Wednesday, January 29, 2014

Winter rabbit sign

During Winter, many small animals become very secretive.  With the leaves being gone from most plants they become extremely wary.  Some species retreat to the space beneath the snow - the area known as the "subnivean zone".  Other species become mainly nocturnal to hide from the eyes of daytime predators, but in some ways Winter makes it easier to tell that these animals have been around.

One of these animals is the Eastern Cottontail Rabbit (Sylvilagus floridanus).  While the Eastern Cottontail  is one of the most common mammals in Eastern North America, it can be difficult to see just how common they are.  They prefer brushy areas where they can hide from their many predators.  Because they browse on leafy vegetation, their feeding often goes unnoticed.  Being small and light (less than 5 pounds) they rarely leave tracks.

However, Winter exposes the lives of Cottontail Rabbits. It becomes easier to see what they are eating and where.  Without green vegetation, the diet of rabbits switches to twigs, bark, and buds.  The rabbits use their sharp incisors to strip bark from small branches and trunks.  If enough bark is removed, this has the potential of killing the plant. 

Cottontail Rabbit sign - stripped bark and clipped branches near the snow line

However, rabbits often get blamed for damage that they do not cause.  Any bark removed by a rabbit will be above the snow line (to a height of about 18 inches).  You can often tell how high the snow was during the previous winter by looking for rabbit damage.  On the other hand, damage right at ground level was probably caused by mice or voles.  When mice or voles chew on trees in the Winter it often goes unnoticed because it occurs in that subnivean zone below the snow.

Cottontail Rabbits have been feeding heavily on this clump of shrubs

In addition to removing the bark, rabbits often leave another sign of their feeding - branches that are neatly clipped off at an angle.  Deer also eat the ends of branches, but because they lack upper incisors the branches that they eat will have a torn or jagged appearance where they twisted or ripped them off.


Branches eaten by Cottontail Rabbits are neatly clipped at an angle

Another sure sign of Winter cottontails is their scat.  Rabbit droppings will appear as piles of dried, brown spheres containing shredded plant fibers.  These droppings look very much like cocoa puffs.  Because their digestive system does not do a good job of processing all the nutrients in the plants, rabbits will often eat their own droppings so the contents can be digested a second time.

Rabbit droppings - Do not eat the cocoa puffs!


A third sign of rabbits that winter makes visible is their tracks.  Snow exposes the movements of rabbits and allows us to track their paths of travels.  While Cottontail rabbits have large feet (in proportion to their body size) that allow them to travel across packed snow, they do not like moving through deep fluffy snow any more than most other mammals.  They usually will stick to well defined paths or runs of packed snow under these conditions. These runs (and individual tracks away from the runs) are easy to see and show us where the rabbits travel between food sources and cover. 

A partially drifted in rabbit run leading to an isolated shrub.
We are not the only species capable of recognizing rabbit runs.  Birds of prey also notice the paths made by rabbits and will often perch over them waiting for an unsuspecting Cottontail to make a move.  If you follow rabbit runs, sometimes you will find places where a hawk or owl stooped down to take a rabbit.  A patch of disturbed snow with wing makes, some fur, and a few spots of blood are often all that indicate a successful kill.

This well used rabbit path runs for dozens of yards in a nearly straight line between patches of cover.
A little bit of snow cover and knowledge of the signs to look for makes it easy to determine if Cottontail Rabbits are around and can help remove some of the mystery from the species' habits.

2 comments:

  1. We've been noticing rabbit tracks in our driveway and around our house in the snow and were just wondering what they eat in wintertime and then happened across your blog.

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    1. I'm glad that I could help. If you have any shrubs or young trees, I would look closely to see if they have been chewing on them. There are numerous products available to prevent rabbit damage.

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