Mysterious signs of Canada Geese

The sound of Canada Geese returning to their northern breeding grounds is one of my favourite signs of spring – “goose music”, as Aldo Leopold called it. Their northerly migration is also marked by the return of feeding signs in PEI’s bays and estuaries, and some related behaviour that may surprise you!

You likely think of Canada Geese (Branta canadensis) as herbivores, feeding on aquatic vegetation and grasses in spring and summer, and remnants of agricultural crops in fall. Like many herbivores (including Snowshoe Hare and Red Squirrels featured elsewhere in this blog), Canada Geese are not strict vegetarians and will eat meat when the opportunity arises. During the spring Goose migration, small shellfish present an opportunity!

Photo 1: Bowl-like depressions on the shore left by Canada Geese feeding on shellfish.

If you’ve walked the shores of our Island’s bays, estuaries, or tidal rivers lately you may have noticed lots of crater-like depressions (Photo 1). Your first thought may be that these were human-made, but that’s not the case: this is the work of Canada Geese. The retreating tide reveals the depressions, but they were made under shallow water. The Geese paddle their feet to move the sediment aside, exposing the shellfish and creating these distinctive bowls in the process.

Photo 2: Canada Goose scat can look very different depending on diet. One the left is the typical cigar-shaped scat from a bird feeding on vegetation. On the right is the much softer scat from a bird feeding on shellfish.

In previous posts, I’ve described how a bird’s scat reveals its diet. Canada Goose scat is usually the firm, cigar-like tube indicative of herbivores (Photo 2, left). When they’re feeding on protein-rich shellfish, it’s much softer and more typical of what you’d see from carnivores and scavengers (Photo 2, right). You can clearly see the remnants of Blue Mussel shells, ground up by the muscular gizzard and excreted (conveniently over some intact Blue Mussels in Photo 3).

Photo 3: Scat from a Canada Goose that has been feeding on Blue Mussels. You can see the ground-up shells in the scat, conveniently located on top of some intact Mussels on the shore.

Keep your eyes open for Canada Goose feeding signs if you’re out exploring Island waterways in Spring. Another part of PEI untamed!