May 2022 Natural Mystery Answered
Our May Natural Mystery proved to be a challenge, but Mike Holtz rose to the occasion and successfully identified the species that left these tracks. Size turned out to be the key feature here. Few other classic bird tracks found in Minnesota fall into this range.
These are the tracks of a Common Grackle, Quiscalus quiscula
I’ll turn it over to Bill to explain how he identified this print:
"These are Common Grackle tracks. Classic bird tracks, about 2 1/8". The metatarsal isn't registering much, but there is a pretty good claw registering on toe 1.
Birds with similar sized tracks might include:
Robin - I would expect more curve to the track and the toes
Starling - Toe 3 would look a lot longer than toes 2 and 4
Blue Jay - Much narrower tracks and segmented, thicker looking toes
Rock Dove - I would expect more like 90 degrees or more between toes 2 and 4."
As Mike's answer suggests, there are actually very few other birds in Minnesota that leave classic tracks this size. And those that do have distinctly different appearance.
The Common Grackle is the largest blackbird in Minnesota. Their tracks share the Icteridae "family resemblance." The tracks of larger grackles, such as the Boat-tailed Grackle of the Southeast coast, can resemble smaller crow tracks. But here in Minnesota, grackle tracks are distinctive enough to be instantly recognizable.
Grackles forage on the ground and can be prolific track-makers. They eat large amounts of grain, but are resourceful omnivores. They have been observed following plows to catch invertebrates and mice, wading into water to fish, picking leeches off the legs of turtles, stealing worms from American Robins, robbing nests, and even predating smaller songbirds. Grackles also have a hard, slightly saw-toothed keel on their upper jaw that they use for opening acorns. They usually score the outside of the narrow end, then bite the acorn open.