Lifecycle of a Beaver Pond

In the Carp Hills beavers are responsible for enhancing the landscape of wetlands and ponds that benefit many plants and animals. Their dams deepen ponds in natural depressions, create new ponds, and expand biodiverse marshes and swamps.

When a beaver arrives at a new site, it needs the water level to be high enough to swim in, protect its lodge from land predators, and support the plants that it eats like willow and waterlily roots.  The beaver is attracted to the sound of running water.  Its instinct is to block the flow with a wall of mud, interlaced branches and even stones, thereby creating or enlarging a body of water behind the dam.

The beaver will construct a lodge, raise a family, and live at the pond, sometimes for many years, until its food runs out (or it dies).  Then it will move on.  Eventually its dam will break and the pond will empty, returning to a stream or small pond or wetland.

Taken between 2016 and 2023, the photographs below show the lifecycle of a 4 hectare (9 acre) beaver pond in the Carp Hills.  The beavers were active in this pond for many years, repairing the dam when it broke in November 2015, but they abandoned their lodge in 2019 for unknown reasons.  The dam – a very old one – quickly breached without  regular maintenance and the pond drained.

In the drained pond, Monarch butterflies feed on Bidens (also known as Beggar Ticks), a common wetland flowering plant.

In 2020 the pond became a beaver meadow, a wetland fed by streams from nearby active beaver ponds.  Dormant seeds lying in the pond’s sediment or new seeds blown in by the wind quickly germinated and now thrive in the rich, moist soil. Butterflies and other pollinators dance among the wild flowers, an abundant display in the otherwise harsh conditions of the acidic rock barrens.

Beavers returned some time in late 2020 or 2021, raising water levels again, but still one meter below high levels. Shallow water allowed cattails to grow. Cattails and the raised water level attracted muskrats, which built five small lodges in the pond in fall 2021. Cattails are muskrat’s preferred food, but they will also eat a variety of other wetland plants and even become carnivorous if edible plant material is scarce.

The cycle has come full circle: the pond water level returned to near pre-2019 levels in late spring 2022.

Beaver pond in the Carp Hills. Sept 2016.
September 2016. The beaver pond in its full glory.
Beaver pond in the Carp Hills. May 2019.
May 2019. The beaver dam is broken. The beavers have abandoned the lodge in the foreground. The remaining water is from the spring melt flowing in from another active beaver pond.
Beaver pond in the Carp Hills. September 2019.
September 2019. The spring melt water is gone. Exposed mud flats show little vegetative growth during the first summer after the pond drained. (Photo by H. Bickerton.)
Beaver pond in the Carp Hills. August 2020.
August 2020. Over a year has passed since the pond drained. It’s now a fertile beaver meadow, a wetland filled with flowering plants, grasses, and sedges.
Beaver pond in the Carp Hills. September 2021.
September 2021. A rise in water level and channels in the marsh vegetation leading to the lodge show that the beavers have returned.  The dam is likely not repaired to its full height, keeping the water level almost a meter below pre-2019 levels. Shallow water has allowed cattails to grow.
Beaver pond in the Carp Hills. November 2021.
November 2021. Fall rains have raised the water levels further. This, combined with the 2021 cattail growth, have attracted muskrats to the pond. Muskrats sometimes live in inhabited beaver lodges, sharing the accommodations with their beaver landlords. We don’t know if they’re sharing the beaver lodge in this pond.
Muskrat lodge in the Carp Hills.
Five muskrat lodges appeared in the pond in fall 2021. Unlike beavers who use sticks, muskrats use only soft material like cattails to construct their lodges, which may also serve as feeding stations.
Beaver pond in the Carp Hills.
June 2022. The pond has returned to nearly full level.
Carp Hills beaver pond in 2023.
October 2023. The pond continues to refill.
Learn more

Read about beavers in the Carp Hills.

Read more about muskrats at Hinterlands Who’s Who.