Monday, June 2, 2008

Brave New World

Golden Eagle Chick. Photo by Ron Kellermueller

Perhaps it was a tussle over a food delivery. Or sibling rivalry. Maybe it was an ordinary exercise session gone amok, the furious pre-flight flapping that strengthens flight muscles in preparation for the aerial maneuvers that will come later. We will never know the real cause of the eaglet’s premature descent from her lofty nest. The wise biologist who had been watching the nest all season knew, however, that there should have been two eaglets still inside the safety of the sizeable stick fortress in which they had been born. The biologist began his search, and easily located the large female chick huddled in natal position on the ground, a behavior common to most unfledged nestlings. With only half-grown flight feathers, she was definitely too young to be out, yet putting her back was a physical impossibility. She would not be flighted for another week or so. Her chances for survival? Reasonable, particularly because she was already quite large, and few animals would attempt to prey on a chick of this size, particularly with defensive parents in the immediate vicinity.

Great Horned Owls do not build nests. As the earliest nesting species other than eagles, they merely select their preferred nest, add a nest lining, and set up housekeeping. Unfortunately, they are not known for their ability to select structurally sound nests. Many disintegrate as the young begin to move around. Such was the case of the nest watched by the female biologist, but its demise was particularly early, when the nestlings were only about 2 weeks old, still covered in gray down, and far too early to expect survival of the young. Two diligent searches a week apart failed to reveal any evidence of survival and this nesting attempt was declared failed. One month later, however, a songbird biologist conducting a survey in the same area called to ask if there had been a Great Horned Owl nest because he had seen two fledged owls and their attentive mother. Interestingly, the sighted trio was within 50 feet of the original nest.

The transmission line that runs through Ted Turner’s Armendaris Ranch bears a special name, “Maternity Row”, bestowed by ranch manager, Tom Waddell. Nearly every transmission tower holds at least one nest, and on average, there is an active nest on one of every two towers. Most are ravens, but Swainson’s and Red-tailed Hawks also crowd into the premium high-rise district. Management practices on this expansive ranch, just east of Elephant Butte Reservoir, are intended to foster healthy populations of all wildlife. The Chihuahuan desert ranch positively teams with life in all shapes and sizes, from large ungulates including Oryx, pronghorn, and bison, to endangered turtles, prairie dogs, Burrowing Owls, bats, and cicadas. In fact, I had never before seen so many cicadas in my life. It was a smorgasbord of food, enough for everyone even the sizeable families of quail with golf ball-sized young speeding along on invisible legs.

We were there to look for a particular nest, one that held two very precious nestlings, the first of their kind in New Mexico – Aplomado Falcon – another species that does not build nests, but generally uses existing nests in oversized yuccas. However, when a bird is reared on a wooden structure, perhaps it views that as the most desirable nest location. One tower held a smallish nest, located in the shade of the crossarms above. It was insignificant in size compared to the others, but I got the scope out just in case. As I watched through the lens, one tiny white fuzzy head bobbed above the nest rim, soon joined by another. Precious cargo here, watched and loved by ranch management and biologist alike, a success story just one year following the first release of 11 young, by the Peregrine Fund in August 2006. Chances of survival for these two chicks are mixed. Birds that attempt nesting when they, themselves, are less than one year old, may not be sufficiently skilled hunters to provide for their young. Here, however, watchful human eyes keep a close, but distant eye on the nest, and food limitations are certainly not a problem.

The woman called to tell me that she and her family had discovered a nest with five featherless nestlings on their boat. She wasn’t asking for information, just telling me about her discovery. As politely as possible, I asked how they had handled the situation and suggested that the best thing to do was to either return the nest to an area very near where the boat had been or to transport them to a wildlife rehabilitator. Her response was to say that they had already driven five miles before the discovery and did not want to take the time to put them back. Instead, they had placed the nest on the ground under the shade of a tree (five miles away from the original location). The disastrous phone call continued as the woman went on to tell me that ‘these birds’ need to learn not to build their nests on people’s boats. So ‘these young’, species unknown, had no chance for survival, and indeed the woman reported that by the next morning only the centermost nestling was still alive. I still haven’t figured out why she felt the need to display her ignorance in this way.

Many chicks of all species end up on the ground before they can fly. It is a stage called ‘branching’ and the young are indeed quite vulnerable at this stage even though it is part of their normal life cycle. The parents continue to feed and care for their young, while at the same time, teaching them to find and consume appropriate food. Most baby birds, especially those that have almost all of their feathers do not need to be rescued.

Another myth is that a mother will reject a baby that has been handled by humans because of the human scent. This is not true. If you can find the nest, the best thing to do is to put the youngster back into the nest. If you cannot find the nest, which is probable because birds hide their nests for protection, then you can build a nest to hold the baby bird.

Find a margarine tub, or similar shape and puncture it with drainage holes. Line it with tissue for support and warmth. Nail the container to the tree as close as possible to where the bird was found, making sure that the location will remain shaded and protected as the sun moves. Watch for a parent to find the nestling and continue to care for it. Monitor for at least two hours. If you still have concerns, contact a wildlife rehabilitator. Two different groups are within an hour’s drive of Jemez Springs. The Wildlife Center, (505-753-9505) located in Espanola, takes all kinds of animals including bears, mountain lions, reptiles, bats, and birds. In Albuquerque, Wildlife Rescue (505-344-2500) takes all species of birds, as well as some small mammals. If you have an injured or orphaned raptor, Hawks Aloft (505-828-9455) will assist you in making sure that the bird gets to a rehabilitator.

Of the four vignettes above, three sets of young were not in need of human interference. Only in the case of the last incident, should humans have taken a different course of action.

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