One size does not fit all: Monitoring faecal glucocorticoid metabolites in marsupials.

Marsupial research, conservation, and management can benefit greatly from knowledge about glucocorticoid (GC) secretion patterns because GCs influence numerous aspects of physiology and play a crucial role in regulating an animal's response to stressors. Faecal glucocorticoid metabolites (FGM) offer a non-invasive tool for tracking changes in GCs over time. To date, there are relatively few validated assays for marsupials compared with other taxa, and those that have been published generally test only one assay. However, different assays can yield very different signals of adrenal activity. The goal of this study was to compare the performance of five different enzyme immunoassays (EIAs) for monitoring adrenocortical activity via FGM in 13 marsupial species. We monitored FGM response to two types of events: biological stressors (e.g., transport, novel environment) and pharmacological stimulation (ACTH injection). For each individual animal and assay, FGM peaks were identified using the iterative baseline approach. Performance of the EIAs for each species was evaluated by determining (1) the percent of individuals with a detectable peak 0.125-4.5days post-event, and (2) the biological sensitivity of the assay as measured by strength of the post-event response relative to baseline variability (Z-score). Assays were defined as successful if they detected a peak in at least 50% of the individuals and the mean species response had a Z⩾2. By this criterion, at least one assay was successful in 10 of the 13 species, but the best-performing assay varied among species, even those species that were closely related. Furthermore, the ability to confidently assess assay performance was influenced by the experimental protocols used. We discuss the implications of our findings for biological validation studies.

Non-invasive assessment of adrenocortical activity as a measure of stress in giraffe (Giraffa camelopardalis).

BACKGROUND: Numbers of giraffes are declining rapidly in their native habitat. As giraffe research and conservation efforts increase, the demand for more complete measures of the impact of conservation interventions and the effects of captive environments on animal health and welfare have risen. We compared the ability of six different enzyme immunoassays to quantify changes in fecal glucocorticoid metabolites (FGM) resulting from three sources: adrenocorticotropic hormone stimulation test, transport, and time of day that samples were collected. RESULTS: Two male giraffes underwent ACTH injections; all six assays detected FGM increases following injection for Giraffe 1, while only three assays detected FGM increases following injection for Giraffe 2. Consistent with other ruminant species, the two 11-oxoetiocholanolone assays (one for 11,17-dioxoandrostanes and the other for 3α,11-oxo metabolites) measured the most pronounced and prolonged elevation of FGM, while an assay for 3ß,11ß-diol detected peaks of smaller magnitude and duration. Both of the 11-oxoetiocholanolone assays detected significant FGM increases after transport in Giraffes 3-7, and preliminary data suggest FGM detected by the assay for 11,17-dioxoandrostanes may differ across time of day. CONCLUSIONS: We conclude the assay for 11,17-dioxoandrostanes is the most sensitive assay tested for FGM in giraffes and the assay for FGM with a 5ß-3α-ol-11-one structure is also effective. 11-oxoetiocholanolone enzyme immunoassays have now been demonstrated to be successful in a wide variety of ruminant species, providing indirect evidence that 5ß-reduction may be a common metabolic pathway for glucocorticoids in ruminants. As FGM peaks were detected in at least some giraffes using all assays tested, giraffes appear to excrete a wide variety of different FGM. The assays validated here will provide a valuable tool for research on the health, welfare, and conservation of giraffes.

Consistency of captive giraffe behavior under two different management regimes.

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

Individualized Target Training Facilitated Transfer of Group Housed Capuchin Monkeys (Sapajus apella) to Test Cubicles and Discrimination of Targets on Computer Touch Screens.

Animals in captivity often experience fear, anxiety and aggression during non-voluntary procedures, leading to adverse behaviors and ineffective outcomes for both animals and caretakers. Negative reinforcement and punishment, often due to ignorance regarding animal learning, can hurt animal welfare. However, voluntary participation through positive reinforcement training (PRT) can decrease stress related to these procedures and increase desired behaviors. Our goal was to demonstrate the positive effects of "target training" on animal welfare by training 10 captive capuchin monkeys (Sapajus apella) in two experiments designed to facilitate movement from a group home enclosure to a test cubicle. In Experiment 1, each monkey was assigned an individualized target (a unique shape/color combination). In daily training sessions, the animal was rewarded with a click-sounding stimulus and a food reinforcer for (a) touching the target, (b) following the respective target into a test cubicle, and (c) touching progressively smaller targets until progressing to digitized images on a computer touch screen. All 10 animals learned to approach and touch their individual physical target in one or two sessions and were able to successfully transition this behavior to an image of their target on a touch screen, although they made more errors with the touch screen. In Experiment 2, the animals were presented with other animals' targets and novel targets. The seven animals in this experiment all touched their target at higher-than-chance rates in Trial 1 without explicit discrimination training, but only five reached the learning criteria for the task (>83% correct for three consecutive testing days. These results demonstrate that target training can make voluntary movement from group housing to test cubicles easier and benefit future animal care and procedures.

Spatial Design of Guest Feeding Programs and Their Effects on Giraffe Participation and Social Interactions.

Guest-animal feeding programs (GFPs) in zoological institutions aim to foster human-animal connections. The growing establishment of animal welfare science emphasizes the assessment of GFPs as permanent environmental inputs to habitats that require analysis of behavioral output. This study assessed the role of space allocation on giraffe participation and interactions in GFPs in two Florida zoos.Analysis of social structure indicates that centrality and influence from affiliative network on exhibit shape sharing interactions at GFPs under varying management protocols and designs. Findings suggest that interactions and significant ties among conspecifics are context and potentially temporally dependent. We propose the use of multiple guest engagement stations to maximize space and facilitate feeding opportunities for central and peripheral members. This proposed shift would provide variable feeding opportunities that represent group composition following ecological theory while maximizing points of guest engagement. Results indicate that increasing space allocation for GFPs increased feeding bout length for individuals, percent of time sharing among conspecifics, and reduced average rate of displacement/minute. Cross-institutional comparisons indicate that guest programs with more space allocation have lower rates of conspecific displacement.

An indicator of cancer: downregulation of monoamine oxidase-A in multiple organs and species.

BACKGROUND: Identifying consistent changes in cellular function that occur in multiple types of cancer could revolutionize the way cancer is treated. Previous work has produced promising results such as the identification of p53. Recently drugs that affect serotonin reuptake were shown to reduce the risk of colon cancer in man. Here, we analyze an ensemble of cancer datasets focusing on genes involved in the serotonergic pathway. Genechip datasets consisting of cancerous tissue from human, mouse, rat, or zebrafish were extracted from the GEO database. We first compared gene expression between cancerous tissues and normal tissues for each type of cancer and then identified changes that were common to a variety of cancer types. RESULTS: Our analysis found that significant downregulation of MAO-A, the enzyme that metabolizes serotonin, occurred in multiple tissues from humans, rodents, and fish. MAO-A expression was decreased in 95.4% of human cancer patients and 94.2% of animal cancer cases compared to the non-cancerous controls. CONCLUSION: These are the first findings that identify a single reliable change in so many different cancers. Future studies should investigate links between MAO-A suppression and the development of cancer to determine the extent that MAO-A suppression contributes to increased cancer risk.

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.

The structure of social relationships among captive female giraffe (Giraffa camelopardalis).

Giraffe herds have been characterized as random associations of individuals, but recent evidence suggests giraffe have a more complex social structure. The authors formulated 3 hypotheses designed to evaluate whether a herd of captive giraffe (Giraffa camelopardalis) associated randomly or patterned their behavior and proximity in a manner indicative of social relationships. Affiliative interaction, proximity, and nearest neighbors for 6 captive female giraffe living in a large outdoor enclosure were analyzed, and all three measures were nonrandomly distributed, indicating female giraffe had social preferences. Furthermore, preferences were consistent across measures and time, suggesting that adult female giraffe maintain relationships. Mother-daughter pairs and pairs with large age differences between members interacted and associated most often. The social structure of this captive herd is influenced by social relationships between individual adult females, and the social behavior of individual females should be examined more closely in the wild.

Environmental effects on the behavior of zoo-housed lions and tigers, with a case study of the effects of a visual barrier on pacing.

Tigers and lions in the wild are nocturnal nonhuman animals who may hunt and mate opportunistically during daylight hours. In captivity, they spend most time on exhibit sleeping or pacing. To better understand their activity budget, this study examined the daily behavior patterns of 2 Sumatran tigers and 3 African lions in different housings. The proportion of scans the large felids spent engaged in stereotypic pacing varied by time of day and environment. The tigers spent different amounts of time pacing when housed in different exhibits; the lions paced more in off-exhibit housing than when on exhibit. These differences suggest changes to the cats' immediate housing environment may decrease pacing but provide little insight into altering specifics. Carnivores' pacing relates to their inability to control sensory access to social partners. Both environments with increased pacing contained chain-link fencing. allowing uncontrolled sensory contact. Where the tigers paced, the study placed a visual barrier between one female and keepers' or conspecifics' cues. This did not significantly decrease pacing. However, the study suggests considering sensory access and environmental variables when designing environments for captive carnivores.

Long-term suppression of fertility in female giraffe using the GnRH agonist deslorelin as a long-acting implant.

Zoological institutions provide an environment conducive to studying proximate mechanisms influencing reproduction that can provide guidance to both field and captive settings seeking to manage their stock. Both national parks and zoos have space limitations that sometimes require the use of reversible contraception in order to reduce reproductive rate or limit specific individuals from reproducing. We designed a study to test the efficacy of a long-lasting contraceptive in female giraffe by monitoring reproductive endocrinology and behavior. We implanted two animals with the GnRH agonist deslorelin and monitored their endocrine status using fecal steroid analysis. We have previously validated an assay for fecal pregnanes and here we report our validation for fecal estrogens. Both sex steroid concentrations were suppressed in two females, although one female exhibited an immediate post-implantation positive feedback response. Sexual activity nearly disappeared in one animal, whereas the other showed regular sexual behavior. The contraceptive effect lasted for at least 472 d, and successfully suppressed estrous cyclicity in one female for >2 y. We conclude that deslorelin implants provide a minimally invasive means for long-term suppression of reproduction in female giraffe.

An overlooked connection: serotonergic mediation of estrogen-related physiology and pathology.

BACKGROUND: In humans, serotonin has typically been investigated as a neurotransmitter. However, serotonin also functions as a hormone across animal phyla, including those lacking an organized central nervous system. This hormonal action allows serotonin to have physiological consequences in systems outside the central nervous system. Fluctuations in estrogen levels over the lifespan and during ovarian cycles cause predictable changes in serotonin systems in female mammals. DISCUSSION: We hypothesize that some of the physiological effects attributed to estrogen may be a consequence of estrogen-related changes in serotonin efficacy and receptor distribution. Here, we integrate data from endocrinology, molecular biology, neuroscience, and epidemiology to propose that serotonin may mediate the effects of estrogen. In the central nervous system, estrogen influences pain transmission, headache, dizziness, nausea, and depression, all of which are known to be a consequence of serotonergic signaling. Outside of the central nervous system, estrogen produces changes in bone density, vascular function, and immune cell self-recognition and activation that are consistent with serotonin's effects. For breast cancer risk, our hypothesis predicts heretofore unexplained observations of the opposing effects of obesity pre- and post-menopause and the increase following treatment with hormone replacement therapy using medroxyprogesterone. SUMMARY: Serotonergic mediation of estrogen has important clinical implications and warrants further evaluation.

Socialization of a single hand-reared tiger cub.

Given the drawbacks of hand-rearing nonhuman animals in captivity, the practice is generally avoided, but it is sometimes necessary. A few scientific publications are available to guide managers toward best practices in hand-rearing, but the majority of articles focus on hand-rearing captive primates. Less is known about hand-rearing carnivores, but early socialization appears to be critical for adult social behavior. This article documents the successful hand-rearing and reintroduction of a single female Sumatran tiger cub at Zoo Atlanta. Reintroduction included a systematic procedure that used scent trials and introduction sessions through a barrier to gauge interest and determine whether or not aggression was a problem. Based on signs of interest, reduced stress-related behaviors, and a lack of aggression, animal managers decided to proceed with reintroduction. During the introductions, the animals were not aggressive and did occasionally interact, although typical mother-infant interactions were rare. The cub has since bred naturally and successfully delivered and reared two litters of cubs. These data suggest limited exposure to an adult tiger may be adequate socialization for normal reproduction even if it is provided relatively late in the cub's development.

A survey of abnormal repetitive behaviors in North American river otters housed in zoos.

Stereotypic behaviors, indicating poor welfare and studied in a variety of species (especially carnivores), appear related to characteristics of current and past environments. Although North American river otters (Lontra canadensis) often develop abnormal, repetitive, possibly stereotypic behaviors, no published reports describe otter housing and management or characterize how these variables relate to abnormal repetitive behavior (ARB) occurrence. The first author developed surveys to gather data on housing, individual history, management, and the prevalence of ARBs in otters housed in facilities accredited by the Association of Zoos and Aquariums. Consistent with anecdotal evidence that otters are prone to ARBs, 46% of river otters in the study exhibit them. ARBs were mostly locomotor and often preceded feeding. Exhibits where otters were fed and trained housed a greater percentage of nonhuman animals with ARBs. This study supports the Tarou, Bloomsmith, and Maple (2005) report that more hands-on management is associated with higher levels of ARBs because management efforts are only for animals with ARBs. Escape motivation, breeding season, feeding cues, and ability to forage may affect ARBs in river otters and should be investigated.

Enrichment and individual differences affect welfare indicators in squirrel monkeys (Saimiri sciureus).

Enrichment aims to improve captive animals' welfare by enhancing their environments. Two of the struggles associated with measuring welfare are identifying when animals' needs are being met or surpassed and identifying how individual differences play a role in these outcomes. Using a group of related Guyanese squirrel monkeys, we studied changes in five welfare indicators under different environmental conditions. Manipulating food presentation, walkways, and toys, we created five enrichment levels ranging from just above USDA standards to considerably more complex than the animals' normal housing. At the end of each level, a novelty test was performed in which an unfamiliar woman entered the enclosure and offered food. Changes in behavior as a function of enrichment condition were analyzed using a repeated-measures MANOVA. Compared to baseline, less enrichment consistently increased negative welfare indicators (abnormal behavior, aggression, and negative responses to the novelty test), while more enrichment sometimes decreased these indicators. Positive welfare indicators were less consistently related to enrichment, but positive response to the novelty test did increase somewhat in the most enriched condition. Across conditions, rank correlations revealed that individuals had highly consistent individual differences in positive responses to novelty and somewhat consistent individual differences in rates of aggression. The goal of the enrichment and the species, sex, and individual animals to be enriched should be considered when selecting a welfare indicator, and facilities measuring animal welfare should study changes in the behavior of specific individuals to control for individual differences.

Social organization of a stable natal group of captive Guyanese squirrel monkeys (Saimiri sciureus sciureus).

Socioecological models suggest competition for food, foraging efficiency, predation, infanticide risk, and the costs of dispersal regulate primate social structure and organization. Wild populations of squirrel monkeys (Saimiri spp.) appear to conform to the predictions of the predation/competition socioecological model (Sterck et al. in Behav Ecol Sociobiol 41:291-309, 1997) and the dispersal/foraging efficiency model (Isbell in Kinship and behavior in primates. Oxford University, New York, pp 71-108, 2004). However, squirrel monkeys in captivity are reported to maintain patterns of social behavior observed in their wild conspecifics despite different food distribution, predation risk, and dispersal options. This behavioral similarity suggests squirrel monkeys' social behavior has limited flexibility to respond to environmental changes. In this study, we experimentally evaluated the flexibility of social behavior within a captive group of S. sciureus. First, we determined whether dominance and affiliative relationships observed under normal laboratory conditions (with abundant, widely distributed, food; no dispersal option; and no predators) better matched published reports of relationships among wild conspecifics or the predictions of the predation/competition model. Second, we made preferred food items defensible to determine whether dominance interactions would become more frequent and linear, as predicted by the model. The model correctly predicted rates of dominance behavior in both conditions and a linear hierarchy in the defensible food condition but did not predict the consistent affiliative relationships and linear dominance hierarchy observed in normal lab conditions. Although hierarchies were linear and male dominant, manipulating food distribution changed the dominant individual within each sex. Our findings suggest interaction rates adapt more rapidly than social structure to environmental changes in Saimiri and recommend caution in interpreting tests of socioecological models.

What defines successful integration into a social group for hand-reared chimpanzee infants?

Hand-rearing of captive great ape infants is sometimes necessary but can have negative behavioral consequences. Modern hand-rearing protocols, including early integration into a diverse group of conspecifics, appear to reduce the negative consequences of hand-rearing, but the process of integration is not well studied. We investigated six potential metrics of success during the introduction of two hand-reared chimpanzee infants into a troop of nine other chimpanzees at the Maryland Zoo in Baltimore. Little aggression was observed and the infants continue to be maintained in the troop at publication. As we predicted, during the introduction the hand-reared infants showed consistent levels of stress-related behaviors, participated in affiliative interactions with all available partners, and acted, received, and mutually engaged in these interactions. Solitary behaviors by these infants were similar to a mother-reared infant in the same group. Each infant also formed a relationship with a specific female that involved nest-sharing, carrying, retrieval, and intervening to reduce risk to the infant; these relationships could be classified as allomothering because they involved maternal behavior but occupied significantly less of the infants' time than a maternal relationship. Contrary to our prediction, the hand-reared infants therefore spent significantly less time in social behavior than a mother-reared infant of the same age. In addition, the hand-reared infants continued to show strong social preferences for each other as introductions progressed and to direct a low but consistent number of nonfeeding social behaviors to humans. The successful introduction of hand-reared infants appeared to involve adding conspecific social relationships to the infants' social repertoire, but not eliminating social interactions directed at humans.

Sociosexual behavior, male mating tactics, and the reproductive cycle of giraffe Giraffa camelopardalis.

Female distribution exerts a major impact on male mating tactics. Giraffe cows have a reproductive cycle, and a social system, that should favor a male roaming reproductive tactic. We conducted a 2-year study of female Rothschild's giraffe (G. c. rothschildi) reproductive endocrinology in order to characterize attributes of the reproductive cycle and investigate how female endocrine and behavioral cues influence mating activity. We used non-invasive fecal steroid methods to determine reproductive state among females residing in a herd in a large outdoor enclosure. We found that females had an estrous cycle of 14.7 days and that they regularly had multiple ovarian cycles prior to conception. Adult males were more likely to associate with, and sexually investigate, females when they were cycling than when they were either pregnant or acyclic. During the estrous cycle, male-female proximity and sociosexual behavior were more pronounced during the probable fertile phase than the rest of the cycle. Sexual activity between giraffe coincided with the periovulatory period, with male interest in females peaking during the fertile window in the absence of proceptive behavior by females. We conclude that males detect reliable cues revealing female reproductive status and partition their reproductive effort in response to such cues. We propose that male giraffe adopt a roaming reproductive strategy with their large size, enabling them to search for and mate guard fertile females while minimizing metabolic costs.

Fecal steroid analysis of female giraffe (Giraffa camelopardalis) reproductive condition and the impact of endocrine status on daily time budgets.

Gestation and lactation can impose substantial energetic costs on female mammals. We developed a non-invasive means to determine reproductive condition in female giraffe using fecal steroid analysis. Giraffe may be especially challenged during their reproductive cycle because of two characteristics: they are impregnated while lactating and they do not breed seasonally. We studied the social behavior and endocrinology of seven female giraffe in a large naturalistic outdoor enclosure in order to chart connections between maternal physiology and behavior across the reproductive cycle. We found that giraffe gestation averages 448 days among females producing a calf that survived, with fecal pregnane concentrations reaching a zenith during the last trimester of pregnancy. Resumption of ovarian cyclicity following parturition was accelerated after neonatal calf mortality, but ovarian cycles resumed as early as 39 days postparturition while nursing. Although time spent feeding was unaffected by reproductive state, pregnant females significantly reduced time allocated to social behavior and had a tendency to locomote less than when cycling or acyclic. We suggest that modifications in foraging strategies as a function of reproductive state among wild giraffe derive from antipredator activity rather than from metabolic demands. Female giraffe probably cope with simultaneous lactation and gestation by producing high quality milk for neonatal calves commensurate with slow fetal growth and accelerating fetal growth simultaneous with weaning of nursing calves.

Amount of training and stimulus salience affect associability changes in serial conditioning.

Q. J. Exp. Psychol. 44B (1992) 17 reported that extended training with a serial compound of two conditioned stimuli, S1-->S2, resulted in losses in the rate at which S1-food associations were formed in a subsequent test phase. However, this ability of S1 to participate in new learning (its associability) could be restored by omitting S2 on some trials. Variables that affect performance in this task were examined in five Pavlovian appetitive conditioning experiments with rats. In Experiment 1, the associability of S1 decreased gradually as a function of the number of training sessions with a consistent S1-S2 relation. In Experiment 2, after extended exposure to a consistent S1-S2 relation, the associability of S1 was restored with as few as one training session in which the S1-S2 relation was made inconsistent by omitting S2 on some trials. In Experiments 3-5, test phase conditioning of S1 after inconsistent training was found to be either greater than, less than, or similar to, conditioning of S1 after consistent training, depending on the relative salience of the events used as S1 and S2. The results showed that both intrinsic and extrinsic relations among stimuli must be considered when interpreting the results of experiments in stimulus selection.