Monday, November 14, 2022

Black-bellied Whistling-Duck nesting update

 

Four of Ohio's now famous Black-bellied Whistling-Ducks loaf along the shoreline of the small pond where the state's first apparently wild nesting record of this species occurred. I visited the Wayne County site yesterday, and all eight juveniles (although there were ten originally) were doing well. Although it was a nippy 30 F, the birds seemed to be fine. For a recap of the nesting record and status of this species in Ohio, GO HERE.

Here are all nine birds - pink-billed adult in front center - seining Lesser Duckweed (Lemna minor) from the pond's surface. They don't call this tiny flowering plant duckweed for nothing, and it seems to be a staple food for this bunch. Unfortunately, the duckweed, which blanketed the pond when the chicks hatched, is quickly disappearing.

A juvenile stretches its wings. There was much stretching and test flaps going on. However, as you can see by looking at the base of this bird's wing, not all of the wing feathers have fully grown in yet. While others have seen some of these juveniles make short test flights across the pond, I suspect they are not yet ready for long sustained flights, thus the reason that they remain in ever colder Ohio. It can take up to 13 weeks for Black-bellied Whistling-Ducks to finish their juvenile molt. In this case, that would be the first or second week of December. But, on the short end of the molt timing, it's about 10 weeks, so hopefully everyone will be ready for the long southward haul before the small pond freezes over.
All nine birds tuck into the vegetation on the pond bank for a siesta. The watchful adult is in the upper left corner. The youngsters are every bit as big as the adult, and all it took was a small one-third acre pond to raise them. Hopefully all continues to go well with them.

There are a few things worthy of pondering in this case. Black-bellied Whistling-Ducks are normally a spring nester, typically April and May. Of course, that's in the core range in North America, which lies far south of Ohio and Wisconsin. But it's interesting to note that the only nesting record further north than this one was of a brood in Wisconsin in 2020. Curiously, the Wisconsin brood was also hatched in mid-September, and was only tended by one bird. Black-bellied Whistling-Duck pairs normally share nesting duties through the duration of parental care of the juveniles. No one has seen a second adult at the Ohio nesting site.

Black-bellied Whistling-Ducks are also cavity nesters, and there doesn't appear to be any suitable cavities near the Wayne County pond that hosts the brood. The Wisconsin nesting site was also unknown. But in a pinch, this species will nest on the ground, and it seems likely that's what happened.

Not to throw a wrench in things, but Black-bellied Whistling-Duck is pretty commonly kept among aviculturists. And there are apparently a fair number of those in this part of Ohio. See THIS POST I made a decade ago and be sure to read the comments. For the record, in the case of the above-sited post, it is my opinion that the Ringed Teal was clearly an escapee, but the Black-bellied Whistling-Duck was more likely a wild vagrant. I'm quite aware that Black-bellied Whistling-Ducks are rapidly expanding their range northward unassisted, and there is a mountain of evidence to prove it. Yet that doesn't mean the species no longer can escape from captivity. In a back recess of my mind, I can't help but to wonder about that possibility in the case of Ohio's decidedly atypical nesting record. We don't have any evidence to prove that, though, and likely never will. However, I guess I would lean towards a wild, unassisted nesting record given the sheer scope of the northward invasion of this species. If the Black-bellied Whistling-Duck continues the course, it stands to reason that there will be more breeding records to come in Ohio and other northern states, and a breeding trend will become established.


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