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

The Domestic Cat: A Miniature Tiger

The cat is a favorite household pet. Around 30 percent of American households have one as a pet. This animal has been a native historically world-wide, except in Australia and the oceanic islands. Their life span is 12 to 18 years.

Cats are famous for always landing on their feet. Try to throw them onto their backs – they will twist their bodies to face the ground. The vestibular apparatus of their inner ear orients their balance and sends a signal to their brain to rotate their head to an upright position – the body then follows suit. As a former wrestling coach of the Burley Bobcats, I stressed the fact that we were cats, and that therefore, we shouldn’t be turned on our backs. But back to ears, cats have phenomenal hearing. Large ears funnel sound waves to their inner ear, which is very sensitive to high-frequency sounds.

Cats have large eyes with binocular vision – a common predator trait. They can see as well as we can in the daylight, but up to six times better after dark. Images are intensified by a reflective layer outside of the retina (tapetum lucidum). Light passing through this layer is usually absorbed and is stimulating to nerve endings. If not immediately absorbed, it is reflected back, making cat eyes glow in the dark.

Your pet purring in your lap is a pleasant sensation. It is a method of communication that is felt as well as heard. Big cats have a hyoid bone in their larynx and this allows them to roar. Small cats, like Bobcats and Cougars, don’t have this bone. They all purr. Purring is associated with contentment, but, may be done under stress. It is a trait not well understood.

As “quick as a cat” is an apt description. This, along with a leaping ability that can extent up to seven feet high when properly motivated, makes this animal as frightening to other small mammals as a tiger would be to us.

Felis catus: A cuddly pet to us – a terror to rodents

 

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.

The Finch Family: Diversity Personified

by Dave Hanks

Fringilladae is a large, world wide family. These are Passerine species – medium to small, perching, terrestrial birds. They are mostly migratory, have 3 toes opposing one, and are fine singers. Finches are seed eaters, and America has 14 species in this category. They range in diversity from Goldfinches, to Grosbeaks, to Crossbills, to Red Polls, to Bramblings, to Siskins; and finally to Purple, House, and Cassin’s Finches. The last three listed resemble each other, and are closely related.

The House Finch is the most familiar, as it is around the feeders in people’s yards most of the year. Purple finches are a dark purplish-red, but are more of an eastern bird. All three birds combine reds with their browns. The females of the threesome are sparrow-like in appearance. Cassin’s Finch is my favorite of this trio. Even though the Cassin’s looks much like a House Finch, when the two are together you will see a noticeable difference. CASSIN’S FINCH has a pinkish-red breast, and a dark red crown. The brightness of these two colors set it apart.

The male Cassin’s sings long, complex songs. He may even mimic other species. The female sings too. Her song is softer than her mate’s and only half the volume. A one year old male sings louder than either. He tones it down when he’s mature. Perhaps it’s to let any female know that he is now ready for mating. Interesting!

Some of the most positive things I did in my Biology classes were the field trips that we were fortunate to go on. We studied all aspects of whatever ecosystem we visited. On one such trip, two girls had situated themselves by a tiny creek. Birds were coming to the water. The girls were having a significant, eye opening experience. They didn’t want to leave the spot to do anything but watch the birds. A species that they were especially enamored with was the Cassin’ Finches that were coming in – their colors extra bright for the spring nesting season.

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!)

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

The land of the one-eyed car

by Dave Hanks

The Alaskan Highway is paved all the way, but they are always digging up miles of it for repair. If you take a side road, you will drive on dirt and gravel. Rocks are always flying which crack windshields and break headlights. Many people combat this with huge screens that cover grills and cause rocks to ricochet over their cabs. At the end of the main highway at Tok, Alaska, most everyone stops to wash their vehicles at a gas station that provides this service free. After leaving Tok, if you jog a little to the south and then to the northwest, you’ll come to the Denali Highway. This is not what it sounds like. It is definitely not a paved highway. It’s more of a dirt –gravel trail. It’s a wilderness road! It is 135 miles long, with a scarcity of human presence that adds to the wildness.

The scenery makes the travel inconvenience worthwhile! A high mountain backdrop: the Alaska Range, the Chugach Mountains, the Wrangell Mountains, and 13.700 foot Mount Hayes add primitive beauty. There are small lakes everywhere, and the stunted, twisted Spruce; touch some inner primeval chord to leave a deep impression. The road is closed from October to May each year and few people travel it in summer because it’s poorly maintained.

It’s a wild place for wild things and we came in contact with three wild species that are only found in the North. The WILLOW PTARMIGAN (grouse that’s the Alaskan state Bird) is abundant. And RED-THROATED LOONS and OLDSQUAWS are present on the ponds. The Ptarmigan is the most familiar of the three. It’s noted for changing from its winter white to summer brown each year. The Oldsquaw is actually a northern sea duck. An interesting fact is that it has three annual plumage changes. It’s mostly white in winter, but with a dark front and white eye patch in summer. It has an extremely long, very thin, stiff set of tail feathers at all times. It can dive, when on the ocean, to 200 feet. The Red-Throated Loon has a red patch on its throat, therefore the name. I’ve always thought loon calls to be most haunting and both sexes of this species will call in unison.

This land of the one-eyed car has a mystic charm that seems to always call one back again.

Ptarmigan

European Starling: Ugly, but a diverse Singer

by Dave Hanks

The Starling was introduced to the USA in 1890 – 60 birds were released in New York’s Central Park. Like most introduced species, they have become a PEST and a giant mistake at introduction. There is always someone thinking up something worse!

This UGLY, short-tailed, black, 6 inch long bird has a yellow beak, and white spots on its head and body during fall and winter. The only good thing that I can think about this species is its ability to SING. It has a very diverse repertoire of attractive songs. It can mimic up to 20 different bird species, and even car alarms. Once we heard a Red-Tailed Hawk in our yard, except it wasn’t a hawk. It turned out to be a starling – perhaps using the call to minimize competition from the other birds.

The starling is very prolific, and unfortunately it nests around homes and barnyards. They are responsible for the decline of other birds, especially woodpeckers. Sometimes, they will lay an egg in another starling’s nest if unsuccessful at their own site. Not only do their nests contain a half dozen blue/green eggs, but also, fleas, ticks, bed bugs, and beetles.

This bird damages vegetable and fruit crops, contaminates cattle feedlots, and is a carrier of disease. Some of the diseases they transmit are: salmonellosis, fungal diseases, protozoan diseases, fowl pox, gastroenteritis, and other livestock diseases.

In spite of the starling’s beautiful voice, I (and many others) wish they had been left in Europe!

Starling on a branch

The Rise and fall of Wildlife Populations

by Dave Hanks

There are only a few wildlife species whose populations fluctuate at regular intervals. The Lemming cycle peaks at four years. Ruffed Grouse increase for four to six years and then decrease at the same rate. The relationship between Lynx and Snowshoe Hare is fairly constant – the cats increase as the hares become more abundant and they in turn reverse the cycle.

However, the fluctuations of most species depend on the weather and food supplies. It is very important to each species that population numbers stay in balance with the available food sources. HIGHLINING is when trees are missing limbs as far up the tree as animals can reach. This is a sure sign of too many individuals utilizing the resources. If this continues, the area may become permanently damaged and unable to support the number that it once did. The Elk population in Yellowstone Park was putting the park’s vegetation in serious straits – hence, the introduction of the wolf. Whether that was a good or bad decision, remains to be seen.

There are more young born each year than the environment can possibly support. Just think of the implications of the following: two rats and their offspring would yield 350 million in 3 years, trout lay hundreds of eggs, and rattlesnakes have 15 to 20 young each year. Even an elephant would raise 6 offspring over a 75 year period, and even that would put undue stress on the available resources.

The cruel fact is that most offspring either die or are food sources for predators. Cottontails lose 80 % of their population each year. If they all lived into the winter, none would survive to greet the new spring. Not only does crowding damage the vegetation, it damages the health of the animals.

Natural predators are a must to increase the vigor of both the habitat and the prey. Where predators are absent, controlled hunting is a necessity.

The adaptable Coyote – A major predator on rodents