Birds Of A Feather: San Miguel’s Midsize Black Birds - Grackles, Anis And Cowbirds

By Bob Graham

Starting with grackles!  First, let’s get the species of grackles that we see in San Miguel correct.  They are not Common Grackles, a species that are very often seen in the skies of the US and Canada, but which doesn’t range into México.  Also, despite at least one local publication’s claim, they are not Boat-tailed Grackles either!  Except in Florida, Boat-tails rarely stray far from saltwater shores and they only range as far south as Houston Texas.  Instead, what we see here are Great-tailed Grackles.

Male Great-tailed grackles are an iridescent black, long legged, flat headed bird with stout, straight bills.  But their most distinguishing feature is their folded, V shaped tails, which are nearly as long as their bodies. They have a whole range of vocalization from rattles, to whistles to explosive static! So varied are these calls that some equate them to the seven passions of life, i.e. love, hate, fear, courage, joy, sadness and anger! The females are mostly brown and about half the size of the males.  Their tails are long too but nowhere the length of the males.  This size and colour difference has led some to think, incorrectly, that they are a different species.   

Grackle’s collective name is “Annoyance of Grackles”! A name that dislikers of the species probably feel is appropriate. So, love them or hate them, Great-tails display what scientists call “behavioral flexibility”.  This gives them the ability to live in a variety of habitat and they do very well around humans.  So here in San Miguel, we see them everywhere, especially at night when they return from foraging to roost together in large numbers.  Those of us who lived in San Miguel up to the early 2000's will remember flocks of them at night in the Laurel trees at the Jardin.  Arriving at dusk, it was a ponderous sight to see and hear. 

Next, let’s look at Groove-billed Anis.  The place I see them most often in San Miguel is from the roof of our home as they forage for insects and seeds in the vegetation that grows along the edge of Arroyo de Las Cachinches in Colonial Guadalupe. But other similar habitats throughout San Miguel de Allende are just as likely to have their own population.  Anis are birds that at first glance one might misidentify as a grackle.  They are about the same size and their black and floppy tail is as long. But the minute you see their bill, you will realize your mistake. 

An Ani’s bill is huge with lengthwise grooves running along the upper mandible. Because of that, you might then think, parrot! Wrong again! Anis are instead a member of the Cuckoo family. Anis usual feed in small flocks moving through the vegetation with quick choppy flaps and short glides.  They hunt by flopping into bushes and shrubs in a disjointed kind of motion that scientists think may be designed to stir up their prey, while giving their distinctive PIT!-tooee vocalization. Groove-billed Anis also nest collectively. As many as five nesting pairs may share one nest all taking turns incubating the eggs.

The last bird that I would like to introduce is the Bronzed Cowbird. Why? Because, at first glance, it looks similar to the previous two.  (“Birds of a feather”, right?)  Unlike the other two photos which are mine, I got this image from the internet because it really highlights the features of this bird that helps you tell them apart. The first obvious thing you will notice are their intense red eyes seen in both the males and females. As well, in good light, the male shimmers with deep, glossy blue wings, while their black body has a velvety bronze sheen. Like their smaller relatives, the Brown-headed Cowbird, these unusual birds are “brood parasites”. That is, they lay their eggs in the nests of other birds, leaving these unwitting hosts to care for their young.  The Brown - headeds chooses to parasitize smaller birds’ nests, like warblers. The Bronzed Cowbirds often select larger bird nests, like Orioles.  In one case, researchers found 17 Bronzed Cowbird eggs in a single Oriole nest!  At dusk in the fall of some years, both cowbirds along with Red winged Blackbirds and other similar species, gather near suitable roosting sites and form beautiful, swirling clouds called a murmuration.  A good place to look for these spectacular displays is in the skies over Charco del Ingenio.