After translocation to Cage 3, cortisol concentrations and hiding also were increased for the first week. However, conditions in Cage 3 were determined to be aversive to the cats, as evidenced by cortisol concentrations that remained chronically elevated for the entire 10-week period. Exploratory behavior was suppressed during this period. When Cage 3 was enriched with a complex of branches and hiding places, urinary cortisol concentrations and stereotypic pacing decreased, and exploration increased. Concealment locations that camouflage were more often used for lying down when urinary cortisol was elevated. These results suggest that reduced exploratory behavior is an indicator of chronic exposure to aversive environmental conditions. Stereotypic pacing may not necessarily increase when adrenocortical activity increases. The results also suggest that enrichment facilitates coping with aversive stimulation by providing behavioral options to confined felids. To promote the welfare of small felids, appropriate camouflaged hiding places should be provided and enrichment programs developed to stimulate exploratory behavior. © 1993 Wiley-Liss, Inc.     

The effects of physical characteristics of the environment and feeding regime on the behavior of captive felids

The behavior of captive felids is influenced by enclosure design and management regime. The behavior of nine felid species housed in 11 enclosures was recorded using instantaneous scan sampling. Stereotypic pacing was observed in 15 out of 19 individuals. Size of enclosure did not affect pacing behavior, but edges of enclosures were found to be used specifically for pacing behavior. Cats in relatively larger enclosures had a higher level of apparent movement, but only about 50% of enclosure space was used. Raised areas such as tree branches were found to be preferred sites in enclosures, particularly for observation of surroundings. The feeding regime was found to affect stereotypic pacing levels. Cats fed on a 3 day cycle paced more on fast days than on days they were fed. Although not statistically significant, 6 out of 7 of these cats paced more in the hour after feeding, whereas the cats fed daily paced more in the hour before feeding. Further research is required to understand the relationship between feeding and stereotypic behavior. Zoo Biol 16:71–83, 1997. © 1997 Wiley-Liss, Inc.     

Fat pad-specific effects of lipectomy on foraging, food hoarding, and food intake

Unlike most species, after food deprivation, Siberian hamsters increase foraging and food hoarding, two appetitive ingestive behaviors, but not food intake, a consummatory ingestive behavior. We previously demonstrated (Wood AD, Bartness TJ, Am J Physiol Regul Integr Comp Physiol 272: R783-R792, 1997) that increases in food hoarding are triggered by directly decreasing body fat levels through partial surgical lipectomy; however, we did not test if lipectomy affected foraging, nor if the magnitude of the lipid deficit affected food hoard size. Therefore, we tested whether varying the size of the lipectomy-induced lipid deficit and/or foraging effort affected foraging, food hoarding, or food intake. This was accomplished by housing adult male Siberian hamsters in a foraging/hoarding system and removing (x) both epididymal white adipose tissue (EWATx) pads, both inguinal white adipose tissue (IWATx) pads, or both EWAT and IWAT pads (EWATx + IWATx) and measuring foraging, food hoarding, and food intake for 12 wk. The lipectomy-induced lipid deficit triggered different patterns of white adipose tissue mass compensation that varied with foraging effort. Foraging for food (10 wheel revolutions to earn a food pellet) abolished the EWATx-induced compensation in IWAT pad mass. The magnitude of the lipid deficit did not engender a proportional change in any of the appetitive or consummatory ingestive behaviors. EWATx caused the greatest increase in food hoarding compared with IWATx or EWATx + IWATx, when animals were required to forage for their food. Collectively, it appears that the magnitude of a lipid deficit does not affect appetitive or consummatory behaviors; rather, when energy (foraging) demands are increased, loss of specific (gonadal) fat pads can preferentially stimulate increases in food hoarding.     

Tongue twisters: feeding enrichment to reduce oral stereotypy in giraffe

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

Enclosure design and space utilization by Indian leopards (Panthera pardus) in four zoos in Southern India

Enclosure design and the use of enclosure space influence the activity budget of captive leopards. The study laid out in grids all enclosures on the base map and segregated these grids into 4 zones. Every 5 min, the study recorded the proportion of time spent in these zones with the leopards' behavior. Captive leopards most frequently used the “edge ”zone. Almost all leopards used the edge zone for stereotypic pacing, the “back ”zone for resting, and the “other ”zone for activity. The study positively correlated the proportion of time spent in the “enriched ”zone with activity levels exhibited by leopards housed in some enclosures and with resting in others. Thus, the study segregated structural objects in the enriched zone into activity-related features (e.g., logs) and rest-related features (e.g., trees and sleeping platforms). Compared with individuals housed in barren enclosures, leopards housed in structurally enriched on-exhibit enclosures exhibited higher levels of activity. Enclosure design was found to be an important factor influencing the welfare of leopards in captivity.     

Memory dynamics in the honeybee

Reward learning in honeybees initiates a sequence of events which leads to long-lasting memory passing through multiple phases of transient memories. The study of memory dynamics is performed at the behavioral (both natural foraging behavior and appetitive conditioning), neural circuit and molecular levels. The results of these combined efforts lead to a model which assumes five kinds of sequential memories, each characterized by a set of behavioral and mechanistic properties. It is argued that these properties, although reflecting general characteristics of step-wise memory formation, are adapted to the species-specific adaptations in natural behavior, here to foraging at scattered and unreliable food sources. Accepted: 12 May 1999     

Behavioral abnormalities in captive nonhuman primates

In this study, we dealt with 11 species of nonhuman primates across 10 zoos in India. We recorded behavior as instantaneous scans between 9 a.m. and 5 p.m. In the study, we segregated behaviors for analyses into abnormal, undesirable, active, and resting. The 4 types of abnormal behavior exhibited included floating limb, self-biting, self-clasping, and stereotypic pacing. In the study, we recorded 2 types of undesirable behavior: autoerotic stimulation and begging. Langurs and group-housed macaques did not exhibit undesirable behaviors. A male lion-tailed macaque and a male gibbon exhibited begging behavior. autoerotic stimulation and self-biting occurred rarely. Males exhibited higher levels of undesirable behavior than did females. Animals confiscated from touring zoos, circuses, and animal traders exhibited higher levels of abnormal behaviors than did animals reared in larger, recognized zoos. The stump-tailed macaque was the only species to exhibit floating limb, autoerotic stimulation, self-biting, and self-clasping. Our results show that rearing experience and group composition influence the proportions of abnormal behavior exhibited by nonhuman primates in captivity. The history of early social and environmental deprivation in these species of captive nonhuman primates probably is critical in the development of behavioral pathologies. Establishing this will require further research.     

Environmental enrichment for zoo bears

The high incidence of stereotypic behaviors in zoo bears (van Keulen-Kromhout: International Zoo Yearbook 18:177–186, 1978) suggests that the environment of these animals lacks essential stimuli for guiding normal behavior. Three experiments investigated ways in which bear husbandry procedures can be altered to promote normal behavior. In experiments 1 and 2, honey-filled logs were given to a sloth (Melursus ursinus), American black (Ursus americanus), and brown bear (Ursus arctos) to determine 1) the role of food in stimulating investigatory behavior, 2) the rate of habituation to manipulable objects introduced into the exhibit, and 3) effects on locomotory behaviors. Results show specific and general habituation to the introduced objects that can be counteracted by refilling the logs with honey and by providing multiple logs in the exhibit. Investigatory activity directed toward honey-logs replaces pacing and walking in the sloth bear and is most effective in doing so when the log is novel. Experiment 3 examined the behavioral effects of feeding an American black bear in three different ways: 1) once daily in the den, 2) once daily with supplemental food from a mechanical feeder, and 3) once daily with food hidden in the exhibit in manipulatable objects. The latter method reduced stereotypic pacing from a median of 150 min/day to 20 min/day; the mechanical feeder method had no such effect. The results of a survey of 67 zoos concerning the diet and manner of feeding these three species of bears, as well as Asian black bears (Ursus thibetanus) are presented. Results are discussed with respect to the ways in which husbandry procedures can be improved to stimulate functional foraging and feeding behavior in confined bears.     

Twenty-four hour activity budgets and patterns of behavior in captive ocelots (Leopardus pardalis)

Activity budgets of captive ocelots (Leopardus pardalis) were assessed from over 547h of observational data obtained from six ocelots; two females at the Dallas Zoo (Dallas, TX), two females at the Caldwell Zoo (Tyler, TX) and a male and female at the Fossil Rim Wildlife Center (Glen Rose, TX). Data were examined for the percentage of active behaviors exhibited during the day and nighttime hours; temporal patterns of active, pace, exploratory and marking behavior, and for significance in pacing behavior between pre- and post-feeding times. The captive cats had a bimodal pattern of active behavior similar to field studies of wild ocelots, except that the timing of the active peaks were closer to the diurnal hours for the captive cats. The captive ocelots were less active than wild ocelots, and more diurnal. Also, the captive cats exhibited stereotypic pacing. When the percentage of time of active behavior was assessed for each cat, a strong variation between individuals and institution was not seen. Pacing behavior was highest prior to the feeding times for the cats. In assessing patterns of behavior, peaks in marking and exploratory behavior in the cats did not occur at the same time as the peaks in active behavior. However, we did see institutional differences in the pattern of exploratory and marking behavior, which may have been influenced by differing management practices.     

The Effect of a Feeding Schedule Change and the Provision of Forage Material on Hair Eating in a Group of Captive Baboons (Papio hamadryas sp.)

Hair eating in nonhuman primates is thought to result from a frustrated appetitive drive produced by an inappropriate diet. To investigate whether hair eating could be reduced through changes in diet, a 2-part study was conducted with a group of baboons (Papio hamadryas sp.). The 1st part involved changing to a twice-daily feeding routine, thus providing prolonged access to an appropriate food source. The 2nd part involved scattering a grain mix to encourage more foraging while maintaining a once-daily feeding routine. Changing the feeding routine unexpectedly resulted in a significant increase in hair manipulation and ingestion. Providing additional grain did not significantly decrease hair manipulation and ingestion, but several individuals did show a reduction in these behaviors. Prolonged access to biscuits and the provision of a grain mix may have failed to satisfy the urge to forage because little effort was needed for their collection prior to consumption. Although the current study failed to significantly decrease hair eating, it provides valuable insight into further avenues of research on the behavior.     

Leopard predation on gelada monkeys at Guassa,Ethiopia

Predation is widely believed to exert strong selective pressure on primate behavior and ecology but is difficult to study and rarely observed. In this study, we describe seven encounters between lone wild leopards (Panthera pardus) and herds of geladas (Theropithecus gelada) over a 6-year period in an intact Afroalpine grassland ecosystem at the Guassa Community Conservation Area, Ethiopia. Three encounters consisted of attempted predation on geladas by leopards, one of which was successful. All three attacks occurred in low-visibility microhabitats (dominated by tussock graminoids, mima mounds, or tall shrubs) that provided leopards with hidden viewsheds from which to ambush geladas. An additional four encounters did not result in an attempted attack but still document the consistently fearful responses of geladas to leopards. In encounters with leopards, geladas typically gave alarm calls (n = 7 of 7 encounters), reduced interindividual distances (n = 5), and collectively fled towards or remained at their sleeping cliffs (n = 7), the only significant refugia in the open-country habitat at Guassa. Geladas did not engage in mobbing behavior towards leopards. Encounters with leopards tended to occur on days when gelada herd sizes were small, raising the possibility that leopards, as ambush hunters, might stalk geladas on days when fewer eyes and ears make them less likely to be detected. We compare the behavioral responses of geladas to leopards at Guassa with those previously reported at Arsi and the Simien Mountains and discuss how gelada vulnerability and responses to leopards compare with those of other primate species living in habitats containing more refugia. Lastly, we briefly consider how living in multilevel societies may represent an adaptive response by geladas and other open-country primates to predation pressure from leopards and other large carnivores.     

Feeding enrichment and stereotypic behavior in spectacled bears

The effect of feeding enrichment on the behavior of three spectacled bears (Tremarctos ornatus) was investigated in a large, complex zoo exhibit. Feeding enrichment significantly extended the time bears spent foraging, but no delayed effect on other behaviors was found. The frequency of stereotypic behaviors performed by an old female and a young adult male was not influenced outside the morning feeding period. As yet, a young adult female has not developed stereotypic behaviors. In the old female, the frequency of stereotypic behavior was inversely correlated with the frequency of resting. In the male, the frequency of stereotypic behavior was inversely correlated with the frequency of social interactions with either female. Zoo Biol 18:363–371, 1999. © 1999 Wiley‐Liss, Inc.     

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

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

Recovery of the snow leopard in Sagarmatha (Mt. Everest) National Park: effects on main prey

Consequences of predation may be particularly heavy on small populations of herbivores, especially if they are threatened with extinction. Over the 2006–2010 period, we documented the effects of the spontaneous return of the endangered snow leopard on the population of the vulnerable Himalayan tahr. The study area was an area of central Himalaya where this cat disappeared c. 40 years before, because of persecution by man. Snow leopards occurred mainly in areas close to the core area of tahr distribution. Tahr was the staple (56.3 %) of snow leopards. After the arrival of this cat, tahr decreased by more than 2/3 from 2003 to 2010 (mainly through predation on kids). Subsequently, the density of snow leopards decreased by 60 % from 2007 to 2010. The main prey of snow leopards in Asia (bharal, marmots) were absent in our study area, forcing snow leopards to specialize on tahr. The restoration of a complete prey spectrum should be favoured through reintroductions, to conserve large carnivores and to reduce exploitation of small populations of herbivores, especially if threatened.