141: Hares and Jackrabbits
Today’s newsletter is dedicated to Freya, the pet rabbit of friends of the newsletter, who has been having some health issues lately but is doing better!
Colorado has eight species of lagomorph – pikas, rabbits, hares, and jackrabbits. We’ll talk about the first two another time, but today we are going to talk about hares and jackrabbits, who are both members of the genus Lepus, distinct from rabbits by their larger size, larger feet, and longer ears, as well as black markings on their fur. What they have in common with rabbits is their kinetic skulls, which means they have a joint throughout their lives between parts of their skull – all other mammals lose this in childhood. For rabbits and hares, this seems to be an adaptation to the force of striking the ground while hopping. Young hares are called leverets, and hares create flattened nests of grass known as “forms” to raise their young.
Colorado has three species of hares/jackrabbits: the white-tailed jackrabbit, the largest in the state; the black-tailed jackrabbit, and the snowshoe hare.
The white-tailed jackrabbit’s coat changes color throughout the year, from brown to white, which seems like it is going to be a problem for it as climate change shortens snow seasons. They live in mountain parks, in shortgrass prairie, and in sagebrush cover throughout the state.
The black-tailed jackrabbit lives in the desert environment of the southern and western parts of the state, as well as in Euro-American agriculture-disturbed areas of the eastern plains. Where agriculture has changed the plains environment (think everything along I-76), these jackrabbits are replacing the white-tailed ones.
The snowshoe hare lives in sub-alpine forests, making its home in thickets of willows and similar vegetation. In learning about them, I read this quite tragic sentence from Colorado Parks & Wildlife: “Understanding and monitoring snowshoe hare density in Colorado is important because hares comprise 70% of the diet of the state-endangered, federally threatened Canada lynx.” Snowshoe hares are important in their own right, not just for being kitty food!! They are named because of their feet – they splay out the toes of their back feet as they bound to create a “snowshoe” effect in snow, so their tracks appear as if the hind foot is much larger than the front. They can also jump into water if threatened and swim using their back feet as flippers. They warn of predators by pounding their back feet, causing other hares in the area to freeze. Much like the white-tailed jackrabbit, they change from brown to white with the seasons. Here’s how:
“The complete change in color takes place over a period of ten weeks. Changing amounts of daylight and shifts in temperature trigger a hormonal reaction in the animal that causes it to produce different biochromes. (Pigment in the living cells from which the hair grows). The fur of animals is like human hair and fingernails – they are actually non-living tissue, therefore the hare has to produce a whole new coat of fur in order to change color. In addition to background-matching coloration the contrasting coloration is called “disruptive coloration”, a pattern which does not coincide to the contour of the body and this also serves to conceal them.”
The article linked above has LOTS of fascinating hare facts. My fav: “The phrase “mad as a March hare” first appeared in print in Chaucer’s Friar’s Tale in the late 14th century and in John Heywood’s collection of proverbs published in 1546. It was based on the antics that medieval Europeans observed in breeding wild hares in March. They would see the hares boxing at other hares, and jumping vertically.”
This drawing of a snowshoe hare: the reference photo also looks angry. That’s all I can say in its defense.