Garceta Bueyer *aka Cattle Egret *aka Bubulcus Ibis

We were up on the roof of the apartment one evening admiring a sunset view after a light rain, and we were astounded by the large number of white birds flying into a big orito grove just south of La Josefina. Oritos are finger-sized bananas that are not commonly found in the US but are quite popular in Ecuador. They are sweet and delicious.

Anyway, back to the birds. . . 

Big white aves flying in droves to join their amigos on the oritos. Some in small groups of 3 or 4, others in v-shaped flocks of twenty. Right at sunset. Seemed like a party or a convention, definitely a planned event.

As we watched the birds converging on the oritos, I tried to count them; several hundred at least, maybe even a thousand? Dense enough in places that it can be hard to see the generous green orito leaves against the background of the white birds. And all fairly concentrated in what I would estimate is about the size of an olympic swimming pool.

My friend, Lucia, doesn't know much about the birds except that around this time of year (early dry season, aka summer), they congregate in large numbers and then suddenly, after an unspecified amount of time -- weeks maybe -- they disperse. She calls them garzas, which is the Spanish word for egrets. 

One of our newish family pandemic hobbies has been bird watching. Inspired by the game, Wingspan (check it out if you have a loved one who loves board games, birds, or both. It is gorgeous), we bought a bird book, and when we are about, we try really hard to identify birds. To be honest, we aren't very good at it -- none of us have any training, we often have forgotten our binoculars, and we wind up having ridiculous family arguments about the color of the wing tips or the shape of the beak. But it's fun! Brynna is famous for insisting she saw pink stripes. 

Ecuador is famous for its birds. For our year in Ecuador, we brought a book called Wildlife of Ecuador: A Photographic Field Guide to Birds, Mammals, Reptiles and Amphibians. Obviously these are not rare birds, but what the heck are they doing here? What is the story?

And so, I went to the book. And then to the internet.

After a fair amount of reading, I am fairly certain that the birds we are seeing are Cattle Egrets (Bubulcus ibis). These are the birds that have a symbiotic-like relationship with cattle -- picking off their bugs and lice -- in exchange for a safe rump to sit upon. In fact, as the book says, "Cattle egret favors disturbed areas, mostly tall grasslands with cattle ranching, and regularly occurs far from water. It is highly gregarious; this is the species that flies in large groups at dusk and dawn to and from communal roots."

Bingo. 

We certainly live in cattle country, far from water. And boy these birds are gregarious. But why are there so many in this one place? Why now? And why here? And is this a migratory pattern?

True to its name, Cattle Egrets are known for trailng after herds of cattle or other large wild animals. They are insectivores and basically eat up the bugs stirred up by and attraced by the large mammals. It also turns out that Cattle Egret are the most rapidly expanding bird populations in the world. Over the last 150 years, they have expanded to every continent. Having originated in tropical Asia and Africa, they flew across the Atlantic some time in the 1870s, made it to mainland Europe in the mid 1900s, to Florida in the early 1940s, and as far south as Chile by the 1970s.  

Scientists aren't really sure about why they have expanded so rapidly, but there are a number of factors: they can fly far, there has been rapid expansion of cattle and cattle grazing over the last 150 years, and they are fairly adaptable creatures. Even though they prefer grassland, they have been known to forage on farms, parks, sports fields, even waste water treatment plants. So, they are basically like Coca Cola. Everywhere. 

 Also turns out some varieties are migratory, and others are not. Isn't that strange? Doesn't answer my questions about these particular birds, but it's kind of fun to have a spontaneous research project. Even more fun to watch them glide in at sunset.

**

We took a little walk yesterday evening down to the orito grove to actually observe the birds up close. They are big. There are a ton of them. They are pretty quiet, though they lifted off in fear when we approached and did some vocalizing at that time. Dillon spied a faint yellow crest on their heads. They are also definitely wreaking havoc on the orito crop that is planted there; their weight has broken plenty of orito leaves, and their poop is everywhere. 

The woman whose property the Cattle Egrets have decided to congregate on was livid this evening; these unwelcome visitors seem to have no intention to move on, the orito crop is damaged, and she's worried they'll be here all summer and mess with her income. She rode up on a motorcycle this evening to borrow a mean dog from her mother-in-law, hoping that perhaps the dog would chase the big buggers away. She managed to heave that dog up onto the moto with her to take him back to the finca. I wish I had a picture of that.

As of this morning, a neighbor was sure it worked. They were gone. But around 6pm this evening, we saw the big white birds making their approach, back to the same orito grove. Definitely not gone. 

If you know more about these guys than I do (which is highly likely), please chime in!

References:

https://blog.nature.org/science/2021/04/26/how-cattle-egrets-took-over-the-world/

https://www.allaboutbirds.org/guide/Cattle_Egret/lifehistory