Characterization and correlations of behavioral and adrenocortical activities of zoo-housed lesser anteaters (Tamandua tetradactyla)

Effect of Feeding Environmental Enrichment on Lesser Anteaters' Behavior, Space Use and Food Selectivity

Studying behavioral response to management and housing conditions provides specific evidence to enhance animal welfare. Feeding environmental enrichment (FEE) is a powerful strategy to meet welfare challenges. Lesser anteaters' (Tamandua tetradactyla; n = 7) response to FEE was assessed by analyzing behavior and space use through focal sampling every 5 minutes/24 hours using cameras. Study 1 (S1): space use of enclosure zones (shelter = SZ, climbing structures = CSZ and ground = GZ) was characterized without FEE during 5 days using the modified Spread of Participation index (SPI). Study 2 (S2) used an ABA experimental design during 18 days (A=pre- and post-enrichment and B = enrichment). The FEE was applied in CSZ, the least utilized zone revealed in S1. S1: The lesser anteaters utilized the zones differently (modified SPI = 0.74 ± 0.02), and stayed mostly in the GZ. S2: An increment in feeding during FEE was detected, but it did not modify total activity, most natural behavior, repetitive locomotion or space use. The electivity index indicated that the routine diet was over-utilized and enrichment items were under-utilized. The provision of enrichment items created new foraging opportunities, improving the behavioral domain of animal welfare.

Video Validation of Tri-Axial Accelerometer for Monitoring Zoo-Housed Tamandua tetradactyla Activity Patterns in Response to Changes in Husbandry Conditions

Accelerometers are a technology that is increasingly used in the evaluation of animal behaviour. A tri-axial accelerometer attached to a vest was used on Tamandua tetradactyla individuals (n = 10) at Biodiversity Park. First, the influence of using a vest on the animals’ behaviour was evaluated (ABA-type: A1 and A2, without a vest; B, with a vest; each stage lasted 24 h), and no changes were detected. Second, their behaviour was monitored using videos and the accelerometer simultaneously (experimental room, 20 min). The observed behaviours were correlated with the accelerometer data, and summary measures (X, Y and Z axes) were obtained. Additionally, the overall dynamic body acceleration was calculated, determining a threshold to discriminate activity/inactivity events (variance = 0.0055). Then, based on a 24 h complementary test (video sampling every 5 min), the sensitivity (85.91%) and precision (100%) of the accelerometer were assessed. Animals were exposed to an ABA-type experimental design: A1 and A2: complex enclosure; B: decreased complexity (each stage lasted 24 h). An increase in total activity (%) was revealed using the accelerometer (26.15 ± 1.50, 29.29 ± 2.25, and 35.36 ± 3.15, respectively). Similar activity levels were detected using video analysis. The results demonstrate that the use of the accelerometer is reliable to determine the activity. Considering that the zoo-housed lesser anteaters exhibit a cathemeral activity pattern, this study contributes to easily monitoring their activities and responses to different management procedures supporting welfare programs, as well as ex situ conservation.

Assessment of Feeding Behavior of the Zoo-Housed Lesser Anteater (Tamandua tetradactyla) and Nutritional Values of Natural Prey

Very little information is available to zoo managers on the nutritional preferences of the lesser anteater, a highly specialized predator. By studying lesser anteater feeding behavior, we expect to contribute to improved management decisions and individual welfare experiences. We studied the response of zoo-housed lesser anteaters (n = 7) to feeders with live ants (Acromyrmex lundi) and termites (Cortaritermes fulviceps), and we also evaluated the nutritional values of these prey. We individually evaluated each lesser anteater (3 sessions), recording activities by camera. We ground insect samples into a coarse meal and evaluated in vitro biochemical parameters (humidity, lipids proteins, ash, and carbohydrates). Lesser anteaters spent more time with termites than with ants and consumed more termites. Ant meal presented a higher protein and lipid content than termite meal (35.28 ± 0.18% vs. 18.19 ± 0.34% and 16.95 ± 0.13% vs. 6.54 ± 0.31%, respectively), and carbohydrate digestibility was higher in termites. These findings indicate an association between the level of insect consumption and nutritional and digestibility values. This is the first exploration of lesser anteater responses to the presence of social insects in feeders and may serve to guide the study of food preferences in captivity.

Non-Invasive Assessment of the Seasonal Stress Response to Veterinary Procedures and Transportation of Zoo-Housed Lesser Anteater (Tamandua tetradactyla)

Management procedures affect behavioural and physiological stress responses of wild mammals under human care. According to the Reactive Scope Model, normal values are presumed to exist within predictive and reactive ranges. First, stress parameters of zoo-housed adult Tamandua tetradactyla were evaluated in winter and summer (29 days each), determining the level of behaviour and/or physiological parameters needed to respond to predictable environmental changes. Secondly, the effects of veterinary procedures and transportation were studied in both seasons. Non-invasive methods were applied, assessing behaviour through videos and adrenocortical activity by faecal glucocorticoid metabolites (FGMs). Lesser anteaters exhibited seasonality (summer > winter) in some behavioural parameters, such as nocturnal activities, as well as in the activity cycle (e.g., acrophase) and FGMs. A veterinary check elicited an increase in total activity (TA), natural behaviours and repetitive locomotion and affected the activity cycle, particularly in summer. Transport produced changes in TA, nocturnal and natural activity and some variables of the activity cycle, mostly during summer. Although the effects of routine management procedures were different from each other and presumably stressful, they elicited changes only at the behavioural level, which was greater during summer. The differences observed according to non-invasive methodologies highlight the importance of a multidisciplinary approach in this context and suggest that it is unlikely that individual welfare was affected.

Visitors' perceptions of zoo-housed lesser anteater (Tamandua tetradactyla) welfare: Observation plays a larger role than a brief informative talk

There is a growing ethical concern in modern society about animals' quality of life. We hypothesize that zoo visitors' perception of zoo animal welfare, particularly in the case of lesser anteaters, changes positively after listening to scientific information. Visitors observing active lesser anteaters in their enclosures at Córdoba Zoo (Argentina) were asked to respond to a questionnaire about animal welfare. The treatment group (T) answered the questionnaire after listening to a brief informative talk based on local scientific studies on lesser anteaters. The control group (C) answered the questionnaire without hearing the informative talk. Visitors (87.2%) considered biological, sanitary, and sociocultural aspects to be necessary conditions for optimum wild zoo-housed animal welfare. The majority of visitors considered that natural surroundings provide the highest level of welfare for wild animals. Visitors in the T group ranked the zoo as providing a higher level of animal welfare than those in group C. In reference to management measurements, the T group agreed on the positive effect of the application of environmental enrichment (Likert Medians: C = 4 and T = 5; p = .0443). On the basis of their perception, most visitors in both groups stated that the lesser anteaters at Córdoba Zoo appeared to be in a good state of welfare. We interpret this as meaning that, what these Córdoba zoo visitors personally perceived while observing the lesser anteaters carried greater weight than what they learned from the informative talk, though the talk did slightly affect their opinion.

Multivariate Analyses of the Activity Pattern and Behavior of the Lesser Anteater on Open and Closed Days at Córdoba Zoo, Argentina

The human factor is one of the major determinants of animal welfare in zoos. Assessing changes in activity patterns, behavior and space use due to human presence might help understanding visitors' influence on these animal welfare indicators. In Córdoba (Argentina), we assessed the activity pattern and behavior of Tamandua tetradactyla (lesser anteaters; n = 5) during natural light/dark phases and the animals' use of space. We analyzed responses of lesser anteaters to humans in days open to the public (Sundays and Tuesdays) and days closed to the public (Mondays), collecting data at 5-minute intervals during 12 days, for each animal. Data were analyzed at two temporal scales: a 24 h period and visiting hours. Multivariate analyses showed no differences in activity pattern, behavior and space use among days, exhibiting a consistent response of each individual over the studied days. Principal Component Analysis showed differences between female and male behaviors. Based on these results, the visitor effect on these lesser anteaters would appear to be neutral, indicating that the presence of visitors is at most, a minor concern in the housing and management of these individuals in Córdoba Zoo.

Fecal progesterone and estrogen metabolite monitoring for cyclicity and pregnancy in southern tamandua (Tamandua tetradactyla)

Reproductive management of the southern tamandua (Tamandua tetradactyla) should include timed introductions for breeding to minimize aggression and pregnancy monitoring. Since serial blood sampling could cause unnecessary stress, and urinary progesterone metabolites are found in very low concentrations, this study sought to validate progesterone and estradiol enzyme immunoassays for measuring fecal progesterone metabolite (FPM) and fecal estrogen metabolite (FEM) concentrations in two females. Peaks in FEM concentrations coincided with breeding and conception, were 5-6 times higher than baseline concentrations, and were followed by clear luteal phases distinguished by FPM concentrations 5-6 times higher than baseline concentrations. FPM concentrations during the first 30-53 days of gestation overlapped with luteal phase concentrations, thereafter increasing to 8-25 times higher than baseline concentrations. FEM concentrations during the first 41-44 days of gestation remained near basal values for one female, whereas concentrations were 1.8 times higher than baseline for the second. FEM concentrations became elevated for the former by 44 days of gestation and increased further for the latter after 53 days, ultimately averaging four times higher than baseline for both females. The biphasic increase in FPM and FEM concentrations, follicular and luteal phase durations (follicular: 7 ± 1 days, luteal: 25 ± 1 days), total cycle length (41 ± 1 days), and gestation (161-165 days) documented in this study were consistent with previous reports from serum and urine analyses. Monitoring FPM and FEM is a reliable noninvasive method for tracking reproductive cycles and pregnancy in southern tamandua that overcomes the challenges associated with serum or urinary hormone analysis.

Assessing and Enhancing the Welfare of Animals with Equivocal and Reliable Cues

Simple Summary

Actions of human caretakers influence the experience of animals under their care, in zoos and elsewhere. These animals often learn to associate stimuli—sights, smells, sounds—with desirable outcomes such as feedings, training sessions, or other positive experiences. Here, we propose that a conscientious approach to providing reliable cues about daily events and observing animal behavior in response to both reliable and uncertain cues can help caretakers support and assess animal welfare.

Abstract

The actions of human caretakers strongly influence animals living under human care. Here, we consider how intentional and unintentional signals provided by caretakers can inform our assessment of animals’ well-being as well as help to support it. Our aim is to assist in further developing techniques to learn animals’ affective state from their behavior and to provide simple suggestions for how animal caretakers’ behavior can support animal welfare. We suggest that anticipatory behavior towards expected rewards is related to decision-making behavior as viewed through the cognitive bias lens. By considering the predictions of the theories associated with anticipatory behavior and cognitive bias, we propose to use specific cues to probe the cumulative affective state of animals. Additionally, our commentary draws on the logic of reward sensitivity and judgement bias theories to develop a framework that suggests how reliable and equivocal signals may influence animals’ affective states. Application of this framework may be useful in supporting the welfare of animals in human care.