Mountain Beavers are widespread in Discovery Park, particularly on slopes, where soil and duff were bull-dozed during the creation of flat spaces for army buildings during the period when it was Fort Lawton. Native vegetation is much more likely to occur on these slopes, including Sword Ferns, Mahonia sp., snd smaller shrubs like Indian Plum, Red Elderberry and conifer saplings. It seems likely, at least from anecdotal evidence from volunteers and indeed my own observations, that their numbers are increasing significantly. There at least two possible reasons for this. One is that through restoration efforts of volunteers in the last few years, the number of young conifers and other small native plants is increasing. Volunteers often report that Aplodontia use the young trees as step ladders to climb up to bite off the outer shoots and tip-leaders. Restoration sites are quickly colonised it seems.The second reason is that the park lacks a predator appropriate to these smaller mammals

Bobcats are very rare in this neighbourhood and coyotes, while probably occurring regularly, are viewed with disfavour by local pet-owners and are discouraged in various ways by the public. A further predator would be owl species. Barred Owls, and Great Horned when they are present, regularly hunt from perches in mountain beaver "warrens" and must represent their dominant predator at the moment. Also I have seen Barn Owls carrying carrying what look like these critters back to their nests in the park. Seems like quite a load for them, but who knows.

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David Hutchinson, Owner
Flora & Fauna: Nature Books
Discovery Gardens: Native Plants
3212 W.Government Way
Seattle,WA.98199
http://www.ffbooks.net/
206-623-4727