Animal & Population Management
Food-related substrate preference in juveniles seastar Echinaster (Othilia) brasiliensis (Müller & Troschel,1842) in captivity (Maganhe et al., 2023)
The food-related substrate preferences of captive juvenile starfish Echinaster were investigated in a study published in Zoo Biology:
✔Feeding started around 40 days of age.
✔Significant preference for biofilm grown on rocks.
✔Sponges the least preferred substrate for post-settlement juveniles.
✔First reported use of biofilm from biological media for feeding juvenile starfish - applications to ex situ management of this taxon.
The effect of basking light provision on sunbeetle enclosure use (Brereton & Brereton, 2023)
A study in JZAR looked into sunbeetle enclosure use and how it was affected by basking light provision:
✔Uneven use of the enclosure, with preference for elevated branches.
✔Basking light was significant predictor of zone use in 3 out of 5 zones.
✔Elevated climbing areas and basking lights should be incorporated in sunbeetle enclosures.
✔Applications to husbandry and management of widely kept but understudied species.
Monitoring Thermoregulation Patterns in Asian Elephants (Elephas maximus) in Winter Months in Southwestern Ontario Using Infrared Thermography (Lefebvre et al., 2023)
A paper in JZBG looked into the thermoregulation patterns of zoo-housed Asian elephants in low temperatures:
✔Infrared Thermography (IRT) was used on 10 elephants of various ages.
✔Surface temperature varied mostly in the ears: "thermal windows" - areas that facilitate heat exchange.
✔Overall findings of this case study suggest Asian elephants may adapt better to low temperatures than previously assumed.
Age and Social History Impact Social Interactions between Bull Asian Elephants (Elephas maximus) at Denver Zoo
(Readyhough et al., 2023)
The social interactions of five zoo-housed Asian elephant bulls were investigated in a study published in JZBG:
✔Adolescent elephants: More affiliative & submissive behaviours, when housed in mixed-aged groups or mature elephants than only with other adolescents.
✔Mature elephants: more affiliative behaviours when housed with only adolescents rather than other mature individuals. Also, more time in promixity and agonistic behaviours when housed with at least one adolescent.
✔New social groups: more affiliative, agonistic, and submissive behaviours, as well as less time in proximity, than in previously established social groups.
✔Bull elephant social interactions are influenced by age and social history.
Exploring the behaviors and social preferences of a large, multigenerational herd of zoo-housed southern white rhinoceros (Ceratotherium simum simum) (Williams et al., 2023)
The social dynamics of a zoo-housed, multigenerational, herd of eight white rhino females were investigated in a study published in Zoo Biology:
✔ Seasonal & temporal variations in grazing & resting behaviours, with no stereotypies reported.
✔ Each female maintained one to two close social bonds with conspecifics.
✔ Except for mothers and their calves, the strongest social bonds were between calf-less adults & subadults.
✔Applications to ex situ management.
Olfactory communication in tamarins: A comparative analysis of scents from wild and captive populations (Poirier et al., 2022)
A study in JZAR compared the chemical compositions of scents collected from wild and zoo-housed bearded emperor tamarins:
✔ Scent samples from wild tamarins had greater number of odorants.
✔ Difference in chemical composition also detected between wild and captive samples.
✔ Demographic dfferences, small sample size and storage conditions may have influenced results.
✔ Results suggest the ex situ artificial diets and environments may alter chemosignalling in this species.
✔ Applications to ex situ husbandry and conservation.
Behavioral development of a captive polar bear (Ursus maritimus) cub in the maternal den (Gartland et al., 2023)
A study in Zoo Biology described the behavioural development of a zoo-housed polar bear cub, which was monitored continuously using video cameras:
✔Nursing behaviours were seen in up to 20% of daily time budget (and in only around 11% of total observations).
✔Time spent nursing was even throughout the day.
✔Cub left nest for first time at 4th week of age, while time spent outside gradually increased.
✔Mother guided cub back to nest first few times it went outside.
✔Longest period of uninterrupted observations on polar bear cub development in the den published so far, with applications to management and husbandry.
Flock size and structure influence reproductive success in four species of flamingo in 540 captive populations worldwide (Mooney et al., 2023)
Ex situ breeding programmes for flamingos have historically shown low reproductive success, but how can they be improved while increasing their long-term sustainability? New paper in Zoo Biology investigated:
✔Records for 4 species, from 540 zoos, between 1990 to 2019, were analysed.
✔Flock size influenced reproductive success for all species.
✔An even sex ratio plus introduction of new individuals to a flock also influenced reproduction.
✔Limited effect found for climatic variables.
✔Flocks of 50-100 individuals (species-dependent) & even sex ratio are therefore recommended.
Designing an assay to evaluate behavioral responses to opposite-sex conspecifics in the endangered black-footed ferret (Mustela nigripes)
(Potratz et al., 2022)
The responses of captive black-footed ferrets to odour cues (i.e. soiled bedding) from opposite-sex conspecifics were tested using a T-maze connected to a home nest box and two novel ones:
✔Novel boxes: ferrets mostly sniffed, stood alert, and scratched.
✔Similar behaviours in both sexes, although males explored more.
✔Ferrets sniffed more in soiled than clean bedding (control).
✔Habituation detected, with less exploration in second trial of the day.
✔This system can be further developed to facilitate mate choice, & improve the success of breeding programmes.
Group composition impacts reproductive output and population viability in captive white rhinoceros
(Scott et al., 2022)
The future viability of the European ex situ population of white rhinoceros was investigated in a new paper in Animal Conservation:
✔Breeding performance was assessed with studbook data & comparison with wild populations in Kenya.
✔European ex situ population is currently declining 2% annually.
✔An average of 10% of females calved every year, which is much lower than the 40% average in wild populations.
✔It must increase to at least 17%, for the captive population to become self-sustaining.
✔Changing social structure may be a key step towards this goal (e.g. larger groups, housing breeding females together).
Giraffes like it hot? Research on giraffe drinking behaviour in response to warm water supply in a cold environment (Okabe et al., 2022)
A paper in JZAR looked into giraffe drinking behaviour in response to warm water provision in a cold environment:
✔Warm water (37ºC) provided in a container.
✔When warm water provided: total drinking frequency increased while frequency of drinking cold water decreased.
✔Higher number of drinking observations shortly after warm water was provided.
✔An increase in foraging observed in 2 of the 3 giraffes, during the warm water period.
✔Applications to giraffe husbandry and management in cold environments.
Forest access restores foraging and ranging behavior in captive sifakas (Greene et al., 2022)
A paper in Zoo Biology looked into the foraging and ranging behaviour of captive Coquerel's sifakas with access to large forest enclosures:
✔Sifakas occupied 3-day home ranges of 1.2 ha, travelled 473 m/day and spent 26% of their time foraging for wild food.
✔They fed on leaves, fruits, nuts, flowers, petioles & bark from at least 39 species.
✔Variations detected across seasons, enclosure areas and groups;
✔Captive sifakas with access to large forest enclosures are able to show foraging and ranging species-specific behavious similar to their wild counterparts.
Activity patterns and reproductive behavior of the Critically Endangered Bermuda skink (Plestiodon longirostris) (Williams et al., 2022)
The behaviour of zoo-housed Bermuda skinks was studied in a paper in Zoo Biology:
✔Bimodal pattern of activity & basking;
✔Apparent preference for fruit-based diet over orthopteran insects;
✔Reproductive behaviour: shorter period of cloacal contact than in other two closely related species;
✔ Oophagia reported in the species for first time;
✔Applications to in situ research & ex situ management.
The historical development of zoo elephant survivorship
(Scherer et al., 2022)
A paper in Zoo Biology looked into survivorship of African and Asian elephants in North American and European zoos, between 1910 & today:
✔ Adult survivorship of both species significantly improved during this period;
✔ Generally higher survivorship in Asian than African elephants;
✔ Little changes in juvenile survivorship since 1960 and it is generally higher for African elephants;
✔ The survivorship of zoo elephants is currently higher than some non-zoo populations but lower than others;
✔ The continuous monitoring of zoo elephant survivorship is recommended.
A new candling procedure for thick and opaque eggs and its application to avian conservation management
(Hall, Potvin & Conroy, 2022)
A paper in Zoo Biology discussed a new candling method for thick and opaque eggs:
✔ Candling methods allow for confirmation of egg viability and vein identification for blood extraction;
✔ BUT traditional methods are ineffective on opaque and thick shells;
✔ Partial fenestration on two areas of shell conducted on emu and cassowary eggs;
✔ Clear vascular development observed in 97% of viable fenestrated eggs, blood samples & DNA successfully extracted;
✔ Hatchability and weight of embryo not affected;
✔ Applications to avian conservation management.
Confronting Back-of-House Traditions: Primates as a Case Study (Brando & Coe, 2022)
A new paper in JZBG looked into back-of-house practices in captive facilities, with primates as a case study:
✔ Little improvements in back-of-house areas in comparison to other indoor and outdoor areas;
✔ Animals often spend considerable amounts of their daily time in these areas;
✔ Suggestions to improve these areas: animal-friendly construction materials, animal-computer interaction, greater control over environment and also taking in consideration periods when caretakers are not around.
Impact of Broad-Spectrum Lighting on Recall Behaviour in a Pair of Captive Blue-Throated Macaws (Ara glaucogularis) (Bryant, Konczol & Michaels, 2022)
A paper in JZBG investigated whether broad-spectrum lighting (High Output T5 Fluorescent lamps - rich in UVA and UVB wavelengths and those visible to humans) affected the recall behaviour of a pair of zoo-housed blue-throated macaws:
✔ When lighting was on, they remained inside for longer after recall;
✔ Better visibility indoors may have improved the environment and encouraged them to use it - applications to the management macaws in captivity.
Evaluation of the time-activity budgets of captive ducks (Anatidae) compared to wild counterparts (Rose et al., 2022)
The activity budgets of wild and captive ducks were compared in a new study, published in Applied Animal Behaviour Science:
✔ Differences between activity budgets of wild & captive ducks;
✔ Abnormal behaviours are low to zero in captive ducks;
✔ Duck behaviour is affected by the environment, sex & season;
✔ Applications to captive duck management & welfare.
Maximum longevity and juvenile mortality in zoo-housed mangabeys (de Visser et al., 2022)
A study in Zoo Biology explored the international studbooks for two species of zoo-housed mangabeys to extract demographic and genetic data:
✔ Females lived longer than males;
✔ Lower longevity in European than North American zoos - possibily due to environmental & founder effects;
✔ Maternal & offspring longevities linked - inheritance of "good genes"?
✔ Age of mother at birth negatively affected offspring longevity - there may be an optimal age range for birth?
✔ Applications to mangabey management in captivity.
Social introductions of multiple groups of dwarf mongooses (Helogaleparvula) (Richmond et al., 2022)
The social introduction of three unfamiliar groups of dwarf mongooses was described in a paper in Zoo Biology:
✔An introduction process was developed, based on the natural social structure of the species;
✔Process included: neutral territories, olfactory introduction, visual introductions with limited physical contact & keeper-animal relationship building;
✔Successful introduction resulting in cohesive social group of four males and six females;
✔Dwarf mongooses may more easily accept unfamiliar conspecifics than previously assumed.
Reproductive non-seasonality in rhinoceroses: A review of the in-situ literature and birth records of ex-situ institutions
(Radeke-Auer et al., 2022)
The birth & conception patterns of free-living and zoo-housed rhinoceroses were compared in a paper in Journal of Zoo & Aquarium Research:
✔Photoperiod does not seem to influence rhino reproduction;
✔Resource scarcity suppresses conception in free-living rhinos, which does not happen in zoos;
✔Slight increase in autumn birth and decrease in spring births in zoo rhinos - related to restricted mating during indoor-housing in winter months?
✔Applications to rhino management & reproduction.
Day Time Activity Budgets, Height Utilization and Husbandry of Two Zoo-Housed Goodfellow’s Tree Kangaroos (Dendrolagus goodfellowi buergersi)
(Finch & Humphreys, 2022)
A case study of time budgets and height use of two zoo-housed goodfellow's tree kangaroos was published in JZBG:
✔ Majority of time spent resting, but locomotion, vigilance and feeding also observed;
✔ Both individuals showed a preference for the highest height level of the indoor enclosure.
✔ With husbandry information also provided, this case study provides useful information to the management of this understudied species.
Survey of current group demographics and management practices of bachelor groups of western lowland gorillas (Gorilla gorilla gorilla) across North America
(Gartland, Carrigan & White 2022)
A paper in Zoo Biology surveyed the AZA-accreditted institutions housing bachelor groups of western lowland gorillas:
✔19 zoos completed survey: 21 social units, 59 gorillas;
✔Most zoos followed the "Best Practices" guidelines for group formation & maintenance;
✔Feeding & training protocols were less standardised across zoos;
✔Further research on feeding variability & wounding recommended.
✔Guidelines & recommendations are effective ways to promote "best practices".
Courtship behaviour of the freshwater pipefish Microphis aculeatus (Syngnathidae): A case study in captive breeding (Christie, 2022)
The complex courtship behaviour of the pipefish was described in a new paper in JZAR:
✔ Spawning occurred immediately after illumination of exhibit - light may be a primary cue for reproduction in this species.
✔ Males initiate courtship, which has five distinct phases as described in paper;
✔ Higher respiration rates during copulatory behaviour;
✔ Husbandry and management information for the captive breeding of this species.
First natural breeding of the endangered dusky gopher frog (Lithobates sevosus) in captivity (Reichling et al., 2022)
A paper in Zoo Biology described first natural captive 𝐛𝐫𝐞𝐞𝐝𝐢𝐧𝐠 of the dusky gopher frog:
✔Seasonal enclosure modifications applied (i.e. temperature & other conditions) to mimic natural environment;
✔Five egg masses laid, 7887 hatchlings;
✔Clutch sizes similar to wild & greater to those typically produced via in vitro fertilisation (IVF);
✔Natural breeding can increase the number of frogs in captive breeding programmes.
Captive rearing of orphaned African wild dogs (Lycaon pictus) in Namibia: A case study (Marker et al., 2021)
A new case study in Zoo Biology described the captive rearing of African wild dog pups, orphaned due to human-wildlife conflicts:
✔18 orphaned pups were rescued in 2017-2018 and placed with Cheetah Conservation Fund (CCF);
✔17 of those successfully reared to yearlings, with 15 translocated for soft release into a game reserve;
✔Information provided with applications to captive management & breeding (i.e. behavior, health, housing, husbandry, diet & growth).
Daily activity profile of the golden mantella in the “Froggotron”—A replicated behavioral monitoring system for amphibians (Edwards, Bungard & Griffiths, 2021).
A paper in Zoo Biology described the daily activity of captive golden mantellas:
✔Frogs were largely diurnal with two peaks of activity (bimodal rhythm);
✔Higher activity under warmer temperatures (20-25ºC) than cooler conditions (16-19ºC);
✔Bimodal rhythm observed in all temperatures but earlier 2nd peak in warmer temperatures;
✔Most activity in >85% humidity ;
✔Applications to ex-situ management & in-situ field work.
The historical development of juvenile mortality and adult longevity in zoo-kept carnivores (Roller et al., 2021).
A study in Zoo Biology investigated the demographic data of 13 families and 95 species of zoo-housed carnivores:
✔ Data between 1950 and 2019;
✔ Neonate mortality decreased;
✔ Adult longevity increased;
✔ Results reflect continuous improvements of zoos through time.
Breeding history and husbandry of the Superb Bird-of-paradise (Lophorina superba) (Rimlinger, Theule & Bass, 2021).
A paper in Zoo Biology described the breeding and husbandry of the superb bird-of-paradise in zoos:
✔Enclosure setup and pair management particularly important;
✔Male & female should be kept in adjacent enclosures with visual contact, given access for copulation & separated again afterwards;
✔Diet and enclosures described;
✔Despite challenges, this species can be successfully bred in zoos.
Offspring survival changes over generations of captive breeding (Farquharson, Hogg & Grueber, 2021).
A new paper in Nature Communications analysed pedigree data from 15 vertebrate species in captive breeding programmes:
✔Some species showed substantial increases or decreases in offspring survival over generations of captivity;
✔Differences between dam and sire effects;
✔Changes in fitness over generations, not explained by inbreeding, are occurring even in properly-managed programmes;
✔Important considerations for breeding & reintroduction programmes.
Understanding sociality and behavior change associated with a nesting event in a captive flock of great white pelicans (Brereton, Fryer & Rose, 2021).
New paper in Zoo Biology looked into sociality and behaviour in zoo-housed great white pelicans:
✔ Increased vigilance levels in pre-nesting periods;
✔ Non-random social associations observed;
✔ Social structure: sub-adult birds associated more with each other;
✔ Wider enclosure use with increased visitor presence;
✔ Applications to captive pelican management and breeding.
Burrowing in captive juvenile Desertas wolf spiders (Hogan ingens) (Rowlands et al., 2021).
New study in JZAR investigated burrowing behaviour in zoo-housed Desertas wolf spiders:
✔ Optimum substrate depth: >50 mm;
✔ Lighter, loosely packed substrates preferred;
✔ Stone size had positive effect on likelihood of burrow construction;
✔ Applications to captive husbandry and future reintroduction efforts.
Photo credit: Bristol Zoo
Assessing saddle‐billed stork (Ephippiorhynchus senegalensis) pair‐bonds and breeding behavior using behavior observed during multiple breeding seasons (Weibel et al., 2021).
A study in Zoo Biology compared the behaviour and breeding success of two pairs of zoo-housed saddle-billed storks:
✔Higher reproductive success in one of the pairs: eggs produced & incubated in all breeding seasons;
✔"Successful" pair: higher rates of nesting behaviour and close proximity;
✔Pair compatibility may influence breeding success in this species.
Documenting nocturnal activity of dragon‐headed katydids (Lesina blanchardi) under artificial light (Baskir et al., 2021).
A study in Zoo Biology investigated the nocturnal behaviour of dragon-headed katydids under artificial light:
✔Higher activity & enclosure use under red LEDs than under artificial daytime working lights;
✔Red LED illumination did not suppress nocturnal activity in this species.
Insights into Activity of Zoo Housed Asian Elephants (Elephas maximus) during Periods of Limited Staff and Visitor Presence, a Focus on Resting Behaviour (Finch et al., 2021).
What are zoo elephants up to when no one is around? A paper in JZBG investigated the behaviour of the elephants at ZSL Whipsnade Zoo between 4 pm and 10 am:
✔Feeding (average 57.7%) and resting (average 28.2%) were the most frequent behaviours;
✔Resting was mostly done in close proximity to conspecifics;
✔Social associations can be formed during resting, and are facilitated by young individuals.
Biological and environmental factors as sources of variation in nocturnal behavior of giraffe (Burger et al., 2021).
Paper in Zoo Biology investigated the nocturnal behaviour of zoo-housed giraffes:
✔Resting behaviours observed in approximately half of observations;
✔Age, subspecies & motherhood influenced nocturnal behaviour the most;
✔Husbandry & environmental factors did not have an effect on nocturnal behaviour;
✔These findings have potential applications to management of giraffes in captivity.
Captive environmental change and induction of natural breeding and egg‐laying in ploughshare tortoises (Astrochelys yniphora) (Kiryu et al., 2021).
A study in Zoo Biology described how to induce natural breeding in captive ploughshare tortoises by replicating natural environmental conditions:
✔Temperature and humidity were seasonally adjusted to replicate the dry and rainy seasons of their natural habitat;
✔Natural breeding and egg laying observed one year after environment changes;
✔Important applications to captive breeding programmes of threatened tortoise species.
When a habitat becomes a home: Housing and husbandry of spotted hyenas Crocuta crocuta at Disney’s Animal Kingdom® (Miller et al., 2021).
A study in JZAR evaluated the impact of a training and enrichment programme on the behaviour of two spotted hyenas, when they moved from a research facility to Disney's Animal Kingdom:
✔Resting was the most common behaviour observed, followed by travelling.
✔Pacing decreased throughout the study;
✔Hyenas learned fast and responded positively to varied feeding strategies.
Photo credit: Disney's Animal Kingdom.
Urine collection conditioning in determining the oestrous cycle of a captive female giant panda Ailuropoda melanoleuca (Tay et al., 2021).
New paper in JZAR described how urine collection conditioning can facilitate monitoring of the reproductive cycle of female giant pandas. The female panda at
Wildlife Reserves Singapore was trained to approach the animal keeper and urinate on cue in a specific location.
✔The urine is then collected and used to monitor the oestrous cycle, helping to identify the best timing for artificial insemination (if necessary) and increasing the chances of breeding success.
Photo credit: Wildlife Reserves Singapore
Do captive golden mantella frogs recognise wild conspecifics calls? Responses to the playback of captive and wild calls (Passos et al., 2021).
New study in JZAR investigated the responses of captive golden mantella frogs to playback calls from both wild and captive conspecifics:
✔Captive frogs showed a natural behavioural response to the vocalisations of wild males;
✔The calls from the captive males (especially the ones that had been in captivity for >5 generations) did not elicit a response;
✔Captivity had an effect on the calls of male frogs, which could affect their reproductive outcome if reintroduced into the wild.
Photo credit: Luiza Passos
Natural environmental conditions and collaborative efforts provide the secret to success for sand tiger shark Carcharias taurus reproduction in aquaria (Wyffels et al., 2020).
A study in Zoo Biology reported the birth of a sand tiger shark young (first time in the Americas), a species notably challenging to breed in captivity... The reasons behind this success were described:
✔Natural environmental conditions: natural seawater, light and seasonal temperature fluctuations;
✔Multi-institutional collaboration: individuals selected and brought together for breeding
Effects of Lupron and surgical castration on fecal androgen metabolite concentrations and intermale aggression in capybaras (Hydrochoerus hydrochaeris) (Yu et al., 2020).
A study assessed the impacts of chemical sterilisation (i.e. Lupron®) & surgical castration on intraspecific aggression between three zoo-housed male capybaras:
✔Testosterone & sperm production decreased with chemical sterilisation;
✔Testosterone decreased in castrated males but in the one male left intact, it eventually returned to pre-Lupron levels;
✔Neither worked in reducing aggression between individuals, resulting in subsequent separation.
Photo credit: Smithsonian's National Zoo
Comparison of reproductive success between parent-reared and hand-reared northern bald ibis Geronticus eremita in captivity during Proyecto Eremita (González et al., 2020)
A study in JZAR compared reproductive success between parent-reared and hand-reared Northern bald ibises:
✔Similar reproductive success between parent- & hand-reared clutches;
✔Colony size had a negative effect on reproductive success;
✔Combination of hand- & parent-rearing improved reproductive output for reintroduction.
Photo credit: Zoobotánico Jerez
Preference of intake of different tree leaves preserved with drying and ensiling by nyala antelope (Tragelaphus angasii) (Przybylo et al., 2020)
Study investigated whether the browse preservation method (drying and ensiling) affects intake preferences in zoo-housed nyalas:
✔The nyalas showed preference for the leaves of some species (e.g. maple & oak) over others.
✔Generally, the method of preservation did not seem to affect their preferences.
✔The palatability of some browse species may be affected differently by method of preservation.
Photo credit: Silesia Zoological Garden
Zoo‐housed mammals do not avoid giving birth on weekends (Hosey et al., 2020)
New study out in Zoo Biology investigated whether zoo-housed mammals avoid giving birth during the (generally busier) weekends:
✔ 16 mammal species covered: including ungulates, primates & carnivores;
✔ No relationship found between birth rates & visitors numbers;
✔ No "weekend effect" found on birth rates.
Photo credit: ZSL