Lions And Zoos

spirit animal

By Garima Prasher

To ensure animal welfare Bannerghatta Biological Park (BBP), the researchers analyzed their level of stress. The results showed that the animals are not only stressed, their level of stress is related to the number of visitors to the park.

The study found that animals were most stressed during weekends (Sunday and Friday) with cortisol levels as high as 288 ng/dl (nanograms per deciliter) in some individuals. However, they were at their most relaxed on Tuesday (the week off), with cortisol levels as low as 192 ng/dl in some individuals.

“Animal welfare is of growing importance and the lack of chronic stress is one of its prerequisites. When animals are in captivity, their welfare becomes our duty. We conducted the study to understand the level of stress in captive animals so that it could be alleviated. We found that stress hormone levels are low in all animals on Tuesday compared to other days of the week,” said Dr. Manjunatha V, Head of Research, BBP.

According to experts, the first-line hormones in animals that help overcome stressful situations are glucocorticoids and catecholamines. These hormones are determined as a parameter of adrenal activity, and now of stress. A high level of these hormones in animals implies that they are stressed.

The concentration of these hormones can be measured in various bodily fluids or droppings. However, faecal samples offer the advantage that they can be easily collected and measured without harming the animals.

“We wanted to quantify faecal cortisol levels to learn about stress levels in animals at different times of the month. We collected fresh fecal samples at different time intervals, seasons and analyzed the samples using enzyme immunoassays (EIA/ ELISA) method,” Dr. Manjunatha told BM.

The results showed that the animals had comparatively lower stress hormone levels on Tuesday. Stress hormones varied between males, females and calves of the same species. While the males were found to be more stressed, the females seemed less harassed. In addition, carnivores were found to be less stressed than herbivores. The two-week study was conducted on zebras, tigers, lion-tailed macaques and giraffes.


“These are ecologically important animals that are the zoo‘s main attractions. Additionally, we wanted both herbivores and carnivores to be represented in our study. Herbivores had higher levels of stress hormones because they are the prey population in the wild. However, carnivores are at the top of the food chain, which means they have one less aspect to be wary of. This distinction is evolutionary,” added Dr. Manjunath.

Reduced stress level

Based on the results of the study, the BBP authorities have proposed some measures to enrich the animal enclosures to alleviate the stress levels. One way is to minimize the viewpoint of visitors.

“We have reduced the area of ​​the gazebo by many enclosures. For example, previously the zebra enclosure had a 360 degree view. Visitors could walk around the perimeter of the enclosure. Now, only 30% of the perimeter is accessible. Similarly, the L-shaped visibility on the lion enclosure is now reduced on one side.

Reducing the vantage points of the enclosure will limit the area of ​​visible exposure and should give these animals a private space,” said Doctor Sunil PanwarChief Conservator of Forests and Executive Director, BBP.

Reducing viewpoints from the enclosure will limit the visible display area and should give the animals a private space.

— Dr. Sunil Panwar, Executive Director, BBP

Animals are also fed food containing nutrients to help reduce their stress levels.

“As the diet is different for herbivores and carnivores, so is how to reduce stress levels through food. While zebras like to chew alfalfa hay, for lions and tigers, we use a different tactic. We freeze the pieces of meat and give them away during the summer,” Dr Manjunatha explained.

BBP has also appointed officers to speak to visitors and educate them on how to see the animals without causing them stress. According to officials, the impact of these measures will be evaluated with another study on stress hormones in the coming months.