Here are 10 animals that have some of the highest levels of testosterone and the impact it has on their behavior and characteristics.

Some animals form lifelong pair bonds that run deeper than simple mating. These connections shape how they live, move, and interact with the world. When a partner is lost, the change is often visible.

Scientists suggest female frogs listen for changes in the male calls as a signal for when it's warm enough to mate.

The Lion King got one thing right: love is in the air on the savanna. From the birds perched in the trees to the foxes curled in their den, plenty of these grassland creatures are monogamous and mate ...

The results of inbreeding can be very distressing to witness. In this Instagram post, we see a captive lion with skull deformities, and in this post, we see another lion with drastically shortened ...

Fatal attractions are a standard movie plotline, but they also occur in nature, with much more serious consequences. As a conservation biologist, I’ve seen them play out in some of Earth’s most remote ...

Across the U.S. between 1 and 2 million large animals are involved in vehicle collisions each year, according to the Federal Highway Administration.

Add Yahoo as a preferred source to see more of our stories on Google. In New Zealand, females from an invasive South African mantis species may be luring native males to their deaths. It's an example ...

Some sanctuaries offer shelter; The Wild Animal Sanctuary in Keenesburg, Colorado, offers rescued animals a place to reclaim their wild spirit. With more than 1,200 acres of land, it’s a refuge for ...

WEST LAFAYETTE, Ind. - When female tiger salamanders choose a mate, it turns out that size does matter - tail size that is - and that's not the only factor they weigh. Findings of a Purdue University ...

Fatal attractions are a standard movie plotline, but they also occur in nature, with much more serious consequences. As a conservation biologist, I’ve seen them play out in some of Earth’s most remote ...