How Covid-19 Zoo Closures Have Affected the Animals

With zoos reopening across the UK on Monday (12th April), I figured this was a fairly logical topic to write about this week. 

Giraffe photographed at Marwell Zoo 2017

A study undertaken by Williams. E. Et al (2021), looked at the effects of zoo closures on animals’ behaviour. The study looked at a few species including Chinese goral (Naemorhedus griseus), Grevy’s zebra (Equus grevyi), Swamp wallaby (Wallabia bicolor), Rothschild’s giraffe (Giraffa camelopardalis rothschildi), Nyala (Tragelaphus angasii), Chapman’s zebra (Equus quagga chapmani), Snow leopard (Panthera uncia) and Amur leopard (panthera pardus orientalis). These species were split across two different zoo sites, with observations carried out by the keepers during a period of when the zoo was closed and when the zoo reopened. 

A scan sampling technique was used during each sampling (observation) period which lasted five minutes each time. The behaviours were recorded for the group as a whole, rather than identifying the individuals to see if the behaviours were unique to that individual. The behaviours being recorded were to collect data on whether specific behaviours were present or absent within the group. 

The behaviours being recorded were listed in an Ethogram so that all participants observing the animals had an accurate description of each behaviour and could identify the behaviours easily. 

The Ethogram used was: 

VigilantAlert – showing a heightened awareness of their environment (including looking at visitors)
Human-animal interaction (positive)Moving towards or seeking interaction from humans
Human-animal interaction (negative)Avoiding, moving away from or showing fear of humans
Foraging/feedingLocating and consuming foodstuffs
ComfortAny self-maintenance or self-grooming behaviour
Social (positive)Engaging in positive social behaviours (e.g. social play, grooming)
Social (negative)Engaging in negative social behaviour (e.g. fighting, displaying)
LocomotionMoving around the enclosure (on land or in water) in a non-repetitive pattern
Interaction with the environmentInvestigation or interaction with things in the environment (other than food).
Resting/sleepingSitting or lying motionless with eyes closed. No other behaviour is being performed
Abnormal repetitive behaviour (ARBs)Repetitive behaviour with no obvious function or purpose
OtherAny other behaviour not detailed in the ethogram
Out of sightAnimal out of sight of observer

The results of the study showed fluctuations in behaviour across all the species studied, however with the inconsistencies of the observations, the significant differences in frequencies of performance were not always detected. 

The behaviours to note from the study included Nyala showing no vigilance behaviours during the period the zoo was closed with no visitors and reduced staff numbers, however, their were signs of vigilance recorded when the zoo opened, which remained at similar levels of the zoo being open <1 month and open > 1 month. They initially showed a decrease in feeding behaviours when the zoo was open less than a month, but then increased their feeding behaviours to even more than the closure period when the zoo had been open for more than one month. 

The Rothschild’s giraffe in the study showed a steady increase of both vigilant and feeding behaviour over time from the zoo being closed to being open for more than one month. Their resting behaviour decreased over this time and no resting was observed when data was collected after the zoo had been open for more than one month. 

The Chinese goral showed more vigilance behaviours when the zoo had been open for less than one month, however, this behaviour decreased over time and reduced to the same levels of vigilance as the closure period after the zoo had been open for more than one month. 

Chapman’s zebra showed a decrease in vigilance when the zoo opened, but showed an increase in feeding behaviour. The Grevy’s zebra had fluctuating levels of vigilance and feeding behaviours throughout all states of zoo opening and closure periods, with no set pattern recorded. 

Swamp wallabies showed an increase of vigilance behaviour over time, from the zoo being closed to being open for more than one month, however the majority of the behaviours shown was resting behaviour in all time periods. 

Amur leopard photographed at Marwell Zoo 2017

Amur leopards showed a reduced level of vigilance behaviour over time, from the zoo being closed to being open for more than one month, however, their locomotion behaviour increased during the period that the zoo had been open for more than one month. Snow leopards were either resting or out of sight during all observation attempts, no matter the time period. 

Overall, most species exhibited behaviours that are what we would expect from them from both zoo sites, whether the zoo was closed or open. The Grevy’s zebra showed more comfort behaviours being performed during the closed periods compared to when the zoo was allowed to open. The Chinese goral showed more interaction behaviours with its environment during closed periods compared to open periods, with no environmental interactions being observed when the zoo was open. 

So what does this mean for the zoo animals when all the zoos start to reopen on Monday? 

It means that they could start to show a few behaviours that we may consider to be negative during the first few weeks of opening, remember, they haven’t seen the public for the last 3 whole months plus a bit, so the noise and visual stimulus of lots of humans is a bit alien to them again. They don’t have an understanding as to why humans they’re not used to keep appearing and disappearing at random times throughout the year, and so it could be a little stressful for them to start with. However, the majority of zoo animals have spent their entire lives in these environments and so it won’t take them long to become habituated to having visitors at the zoo again. 

Do we need to do further studies in this area as to whether reduced visitor numbers are better for zoo animals? 

It would certainly be an interesting study, especially to determine if having limited guest numbers is better for them than unlimited numbers where there could be tens of thousands on any one day during the summer, and only a couple thousand in the winter during normal times. 

Studying juvenile animals that have been born during the lockdowns who haven’t witnessed crowds of people would also make for an interesting study, to see how dramatically their behaviour changes with different stimuluses in their environments that they have never seen before because it was not possible. A study into how their behaviours adapt and change over time to the new stimulus of a large crowd would also be interesting. 

In the majority of animals, we shouldn’t see that much of a change in their behaviours as it has been a part of their lives for a long time, but it may take a few days or weeks for them to become used to it again. Please remember when visiting your local zoo, that you should try and be respectful to the animals by not being too loud, this will help them a lot if we show them some respect. Please also remember to follow the directions of staff at the zoo and follow covid rules so that they are able to stay open to not suffer any more drastic financial losses. 

Close up of giraffe (potentially Cotswold Wildlife Park)


  • Williams. E., Carter. A., Rendle. J., Ward. S. J. 2021. Impacts of COVID-19 on Animals in Zoos: A Longitudinal Multi-Species Analysis. J. Zoo. Bot. Gard. 2021, 2, 130-145.


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