Tracks and Sign: Great Blue Heron
When you think about reading PEI wildlife tracks and sign, it’s likely that mammals such as Foxes, Coyotes, Raccoons and Skunks are the first things that come to mind. But all animals leave tracks and sign: invertebrates, reptiles, amphibians and even birds. Today let’s look at the Island’s bird with the largest tracks: Great Blue Heron (Ardea herodias).
There are five patterns of toe arrangement among birds, and I’ll give examples of each of these as part of this Track and Sign series. The first, shown by this Great Blue Heron (Photo 1), is the classic arrangement – three toes pointing forward and one pointing back. The technical term for this is ‘anisodactyl’, and you’ll see this in many of the birds around your neighbourhood: Ravens, Crows, Blue Jays, Chickadees, Nuthatches, Mourning Doves, Pigeons and many others.
Size is important in tracking, and it’s always useful to have something for scale. I know a tracker who’s had a ruler tattooed on her index finger. I haven’t quite made that commitment (!) but do know that the distance from the tip of my index finger to the knuckle is four inches (about 10 cm). When I go tracking I take a ruler with me; when I just happen upon nice tracks like these, that’s a useful estimate. Great Blue Heron tracks range from 6.5 to 8.5 inches (16.5 to 21.6 cm) long. The only other bird we have that comes close is the Bald Eagle, but those tracks look quite different from this (I’ll show you an example in a future post).
Gait also tells you something about the bird. You can see that the Great Blue Heron walks rather than hops or skips (Photo 2). Walking is used by birds that spend a lot of time on the ground: Ravens, Crows, raptors, game birds, and waterfowl among others. If you find a walking gait but are unsure of who left it, knowing that can help you narrow it down a bit.
Of course, tracks aren’t the only thing birds leave behind: there’s also scat! Like tracks, scat can give you clues about who made it. Great Blue Heron scat (Photo 3) is a splash of mostly-white liquid. A soupy splat like this is indicative of meat-eaters such as Eagles and Hawks, and fish-eaters such as Osprey and Cormorants. Our Great Blue Heron is mostly a fish-eater but won’t pass up a tasty Snake, Frog, Mouse, Vole, or even a Muskrat if opportunity arises, and has the scat to show it.
As evidence of Great Blue Heron scat (so you know I’m not just making this stuff up), I’ll leave you with this fantastic action shot from well-known Island photographer Brian McInnis (Photo 4, used with permission). Tracking PEI wildlife can be cool or crappy, depending on your point of view!