Sunday, July 20, 2008

Li'l Red Devils

Rufous Hummingbird
Photo by David Powell

They’re Baaaack! All summer long, up until now that is, the two species of hummingbirds that nest in the Jemez Mountains have maintained a certain decorum in their daily activities with only occasional territorial squabbles. All that changes in the blink of a night, when the brash newcomer with the extremist lifestyle arrived on the scene in early July, confidently aggressive in his bright orange-red body, much like Lightning McQueen in the recent movie “Cars”. The “Ka-chow” of Lightning when he flashes his stickers is replaced by the time bomb-like “tick-tick-tick-tick” of the male rufous hummingbird as he twitches his head from side to side alertly watching and waiting. Suddenly, no feeder is safe from the stealth attack of Attila, the Hum, as he stakes out his favored feeder, and jealously guards it from unwary intruders.

The tiny rufous hummingbird breeds farther north than any other species of hummingbird, into southern Alaska and far from the equatorial tropics in which its ancestors evolved. If measured by its diminutive body length, the species has the longest known avian migration. Although the Alaskan breeding season is short, it has the longest day-length seen by any hummingbird. In fact the day length exceeds the needs of this bird, which requires 5-6 hours of rest each night.

Males breed with as many females as possible, and their only contribution to the reproductive success is sperm. Their elaborate courtship flight is described as a complete oval, which they pursue repeatedly in the presence of any female. I found one intriguing description of an individual attempting to impress a female with his prowess and superior physical attributes. After climbing to a great height above the female perched near ground level, the male reversed heading after entering a dive and then leveled out after passing the female. He uttered a series of short dit-dit-dit-deer calls increasing in pitch, followed by a few dull “plops” from using his tail feathers as a dive-brake. Very impressive, I’m sure. Another tactic is called whisking, in which the male flies rapidly back and forth at a consistent level in front of the female, much like a whisk broom. Perhaps this tactic wears down female resistance by its endless repetitions. When I consulted the references for actual mating activity, I found only a brief paragraph which stated, “After the dive display, a female joined the male in a swinging flight, which he thought included actual mating, but he was totally unable to see the birds except as a blurred streak of color. Further study needed.”

The nest is constructed by the female alone, who also incubates the eggs, and provides all sustenance for her young. Nesting in the far north, it’s a life on the edge for one of the smallest birds in the Western Hemisphere. Because the males finish their reproductive role early in the season, they are the first to arrive and that’s when chaos ensues in southern lattitudes. Males maintain territoriality at re-fueling stopover sites for 1-2 weeks at a time during migration. The more dense the flowers, or feeders, are the smaller the territory of individual males. One of the ways to reduce aggression at your feeder is to hang several feeders on opposite sides of the house out of the line of sight of an individual bird. However, often several territorial males set up a defense network around all of the feeders. Another trick is to make syrup with a mixture of one part sugar to three parts water for one feeder. The sweeter syrup may attract the rufous away from the other feeders. However, as part of the bigger picture of hummingbird conservation, the practice of hummingbird feeders is thought to have had a positive effect on hummingbird populations overall.

When the first Attila on the scene has enough fat reserves, he will move on, only to be replaced by a later arriving male, and then the females and juveniles. Soon, they also will be joined by the Calliope and Broad-tailed Hummingbirds that nest farther north as well. Experts recommend leaving your hummingbird feeders in place until about two weeks after the last hummingbird observation, or until about October 30 in this area. That last remaining feeder may mean the difference between life and death for America’s smallest bird, the last one to depart from his Alaskan summertime residence.

All About Baby

American Robin
Photo by David Powell

You might have heard the old myth, the one that says you can’t put a baby bird back in its nest because the mother will smell the human scent and reject it. Today, avian savvy folks know that this just isn’t true, as evidenced by solid data. We also know that branching is a normal stage for baby birds of all species. This is the time when they have left the nest, but are not yet able to fly.

At this time, the parents are still caring for their young, although many young birds run into problems at this time of their life cycle due to cats, dogs, vehicles, and human intervention.
Yes, it’s true. This is the time when well-meaning humans notice those unflighted youngsters, think they have been abandoned, and KIDNAP them. They gather up the avian equivalent of a toddler, put it in a box and begin calling rescue groups looking for help for their “orphan”. We, along with wildlife rehabilitation groups nationwide, receive loads of call each spring and summer from frantic humans looking for other humans to take care of baby.

Flash back to Memorial Day 2008. It had been a gloriously long, full day of hiking in the Ojito Wilderness Area with friends, but I was tired that evening. While I reclined on my sofa, watching the news, I heard frantic shouting in my Rio Rancho back yard. Puzzled, I arose to investigate the cause of all the commotion. A male voice shouted,

“Gail! Gail! GAIL!”

Neighbor John leaned over the fence looking very relieved. Seems he had found a baby robin running around in his back yard, and felt the need to rescue it. Shortly, he produced a small cardboard, holding a small, very confused fledgling robin. We talked about nature, and how it was best to leave them be, but John wasn’t having any of that! Proudly, he handed over the box.

I waited until he went indoors, and promptly opened the box to set the little one on the ground near some dense shrubbery. My logic was that since our yards were adjacent, surely Mama Robin would hear her baby only 20 feet further away in the next yard. But, the baby didn’t cheep, or beg, or do anything except stare at me. I hid behind the door, peeking out every once in a while. After 30 minutes or so, baby was no longer visible. A few minutes after that, a plaintive cheep, cheep, cheep arose from the shrubs.

It was about then that I began to doubt all the literature, as well as my hands-on experience, and the worry set in. It was windy that evening, terribly windy. What if Mom could not hear her little one calling? After all, I hadn’t seen a robin in my yard in days, nor had I heard one. What if I had made a terrible mistake? The cheeping went on; the wind kept blowing, and I knew that I had done the WRONG thing.

Just before dark, I heard an adult robin call. But the irrational worry didn’t end there. In fact, it continued for three days, even though I was now noticing robins foraging in my yard every day. But, there was still no sign of baby. Maybe one of the neighborhood cats got him.
Finally, three days later, when I looked out my back window, there he was, and quite proud of himself too. With a stubby little tail, and half-grown wings, he had climbed up to the lofty height of about 2 feet in a sand sage. He preened; he stretched; he exuded confidence as only the very young can. Mama Robin returned and stuffed a giant worm down his throat.

All was well. There was nothing to worry about! Really! I knew that it would work out just as I intended. Whew! I hope that particular issue doesn’t happen again anytime soon.

Speaking of orphans: Hawks Aloft has already placed one Cooper’s Hawk fledgling back into its nest at an apartment complex in Albuquerque. Its kidnappers had driven it all the way to the Wildlife Center in Espanola, where it spent four days in captivity while we coordinated its return to its natural parents. Coordination meant working together to get baby back to Albuquerque, as well as assistance from our friends at PNM who donated the use their bucket truck and crew. Fortunately, there were two other siblings in the nest so the parents were still in attendance. Baby settled in nicely and, when our biologist checked on it an hour later, all three were being fed by Mom. This particular hawk baby just got an early lesson in human avoidance.

If you find a feathered baby bird on the ground, observe it from a distance to see if it is being attended by its parents. If the bird is constantly begging and the parents are not responding, only then should it be caught and taken to a wildlife rehabilitation organization. If, however, you find a naked baby bird on the ground, try to return it to its nest. If that isn’t possible, line a berry basket or shallow plastic container with some ventilation holes punched in the bottom with paper towels or tissue to simulate a nest and securely fasten that to the tree as high as you can place it. If the nestling is in danger of being harmed by pet animals, then capture it and call a wildlife rehabilitator.

The two largest rehabilitation groups in New Mexico are the Wildlife Center, Espanola, at 575-753-9505, and Wildlife Rescue, Albuquerque 344-2500.

Friday, July 18, 2008

Little Yellow Fellows

American Goldfinch
Photo by David Powell

In the world of birds there are no books; the language is unfamiliar to two-legged mammals, and self powered flight is almost a given. Of course, exceptions occur to most of the above phrases; birds don’t print or read books; some birds do mimic human speech and some humans can correctly interpret the meaning of bird sounds; and flightless birds, such as the Kiwi, the Weka, and the Emu, traverse the same paths as land-bound mammals. As with many apparent rules that govern our planet, the only hard and fast reality may be to expect the unexpected, and that the chaos theory is alive and well.

The question arrived via e-mail just the other day. In late June or early July, a Jemez resident had noted a bright yellow bird with a black cap, and wondered if it might have been a Wilson’s Warbler, a small songbird that primarily eats insects. Now, the books that determine where birds nest, winter, and migrate state that while Wilson’s Warbler travels through New Mexico during migration, sometimes in staggeringly large numbers in the fall, the breeding range occurs father north. Additionally, there are almost no recorded sightings of this species during the breeding season (June), another indication that the species nests elsewhere. However, New Mexico is a large state, and the Jemez region is definitely under-birded by the ornithological community. And, birds don’t read the books!

Among scientists, there is a theory that all bird life evolved in the tropics, lush habitat with few temperature extremes. In this Garden of Eden, food was plentiful and animal forms flourished, increasing their populations and evolving into additional species. Population expansion, in turn, may have taxed food resources, forcing animals to expand into nearby areas in search of sustenance and breeding territories with less competition. Birds, with the power of flight, could travel the greatest distance, easily reaching temperate zones. Here, these pioneer birds found abundant food, nesting habitat, reduced threat of predation and competition for resources. The limiting factor for temperate zone nesters was, and remains, weather extremes and the associated food shortages.

Perhaps the little yellow bird with the black cap was a pioneer, exploring new habitat, and searching for better nesting territory. Another well-documented pioneer set up shop along the Rio Grande in the summer of 2007, singing his heart out for a full six weeks. As of this writing, it remains unknown if the Chestnut-sided Warbler attracted a mate. If he did, and they were successful, then there is a good chance that they would return to the same area the following year, thereby expanding the range for their species. Range expansions for some species are well-documented, such as the White-winged Dove, and the Great-tailed Grackle. And just last year, in July 2006, Jo Wargo, US Forest Service Biologist, and I found a singing American Goldfinch along the Jemez River. With a bright yellow body and perky black cap, it might have been mistaken for a Wilson’s. Also out of range, this bird should have been to the north, in Colorado or beyond during nesting season. That goldfinch was well documented, and has been added to the reports for this species in New Mexico, although a nest was not found. In 2008, another American Goldfinch was observed in the same general area, perhaps representing a range expansion.

Our little yellow goldfinch of summer and cousin to the American Goldfinch, is the less common, and more range restricted Lesser Goldfinch. Like the birds above, its body is bright yellow, but the black on its head trails down the back of the neck (nape) and covers its back. His sweet song brightens summer days when most of the other songsters have finished their last aria. Like its cousin, it is one of the last to begin nesting, often not until the summer monsoon season, when its preferred foods, thistle, sunflower, and other weedy plants, set the seed crop that will easily satisfy the rapidly growing young as well as their parents. Uniquely adapted for seed-eating, their diet is almost entirely vegetarian, unlike most other birds. In fact, it is the goldfinch’s mostly vegetarian diet that makes them a poor host for the nest parasite, Brown-headed Cowbird. Although cowbirds do select goldfinch nests in which to deposit their eggs, the young cowbirds are unable to thrive on the seed only diet lacking in animal protein, and do not survive.

Both goldfinches adapt well to human activities and can be found in weedy fields, as well as in your own back yard. To attract goldfinches to your back yard, consider hanging a thistle, or niger, feeder. In New Mexico, you might just see the bright yellow Lesser Goldfinch during the summer, replaced by its northern cousin the American Goldfinch during the winter. At the higher elevations in mostly coniferous forest, thistle feeders will attract another finch with only a hint of yellow in its wings and tail, the Pine Siskin.

These hardy little birds are survivors in a human dominated world, and in fact, populations have benefited from our activities. The only threat reported in the literature is capture for the pet trade! While this is unthinkable within our country’s borders, our little yellow fellows spend at least a portion of the year in the tropics where there is little protection or understanding of the impact of poaching on wild populations.

The identity of the little yellow bird that was the subject of the question that motivated this article–what it mighta’ been, coulda’ been, but shoulda’ been–is anyone’s guess.