Forest Hawk

Juvenile Cooper's Hawk. Image by David Powell.

Just two days ago, two juvenile birds joined our avian ambassador team, a young Common Raven and a male Cooper’s Hawk (more about the raven in a later issue), courtesy of the Wildlife Center in Espanola, New Mexico. Both had wing injuries that rendered them non-flighted and permanently non-releasable. The good folks at the center had toiled long and hard to rehabilitate the two so they could be returned to the wild, but unless a bird is nearly 100% fit, it would not survive. In cases like these, the only choices are to place them with an educational organization like Hawks Aloft or toeuthanize them.

Coops, as we affectionately call them, are notoriously challenging to handle in captivity and have a well-deserved reputation for aggression. They belong to the Accipiter family, forest hawks that have short, rounded wings and long tails to help them maneuver through dense vegetation in search of prey, primarily other birds. The other two species of Accipiter in North America are the tiny, Sharp-shinned Hawk and the Northern Goshawk. Both of these species nest in coniferous forest where they can coexist because the size of their prey it significantly different.

Adult Cooper's Hawk. Image by David Powell.

This little fellow, who still wears the bright yellow eyes of a youngster, arrived thrashing around in a pet carrier, acting every bit like he could take me on and win. Patience and extreme calm are essential when training a bird that arrives from the wild, helping the education bird adjust to life in captivity, and ultimately being presented at public education programs.

You might wisely ask why we would want such a volatile species for our education program. Our most common urban nesting raptor -- the Cooper's Hawk – is reknowned for its aggressive nest defense behavior. Each year, during the month of June, we field numerous phone calls about aggressive hawks. During the courtship, egg-laying, and incubation stages the birds are unobtrusive and, in fact, are very difficult to detect.

We attached jesses almost immediately after he arrived, figuring that it already was a stressful day, and it might be better to get on with the final indignity of attaching the leather straps that would tether him throughout his training and also later during public programs. Then, we let him rest for a full 24 hours before bothering him again.

Adult Cooper's Hawk with prey. Image by David Powell.

All this changes; however, once the young have hatched, and the parents have a greater investment in this year's nest. They can become extremely defensive, and the unwary human who inadvertently crosses into their territory first hears the loud, scolding call, "Kek, Kek, Kek, KEk, KEk, KEK, KEK, KEK!" Then, when they turn to see the source of the insistent warning, they find themselves face-to-feather with a furious, rufous-breasted, gray-backed bullet with blood red eyes. The automatic response for most humans is to fall to the ground, cringing in terror, lest the bird actually strike them. Then, after escaping from the incident unharmed, they scramble to the telephone and begin calling anyone who might help with the situation. Enter the Hawks Aloft education program for homeowners.

This morning, when I lifted the cloth that covered the carrier, he looked ready for battle, all 2/3 pound of him. He flipped over on his back and presented his talons, ready to grab me. A quick flip of the towel and I had him in my hands, attaching the lead. We sat together in the sunny living room as I tried nonverbally to communicate that this really would be okay, that I would never hurt him.

Adult Cooper's Hawk. Image by David Powell.

Most of the callers appreciate 'their' hawks, and just need a little education and assistance to avoid arousing the defense mechanism of the feisty parent, doing their best to protect their young nestlings from the perceived human danger. It helps when we give them tips to avoid arousing the angst of the hawk, and reassure them that Cooper’s Hawk will only rarely actually strike a human. Generally, they pull up at the last minute. Biologically, it would not be wise for a bird weighing between ½ and 1 pound to take on a 100+ pound human. There have been no reports published of serious human damage incurred from the attack of a Cooper’s Hawk. We work with them through the 3-4 week period, and the result is usually a happy home or business owner once the young are out of the nest, and the aggression stops as suddenly as it began.

Now, several hours later, he is quietly sitting on a specially made perch atop a covered table in the shrouded extra room (Coops can eject their waste stream with considerable force over great distances). A de-feathered quail carcass sits by beside him, hopefully tempting him to dine. I only pause at the door to check on his well-being. It is enough for today and tomorrow, until this becomes normal to him. Only then will we move on to the next part of training. We have all the time in the world.

Then, as the young begin to disperse with their newly earned fledgling independence, the phone begins to ring again, with a call arriving almost every day. The young birds, in their early hunting attempts, chase anything feathered, often pigeons or sparrows. The juvenile Coop pursues them with great abandon right into the warehouse, building, or batting cage and, once inside, cannot figure out how to get back out. We have become adept at catching and releasing them. It makes for a busy summer.

One day, possibly months from now, he will make his debut, educating the public about an often misunderstood raptor, the Cooper’s Hawk. While all of our education birds do have names that we use to distinguish them from one another, they do not respond to being called by name. We rarely use their names in presentations. Only when the name is educational in some way, relative to the species, the injury, or the location where the bird was found, is it ever revealed. This little guy will have just such an educational name. We call him Forest – Forest Hawk.

Tiny Titans: Hummingbirds

Juvenile and female hummingbirds can have remarkably similar plumage, making identification very difficult. Image by Keith Bauer.

There’s something mesmerizing about watching them buzz around a feeder, a seemingly endless line of thirsty beaks. Have you ever tried to count how many hummingbirds actually visit your feeders at one time? Some folks I know maintain 10 or more feeders, going through 50 pounds of sugar a week! A friend stopped by today to drop off one of his fabulous hummie images and professed to know, not the total number that visit his feeder, but the number Rufous Hummingbirds present at his feeders. Two! There’s only room for one little red devil at each feeder – they drive off all others. We all watch them; and many of us feed them. These tiny titans are found only in the Western Hemisphere. They might look tiny and fragile, but hummies are anything but. They pack some amazing adaptations suited to their diminutive lifestyle.

They weigh in between 2 and 20 grams, depending on the species, about three cents worth, or the weight of 3 U.S. penny coins at 3 grams each. The world’s smallest living bird is the Bee Hummingbird, native to Cuba, at 1.8 grams (0.063 oz) and 2 inches in length. Our most common nesting hummingbird is the Black-chinned that weighs 9 grams. The slightly larger Broad-tailed Hummingbirds dominate at higher elevations. And, Rufous and Calliope Hummingbirds arrive in July on their way south. For me, the Fourth of July weekend, is filled with anticipation as I wait and watch my Jemez mountain feeders for the little red hummer that always seems to appear just then.

Hummingbirds can fly vertically in order to capture fluid in pendulant flowers, like this juvenile Rufous Hummingbird. Image by David Powell.

Hummingbirds got their name because their wings beat so fast that they make a humming sound, similar to that of a bee’s buzz. They can fly forward, backward, rise vertically, and hover. In order to understand how this type of flight is possible, consider that their wings move in a figure 8 motion with about 50-80 wing beats per second. At the same time their tiny heart races too, ranging from 250 beats per minute while at rest to 1,250 beats per minute in flight. Hummingbirds can reach speeds of up to 60 miles per hour.

With such a high octane lifestyle, hummingbirds require disproportionate quantities of nectar or sugar water to fuel their high-energy life style, as much as 90% of their diet. Their elevated metabolism requires an enormous food intake, typically more than one and one-half times the bird's weight in nectar alone each day. Flowers provide their food naturally, but when temperatures plummet, these sources dry up or disappear. Then, artificial sugar water feeders become critically important to survival.

The diminutive Calliope Hummingbird is the smallest North American species. Image by David Powell.

Hummers eat small insects, spiders, ants, and caterpillars, and even poach trapped insects from spider webs. When you see them hovering in mid-air or zipping to and from a perch they are almost certainly picking off flying insects. Although, high-calorie nectar or sugar water is the dominant part of their diet, protein-rich insects are also important, which also is affected by unexpected temperature drops.

Some hummingbirds are quite confiding when around humans, seemingly oblivious to our presence. Image by David Powell.

Most North American hummingbirds avoid cold weather extremes by migrating to Mexico or further south. However, many hummingbirds, remain year-round in the southern U.S. , in places like California and Arizona. Increasingly, some hummingbirds that typically migrate to Mexico, such as Rufous Hummingbirds, are wintering in the southeastern U.S. , trading a southerly migration for an eastward journey. Parts of the southeast are seeing increasingly large populations of our western species during the winter months.

They migrate in response to hormonal changes, which are triggered by decreasing daylight hours. Nothing you can do will make them stay too long, so it's not necessary to stop feeding them to force them to go south. On the contrary, they need to fatten up to nearly double normal body weight to survive the journey, and appreciate your feeder more than ever up until literally the last minute before they depart. The standard recommendation now is to keep feeders in place and until two weeks after the last hummingbird sighting.

The Black-chinned Hummingbird is the most common nesting bird in the Middle Rio Grande Bosque. Image by David Powell.

When late-departing migrants are surprised by cold weather, or when abnormal freezes affect resident hummingbirds, intervention by well intentioned people with back yard feeders can be life-saving. Hummingbirds survive the night by ingesting copious amounts of nectar at dusk, storing this reserve in their crops and digesting it throughout the night, during sleep. In cold conditions, hummingbirds drop into a hibernation-like state (torpor) which conserves energy through reduced heart rate, breathing and temperature, but which also increases the birds' risk to predation. You can help hummingbirds during these extremes by providing plenty of sugar water, and by insuring that the syrup remains unfrozen.

Sugar water in feeders will remain liquid at 32 degrees Fahrenheit, the temperature where plain water freezes, but if temperatures drop much below this level, even sugar water will freeze. Higher concentrations of sugar to water lower the freezing point, but become difficult for hummingbirds to ingest, and are not recommended. Monitor your feeders closely. If temperatures are forecast to fall below freezing overnight, bring your feeders indoors after dark, after birds have quit feeding, and then re-hang them at the earliest light, before hummingbirds begin feeding.

Increasing numbers of Rufous Hummingbirds and other species now are wintering in the southeastern U.S. in an easterly rather than southerly migration. Might that be fueled by the presence of feeders? Image by David Powell.

In early February 2011, much of the U.S. was hit by arctic air. In southeastern Arizona, where Costa's and Anna's Hummingbirds are common throughout the winter, early morning temperatures dropped to the mid-teens and below, impacting insects and flowers. Artificial feeders became critical to hummingbird survival, and even these would freeze solid if unattended. Fortunately, bird lovers across the area stepped up and kept feeders filled and thawed. Freezing weather is unavoidable, but when it comes, a little effort on our part will make a world of difference to our hummingbirds.

Hummingbird populations appear to be positively affected by our penchant for watching them at our feeders. Let’s give them a helping hand this fall, by keeping our feeders cleaned and filled until all have had a chance to move south.