John Stella, Ph.D. State University of New York, Syracuse Environmental Science and Forestry (SUNY ESF) Key Concepts

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1 Beaver Life History, Biology & Habitat Requirements Photo by Michael S. Quinton, National Geographic Society John Stella, Ph.D. State University of New York, Syracuse Environmental Science and Forestry (SUNY ESF) Key Concepts Beaver life history and global distribution Settling in: the colony, lodge, and food cache Beaver diet and food preference Dams and pond complexes Beaver as ecosystem engineer vs. nuisance Design 1

Largest rodent in North America Beaver skeleton at The Museum of Osteology,

hemisphere temperate ecosystems Castor canadensis (N.

2 Largest rodent in North America Beaver skeleton at The Museum of Osteology, Oklahoma City, Oklahoma. Ubiquitous within N. hemisphere temperate ecosystems Castor canadensis (N. America) Historically, million pre European settlement (Seton 1929) Currently, 6 12 million (Naiman et al. 1988), but estimates are crude Spatial distribution approaches its historical range C. fiber (Eurasian beaver) More limited current distribution, but expanding back to parts of its historical range. Pollock MM, Heim M and Werner D Hydrologic and geomorphic effects of beaver dams and their influence on fishes. Design 2

3 A habitat generalist, and highly adaptable. Lakes Rivers and streams Abandoned channels on floodplains Wetlands Pierre Côté California Academy of Sciences Fred Hirschmann Science Faction/Getty Images From boreal forests. Design 3

4 to deserts boondocking the good life.com/ Even some unlikely places Estuaries Glacier outwash streams Mendenhall Glacier, AK (Photo Bob Armstrong) Beaver Dam Creek, Long Island, NY Design 4

Common habitat ingredients: water + trees Northern tundra and treeline range

and/or wood limitation Water and/or wood limitation Wood limitation The Colony

litters = 2 5 kits Young stay with parents at least 2 years Adults (>2 yrs)

5 Common habitat ingredients: water + trees Northern tundra and treeline range boundary: wood limitation Southern desert range boundary: perennial streamflow and/or wood limitation Water and/or wood limitation Wood limitation The Colony Colony unit = 6 8 related individuals Avg. litters = 2 5 kits Young stay with parents at least 2 years Adults (>2 yrs) disperse to establish new lodge Territories marked with scent mounds Home ranges tend to follow shorelines Design 5

The Lodge and Food Cache Active lodges indicated by fresh food cache in fall Active lodges spaced at least 0.

5 5 colonies/km 2 (Hill 1976, Novak 1987, Baker and Hill 2003) lodge active lodges (Adirondack Mtns.

6 The Lodge and Food Cache Active lodges indicated by fresh food cache in fall Active lodges spaced at least km apart Colony saturation densities vary with landscape and region Max. density ranges colonies/km 2 (Hill 1976, Novak 1987, Baker and Hill 2003) lodge active lodges (Adirondack Mtns., NY) cache Aquatic Habitat is Critical to their Success Photo by Anna M. Harrison Beaver more agile in water than on land; maximize time in the water Ponds provide cover from predators and foraging pathways Lodge includes underwater entrance, nest area above water Design 6

Bank den (Colorado Natural Heritage Program) Location, location, location.. Bank dens vs.

County, CO (Colorado Natural Heritage Program) Mid lake lodge Beaver Diet: A choosy

Demers, SUNY ESF Food is not usually limiting Spring/Summer: herbaceous plants, incl.

cambium of cached woody plants Woody plants comprise 86% of winter diet; 16% of summer

7 Bank den (Colorado Natural Heritage Program) Location, location, location.. Bank dens vs. aquatic lodges Food caches can be submerged or exposed Mid stream lodge in Hinsdale County, CO (Colorado Natural Heritage Program) Mid lake lodge Beaver Diet: A choosy generalist herbivore Photo: C. Demers, SUNY ESF Food is not usually limiting Spring/Summer: herbaceous plants, incl. aquatic and riparian forbs, grasses, grains and row crops Fall/Winter: tubers, bark and cambium of cached woody plants Woody plants comprise 86% of winter diet; 16% of summer diet (Roberts and Arner 1984) Number of woody species consumed range from 3 at northern range limit to >30 in southern region (Aleksiuk 1970, Hill 1982, Novak 1987) Design 7

Woody Food Considerations Maximizes energy intake with low

tasting secondary compounds Willows, aspen most commonly

Quinton, National Geographic Society Photo by Anna M.

around lodge Dam location cued by running water Photo by Anna

, plastic, metal) Where palatable species are rare, conifers

8 Woody Food Considerations Maximizes energy intake with low costs Easy digestibility; short gut retention time Avoid bad tasting secondary compounds Willows, aspen most commonly preferred; conifers avoided Photo by Michael S. Quinton, National Geographic Society Photo by Anna M. Harrison Dams & Building Materials Created to impound water around lodge Dam location cued by running water Photo by Anna M. Harrison Dams constructed of wood and available debris (e.g., plastic, metal) Where palatable species are rare, conifers are used more in dams, with hardwoods saved for the food cache (Barnes and Mallik 1996) Design 8

9 World s largest beaver dam Images courtesy of Ecoinformatics, Inc. Found in Alberta, Canada (2007) using Google Earth 850 m; longer than Hoover Dam! Dam/Pond Complexes Multiple dams create safe transportation corridors to connect large ponds Dams complexes grow over time, allowing beaver more access to food sources Photo: G.S. Haulton Photo by Anna M. Harrison Design 9

10 Ecosystem Engineer, or Nuisance? Unintended beaver damage includes timber, crops, ornamental plants, and even buildings Common management concerns include culvert blockage, road flooding, dam removal and beaver control structures References Aleksiuk, M. 1970b. The seasonal food regime of arctic beaver. Ecology 51: Barnes, D. M., and A. U. Mallik Habitat factors influencing beaver dam establishment in a northern Ontario watershed. Journal of Wildlife Management 61: Baker, B. W., and E. P. Hill Beaver (Castor canadensis). Pages in G. A. Feldhamer, B. C. Thompson, and J. A. Chapman, editors. Wild Mammals of North America: Biology, Management, and Conservation. Second Edition. The Johns Hopkins University Press, Baltimore, Maryland, USA. Hill, E. P Control methods for nuisance beaver in the southeastern United States. Pages in Proceedings of the seventh vertebrate pest control conference. Karraker, N.E., and J.P. Gibbs Amphibian production in forested landscapes in relation to wetland hydroperiod: a case study of vernal pools and beaver ponds. Biological Conservation 142: Naiman, R. J., C. A. Johnston, and J. C. Kelley Alteration of North American streams by beaver. Bioscience 38: Novak, M Beaver. Pages in M. Novak, J. A. Baker, M. E. Obbard, and B. Malloch, eds. Wild furbearer management and conservation in North America. Ontario Trappers Association and Ontario Ministry of Natural Resources. Roberts, T. H., and D. H. Arner Food habits of beaver in east central Mississippi. Journal of Wildlife Management 48: Seton, E. T Lives of game animals, Vol. 4, Part 2, Rodents, etc. Doubleday, Doran, Garden City, NY. Wright, J. P., C. G. Jones, and A. S. Flecker An ecosystem engineer, the beaver, increases species richness at the landscape scale. Oecologia 132: Design 10

USING BEAVER DAM ANALOGS TO REDUCE DOWNSTREAM SEDIMENT LOADS

USING BEAVER DAM ANALOGS TO REDUCE DOWNSTREAM SEDIMENT LOADS A Pilot Project in California Creek, Spokane, Washington, USA Sue Niezgoda, Ph.D., P.E. Associate Professor of Civil Engineering Gonzaga University