Using technology and science to monitor an animal’s comfort in extreme weather
Have you ever wondered how zoos know whether an animal is too hot or too cold? While many people assume there is a single "right" outdoor temperature for a species, the answer is much more complex. Every habitat is different, and animals can respond to weather in different ways depending on their age, health, coat condition, activity level, and the choices available within their habitat.
Checking the temperature of an animal’s environment
Rather than relying on a single air temperature, Brookfield Zoo Chicago’s environmental quality monitoring team uses something called the thermal neutral zone (TNZ) to understand an animal’s environment. “Thermal” refers to temperature and heat energy. A thermal neutral zone is the environmental temperature range an animal needs to stay within to maintain its normal body temperature without using too much extra energy.
When we are too hot or too cold, it’s much harder to focus on more important things. We may feel sluggish or tense because our bodies are working hard to get back to a comfortable temperature. Like us, when an animal is within their thermal neutral zone, they can use more of their energy on natural behaviors. They can spend time exploring, socializing, and caring for offspring instead of regulating body temperature.
What do we mean by “environmental temperature?” An animal's thermal environment is influenced by much more than the day’s high and low temperatures. Sunlight, shade, wind, humidity, rain, snow, and the design of the habitat all affect how warm or cool an animal actually feels. Habitats are designed to provide animals with choices, allowing them to move between sunny and shaded areas, seek shelter from wind or precipitation, or use pools and other cooling opportunities depending on their needs.
We take all these factors into consideration when we evaluate an animal’s environment.
Watching how animals respond to weather
Animal care staff also monitor how each individual animal responds to changing weather conditions. When humans are uncomfortable, we often engage with our environment to change our body temperature. We may go inside, turn on the air conditioning, or sit in the sun or by a fire. Or we adjust how our bodies feel by getting active, changing clothes, or taking a nap.
Our staff watch for similar kinds of behaviors in animals. Behavioral observations, body condition, activity patterns, and overall health provide valuable information about whether an animal is comfortable. Examples might include a lion seeking shade on a warm day, a spiny-tailed lizard seeking heat from a lamp provided for its care, or a group of penguins huddling closely together for increased warmth. If an animal consistently chooses shade during warm weather, seeks heated areas during cold conditions, or changes its normal behavior, this is a clue to animal care staff that they may need to make an adjustment. Observing closely helps them evaluate what kinds of adjustments need to be made, be it care or habitat conditions.
Keeping animals comfortable year round
Brookfield Zoo Chicago combines thermal neutral zone measurements with ongoing welfare monitoring and veterinary expertise to make informed decisions about animal care. Rather than relying on rigid temperature limits, this output-based approach focuses on the animal's actual response to its environment.
Every day, this combination of science, observation, and animal choice helps ensure that the animals at Brookfield Zoo Chicago remain comfortable throughout the changing seasons. By monitoring how animals interact with their environment instead of simply measuring the temperature outside, we continue to advance evidence-based animal welfare and provide the highest standard of care for every species that calls the Zoo home.
