Dear Grackle,
You are one of my favorite birds. I love to watch you at the birdbath and enjoy listening to your conversations with each other, even though I don't know what it is you are saying to your friends! However, I am concerned about the various items that show up in my birdbath. I once found a 2-inch nail, and on another day a small black plastic clip showed up. I think it is coming from the construction site near my home.
Are you mistaking these items for bugs that are normally found in the ground, and once you wash them off and taste them realize that they aren't what you thought they were? Or are you simply drawn to shiny and novel objects? I have never seen this before with other birds. I am concerned about your safety and want to do what I can to keep you happy and healthy and always coming back to my house for special treats of Butter Bark and nuts and, of course, plenty of fresh water in this desert area in which I live.
Thanks,
A fan of the great-tails
Dear Fan,
Thank you for the compliments, I'm so glad you enjoy our grackle conversations! While I don't know exactly why your specific grackle friends are leaving nails and pieces of plastic, I can make an educated guess based on general grackle behavior.
Grackles (especially common grackles) have been observed dunking pieces of food in water, possibly to wash or soften them. So, it could be that your grackles are, as you mentioned, mistaking these objects for food and then realizing later they're not edible.
The collecting theory is an interesting one. While I don't know of any grackles exhibiting collecting behaviors, I do know of several other species of birds that collect non-food items. The satin bowerbird, which lives in Australia, collects objects to attract a mate. Bowerbirds have a special affinity for blue objects, and will spend much time seeking out blue flowers, feathers, pieces of plastic and glass to impress potential suitors. Crows have been documented bringing shiny objects such as coins and pieces of glass to humans who regularly feed them. You might wonder about magpies — billed in folk stories and anecdotally as avid collectors of shiny objects — but magpies were shown in a 2014 study to have no affinity for trinkets, and actually proved to be a bit scared of shiny, novel items.
Sorry I don't have a better answer for you, grackle fan. In this world so full of mysteries, thank you for being kind to birds!
Yours,
Grackle
