Goshawks again brooding over Evergreen

-A A +A
By Sylvia Brockner

While I was visiting Bosque del Apache, an exceptionally fine photograph of a northern goshawk was printed in the Community Eye feature of the Canyon Courier. It was taken by Richard Gristak on Bear Mountain. I was pleased to see this beautiful bird’s photo for two reasons: one, because I have not seen a goshawk in the area for some time, and secondly, because I had been wondering what hawk was making the birds at my feeder so antsy.

From the top of Bear Mountain to my house in the valley below is no distance for a goshawk to fly when searching for food. They are the largest of the three accipiter that can be seen in this area and are very fast fliers that travel some distance looking for food. They are not anywhere near as common as they formerly were in this area. When we first moved here in 1965, a pair was nesting in Bell Park not too far from our house. Unfortunately, the two-thirds-grown young were shot on the fourth of July and hidden beneath some nearby shrubbery where the perpetrators hoped they would not be found. The adult goshawks never returned to that nest site, but for a few years after that they nested on Kinney’s Peak. Then a new road and development brought more people to that area. They moved again, but I could not locate them that time. Now, it seems that a pair has found a much less developed place on Bear Mountain suitable for goshawks, or perhaps this was just a migrating bird passing through on its way north.

In the 45 years we have lived in Evergreen, I have known of six nesting sites and have seen perhaps as many as another dozen birds. One of these was on a Christmas Bird Count, flying over Bear Creek in downtown Evergreen. Another was here on our patio, where it was stalking our golden-mantled ground squirrels. They obviously are not what you could call common, but they are — unfortunately, for their own sake — not very afraid of man.

However, they are known to prefer large blocks of mature forest in which to nest and therefore are becoming less common locally as development breaks up our forests and they are forced to move into the large national forest areas.

Goshawks are known to use the same territory for many years, providing they are not disturbed or their nest vandalized. Under normal conditions, they may have two or three nest sites within their territory. They may use one site for several years and then change to another, or they may alternate between sites more frequently. The nest I studied in Bell Park was on a horizontal limb up against the trunk of a medium-size ponderosa pine. It was about 30 feet above the ground, and the limb directly above the nest had been broken off in a storm so that the birds had plenty of room to fly in and out and an open area around the nest to feed the young.

Goshawks lay from two to five eggs, but the more normal figure is three. The nest was built of fairly good-size sticks and lined with dry plant material, pine needles and fresh evergreen twigs. Young goshawks usually stay in the nest for 45 days, and eggs are incubated for 36 to 38 days. This would mean that the nest I observed, allowing for estimating two-thirds of the nesting time (30 days) plus an estimated incubation time of 37 days, would have been completed about the end of April or the first of May, which would appear to be a reasonable nesting date for this location. Many hawks start their courtship early and build their nest over a period of several weeks. Therefore, the pair bond could have been made as early as late March.

This hawk hunts for smaller birds and mammals. It apparently feeds its young on both ground squirrels and tree squirrels whenever they are available. I one time watched a goshawk at Rocky Mountain National Park that was trying to take a spermophile. It missed the ground squirrel on the first strike but then ran after it on the ground until it caught it. I had never seen this form of hunting but finally found a reference to it in the literature. Its long yellow legs flashed in the sunshine as it took long strides and hops, zigzagging after the ground squirrel with great speed until it finally caught it in its talon — an amazing sight to see and probably only possible because of its long, unfeathered tarsus.

Male and female goshawks wear the same gray plumage, so cannot be easily separated in the field except by size and eye color. The female is conspicuously larger then the male and has an orange-yellow eye, while the male has a brilliant scarlet red iris. The female does most of the incubating, but the male supplies her with food and is usually nearby. When the young are bigger and demand more food, she also leaves them to help in the hunt.

At one time the goshawk was divided into two subspecies, the eastern and western goshawk. Recent literature seems to consider them as the northern goshawk, only mentioning that western birds often are darker gray, so perhaps they are just color phases. Like all accipiters, they have short wings and long tails, which enables them to move silently and quickly among the forest trees. The goshawk’s nearly black cap, white eyebrows and red eyes are a positive identification.