Animal & Population 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