Evaluation of the time-activity budgets of captive ducks (Anatidae) compared to wild counterparts

Never be mute about bird welfare: Swanning around with environmental enrichment

Environmental enrichment (EE) is commonly provided to animals managed under human care, being beneficial to behavioral diversity and improving animal welfare. Use of EE appears to be particularly beneficial to individual wild animals spending a short period of time in captivity, for example, as part of conservation or rehabilitation programs. This paper documents a case study on the application and relevance of EE for a group of captive mute swans housed in a rescue center. Observational data were analyzed for two groups of juvenile swans that were provided with a physical EE device to increase time spent foraging. Periods of no EE were observed and compared to data from when birds were provided with EE. Results show that EE promoted foraging time and helped to reduce long periods of inactivity in captive birds. EE helped to reduce occurrence of captive-focused (i.e., abnormal behaviors) although these was already seen at very low rates. Inactivity as a measure of welfare in captive swans specifically (and waterbirds generally) should be further investigated to understand potential impacts on bird health. Our research shows the benefits of simple and easy-to-use EE devices on captive animal behavior and how use of EE for individuals spending a short amount of time in captivity (e.g., within a rescue center) could ensure diversity of behavior patterns and promote the performance of adaptive behaviors upon release to the wild.

Does the provision of live black soldier fly and yellow mealworm larvae improve Muscovy duck welfare?

BACKGROUND

The provision of environmental enrichments to Muscovy ducks could reduce the expression of the aggressive behaviors. The aim of the present study was to evaluate the effects of black soldier fly (BSF) and yellow mealworm (YM) live larva provision on Muscovy duck performance, excreta corticosterone metabolites (ECM), behavior, and blood parameters.

METHODS

A total of 126 3-day-old female Muscovy ducklings were allotted to 18 pens (6 replicates/treatment, 7 birds/pen) and assigned to 3 experimental treatments: a control group fed commercial feed, and two experimental treatments fed commercial feed plus the 5% (based on the expected daily feed intake, as fed basis) of BSF and YM live larvae (BSF and YM groups, respectively). A two-phase feeding program was applied: starter (from 3 to 31 days of age) and grower-finisher (from 32 to 55 days of age). The live weight, average daily gain, average daily feed intake, and feed conversion ratio were calculated. Larva consumption times were collected, and video recordings were performed during 3 periods (P) each day: the hour before (P1), during (P2), and after (P3) the larva administration. ECM were evaluated at 3, 31, and 55-day-old. Finally, the total red and white blood cell counts, serum proteins, lipids, and liver and renal function serum enzymes were evaluated on 12 birds/treatment.

RESULTS

The experimental treatment did not affect the growth performance of the birds (P > 0.05). Larva consumption times were always similar between the two insect species, except at 14-18 days of age, were BSF larvae were consumed faster than YM larvae (P < 0.001). The birds showed less walking activity during P2, and preening behavior increased in YM birds during P3. The C birds increased the attack behavior over the weeks (P < 0.05). During weeks 1-3 the YM group reduced the attack frequency (P1 > P3; P < 0.05). Finally, the provision of live BSF and YM larvae significantly reduced the ECM at 55 days of age and the heterophil to lymphocyte ratio (P < 0.05).

CONCLUSIONS

Live BSF and YM larva supplementation in Muscovy duck improves duck welfare, without impairing birds' growth performance.

Physiological differences between wild and captive animals: a century-old dilemma

Laboratory-based research dominates the fields of comparative physiology and biomechanics. The power of lab work has long been recognized by experimental biologists. For example, in 1932, Georgy Gause published an influential paper in Journal of Experimental Biology describing a series of clever lab experiments that provided the first empirical test of competitive exclusion theory, laying the foundation for a field that remains active today. At the time, Gause wrestled with the dilemma of conducting experiments in the lab or the field, ultimately deciding that progress could be best achieved by taking advantage of the high level of control offered by lab experiments. However, physiological experiments often yield different, and even contradictory, results when conducted in lab versus field settings. This is especially concerning in the Anthropocene, as standard laboratory techniques are increasingly relied upon to predict how wild animals will respond to environmental disturbances to inform decisions in conservation and management. In this Commentary, we discuss several hypothesized mechanisms that could explain disparities between experimental biology in the lab and in the field. We propose strategies for understanding why these differences occur and how we can use these results to improve our understanding of the physiology of wild animals. Nearly a century beyond Gause's work, we still know remarkably little about what makes captive animals different from wild ones. Discovering these mechanisms should be an important goal for experimental biologists in the future.

Wing condition does not negatively impact time budget, enclosure usage, or social bonds in a flock of both full-winged and flight-restrained greater flamingos

Zoo management techniques for captive birds, such as flight restraint and enclosure type, may affect behavioral performance and are consequently worthy of investigation. Flamingos are amongst the most popular of zoo-housed birds and, as such, research into their captive management and associated behavioral responses are widely applicable to many thousands of individuals. As a highly social species, understanding social bonds and behavior of the individual bird and the flock overall can help inform decisions that support husbandry and population management. In this project, 41 greater flamingos at Bristol Zoo Gardens were observed for 49 days across spring and summer 2013 to assess the following: (i) social associations within the flock, (ii) overall activity patterns, and (iii) distribution of time within specific enclosure zones for both full-winged and flight-restrained birds living in the same enclosure. Results showed that pinioning interacted with age in regard to flamingo time-activity patterns, but wing condition did not significantly influence association patterns, performance of social interactions, or performance of breeding behavior. Social network analysis revealed that associations were nonrandom and flamingos, of either wing condition, displayed different roles within the network. Birds of similar age formed the strongest bonds. Enclosure usage was not even, suggesting that the flamingos favored specific areas of the enclosure during the observation period. This study showed that wing condition does not affect flamingo behavior, social bonds, or space use, and that age and sex have more of an overall influence on what flamingos do, and with whom they chose to do it. Further research should extend this study into other, larger captive flocks to further refine behavioral measures of welfare for these popular zoo birds.

An Improvement in Enclosure Design Can Positively Impact Welfare, Reduce Aggressiveness and Stabilise Hierarchy in Captive Galapagos Giant Tortoises

The interest in the welfare of zoo animals, from both the public and the scientific community, has long been biased towards mammals. However, growing evidence of the complex behavioural repertoires of less charismatic animals, such as reptiles, reveals the necessity to better comply with their welfare needs in captivity. Here, we present the effects of an enclosure change towards a more natural habitat in captive Galapagos tortoises (Chelonoidis spp.) held at ZSL London Zoo. Using behavioural observations, we found that the tortoises habituated to their new enclosure in six days. This represents the first quantification of habituation latency to a new enclosure in a reptile model to our knowledge—which is important information to adapt policies governing animal moves. The tortoises expressed time budgets more similar to those of wild individuals after their transition to the new enclosure. Interestingly, the hierarchy between the individuals was inverted and more stable after this change in environment. The tortoises interacted less often, which led to a decrease in the frequency of agonistic encounters. We also found that higher ambient sound volume was associated with increased likelihood of interactions turning into fights. Taken together, our results demonstrate the potential of appropriate enclosure design to improve reptile welfare.

Environmental and Social Influences on the Behaviour of Free-Living Mandarin Ducks in Richmond Park

Simple Summary

Collecting information on how wild animals behave in the free-living environment can be useful for improving how such species are managed when under human care (e.g., in the zoo). Mandarin Ducks are an example of a species with a large captive population where research into the behaviour of wild birds can help with explaining and evaluating how this species is coping in captivity. This research collected data on free-living Mandarins in a large public park and compared such data to published research on captive Mandarins to evaluate any differences in time budgets. The overall aim of this research was to provide information on what behaviours are commonest amongst free-living Mandarin Ducks to help others with the assessment of behavioural normality of captive birds.

Abstract

Many species of birds are housed in zoos globally and are some of the most popular of animals kept under human care. Careful observations of how species live and behave in their natural habitats can provide us with important knowledge about their needs, adaptations, and internal states, allowing identification of those behaviours that are most important to the individual’s physical health and wellbeing. For this study, Mandarin Ducks (Aix galericulata) were chosen as a study species because, like many species of waterfowl, they are widely kept in both private institutions and zoos, yet little research has been conducted on their core needs in captivity. A free-living population of naturalised Mandarin Ducks living in Richmond Park was used for this research. Data on state behaviours (resting, swimming, foraging, perching, preening, and vigilance) were collected five days a week (08:00–18:00) from the 26 March to 26 May 2021. Secondly, temporal, seasonal, environmental, and animal-centric factors (e.g., Sex) were recorded to assess any impact on the Mandarin’s time-activity budget. Lastly, a comparison between free-living anmd captive activity was conducted (via the literature) to evaluate whether captive behaviours differ to how they are expressed in the wild. Results showed that free-living Mandarins predominantly rested (19.88% ± 28.97), swam (19.57% ± 19.43) and foraged (19.47% ± 25.82), with variations in activity related to factors such as vegetation cover and pond size. Results also showed differences between the time-budgets of free-living and captive Mandarins, suggesting that captive birds may not always have the opportunity to express species-typical behaviours. This research indicated that study of natural behaviours performed in the wild may help to evaluate “normal” behaviour patterns of zoo-housed individuals and provide evidence for environmental and husbandry alterations that can promote good welfare. However, any potential impact on the activity patterns of free-living species due to human interactions should be considered when assessing deviations between the behaviour of wild and captive individuals.