Field of Science

Snow base makes higher trophic levels available

Along a portion of the Phactors' driveway is an old privet hedge. Because of limited options, snow shoveled out of the driveway ends up piled in the hedge, and with each successive snowfall, the base has been raised. This has worked out well for the bunnies, who when denied other sources of food turn to eating bark from shrubs and young trees . First they started out chewing the bark off stems near the base of the hedge, and as the snow has piled up higher, they have used the snow bank to move up the hedge to ever higher regions on the stems, now 2-3 feet above the ground level. A colleague asked if this was "bad" for the shrubs.  Duh-uh! When a bun-bun chews all the bark off a stem, the phloem and vascular cambium get eaten too, in fact this is probably the best part.  Completely girdled stems die above the damaged zone. What's been interesting is watching how the snow has given the bunnies access to parts of the hedge generally out of their reach. After each new addition to the snow bank, white, debarked portions appear higher in the hedge.  Mrs. Phactor has bought some hay to feed the bunnies figuring it might be less expensive in the long run to feed them hay than shrubbery. Rabbit damage to shrubbery on our campus has been extensive too, although almost no one notices.  Some of these shrubs will sprout new shoots from the base after the dead portions have been pruned away.


Anonymous said...

Once the lower levels of bark are gone and the tree/shrub is girdled I figure that anything above is a goner anyway. But the deep snow gives the voles so much protection that their population isn't reduced by owls or foxes or bobcats or - any of the local predators - and they chomp away to their heart's content. Come spring and the grass can be peeled away in sheets where the busy little buggers have been. BTW, do you know that hares can climb? As soon as the bright new candles on the spruce are out the hares will work their way up. from branch to branch eating the soft green foliage. Maximum height here seems to be about six feet.

The Phytophactor said...

Oh you are so right! Don't want to know what's going on beneath the snow.