Deferred Maturity

by Dave Hanks

Young song birds hatch, fledge, and are ready for migration. The young birds usually resemble the female parent. However, by the following spring the males acquire their adult breeding plumage and assume parenthood. Their development is relative simple and quick. However, most raptors and gulls go through several stages before reaching sexual maturity. Large birds like eagles or buzzards have 4 to 5 stages of development. Hawks usually have two stages to go through over a two year period to reach maturity.

Buteos are large hawks with broad wings. The FERRUGINOUS HAWK (pictured) is the largest American Buteo. Only the Bald Eagle, Golden Eagle, and female Snowy Owl weigh more than this hawk. Ferruginous Hawks go through three stages after the nestling stage: juvenile, sub-adult, and finally adult – three years from hatching to adulthood. This species has been known to live for 20 years (determined by re-catching banded birds), although the majority die within a 5 year period –which allows a five year old bird two opportunities to nest.

Ferruginous Hawk’s first year mortality is estimated at around 66% and adult mortality at about 25% per year thereafter. This ground nesting bird is preyed upon by Coyotes, Golden eagles, and Great horned Owls. Jackrabbits rank high on this species food list. When prey sources are at a low, many hatchlings will die of starvation. Illegal shooting of adult birds has also caused a problem to this not-so-common species.

This magnificent hawk has been used as a falconry bird in its native range.

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A young Ferruginous in the sub-adult phase

 

Arizona: A winter month bird bonanza!

By Dave Hanks

First, this southerly location receives visitors from Mexico – a country with birds not found in the more northern states of America. Also, its desert landscape causes many species to be in abundance in the less arid and lusher areas. Some special areas Carolyn and I would visit during winter months to do photography start at the top of the state and extend into its southeastern corner.

Just below Flagstaff at Cottonwood is Dead Horse Ranch. It has many water birds, many scrubland species, and River Otter. This spot has always been productive enough for a several day stay.

South of Phoenix is Picheco State Park with its desert adapted species. Further south at Tucson is a very rich area. The Sonora Desert parks, both west and east portions add more variety, and all three parks increase the winter picture bounty.

Perhaps, Catalina State Park, north of Tucson, has yielded the most variety: Cardinals, Pyrrhuloxia, Cactus Wrens, Roadrunners, Goldfinch, Thrashers, and several Woodpeckers to name a few.

Further south, just north of Nogales, is Madera Canyon. This higher elevation provides a woodland habitat of Scrub Oak, Juniper, and Yucca. It sports four special species: Arizona Woodpecker, Bridled Titmouse, White-Breasted Nuthatch, and Scott’s Oriole.

From Patagonia Lake we travel to the Chirricahua Mountains and Portal in the southeastern corner. This is the real bird capital of Arizona. One can hardly get the feeders out before the birds that are waiting in the trees swoop down to feast. Peccary and Coati Mundi are two mammals that are there to experience also.

Crissel’s Thrasher: An exciting discovery and photo session

Crissel’s Thrasher: An exciting discovery and photo session

Phainopepla or “The Black Cardinal”

by Dave Hanks

The Phainopepla only looks like a Cardinal in its body configuration and crest. It is actually in a different family – a family known as silky flycatchers. They are closely related to waxwings. The erect crest, deep red eye, silky black body, and white wing patches (seen when in flight) give it a distinctive aura. The female is a brownish-gray, but still quite distinctive. She shows evidence of the white in her wings while perched – which the male doesn’t. I personally think that the female of this species is as attractive as the male.

This bird is found in the arid regions of the south-western USA. They prefer vegetative tangles in trees, such as old Mistletoe, in which to nest. They have a special relationship with mistletoe. They not only nest in it, but feed upon the berries and spread the seeds. This black flycatcher also eats a great quantity of insects.

Their flight is fluttery but direct, and their call is a low-pitched, whistled “wurp.” They will raise two broods a year. The second nesting occurs after they have moved into habitat that is cooler and wetter.

Whenever we find ourselves in the arid regions of Southern California, we almost always experience this bird. My wife is always calling to me to come and see a bird. The bird is usually gone by the time I arrive. The bird in this picture was an exception. He sat there patiently and allowed me to photograph him.

This male is perched in Mesquite

Magic Sap Trees

by Dave Hanks

Sapsuckers are aptly named. They excavate tree cavities for nesting, and other birds use the holes after the original owners are done with them. They also drill series of small holes in a tree’s bark, which then becomes a source of sweetness for all to utilize. Cassia County has large populations of sapsuckers – Red-Naped ones. This woodpecker is especially evident at the City of Rocks. Its red chin differentiates it from other woodpeckers.

On a trip to New Mexico one winter, we camped in an out of-the-way place called Water Canyon. It was reputed to have wild turkeys, and my wife wanted to observe them. It was wintry, but that situation was disregarded. Snow limited where we could park our truck, but there was a spot just off the road by a forest service restroom. There was considerable bird activity around that restroom. We soon discovered the reason. An Arizona Black Walnut tree with brown, withered leaves that hadn’t been totally shed stood next to that outhouse. It was oozing sap and, as if by magic, a wide variety of birds were visiting that tree.

A Red-Naped Sapsucker would arrive at 20 minute intervals and work on two or three branches. There were dark areas on the bark and, with binoculars, I discovered that each spot was covered with tiny holes. Obviously, sapsuckers are not the only ones that love sap. White-Breasted Nuthatches were all over the tree. Ruby-Crowned Kinglets preferred a spot where a freshly broken limb made a large stain on the dangling branch. Other species invading that tree were: Common Bushtit, Mountain Chickadee, Bridled Titmouse, Juniper Titmouse, Stellar’s Jay, and Scrub Jay.

We didn’t find any Wild Turkeys, but it was great to get such a close-up glimpse and an expanded knowledge of sap holes. The time spent at the base of that “Magic Sap Tree” and all the many birds in it, made that short side-trip most rewarding!

His red chin identifies him as a sapsucker

Types of Migration

by Dave Hanks

When one thinks of migration, one usually thinks that animals go south in the autumn and go north in springtime. That is what is called COMPLETE MIGRATION, but it is an over simplification. Amount of daylight, weather conditions, or food supplies; are factors that influence the time or type of movement. Some species like Robins, Red-Tailed Hawks, and Towhees are PARTIAL MIGRATORS. Many of these species migrate but a portion stay around all year long – especially if food sources are adequate or to protect a territory and nesting site. Young birds are more apt to make the long trip because of a low social rank. Adult individuals force them to vacate the area.

DISPERSAL is the result of newly fledged birds moving to find space where they can establish their own territory. It is believed that this type of movement is the origin of complete south/north migratory patterns. Another type of migration is called DIFFERENTIAL. This type is influenced by existing conditions. Where nest cavities are in short supply, the American Kestrel may not move away from his established nest box. Water birds may move to the closest area that has open water. ALTITUDINAL MIGRATION is from High Mountain (where weather conditions mimic the more northern latitudes) down to lower elevations to spend the winter. Pine Grosbeaks and Juncos fit this type. Juncos that are abundant around bird feeders in winter are absent in summer.

IRRUPTIVE MIGRATION is very irregular. This is not necessarily a north/south trajectory, but often a lateral movement for better feeding conditions, and is not made every year. Years of severe weather can be a stimulus. A shortage of conifer cones makes Crossbills move to more productive forest areas. Abundance of small rodents (voles, mice, gophers, etc) affects predator movements. Owls especially are birds that are subject to these conditions.

Like all things in life, what appears simple on the surface is usually much more complicated.

A Great Gray Owl: An irruptive species

A Great Gray Owl: An irruptive species

Courtship Variety

by Dave Hanks

You are probably aware of some common bird courtship rituals – such as a male feeding a female, or the male and female preening each other; the cooing of doves, and the singing rituals of many other bird species. Grouse and turkeys display by strutting. Some mammals appear to be fighting, but it is only the male and female rough-housing – which gets their hormones flowing.

Other species have some unique courtship methods. Spiders are especially unique. The Australian Red-Back male is much smaller than the female. The female requires the male to do an elaborate dance for over an hour to two hours. During the dance, the male connects his web to her web. He then taps a drum-like rhythm on her abdomen. If he stops too soon, she will bite his head off – which she does anyway, after mating.

Rhino courtship is called “Bluff and Bluster”. When in estrus, the female urinates on dung piles to lure a male on. The male will scatter these piles in an attempt to keep other males away. The bull then snorts and swings his head side to side and runs from the female. Afterwards, the pair will then snort and spar, with the female working the male over vigorously. The couple will stay together for several days or up to several weeks.

The Leaf-Nosed Bat will find an opening in the rock of a cave that is narrow enough to only allow one other to enter, thus keeping other males out. He will call and flap his wings to entice any available female. If one enters his little abode, he wraps his wings around her and nuzzles her. If she doesn’t fly off, they will mate.

A favorite bird of mine is the COMMON SNIPE (pictured). I like him, not only for his looks, but for his “winnowing” display that can be heard on a spring morning over a meadow. He gains altitude and then descends in a spiral pattern. The air rushing through his wings makes sounds like the bleating of a goat. In many languages he is known as the flying goat. He will, also, make shallow dives to produce a “drumming” sound with his tail. Such a repertoire to go through in order to attract female attention!

Resting after the morning’s aerial displays

Females: Larger than Males in many Species

by Dave Hanks

Predatory birds, many snakes, many fish, insects and spiders, the Blue Whale, and even the Spotted Hyena; are species where the female is the larger of the sexes. This is especially true with species that prey on vertebrates, or species that lay tremendous amounts of eggs. Obtaining food for herbivores is relatively easy, as long as the vegetation has not been denuded.

Natural selection has favored bigger females in many species, as it is a fecundity advantage. It takes more energy to produce eggs than to produce sperm. This requires the female to carry more weight, and the female must be larger to carry the extra weight that is required for that energy. Also, she is on the nest much of the time. Males are smaller because there is less demand on them to care for the young, and smaller sized males are more agile, and therefore more maneuverable when pursuing prey.

In predatory birds, such as hawks and eagles, the size difference reduces the competition for food between mated pairs. The bigger female will take bigger prey, which the male has trouble capturing. This division of what’s hunted puts less stress on the various prey species.

The NORTHERN GOSHAWK is a large falcon (21 to 26 inches) – larger than its cousins the Sharp-Shinned and Cooper’s hawks. It is a northern species that is not common. It mostly preys on larger birds (even ducks), but will take squirrels and hares. It is a resident of mixed coniferous woodlands, where it fiercely defends its territory and nest. This bird is a “home body” and rarely migrates, except from extremely cold regions.

We were most surprised to see one in our big maple tree. It had killed a Collared Dove. Feathers were floating down, as it plucked them out in preparation to eat its catch. We had only seen this bird (briefly) on two previous occasions.