The Varied Thrush – The Northern Robin

by Dave Hanks

If you are in “wild” country, and will but stop to listen, there is a whole cornucopia of sounds. Some sounds, like Elk bugling or geese honking overhead, are very intriguing. One such sound haunted my wife and I over and over again whenever we were in northern Canada. It was a bird call. We could never pin-point the location from which it came and, because it was a call we were not familiar with, could not identify the species. One evening, southward bound out of the Yukon into northern British Columbia, we were resting our bodies by lying in an open-air hot pool at Liard Hot Springs, B.C. We heard that haunting call again, very close this time. It was coming from a branch just above our pool. It was a Varied Thrush, and it was very mesmerizing to be soaking in hot water, out of doors, and having that bird serenade us!

This Thrush is slightly smaller than the American Robin, but it also has a reddish-orange breast. The breast, however, has a bluish stripe across it. The face also has a stripe across the eye, and the male’s back and crown are a bluish tint. This summer resident of the far north migrates to the Washington, Oregon, and California coasts for the winter months. We have even been lucky enough to have had one of them in our yard one spring – a rare southern Idaho occurrence.

Varied Thrushes like to nest in mature, coniferous woodlands that are dense and moist. If you have been in the far north, you will realize that there are lots of insects. These birds like to spend much time in the trees feeding upon them and will defend their feeding territory from intruders. They do this by first turning their back and giving a tail-up display. If that doesn’t work, the male will then turn to face the problem and extend his wings to display the colors on his under-wings, plus the white tips on his tail. The tail is then extended over his head.

The logging of mature forests has caused a reduction of breeding populations of this species. My wife has a love affair with this beautiful bird, and we would feel sad if we could no longer hear its eerie song.

Along the Oregon coast in February

Mysterious Interloper

by Dave Hanks

In 2003 and 2004 I was called upon to identify a mysterious bird seen in the tall trees in the south-west section of Burley. I say mysterious because the species involved managed to stay hidden most of the time, or at least when I was called to observe it. After much searching and discussion of behavior, an unlikely visitor was identified. Unlikely because this bird is closely associated with marshes, where it nests. Because the river is within easy flying distance is the only reason that seems logical for this large wading species to be where it was sighted.

The AMERICAN BITTERN is 28 inches long with a voice that sounds like water gurgling. When alarmed it will stand in the sedges with neck stretched skyward, looking much like the reeds that surround it.

Immature Night Herons are also streaked and could possibly be confused with the bittern.

It is a hard species to approach and to get photographs requires a bit of luck.

Homeostasis and Waterfowl

by Dave Hanks

The bodies of all of us, both human and animal, have homeostatic mechanisms. These are both physiological and behavioral. Homeostasis means a state of constancy. The body must maintain its functions on a steady plain. If we’re too hot, we sweat; if we are too cold, we shiver; if we are sick to our stomach, we vomit. We could, also, turn on the air conditioner, or turn up the furnace, or take some Alka Seltzer. These are all examples of how we keep our bodies running on an even keel.

Waterfowl, with basically the same problems as ours, do basically the same things. “WATER RUNS OFF A DUCK’S BACK” is true, but only with a little homeostatic help – both physiological and behavioral. When trying to photograph waterfowl, it can be disconcerting when they won’t remain still – always fixing their feathers and probing at their tail. There is an oil gland at the base of the tail. The oil is the body’s answer for water proofing feathers, but can’t reach its destination without some help.

BARROW’S GOLDENEYE (pictured) is a northern species that graces our area’s open water during the winter months. By staying dry, their hollow, air trapping, feathers will protect them from the cold. To do this the feathers must repel the cold water. Hence, the duck rubs oil up and down each feather’s shaft. The feather filaments each have barbules which hook on to the adjoining filament. This forms a continuous covering to keep out the wet. When you observe the bird preening, they are doing two things. They are re-hooking the barbules and oiling their feathers. Also, without this constant oiling and barbule hooking, the bird would be unable to fly because the feathers would be waterlogged, and the unhooked feathers would be unable to trap air.

Comfortable swimming in an icy pool

Prey species must be Vigilant

by Dave Hanks

The world contains both predator and prey. Prey species do not live very long by being careless! Predators come in all sizes and shapes, and they must eat too. Because their prey is alert to them, they usually only make a kill after many tries. Therefore, they must use deception, speed, or make many attempts to satisfy their hunger.

Prey species may gather in large groups and depend on the many eyes, ears, and noses to alert the group to danger. Some depend on disguise to not be noticed. I don’t know how many times I would never have seen an animal, if it had not panicked, and remained motionless. Remaining in disguise is, also, a predator trick that lets the victim come close enough to surprise. Heavy bodied snakes are labeled as “Lay in wait snakes”. They can be so well concealed, that they simply latch onto a meal as it passes close by. Another interesting tactic is to look dangerous. By mimicking a poisonous species, or by looking scary (like butterflies with large eye-like spots on their wings) will deter many attacks.

Some fish simply make friends with bigger fish. By offering their services to pick parasites off the host’s back, or to clean their teeth; makes the smaller fish more valuable for its service than it would be as a meal. The predator protects them because they are far more useful alive than dead.

Muskrats are the epitome of wariness. They are most difficult to photograph, even though you may be aware of their presence. They rely on well camouflaged, safe havens. Their speed of swimming, while keeping a low profile in the water, lets them escape to burrows excavated in the banks of slow moving streams. These burrows are well hidden amid the stream’s sedges. The dens have many underwater tunnels leading to several dry chambers that have ventilation holes. Here the animal can bring in food, or wait out any perceived dangerous situation.

A Muskrat caught unawares

A Muskrat caught unawares

Feathers equal Warmth

by Dave Hanks

Vertebrates (animals with backbones) have four general types of body coverings: skin (amphibians and humans), scales (reptiles and fish), hair (mammals), or feathers. Birds and feathers go together. Feathers are what define a bird!

Birds have claws, but so do mammals. Birds have beaks, but so do turtles and squid. Birds lay eggs, but so do fish and reptiles. Birds can fly, but so do bats and insects. And, also, some birds don’t fly. Feathers are the one thing that all birds have, and only birds have, that other species don’t have.

Feathers have several uses. One such purpose is for warmth. Military airmen must wear cold inhibiting clothing to withstand the increased cold at high altitudes. Birds are unaffected and have no concern about leaving ground temperatures because of their feathers. No synthetic insulation has yet been invented that is equal to feathers. “A mountain climber would have to wear 11 pairs of polypropylene long johns to achieve the same heat retention as one down-filled expedition jacket”. (Thor Hanson – Audubon Magazine – January/February, 2012). Nothing compares with the soft, fluffy down that is close to a bird’s body for warmth. The bristle-like projections that cover most of an owl’s beak, or feet, are actually feathers.

The WESTERN SCREECH OWL (pictured) can be found in urban areas as well as western wild lands. They get their name from a very high pitched call. They have feathers that extend over the base of their beaks and down their legs. They are well equipped for the cold, as they stay year round in their habitat.

Looking like a miniature Great Horned – A distant relative)

How to digest an Alligator!

by Dave Hanks

People like pets. Some people like exotic pets, like wildlife babies. They are so cute! But, those babies grow up and then what? You might give them to a zoo, or (like most) just take them out to forested or marshy areas and turn them loose. Some of these pets have been purchased from pet stores, and therefore are not native to this county. Problems then arise when they are free to multiply in areas that are not adapted to their presence.

Some folks like snakes. What’s nicer than acquiring a small, young constrictor, like a Reticulated Python? This is a snake that can grow up to 30 feet long. Obviously it can’t be contained in the home any longer, so let’s set it free. This scenario has taken place in Florida. Snakes have done quite well in Florida’s wetlands, and now the swamps and Everglades have a problem. Snakes must eat occasionally. Snakes are carnivores and therefore wreck havoc on wild life populations – birds, small mammals, and other reptiles. Big snakes can consume your dog, or other large prey, and have been known to even eat small alligators.

Goodness! How can they eat an alligator? Snake jaws unhinge to let the prey, which is swallowed head first, slip into the alimentary canal. The snake then wiggles its jaws and they re-hinge. A large meal, like an alligator, will serve the snake for a month or more before another meal is necessary. Snake organs are unusual. First, everything is in a pipe (so to speak) and is arranged in a single file. Snakes are masters at conserving energy. Their digestive organs are usually small and non-functioning, but under go a major change when required for digestion. Smaller prey requires a week for total assimilation. Something as large as a “gator” will take two weeks or more. A snake’s enzymes are powerful, and the prey’s total body is digested.

This animal will rest for an extended period, before hunting again. Digestive organs now shrink back to pre-meal size. The heart will also shrink, as it enlarged to pump blood faster during the period of nutrient absorption.

Snakes can go months between meals, as my classroom snakes did over the summer, non-school months.

The Everglades have more than American Alligators – be alert!)

Wildlife Sentinels

by Dave Hanks

There is a constant need for all animals (human animals included) to be alert to dangers – whether it is in the form of a predator, or other individuals trying to usurp their territory. Armies always post lookouts, and so do animals. As a former cattle breeder, I became aware of baby-sitting cows. The cows would take turns watching over a large group of young calves – thus providing the other mothers the time to graze and take care of their individual needs.

Creatures that live in grasslands make highly visible prey. Prairiedogs are famous for always having a sentinel to give the signal for all to take to their burrows. Likewise, I’ve read accounts of White-Tailed Deer and Bison always staying vigilant. When resting, they may lay down tail to tail and, between them; they can see a 360 degree scope of the countryside. A sentinel is the last to flee the scene, and so is in the greatest danger, but the interest of the group is paramount – especially if the group is comprised of offspring that a parent is concerned about. Geese flying in their famous V formation are depending on the leader to lead the flock safely. If that goose is delinquent, the group will noisily vent their frustration and a new bird will move to the front.

I know that it is much easier to sneak up on an individual to photograph if he/she is alone. It’s very difficult to do so if there’s a group. The group’s many eyes will result in some individual sensing your presence and the whole bunch will suddenly be gone.

The HOARY MARMOT (pictured) is found at high elevations, or in northern latitudes. I have observed them in Canada’s mountainous parks, Alaska’s Denali Park, and Colorado’s Rocky Mountain Park. They are referred to as Whistlers. The nick-name is in reference to the shrill alarm they sound to warn their companions. Contrasted with their cousin, the Yellow-bellied marmot; they are not as dark, and their silvery color blends well with their rocky habitat.

Taking his turn as look-out

Twin Woodpeckers

by Dave Hanks

HAIRY and DOWNY WOODPECKERS are look-alikes. The major difference is their size. The Downy is 6 1/4th inches and looks very much like a miniature Hairy, who is 9 1/4th inches long. Both have white breasts, black backs with a white stripe down the center, black wings speckled with white, a white and black striped face, and a red spot on the back of male heads. They remind me of “Big brother and Little brother”. A role I was much aware of in my life as the youngest.

Both the Downy and Hairy Woodpeckers are found all over North America. Our south hills are replete with Hairy Woodpeckers. But, both species can be found at City of Rocks and Lake Cleveland. The Downy is more apt to be in your yard. In fact it likes our apple trees (that have some age on them) and we can hear a soft pecking away in our yard. Their drilling is much louder when attacking a telephone pole.

The Downy’s call is softer and higher pitched than the Hairy’s, which includes a loud, sharp peek and a slurred whinny. Rocky Mountain birds tend to be slightly duller, with less spotting on their wings.

All woodpeckers have four toes, bristle-like feathers over their nostrils (to keep wood chips out), and very long tongues for probing in hard to reach places and for lapping up sap. Their eggs are white, and both parents are involved in caring for the young.

Sitting by a nest cavity is futile. The birds know you are there and will wait you out. These shots came from patiently waiting in a blind. The Hairy photo was shot at Cabin Lake, Oregon: and the Downy in Raccoon National Park, Indiana.

Hairy Woodpecker

Downy Woodpecker

Making Bird Photo Studios

by Dave Hanks

I sit in a blind on a Texas ranch. It is on a high spot overlooking a swale that has a large, bare tree branch set in the ground to serve as a bird perch – a bird photo studio – so to speak. A beef kidney has been attached as a lure for the hawks of southern Texas.

In our efforts to photograph birds, we have found it very useful to set the stage beforehand and wait for the birds to come to us. If a permanent blind is unavailable, I set up our portable one. It is like a small tent, which is supported by PCV pipes that I can quickly plug together to form a frame. Several perches are created from surrounding vegetative material – or we carry a couple of sticks for that purpose in case suitable items are unavailable in the area. Feeding stations, out of sight from the perches, draw the birds in. Seed eating and sugar loving species come readily to the feed – usually alighting on a perch to survey the scene before dropping down to eat. Creating a water source is even better than food, especially where water is scarce.

But, back to the Texas blind. A HARRIS HAWK comes in to the feast, almost as soon as I get situated. This is a Buteo that lives in the southwestern states. (Buteos are high soaring hawks with broad, rounded wings and broad tails.) He goes right to work on the kidney that is wired just below the perch.

Harris Hawks hunt in cooperation with other Harris Hawks – usually in pairs or trios. This mode of hunting allows them to bring down jackrabbits and other speedy, difficult to catch, prey. They surround the prey and one will flush it and another will make the kill. They will take turns at each role. This species defends its hunting territory as a group, which is unlike most birds where a single male fills that role.

Factors Influencing Speed

by Dave Hanks

T-Rex was a scary dinosaur! Could I have run fast enough to avoid him? Thankfully he is extinct and I don’t have that worry. Why can some of us run faster than others and some animal species run faster than other species? Body structure and physiology are major factors.

Newton’s third law of motion is: “That to move forward an animal must push something backwards”. Obviously the quicker one pushes backwards, the faster one can move. An individual’s weight, leg length, stride length, and foot placement are factors. I have personally observed that the faster human athletes have well developed buttocks, and tend to be slightly pigeon toed. Persons that walk with toes pointed outward are not sprinters. I have, also, been told that it is helpful if your second toe is longer than your big one. I suppose that it would be a factor in helping keep one’s stride straight down the track in a line of single file tracks.

But back to animals, the Cheetah (with its flexible spinal column) is the world’s fastest sprinter at 70 mph for short distances. But our American Pronghorn can do 60 mph and has much greater endurance than the Cheetah. They can even race cars, and maintain 40 mph over several miles.

Pronghorns are equipped with an enormous windpipe and oversized lungs. They can take in oxygen three times as fast as other animals of comparable size, and their heart is twice as large as a sheep’s of the same body weight. Their muscle masses are above their legs which allow the legs easier movement and heat diffusion. Those muscles are packed with extra mitochondria for greater energy release. This combined with a large liver allows a large release of glycogen.

The rapid intake of oxygen, combined with extra energy, is essential in critical situations when fleeing to escape a predator. Pronghorn are a holdover from a distance past. Their survival success has a lot to do with their incredible speed.

pronghorn Pronghorn running