An adult California condor, part of the reintroduced population in Arizona and Utah, died last month, and tests revealed elevated levels of lead in its blood.

That indicates that the condor likely consumed the remains of an animal hunted with lead ammunition, which drove condors to the brink of extinction in the 1980s. Lead causes paralysis of a condor's digestive system and eventually causes the bird to starve.

There now are a few hundred condors in the wild, and about 70 of them inhabit an area in Northern Arizona and Southern Utah.

This bird, Condor 337, was the father of a chick that recently hatched at Zion National Park in Utah. Biologists monitoring the chick noticed that Condor 337 was acting strangely, and the bird was brought to The Peregrine Fund's Arizona facility for treatment, but it died the next day.

Biologists now say they're concerned about the chick's well-being, but they say it may be old enough to survive while its mother searches for food for the two of them.

John "Verm" Sherman, a frequent Arizona Highways contributor, has been photographing the condors for years. He provided the above photo and wrote about Condor 337 on his website. It's a touching tribute to the condor and a plea for hunters to switch to non-lead ammunition. As Sherman writes:

There are only 74 wild condors in the Arizona/Utah population, of those perhaps 20 are males of breeding age.  At twelve years old, 337 was one of the elder males.  He had terrific attributes - he was one of the more independent birds in the population, preferring to seek out his own food sources rather than rely on food left out by the biologists.  It is this sort of independence that will be needed for condors to become a self-sufficient population in the future.  Sadly, it is also this independence that made 337 more susceptible to ingesting the lead that caused his death. I’ll remember 337 as a hard bird to find, but one of the most rewarding to photograph.  I hope his chick survives and leads me on more wonderful adventures.

To read more of Sherman's tribute and see more photos of Condor 337, click here.