Burrowing Owls
The vast open prairies and grasslands of the American west are marvelous places for nature lovers like myself.
Arizona Part 2
After a week of roaming the high mountains and canyons of northern and eastern Arizona in search of unusual trees, wildflowers and condors, this week finds me in the far southeastern corner of the state, about 12 miles from the Mexican board. I am at a privately owned research ranch. This is a 7000 acre ranch that plays host to researchers from across the country that come here to study a wide range of plants, birds and animals. I am here for all of it. I am greeted by the ranch manager and assistant manager who show me around and make me feel right at home. I toss my stuff in the bunk house and head for the lab, both of which are situated in the middle of the rolling hills of the desert grassland. What few trees that are here dot the landscape. As usual at this time of year the temperatures are running in the low 100’s but there is a breeze making it comfortable. My first evening is spent helping to prepare hundreds of small metal live traps that the researcher will use to capture as many small animals as we can. As it does most afternoons the intense heat builds up clouds that produce locally heavy thunderstorms. Just before sunset I head out with the researcher to set our traps. Lightning dances across the evening sky but no rain falls. Thunder rolls across the hills and valleys. Meadowlarks and the very uncommon Boteri’s Sparrows sing in the heat of the evening air. Common Nighthawks are flying overhead giving their courtship calls. What a spectacular place! After laying down the traps we head out into the night to drive the roads of the ranch to see what we can find. Just as you would expect, in this part of the country we find the first of many Mohave Rattle Snakes. It is a large bodied snake that quickly coils up and begins to rattle its tail to warn us not to mess with him. Using a large flash attachment on my camera I capture the beauty of this deadly snake in the darkness of the desert night. Down the road in our headlights I can see Black-tailed Jackrabbits running ahead of us in a zigzag, predator avoiding pattern, before jumping off into the desert night. Kangaroo Rats and other small mammals dash across in front of us proving that the desert does come to life at night. During the day you never see these critters. Continuing down the road we come across several large Tarantulas that are looking for an evening meal. The spiders don’t seem disturbed by our flashlight. Again I capture a great image of these incredible creatures. Several more snakes and spiders later we stop by one of the few large trees in the area. In the main trunk of the tree, about nine feet up, is a small hole made by a woodpecker many years ago. Peering out of the hole is two of the cutest faces you can imagine. These are the babies of the smallest owl species in the world, the Elf Owl. The young are no larger than three inches tall with the parents not much taller. The young owls are giving a raspy call that intensifies when one of the parents approaches the nest cavity with a large June Bug in its beak. The adults hesitate only momentarily before flying to the cavity entrance to feed one of the young. It’s dark and still very warm and again lightning flashes across the sky but still no rain. We stay here at the Elf Owl nest for the next hour or so until we are ready to go to bed. What a great day. We wake before dawn. As usual the days start out clear and warm. We head out to gather our traps. The sun is just poking over the horizon when we arrive at the trapping line. We gather up the traps that contain the rodents the researcher is looking for and head back for the lab. It’s like Christmas morning as we open each trap to reveal the critter inside. Each animal is alive and doing well. The rest of the day is spent walking around the ranch in search of birds such as the Montezuma’s Quail and Cassin’s Kingbird to photograph. In the afternoon I get word that a very large Western Diamond-backed Rattle Snake is sitting beneath a large shrub next to one of the buildings. I head over there and find a huge five foot long rattler trying to keep cool in the shade of a shrub. Everyone is concerned for their dogs so we gather up the snake and move it down the road away from any human contact. It’s a good reminder that this is a wild place with several major dangers to keep in mind. The second morning I wake before dawn to the sounds of Montezuma’s Quail calling in the distance. Javelins can be seen running up the side of the hill across the valley returning from a night of foraging. Again we head out to explore the desert before it gets too hot. Until next time…
Alaska Bears Part 1
I woke with a massive headache. The kind of pain in your head that hurts so bad it wakes you from a deep sleep.
American Kestrel
It is nearly raptor photography season again and I can hardly contain myself. For a wildlife photographer there are few species of bird that are as exciting to photograph as the raptors. Raptors as a group are also known as the birds of prey. They include hawks, eagles, falcons, owls and kites. The word raptor is a general term to describe any of these birds. In fact the word raptor is Latin and means “one who seizes” or “grabs”. I would say that is a good translation because raptors catch their dinner by grabbing their prey with their powerful feet. A recent report on one of the raptors—the American Kestrel was recently published. These are the kinds of issues I like to follow closely so I thought I would summarize a few of the highlights from the report for this week’s column. First a little background about the kestrel. It is the smallest species of falcon in North America, measuring only 9 inches from head to tip of tail. Compare that to the American Robin which is 10 inches and you can get an idea of how small this falcon really is. The American Kestrel is by far our most common falcon and can be found all across the U.S. and Canada from coast to coast. In Canada and the northern states, it is a migratory bird with most but not all the kestrels migrating to the southern states for winter. In the states where winter is mild it is non-migratory. In summer much of its diet consists of large insects such as grasshoppers. It hunts in open fields and prairies by perching on prominent objects such as posts or trees. It will also hover in flight over a field looking for its next meal. Raptors such as the kestrel have been monitored and counted during migration at several locations throughout the country for the past 50 or more years. This has produced a large set of data that gives researchers a glimpse into the population trends of these birds. Recently the data from seven raptor monitoring sites in the eastern half of the United States was examined to reveal some interesting population trends concerning the American Kestrel. Over the past 30 years from 1974 to 2004 the population of the kestrel has been declining. Upon further examination the sharpest declines have been over the past 10 years. For example at Cape May, New Jersey there has been a 4.5 percent drop in just the past 10 years. Hawk Mountain Pennsylvania reports a similar drop. Hawk Ridge in Minnesota is the exception with less than 1 percent drop. Analyzing the Christmas Bird Count data, which is another long term study of the population trends of birds, confirms a similar decline in numbers in the same states where the hawk watch data was collected. The same trends are observed in the western half of the country leading researchers to conclude the decline is widespread across the U.S. So what might be causing this decline? It is important to understand that there is no “one” reason for these kinds of declines. So with that in mind here are some possible explanations. The use of chemical pesticide used to kill insects could be a problem. During the summer Kestrels feed heavily on large insects such as grasshoppers. Eating dozens if not hundreds of contaminated grasshoppers would accumulate large amounts of pesticide in the bird. We saw this same problem with DDT about 40 years ago. Changing habitat may also be a problem. Kestrels require open habitat. All across the eastern half of the country the forests are expanding and maturing. Combined with fire suppresnnnnsion any open habitat is quickly changing to forest habitat. Increased predation from the larger Cooper’s Hawk may be contributing to the kestrels declines. The Cooper’s Hawk is a forest dwelling species that is benefiting from the reforestation and feeds upon smaller birds such as the kestrel. Lastly is West Nile Virus which has had an impact on many species of bird including the kestrel. Only time will tell what will happen with this species. Until next time…
Summer
Last time I sent out two columns at the same time but apparently only one was successful. So this week I will be sending two columns.
Whooping Cranes
I step out of my truck into the cold pre-dawn darkness. I can see nothing but I can hear a great diversity of birds. Immediately I hear a pair of Great Horned Owls hooting back and forth no more than a hundred yards away. In the distance is the honking of a flock of Canada Goose. I can also hear dozens of Sandhill Cranes sounding off with their ancient bone rattling call. But it is none of these birds that I am in central Wisconsin to see and photograph. No, I am here for a very special and rare bird, the Whooping Crane. This week’s column comes to you from the Necedah National Wildlife Refuge. It is Wisconsin’s largest federally owned refuge consisting of over 44,000 acres but when you count the adjacent federally managed land it totals a whopping 114,000 acres. Needless to say it’s a wildlife haven. Refuge manager Larry Wargowsky tells me “this place is really an endangered species refuge” because it is home to 3 high profile endangered species— the Karner Blue Butterfly, Eastern Gray Wolf and the Whooping Crane. Larry tells me that this large continuous block of habitat allows uncommon species such as the Fisher and Porcupine along with wolves and bears to live further south in Wisconsin than they would normally occur. I can bear witness to that because I saw and photographed one of the wolves early this morning. With over 5,000 acres of wetlands and impoundments (large shallow lakes) this refuge was selected to be the place where an experimental free flying flock of endangered Whooping Cranes would be established. After years of planning the project released its first cranes in 2001. Young Whooping Cranes were raised by staff members of Operation Migration who dress in costumes that mimic adult cranes. Each year an average of 8-21 young cranes are trained at this facility and are taught to fly behind an ultra-light aircraft to learn how to migrate. I am sure this is not the first time you have heard about this amazing story. By all means of measurement this project to establish a migrating flock of Whooping Cranes has been a success. But last spring disaster struck when nearly all of the young cranes raised and flown to Florida were killed in a freak accident—a tornado. Set backs are part of any success story but they are usually never the end of the story. And the Whooping Crane project is no exception. Beverly Paulan from Operation Migration tells me that this past spring 35 Whooping Crane eggs were hatched in preparation for the class of 07. Seventeen of these new crane chicks are now at this facility learning how to eat, drink and most importantly fly and migrate by following the ultra-light. I had a chance to spend a couple days with the staff of Operation Migration to see first hand how this process is working. Weeks before my arrival the staff of OM had spent hundreds of hours feeding and training the young cranes. This involves dressing in an all white costume and hand holding a life-like head of an adult Whooping Crane to feed the young birds. Now standing almost as tall as their parents the young cranes of 07 are learning to fly and follow the ultra-light aircraft. Each morning just as the sun is peaking over the horizon pilots from OM take off from their hanger and land at the holding pens of the young cranes. The young birds are released from their protective enclosure and immediately start to stretch their wings and dance about. It doesn’t take too much encouragement to get the young birds to follow the air craft. Within a minute they are off and flying. They make several circles and land again. All total they are airborne about 25 minutes. The young birds are returned to the holding area. Another successful flight. This goes on day after day (weather providing) until Oct when its time to migrate south. All the months of preparation pay off when the pilots and support staff take off and head south with the ultimate destination being Florida where they will spend the winter. Interesting the Whooping Cranes only need to be shown the way down to Florida once. After that the birds will return to central Wisconsin on their own where they will spend the summer and hopefully reproduce, thus establishing a free flying, migratory flock of the endangered Whooping Crane. Until next time
Autumn Colors
Who doesn’t love it when the trees turn from their uniform green to the many shades of autumn? I know I do. The only thing that bothers me is how short the autumn colors can be. One good windy day or a heavy rain storm and all the blaze and glory are gone. And you’ll have to wait another year before it’s back again. Leaves are green because of a pigment known as chlorophyll. When the chlorophyll is healthy and happy it dominates any other pigment found in the leaf. But chlorophyll doesn’t just give leaves their color; they are vital in the life of the tree. Chlorophyll cells capture some of the sun’s energy and combines it with water that is taken up by the tree roots and carbon dioxide which it takes from the air, to produce the trees food—simple sugars. The bi-produce is oxygen. During summer, chlorophyll is constantly breaking down and is replaced by the tree so the leaves remain green all season. But as autumn approaches the tree reacts to the reduce daylight and starts to get ready for winter by shutting down the flow to the leaves. In addition, the leaves are starting to wear out from a season of hard work producing food for the plant so the tree is ready to shed the old leaves. At the base of the leaf stalk (where the leaf attaches to the tree) a thin layer called an abscission layer starts to close off, reducing the flow to the leaves. As this happens the food manufacturing chlorophyll start to die off making it no longer the dominant compound in the leaves. Other pigments such as carotenoids, which give off the color yellow, brown, orange and all the shades in between start to show. Another group of pigment cells called anthocyanins, which are not found in the leaf during summer start to develop. These pigments, common in maple trees, give us the reds and purples of autumn. Unlike the carotenoids, the anthocyanins develop in late summer in the sap and have a complex reaction inside the leaf when in the presents of bright sunlight and a chemical phosphate. During summer, phosphates breaks down the sugars manufactured by the chlorophyll, but in autumn the amount of phosphates decrease and start to move out of the leaves and into the tree. When this happens the sugar breakdown decreases. The brighter the light during this period the greater the production of anthocyanins and the brighter red the leaves become. If the tree is under drought stress or has poor health from a fungal or viral infections the colors won’t be as bright. Also if the autumn is dark and cloudy the brightest colors won’t develop. When conditions of temperatures, moisture and sunlight are all in the right amounts we will have a bright and colorful autumn. Soon the abscission layer will completely close off and the leaf will die and fall from the tree. Since leaves are expendable it really isn’t a big deal for the trees to drop their leaves. Besides the break down of the leaves on the forest floor feeds nutrients back into the soil where the trees roots can reabsorb them and help to produce the new leaves the following spring. Think of all these chemical reactions that are taking place before your eyes the next time you stop and admire the blaze of autumn. Until next time…
Alaska Bears part 2
Continuing my Alaskan bear photography adventure in this column. Over a two week period during late August,
Common Poorwill
At the risk of sounding like a broken record, this week’s column comes to you from the desert of Arizona. As you may have guessed, I am currently working on several new field guides for the state of Arizona so I am spending a lot of time here in the desert. During the day, I am working on locating and photographing several species of tree, cactus, wildflowers and small mammals. But at night I have some time to explore the desert. In fact if you ask me, night time is the best time to be in the desert. All the desert critters become active. One night just after dusk, I came across a very unusual bird—the Common Poorwill (Phalaenoptilus nuttallii). When I say, unusual, I don’t mean uncommon I mean different from other birds. The poorwill occurs in the western half of the country but because it is a nocturnal bird and one that is also very cryptic in color it often goes unnoticed by the average person. The Common Poorwill is a resident of high rolling prairies, desert scrub and rocky foothills at elevations around 4,000 feet. It is noted for its distinctive call and ability to enter a temporary daily hibernation called torpor. In fact this is the only known bird to spend long periods during winter months completely inactive, day and night. In 1946, a California ornithologist found a Common Poorwill in a rock crevice one day during winter. When he picked up the bird he could not detect a heartbeat or respiration, yet the bird was not dead. The temperature of this bird was between 64-67 degrees F, whereas its normal temperature would be around 106 F. Over the next 88 days during which the air temperatures remained around 40-42 degrees the bird was examined, temperature and weight were monitored and returned to the rock crevice. The temperature and weight of the bird remained the same and after 12 weeks the bird woke up and few off, just as the air temperatures began to rise and its chief source of food, insects, became available. This was the first time that temporary hibernation (torpor) was reported in birds. Since then, we have learned a lot about the Common Poorwill. We now know that they become torpid when the air temperatures range between 35-66 degrees F and will only use 0.35 ounces of stored fat over a 100 day period to keep alive. We have also discovered several other species of bird that use torpor to make it through cold temperatures. I have discussed Black-capped Chickadees in this column in the past. However the poorwill is the only bird that uses torpor for extended periods of time, kind of like hibernation. Recent studies show that poorwills in Arizona remain completely inactive on as many as 90 percent of all winter days and nights. The poorwill is an insect eater who hunts from the ground or low perch at night just after the sun sets. They use the stars and moon to help illuminate the sky and to see flying insects in the night sky. They have extremely large eyes that allow them to see in the dark. When they see a large moth or beetle fly by they quickly fly (sally) up to capture the insect before returning to the ground and to wait for another insect to pass by. They use very little energy to obtain their high protein diet. They are such proficient hunters they only need to be active for a couple hours each evening after the sunsets to capture enough calories to last until the next night. Back in the desert, I am driving down a dirt road just after sunset. The first poorwill that is illuminated in the headlights quickly flies off as well as the second and third one. However the fourth one holds still. I am able to quietly exit the truck and sneak up close enough to capture a couple images of this elusive night bird before it takes to the night sky and leaves me standing there in the glow of the headlights and the stars shining brightly above. Another great night in the desert. Until next time…
Hawk Ridge
The morning broke clear and crisp. Another picture perfect autumn morning in one of my most favorite places.