The phrase “endemic” has at all times appeared relatively imprecise to me. Oxford Languages affords this definition: 2. (of a plant or animal) native and restricted to a sure place. When a birder makes use of the phrase, we often discuss with a species that canbe principally or solely present in a single nation. Which implies that the massive nation of Mexico boasts (in accordance with one record) 127 endemic fowl species, whereas the well-known birders’ vacation spot of Costa Rica has solely 6. It doesn’t appear honest in any respect.
I’ve seen a few fifth of Mexico’s endemic birds, nearly all of them proper right here within the state of Michoacán. However one in all Michoacán’s endemics beats most of those for sheer endemism; it’s complete vary would simply match inside solely two of Costa Rica’s tiny provinces. The Black-polled Yellowthroat is generally solely discovered on three our bodies of water: Lakes Pátzcuaro and Cuitzeo, in Michoacán, and the Ciénega de Lerma (Lerma Marsh), in Mexico State. Listed here are a few my greatest pictures of a male Widespread Yellowthroat, discovered throughout North America, and a male Black-polled Yellowthroat. Females are way more related, however their songs are nonetheless straightforward to inform aside.
Widespread Yellowthroat
Black-polled Yellowthroat: It’s all within the brow.
Now, when a species can solely be discovered on three our bodies of water, it have to be disruptive when a kind of, Lake Cuitzeo, primarily dries up, and water ranges on the opposite two are drastically diminished. I used to be fearful about my oh-so-special little buddies. How would our Black-polled Yellowthroats survive?
Luckily, I now have some solutions. Final month, I took 4 of my biologist mates to a small reservoir inside Morelia’s metropolis limits. This reservoir isn’t often a really birdy physique of water, despite its good stands of cattails and reeds. However I wished to see if a few of Lake Cuitzeo’s waterfowl won’t have moved there when their normal wintering grounds disappeared. And certainly they’d; we noticed 7 wild duck species, the place often there are none.
However extra thrilling, an ornithologist everyone knows had additionally simply reported the presence of three Black-polled Yellowthroats transferring amongst this reservoir’s cattails. This was the primary report ever for this web site. Would we discover them as properly? Certainly we did!
Twelve days later, and all of us took off for Lake Pátzcuaro for our area’s solely Christmas Fowl Rely. Lake Pátzcuaro isn’t deep, however it’s apparently about twice as deep as Lake Cuitzeo, and doesn’t dry up like that lake often does. Nonetheless, by far the lion’s share of Black-polled Yellowthroat sightings happen at a web site I do know properly, Puente de Jarácuaro, on the lake’s southern shore. Because it occurred, that was the start line for our CBC workforce, and it didn’t disappoint. The cattails had been rising out of what’s now dry floor. However the Yellowthroats nonetheless turned up rapidly.
However this 12 months, the CBC solely included a complete of ten observers, so half the lake shore was ours. And in the long run, we discovered Black-polleds not solely within the normal place, but additionally at two extra websites, the place it had by no means earlier than been reported. Extra proof of resilience?
As I ready to put in writing this submit, I discovered {that a} very dependable birder has additionally seen the species on one more lake, Lake Zirahuen, for the very first time. It was additionally reported for the second time by Lake Yuriria, simply throughout the state border with Guanajuato — however a number of anomalies with that report make me much less optimistic about its veracity, though the lake would definitely be an affordable vacation spot for Cuitzeo “refugees”.
Nonetheless, it is extremely encouraging to search out that such an especially site-specific and water-dependent species can handle to fly throughout many kilometers of dry land to search out the habitat on which it relies upon. And who is aware of, maybe it’d use this disaster to search out a couple of new breeding grounds, to make sure its survival within the close to future?