Two elusive creatures were finally captured at the Port’s habitat site — on film. A motion-activated trail camera that was hidden in the swamp caught the creatures as they emerged from the shadows of the night.
One creature has beady eyes and long, orange teeth. The other impales its prey before swallowing it whole.
Fear not.
These creatures are none other than a beaver and a great blue heron (GBH)!
Beavers are mostly active at night, but their biology suggests they may prefer to be creatures of the day. Unlike other nocturnal animals, beavers have poor eyesight and haven’t adapted to see in the dark. Because they are herbivores, they don’t need to stay awake all night to find food. It would also make more sense for them to be active during the day when it's warmer because they would use less energy maintaining their body temperature.
So why are beavers active at night then?
Once upon a time, long, long, ago, beavers were heavily hunted by humans during the day. Beavers gradually changed their activity pattern to be more active at night to avoid daytime predation. This adaptation pattern of continuing anti-predator behavior when the threat is no longer present is called “the ghost of predators past” (actual scientific name).
The GBH is also not a true creature of the night. GBHs sleep at night and the bulk of their hunting occurs during the day. But they have excellent eyesight for spearing fish and sometimes take advantage of moonlit nights to do some extra hunting.
The beaver dam provides the perfect heron hunting spot on a bright night. Perhaps this GBH was out for a midnight snack?
Or maybe these two creatures are just old friends that are staying out way past their bedtime together!