Animal Welfare

Scientific Papers

Red Ibis

© Rory Harper

Japanese macaques behaviour in vegetated enclosures_Zoo Biology 2021.jpg

Costs and benefits of living in a vegetated, compared with non-vegetated, enclosure in male Japanese macaques (Macaca fuscata(Alejandro, Huffman & Bercovitch, 2021)

November 2021

A study in Zoo Biology investigated differences in the behaviour of Japanese macaques in a vegetated and in a non-vegetated enclosure:

Vegetated: Better coat conditions, more social play and feeding-related behaviours, less resting;

Non-vegetated: More stereotypic behaviours & agonistic interactions;

Findings suggest better welfare in vegetated enclosure, highlighting importance of recreating some features of natural habitat.

corn snake Exmoor Zoo.jpg

Does enclosure size influence the behaviour & welfare of captive snakes (Pantherophis guttatus)? (Hoehfurtner et al., 2021)

October 2021

A new paper in Applied Animal Behaviour Science investigated the impact of enclosure size on corn snake behaviour and welfare:

Snakes more active in a large enclosure (longer than snake length) than in a small enclosure (2/3 of snake length);

Snakes stretched out in the large enclosure, spending almost 20% of resting time in this position (no opportunity for this behaviour in small enclosure);

"Loosely coiled" posture significantly higher in large enclosure;

Preference tests: active snakes preferred large enclosure;

Enclosure longer than snake length is recommended to improve behaviour and welfare of captive corn snakes.


Photo: Exmor Zoo

Elephant herd separation_JZBG 2021.jpg

Behavioural Responses to Temporary Separation of a Captive Herd of African Elephants (Loxodonta africana
(Armstrong & Johnson, 2021)

September 2021

A study in JZBG investigated the behavioural responses of two captive female African elephants to temporary separation from other two herd members as they were being transported to other zoo:

Elephants travelled to the other zoo in two pairs: a mother-daughter pair & and an unrelated but bonded pair of females (short gap between transports);

The mother-daughter pair showed an increase in human-audible vocalisations, temporal gland secretions & decrease in play behaviour when the other pair left ahead of them;

Despite being mostly unrelated, the group showed similar signs of stress as expected if the group was highly related;

Applications to elephant management.

Cetacean welfare study_Plos One 2021_Squared.jpg

Towards understanding the welfare of cetaceans in accredited zoos and aquariums (Lauderdale et al., 2021)

August 2021

Last week we shared the news that the results of the largest-ever captive cetacean welfare study were out... Here is an overview of their findings, published in Plos One:

Four species: Common & Indo-Pacific bottlenose dolphins, beluga whale & Pacific white-sided dolphin;

Data collected at 43 institutions between 2018 and 2019;

Reference values established for blood variables and fecal hormone metabolites available in app ZooPhysioTrak;

Enrichment & social management showed higher impact on welfare than habitat characteristics;

Applications to cetacean management & welfare in captivity.


Using individual-specific conditioning to reduce stereotypic behaviours: A study on smooth dogfish Mustelus canis in captivity (Hart, Reynolds & Troxell-Smith, 2021)

July 2021

A study in JZAR discussed the impact of two interventions (relocation to a less dynamic pool & individualised feeding & conditioning method) on the behaviour of a captive female smooth dogfish:

Reduction of stereotypic behaviours after interventions;

Increase in species-specific & resting behaviours;

Increase in enclosure use;

Small sample size & more research recommended but interesting findings with applications to fish management & welfare.

Fossa Husbandry_JZBG 2021.jpg

A Global Survey of Current Zoo Housing and Husbandry Practices for Fossa: A Preliminary Review 
(Harley, O'Hara & Rose, 2021)

July 2021

New study in JZBG surveyed the global zoo husbandry practices for the fossa:

All animals receive enrichment & most have at least an area away from visitors but majority express unnatural behaviours;

Unnatural behaviour may be reduced with dense cover, restricted public viewing areas, variable feeding schedule & reduced view of other species;

41% of surveyed "breeding individuals" have bred at the zoo;

Important applications to fossa husbandry & welfare.

Visitor interactions with dolphins_Zoo Biology 2021.jpg

Visitor attachment to dolphins during an interaction programme, are there implications to dolphin behavior? (Welsh & Ward, 2021)

July 2021

A study in Zoo Biology investigated the impacts of human-dolphin interactions on both bottlenose dolphins and the visitors:

Human participants reported a sense of attachment to the animals after interaction -applications to conservation education?

Dolphins showed no significant changes in behaviour - neutral effect on their welfare?

Small sample size - further research required.

Grizzly-Boys_Detroit Zoo.jpg

DNA Damage as a Potential Non-Invasive Indicator of Welfare: A Preliminary Study in Zoo-Housed Grizzly Bears (Ursus arctos horribilis(Fuller, Hamilton & Allard, 2021)

June 2021

A new paper in JZBG investigated the applications of DNA damage as an indicator of animal welfare in three zoo-housed grizzly bears:

DNA damage significantly increased with adrenal activity (faecal glucocorticoid metabolites);

Relationship between DNA damage and social affiliative behaviours varied between individuals;

Potential for DNA damage to be used in animal welfare assessments, but further research & validation required.


Photo credit: Detroit Zoo

Elephant Locomotion_Dublin Zoo_JZAR 2021.jpg

Estimates of locomotion in Asian elephants Elephas maximus using video monitoring at Dublin Zoo, Ireland (Brady et al., 2021)

April 2021

A study in JZAR looked into behaviour & locomotion of the Asian elephants at Dublin Zoo, using CCTV footage:

Mean daily distance travelled (9.35 km/day) comparable to wild individuals (5-10 km/day);

50% of time spent foraging & 18% spent moving;

Locomotion & behaviour in these elephants closer to wild than previous zoo studies;

CCTV footage offers opportunities for behavioural research.


Photo credit: Dublin Zoo

dolphins_CZS_Social study_JZBG 2021.jpg

Activity, Social Relationships, and Maternal Care in a Bottlenose Dolphin Group under Professional Cares (Lauderdale & Miller, 2021)

May 2021

A study in in JZBG looked into social relationships and maternal care in zoo-housed bottlenose dolphins:

Affiliative behaviours were dominant;

Strong mother-calf associations through 2nd and 3rd years of life;

Some individuals kept preferred associations, while others changed;

No large reductions in associations observed - strong relationships between individuals.

jzbg dolphin 2021.webp

A System for Monitoring Acoustics to Supplement an Animal Welfare Plan for Bottlenose Dolphins (Jones et al., 2021)

April 2021

A study in JZBG described the application of an acoustic monitoring system for captive bottlenose dolphins:

Software automatically compares acoustic behaviour of dolphins with past records;

Changes in acoustic behaviour can be detected - health & welfare problems?

Can help identifying problematic acoustic sources for the dolphins;

Applications to welfare monitoring of dolphins in zoos & aquariums.

Flamingo Rearing Environment_ Kidd and R

Influences of Rearing Environment on Behaviour and Welfare of Captive Chilean Flamingos: A Case Study on Foster-Reared and Parent-Reared Birds(Kidd & Rose, 2021)

April 2021

How does rearing environment affect the behaviour of captive Chilean flamingos? A new study in JZBG compared foster-reared and parent-reared chicks:

Foster-reared chicks: less time feeding, fewer preferred associations and more likely to occupy nesting area;

Social bonds were equally strong and durable in both foster-reared & parent-reared chicks;

Cross-fostering has limited impacts on behavioural and social development.

Riley et al_Visitor effect on crocodiles

Evaluating the Effect of Visitor Presence on Nile Crocodile (Crocodylus niloticus) Behavior (Riley et al., 2021)

March 2021

A study in JZBG looked into visitor effects on zoo-housed Nile crocodiles:

Behaviour was significantly affected by time of day, temperature & month;

Visitor effects on behaviour were found to be small/neutral.

Environmental variables should be considered when assessing behaviour and welfare in zoo-housed reptiles.


Photo credit: David R. Tribble (Nile crocodiles at Disney's Animal Kingdom).

Orca Welfare_March 2021_Loro Parque.jpg

Personality of killer whales (Orcinus orca) is related to welfare and subjective well-being (Úbeda et al., 2021)

March 2021

A paper in Applied Animal Behaviour Science investigated whether questionnaires can be used to reliably assess and monitor the welfare of captive killer whales:

Results validated questionnaires as an accurate welfare assessment tool for captive orcas;

High correlation between personality, welfare & subjective well-being;

Findings were similar to previous research on primates.


Photo credit: Loro Parque

Graphical Abstract.jpg

Assessing the behaviour, welfare and husbandry of mouse deer (Tragulus spp.) in European zoos (Lemos de Figueiredo et al., 2021)

March 2021

A study in Applied Animal Behaviour Science, authored by our very own Ricardo, investigated what husbandry & management practices were affecting mouse deer breeding & behaviour in European zoos:

Vegetation cover positively affected breeding, activity & natural behaviours;

Water ponds and enrichment also had positive effects on activity & natural behaviours;

Close proximity between males and females negatively impacted breeding;

Diet and temperature they are housed in is likely suboptimal and requires further research;

Mouse deer benefit from complex enclosures, with ample vegetation, natural features and opportunities to avoid conspecifics.


Photo credit: Copenhagen Zoo

Effects of construction on lion work_Zoo

Effects of Nearby Construction Work on the Behavior of Asiatic Lions (Panthera leo persica) (Williams et al., 2021).

March 2021

Research in  JZBG looked into the effects of construction work on the behaviour of zoo-housed lions:

During construction: increased pacing (male), decreased resting (all three lions);

Sound & ground vibrations more likely to have been the stressors;

No long-term effects - behavioural changes not detected one year later;

Mitigation measures suggested.


Photo credit: Chester Zoo


Activity budget of zoo-housed Dolichotis patagonum mates (Baechli et al., 2021)

January 2021

A new study in JZAR looked into the activity budgets of zoo-housed Patagonian maras:

"Resting", "Feeding" & "Alert" were the most frequent behaviours;

High behavioural synchrony between mates;

Available data from wild individuals suggested a positive behavioural activity in these captive individuals.


Photo credit:

Soundscape at the zoo_Zoo Biology paper.

Zoo soundscape: Daily variation of low‐to‐high‐frequency sounds (Pelletier et al., 2020)

July 2020

Noise at the zoo is a concern for animal welfare. Study in Zoo Biology assessed the soundscape (infrasounds and ultrasounds) of Zoo de Granby:

Sound levels increased during the day & with visitors present;

Sound levels generally not problematic for animal welfare;

Some locations showed high sound levels (e.g. indoor areas & touristic features);

Mitigation actions proposed.

Yangtze finless porpoise_Baiji.jpg

Contextual impacts on individual and synchronous breathing rate variations in three captive odontocete groups (Serres et al., 2020)

November 2020

A study investigated individual & synchronous breathing rate variations in three captive cetacean species:

Highest rates during energetic & social behaviours;

Higher rates during unusual events;

Enrichment: lower individual but higher synchronous rates;

Higher rates for ONE of the species in presence of public & during social separation;

Breathing rates are a useful parameter BUT should be interpreted carefully & integrated with other indicators.


Photo credit: Baiji Dolphinarium

Asian elephant_ZSL.jpg

Longitudinal Improvements in Zoo-Housed Elephant Welfare: A Case Study at ZSL Whipsnade Zoo (Finch et al., 2020)

November 2020

New study assessed the welfare improvements of the Asian elephants at ZSL Whipsnade Zoo, using data from their species-specific behavioural monitoring programme. Some of their findings include:
Species-appropriate levels of feeding;
Low levels of stereotypic behaviours;
Rare agonistic behaviour between group members;
Positive social associations & interactions between group members.

Nile lechwe San Diego Zoo.jpg

Specialised for the Swamp, Catered for in Captivity? A Cross-Institutional Evaluation of Captive Husbandry for Two Species of Lechwe (Rose & Rowden, 2020).

October 2020

There is a new published paper on zoo husbandry practices in lechwe - a wetlands social antelope that is understudied in captivity:
Similar male:female ratios in captive and wild herds;
Enclosures usually included wetland areas, which were rarely managed;
Vegetation cover was limited;
Similar diets between zoos, but different from guidelines;
Abnormal behaviours reported but causes not identified.


Photo credit: San Diego Zoo

Five Domains of Animal Welfare.webp

The 2020 Five Domains Model: Including Human–Animal Interactions in Assessments of Animal Welfare (Mellor et al., 2020).

October 2020

The Five Domains Model of animal welfare assessment has just been updated in a new paper:
Five Domains: (1) Nutrition, (2) Physical Environment, (3) Health, (4) Behavioural Interactions, (5) Mental State;
Update adds human-animal interactions to the model;
Applicable to all animal caretakers, including zoo keepers, researchers & veterinary staff!

aquarium of the bay_octopus.jpg

The Use of a Species-Specific Health and Welfare Assessment Tool for the Giant Pacific Octopus, Enteroctopus dofleini (Holst & Miller-Morgan, 2020)

September 2020

A new study has proposed a health & welfare assessment tool for the Giant Pacific octopus:

 Categories assessed: external appearance, behaviour & signs of stress and disease;

 Severity score system;

 Upward trend in score identified within 3-4 weeks of death - predictor?


Photo credit: Aquarium of the Bay

grizzly bear zoo study.jpg

Seasonal and Daily Activity of Two Zoo-Housed Grizzly Bears (Ursus arctos horribilis)

August 2020

New study investigated activity patterns in two zoo-housed grizzly bears:
Most inactivity recorded in winter;
Stereotypies and general activity emerged in spring and summer;
Stereotypies more frequent in the morning.