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Beaver food caches: the winter pantry of sticks beside the lodge

October to November

Beavers do not hibernate, so through the autumn a family cuts branches and anchors them in the mud on the pond bottom by the lodge entrance, building a food cache they can swim to under the ice all winter. The gnawed stumps on the bank show where the wood was cut; the tangle of stripped branch ends out in the water near the lodge is where it is being stored.

Why this time of year

This is the build, and it happens on a schedule. In a study on the Prescott Peninsula at Quabbin, which is about eighty miles west of here, cache construction started in late September both years and the median start was the week of October 9-10, with cache volume growing by roughly nine to eleven cubic metres a week and the heaviest building from late October into November. Quabbin runs colder than Sudbury, so if anything a pond here starts a little later rather than earlier.

How to notice it

  1. Find an active beaver pond with a visible LODGE, a mounded dome of sticks and mud out in the water, rather than only a dam.
  2. Look at the water near the lodge entrance for a low raft of stripped, leafless branch ends breaking the surface. This is the top of the pile; the bulk of it is underwater, anchored in the mud.
  3. Keep it separate from the cut stumps and felled trees on the bank. Those are the sawmill. This is the pantry.
  4. Come back across a few weeks in late October and November. The pile should visibly grow, because fresh branches are being added faster than the older ones waterlog and settle to the bottom.

Try this with kids: Beavers do not sleep through the winter like bears. They stack a woodpile underwater and swim down to it under the ice. How many branches do you think are hiding below the few you can see?

a cache is a store of food put away for later, here branches pushed into the pond mud

Safety

  • Stay off beaver dams and lodges. Sticks and mud are not footing, and the water beside them is deeper than it looks.
  • Pond banks are soft and saturated in late autumn and are often undercut near lodges and bank dens.
  • Do not step onto early pond ice to get closer. It forms unevenly and is thinnest exactly where water moves.

Sources

  • massaudubon.orgMass Audubon, and the only Massachusetts source here for the behaviour itself: in fall beavers collect edible branches and anchor them in the mud at the bottom of the pond near the entrance to their lodge, and in winter the colony stays inside the lodge, only leaving it to gather the cached food from the bottom of the pond.
  • northernwoodlands.orgNorthern Woodlands: beavers cut aspen, willow, alder and red-osier dogwood through the fall and make a huge pile of sticks underwater, anchored in the mud on the bottom of the pond, and collect from it as late into the winter as they are able. NOTE this article does NOT use the word hibernate; what it says is that adult beavers reduce their energy demands by decreasing metabolic rates and activity levels in winter. The no-hibernation claim on this card comes from the Vermont and Maine agencies below, not from here.
  • zodion.nlBusher, P. 2003, Lutra 46(2):139-146, a peer-reviewed study at the Prescott Peninsula, Quabbin Reservation, described in the paper as western and also as central Massachusetts, 130 km west of Boston; zodion.nl is the access copy of the journal reprint. Cache construction began September 28 in 2001 and September 18 in 2002, median start the week of October 9-10 in both years, with increased cache-building behaviour from week 43-44 and volume growth of 8.9 to 11.2 cubic metres per week. Every active family area built a cache each year. The paper's statement that all caches were initiated by week 44 covers the ANALYSED set only: one family in 2001 did not start until week 47 and was excluded, so the figure is 7 of 8 families in 2001 and 8 of 8 in 2002. The paper tested autumn cooling as the cue and found the correlation significant in only one of four period-year cells, closing that the actual environmental cues need further investigation.
  • vtfishandwildlife.comVermont Fish and Wildlife, verbatim: since beavers do not hibernate, they store their food, branches of edible trees, in a large underwater pile near the lodge, a food cache, pulling mud or rocks over the base stems, and the pile soon becomes waterlogged and settles to the bottom. This page returns 403 to a bare curl and 200 to a browser user-agent; it was opened both here and in the refute pass on 2026-09-13.
  • maine.govMaine Department of Inland Fisheries and Wildlife, a second New England agency for the same points: beavers store food for winter by stashing stems underwater, anchored to the bottom; they do not hibernate but are less active in winter, spending most of their time in the lodge or den; and in frozen conditions they feed on the bark and stems in their cache.

Checked against these sources on September 13, 2026.

In the guide for October, November

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