With their furry potbellies and twitching noses, rabbits are adorable pets loaded with charm. But there’s one distinguishing feature that gives these cuddly creatures an added element of quirkiness – the “dewlap” dangling beneath their chins. This doughy flap of skin is the rabbity equivalent of a double chin, jiggling amusingly as they hop and wiggle their nose. But the dewlap is more than just a cute curiosity. This unique anatomical trait reveals insights into rabbit history, biology, and health. There’s more to the floppy dewlap than meets the eye. Let’s explore why domestic rabbits have these distinctive droopy necklaces and uncover the mysteries behind bunny chin folds.
The characteristics of a dewlap
A dewlap is the fold of loose skin that hangs from the neck of certain animals, like rabbits. It is located on the ventral surface, meaning the underside, of the neck. The dewlap on a rabbit forms what looks like a double chin. It starts just below the jawline and extends down the neck in a tapering triangular shape. The size and shape can vary between individual rabbits. Typically a doe’s dewlap is larger and more pronounced than a buck’s. The loose skin of the dewlap is covered in fine fur like the rest of the rabbit’s coat. The dewlap serves little purpose beyond being a distinguishing feature of domestic rabbits.
Why do rabbits have dewlaps?
Many people wonder why rabbits evolved to have a dewlap when it doesn’t seem to serve anyuseful purpose. The origins of the rabbit dewlap are not definitively known, but there are some theories. One is that it helped regulate body temperature. The skin of the dewlap is well supplied with blood vessels, so dilating these vessels would allow heat to dissipate. Another theory is that it helped protect the throat during fights. The loose skin may have cushioned blows. Does may also have used dewlaps to line nests and shelter newborn kits. Modern domesticated rabbits do not rely on dewlaps for any of these functions, but they have inherited the anatomical trait from wild ancestors. The dewlap remains as a vestigial feature.
When does a dewlap develop?
A rabbit’s dewlap begins developing around 3 months of age as part of sexual maturation. It grows most prominent when the rabbit reaches full maturity between 6-8 months old. The change is triggered by hormones. A surge in growth hormones causes the loose skin to form, while sex hormones like estrogen enlarge the dewlap further as the rabbit goes through puberty. The dewlap reaches maximum size when rabbits become fertile adults. After that point, the dewlap does not change much throughout the rabbit’s life. It may shrink slightly in elderly rabbits as skin elasticity decreases with age. But the basic presence of a dewlap remains a lifelong trait.
Can a rabbit’s dewlap be too big?
In most cases, the size of a rabbit’s dewlap is perfectly normal. But occasionally oversized dewlaps can develop and cause health issues. A dewlap that is excessively large and pendulous is called a “giant dewlap.” It can result from genetics, obesity, or hormonal imbalances. The heavy fold of skin drapes over the chest and can impede movement and breathing. It may also become irritated and infected from rubbing on surfaces. Giant dewlaps tend to occur more frequently in unspayed does. The treatment involves surgically removing the excess skin. After recovery, the rabbit can move comfortably again.
What if my female rabbit doesn’t have a dewlap?
It’s quite rare for a female domestic rabbit to naturally lack a dewlap. But there are a few explanations if your doe has no noticeable dewlap:
– She may be a dwarf breed that tends to have very small dewlaps.
– She may still be too young for her dewlap to have developed.
– Previous trauma or surgery could have damaged the dewlap skin.
– Hormonal issues or reproductive disease could be suppressing dewlap growth.
If your doe has reached full maturity and shows no signs of injury or illness, then natural lack of a dewlap could just be an uncommon genetic anomaly. As long as she seems healthy otherwise, there’s no cause for concern.
Why does my male rabbit have a dewlap?
It’s common for male rabbits to have small dewlaps too. This is because all rabbits initially develop dewlaps before hormonal differences cause dimorphism between the sexes. High estrogen levels result in females growing the large, pendulous dewlaps associated with does. Meanwhile, males are influenced by testosterone to retain only a smaller flap of fur-covered skin. So a dewlap on a buck is normal, if less pronounced than on a doe. Be aware that neutered males may develop slightly enlarged dewlaps after the surgery alters their hormone levels. But this change is harmless.
Dewlaps in show rabbits
For rabbits being shown competitively, dewlap characteristics are an important consideration. Show standards emphasize evaluating the ideal dewlap for the breed. Short compact dewlaps are favored in some breeds like Himalayans. Long wide dewlaps that taper gracefully are preferred in other breeds such as the Flemish Giant. Fur density covering the dewlap is also judged. Dewlap faults like irregular margins or asymmetry will penalize a rabbit’s score. Proper dewlap conformation counts when breeding show rabbits, because the trait is partly heritable. By selecting top specimens, breeders perpetuate dewlaps meeting the breed standard. So the humble dewlap plays a subtle yet influential role in the rabbit show world.