On this “National Polar Bear Day”, we explore how these formidable animals keep warm. Arctic polar bears, Ursus maritimus, live in very cold environments where temperatures are often colder than a home freezer and can dip as low as -40 degrees C. They thrive on ice and routinely hunt and swim in ice-cold water. Unlike humans, and many other mammals for that matter, polar bears have several characteristics that help […]
A new study published in Biology Letters found that wild fish could distinguish between two divers based on the colors they were wearing. The investigators began by training two species of wild sea bream (Oblada melanura and Spondyliosoma cantharus) to obtain a food reward from a diver by following them. They then had two divers enter the water wearing different colors and found that the fish were able to tell […]
Do you ever find yourself intentionally blinking when you notice other people blinking? It’s as if we all have something stuck in our eyes at the same time. A new study published in Royal Society Open Science found that dogs appear to have the same reaction when seeing other dogs blink, which suggests that blinking may be a form of non-verbal canine communication. They also observed increased blinking in response […]
Heat is a major physiological stressor that can damage proteins in the body, promote dehydration and even lead to death. Organisms living in hot environments must develop both behavioral and physiological mechanisms to prevent heat-related damage or illness. A recent review published in Physiology examined how humans and experimental animals adapt to heat (Laitano et al., 2025). Organisms that tolerate heat effectively can maintain normal physiological functions even when […]
Cell membranes are incredibly complex environments that play crucial roles in interacting with other cells, sensing specific molecules in the body, controlling what crosses the membrane, and other vital functions. The composition of these membranes varies between organs in an animal, between similar organs in different species, and even between individuals of the same species. Think of cell membranes as gatekeepers, responsible for detecting various chemical signals (such as ions […]
Did you know that your brain is really greedy? It uses about 5.7 kilograms of ATP every day, which is an incredible amount of energy! To keep up with such demand, the brain depends on an adequate supply of oxygen and nutrients, such as glucose. When oxygen or nutrient delivery are limited, like during a heart attack, stroke or in low-oxygen environments, the brain is unable to produce enough ATP […]
I am thrilled to have come across a calendar of fun and interesting “holidays” for all sorts of occasions, including celebrating nature and the animals around us. In honor of ‘National Squirrel Appreciation Day’, let’s take a moment to marvel at furry survival experts and the incredible science behind winter slumber in ground squirrels. When temperatures drop, ground squirrels settle down for a long winter’s nap. During hibernation, their […]
In this post, we travel back to 1947 to explore a fascinating review by Dr. Max Kleiber from the University of California – Davis. Published in Physiological Reviews, this review examined the relationship between body size and metabolism. Simply asking the question of whether horses produce more heat per day than humans or rats will lead one to conclude that indeed they do because of their larger body size. However, […]
On this National Bird Day, let’s dive into some fascinating research about one of nature’s most amazing species: hummingbirds. Last spring, Dr. Derrick Groom and his team in The Avian Energetics Lab at San Francisco State University, including students Cecilia Doan and Christian Guerzon, presented their research at the 2024 American Physiology Summit. Their study explored how these tiny birds manage water loss in a warm environment (30 degrees C). […]
Ever wonder how your body knows when, what and how much to eat, what to crave, or when to stop? Have you ever found yourself indulging in a little extra during the holidays, even though you’re not actually hungry? It turns out, the science behind our eating habits is far more complicated than we realize— and it’s not just about willpower or self-control. A fascinating comprehensive review published by Watts […]
Life Lines by Dr. Dolittle 