Tired of waiting for mom, this isabelline wheatear chick (Oenanthe isabellina) faced the morning sun and achieved its first airborne moments. (11 additional photos.)

Many species of animals are highly adaptable – if given half a chance. Until recently, this construction site in Ulaanbaatar, Mongolia, was steppe grasslands. Chock full of the abandoned rodent holes isabelline wheatears seek out to make their nests, it was perfect habitat for these passerines.

But as Mongolia’s population continues to grow, the grasslands which once seemed limitless are shrinking. This fortunate adult and her mate successfully reared a pair of chicks in a cavity beneath an old truck tire. Here, safe from the stray dogs that plague this city, and unnoticed in a lot that has yet to be developed, the chicks’ parents have been able to forage the steady supply of grubs and insects their offspring thrive on.

Unfortunately, these will likely be the last wheatears to brood on this lot. On our morning run today, we noticed that the bulldozers have arrived. Yet another apartment building and adjoining parking lot will replace the last remnants of suitable habitat.

We had been observing the adult wheatears in this area for some time. But only on this, the final day the birds were here, did we realize a nest and chicks were in such close proximity. We shot these photos through a locked gate, at a far enough distance that it was a challenge to get clear captures.

At one point we observed an interesting behavior. The chicks were pecking at a piece of plastic. The mother, observing this and perhaps understanding, somehow, that ingesting the plastic could be fatal to her offspring, picked up the rubbish and flew off several meters from the nest before dropping it and returning.

There seemed to be no sating the young birds’ appetites…The adults returned again and again…

With much anticipation…

Their stubby wings and chubby bodies hardly seemed to bode well for flight. Was it out of boredom or hunger – or something even more primal – that prompted one of the birds to begin vigorously stretching its wings?

Suddenly it occurred to us. These little guys are going to fledge, right now!

And just like that…

The female returned for a final look at her empty nest, then caught up with the chicks. They hid behind a a pile of rusted junk, and that was the last we saw of them.

Who would suspect that a a nest of birds was once here, hidden safe and well-fed beneath this rotting tire?

A while later, we encountered this juvenile perched on the ledge of an apartment near ours. Where will they go next year? It’s a question with no easy answer in a world that continues to fill up with people.