Sunday, October 9, 2022
Yesterday my Zoom book club discussed West with Giraffes by Lynda Rutledge. Based on the real-life cross-country journey of two young giraffes to the San Diego Zoo in Depression America, the story brought out how people flocked to see the giraffes pass through their town–and how the giraffes leaned forward to see the people.
Animals do notice people, and the temporary closing of zoos around the world provided an opportunity to study how animal behavior changes when the visitors don’t show up and even how they react to masks. Whether the results are positive or negative sometimes depends on the observer’s interpretation.
For example, a primate study (3) showed that gorillas spent more time resting and more time alone when people weren’t around. But does this mean that people keep gorillas from getting enough rest or that the gorillas find life more interesting when they can see the people going by? Chimpanzees engaged more with their environment and spent more time feeding when people were present, which may show that they were stimulated by having an audience. Or maybe they liked the warmer weather.
I have to admit that I had never heard of meerkats before I saw “Life of Pi.” Apparently, they are very popular in zoos, with their habit of standing up and their alert expressions. When the zoos were closed, they relaxed and used more of their living space, but when the people came back, their alert behavior increased and they spent more time in the areas away from public view (4). The study contrasted this behavior with African penguins, who just went on with their lives, whether visitors were there or not. Studies like this enable zoos to take the animals’ response to visitors into account when designing their environment.
Prior to the pandemic, a number of studies had been published on how animals recognize and interpret human facial expressions. Pre-covid studies (1) of facial discrimination have been carried out in dogs, cows, horses, sheep, pigeons, and chickens, and even invertebrate like honeybees and archerfish. Masks, the study points out, change both the appearance of the human face and the facial expression. Studies showed, for example, that the Nubian ibex were more vigilant when people wore face masks, but the Eurasian tree sparrows were less afraid of people wearing masks. Positive for sparrows, perhaps, but negative for animals who pay close attention to the human face. I’d like to see similar studies for people.
In the early days of the pandemic, back in 2020, we heard about zoo animals getting COVID from their caregivers. Big cats have been particularly susceptible. (See Pandemic Day 311, Jan. 16, 2021: historysedge.wordpress.com/2021/01/16/pandemic-day-309-lions-and-tigers-and-more/) Last November, three snow leopards died of COVID-19 complications at the Lincoln Children’s Zoo in Nebraska. Since mid-2021, zoo animals most at risk have been getting a vaccine designed for animals developed and donated by Zoetis (5), beginning with the Oakland Zoo in northern California. Two vaccinations are required to be fully vaccinated. The first zoo animals vaccinated on June 30, 2021, included: tigers, black bears, grizzly bears, mountain lions, and ferrets. These were followed by chimpanzees, fruit bats, and pigs. Since then, Zoetis has donated vaccines to over 200 zoos in over a dozen countries.
Vaccinating zoo animals is not without controversy. Last November, when the Dallas Zoo was preparing to vaccinate at-risk animals, there were reports on social media that three giraffes had died in one month from receiving the vaccine. However, it turned out to be a false alarm, in that the giraffes, who died from unrelated causes, had not received the vaccine and none of the giraffes were scheduled to be vaccinated anyway (6).
It’s easy to find news reports on the incidence of zoo animals who got COVID and the development of vaccines for them. However, my search for behavioral changes pre- and post-pandemic closures turned up plenty of studies, but few interpretive news articles like the one in Science Alert cited below. This may be because the results are hard to interpret. Behavioral research is usually based on systematic human observations of behavior and on measuring adrenal activity measured by analysis of metabolites in fecal specimens. Sample sizes with animals like giraffes are small. And there are differences in behavior between individuals within a species as well as between species.
For example, some giraffes are used to feeding bridges where visitors, under supervision, are allowed to hand feed the giraffes food such as pellets, acacia leaves, or lettuce leaves. One study (7) compared the impact of the pandemic reopening on cheetahs to giraffes at the Oregon Zoo. When the zoo reopened, the cheetahs temporarily responded by spending more time out of sight and less time moving around than they had when the zoo was closed. The giraffes displayed more vigilance when the zoo was first closed, but the two male giraffes were used to getting handouts from the visitors’ platform and may have been just looking for food.
The study goes on to muddy the waters by discussing the weather and temperature changes within the enclosures, the fact that only two individuals of each species was available for study, and possible differences due to gender, age, life experience, etc. The variables go on and on.
But, having read Lynda Rutledge’s book, about two young and curious giraffes, I can point out one thing. Zoos and wild animal parks have platforms for visitors to feed the giraffes. But not the cheetahs. So why would the cheetahs come out and look around?
Today’s Notable Headlines
“When The Pandemic Came, The Zoos Closed, And The Animals Began to Act Differently,” Science Alert, Sept. 9, 2022. https://www.sciencealert.com/when-the-pandemic-came-the-zoos-closed-and-the-animals-began-to-act-differently
“Minnesota zoo animals are getting their COVID shots, too,” StarTribune, May 30, 2022. https://www.startribune.com/minnesota-zoo-animals-are-getting-their-covid-shots-too/600177661/
“Snow leopards die of Covid-19 complications at Nebraska zoo,” CNN, Nov. 13, 2021. https://www.cnn.com/2021/11/13/us/coronavirus-snow-leopard-deaths-trnd/index.html
“Why we don’t have more COVID-19 vaccines for animals,” The Pig Site, 25 August 2022. https://www.thepigsite.com/articles/why-we-dont-have-more-covid-19-vaccines-for-animals
Other Notable References
- “Communication from the Zoo: Reports from Zoological Facilities of the Impact of COVID-19 Closures on Animals,” Journal of Zoological and Botanical Gardens, 15 June 2022. pdf available at https://www. mdpi.com
2. “Anti Covid-19 face-masks increases vigilance in Nubian ibex (Capra nubiana),” Biological Conservation, Volume 263, November 2021, 109339. https://www.sciencedirect.com/science/article/pii/S0006320721003918?via%3Dihub
3. “The Impact of COVID-19 Zoo Closures on Behavioural and Physiological Parameters of Welfare in Primates,” NIH National Library of Medicine, v.12 (13); 2022 July. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9265073/
4. “Understanding impacts of zoo visitors: Quantifying behavioural changes of two popular zoo species during COVID-19 closures,” Applied Animal Behavior Science, Vol. 236, March 2021, 105253. https://www.sciencedirect.com/science/article/pii/S016815912100040X
5. “Zoetis Donates COVID-19 Vaccines to Help Support the Health of Zoo Animals,” Zoetis Press Release, JUly 2, 2021. https://news.zoetis.com/press-releases/press-release-details/2021/Zoetis-Donates-COVID-19-Vaccines-to-Help-Support-the-Health-of-Zoo-Animals/default.aspx
6. “Fact Check: Did Dallas Zoo Giraffes Die After COVID Vaccine?” Newsweek, Nov. 9, 2021. https://www.newsweek.com/dallas-zoo-giraffe-covid-vaccine-death-sick-1647415
7. “Applying Behavioral and Physiological Measures to Assess the Relative Impact of the Prolonged COVID-19 Pandemic Closure on Two Mammal Species at the Oregon Zoo: Cheetah (A. jubatus) and Giraffe (G. c. reticulata and G. c. tippelskirchii),” NIH National Library of Medicine. v.11 (12):2021 Dec. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8698047/
Why am I doing this?
The coronavirus pandemic is a classic watershed historical event. People will be referring to “before the pandemic” or “after the pandemic” for decades to come. Since March 11, 2020, this blog has examined the modern pandemic experience, drawing on my background as a medical technologist, a historian, and an ordinary person living through an extraordinary world crisis. My sources, both primary and secondary, are documented with links for easy reference.