By Naomi Klouda
Homer Tribune
BobbieLee Briggs took her 11-week old puppy, Kookie, out to do its business Saturday morning, never suspecting that she might need to protect her pet from predators.
Little Kookie, (pronounced like Cookie), a Chihuahua, was so small it fit into Briggs’ hands. She paid $300 for the dog and brought her home about five weeks ago. On Saturday, Briggs set Kookie down, and along came an eagle.
“It was a full-grown eagle. It hit me on the head and shoulders and knocked me down. I looked up and he’s got my puppy,” Briggs said.
“Chihuahuas are small. When I looked up, the eagle had it like it was a mouse in its claws. She didn’t even struggle. The way she was held by the eagle was the way I would pick her up. The eagle kept flying off and didn’t drop her.”
Shaken and upset, Briggs said she didn’t know where to turn. On Monday, she spoke to a person at the Islands and Oceans Visitor’s Center, who suggested she write a letter to the editor. She also was told she might tell the Homer Police and contact the city of Homer.
“But I was afraid they would just laugh at me,” she said.
One of Briggs’ complaints is she believes this winter’s congregation of eagles poses a menace to small pets in town. She said city actions regarding eagles on the Homer Spit might be at fault.
“There haven’t been eagles in this area for a while,” Briggs said, speaking of the Fireweed neighborhood in Homer. “They were definitely looking for food. It’s like they are out hunting for squirrels. I want people to keep an eye out. Though, even if they are keeping an eye out, it could happen.”
Briggs said she hasn’t seen many eagles down on the Homer Spit, where they get a free meal for a few more weeks.
After the “Eagle Lady” Jean Keene died Jan. 13, the Homer City Council permitted Keene’s assistant to continue feedings through March 27. The council acted on the advice from wildlife officials who recommended against an abrupt halt to feeding eagles.
“I don’t think they are being fed anymore,“ Briggs said. “I was down there Friday, Saturday and Sunday, and I saw maybe one eagle the whole time.”
That makes her believe eagles are dispersed through town, hunting for food and searching out other eating opportunities.
“I think people need to be warned. I’m afraid somebody else’s animal might get taken. The eagles are hungry, and they are going to take food any way they can take it,” she said.
Steve Tarola, who feeds the Homer Spit eagles at the former home of Jean Keene, said he continues to feed a large grouping of eagles each morning.
“They are being well-fed here. Eagles are getting full,” he said.
The eagles will take off when longer days come, he said. They return to home territories to defend them.
“But we see them go even if there was food here,” he said.
Showing posts with label wildlife. Show all posts
Showing posts with label wildlife. Show all posts
Tuesday, March 3, 2009
Tuesday, February 24, 2009
Science of the seasons: Textbook case of collaboration
Did you ever wonder what it takes to write a book on topics like the “Birds of Alaska” or the “Insects of South-Central Alaska?” Is it possible for one person to have visited every part of Alaska? And have they been able to find every bug or bird that is found there?
Sometimes one person actually can put together a book about something they have studied extensively for a long period of time. In virtually every case, the author has done extensive field observations and some of these are from a lifetime of collections and investigations. As an example, Dominique Collet, who has recently written the above-mentioned insect book, has an extensive personal collection of insects from many parts of Alaska.
However, most authors look beyond their own experiences and collections. There are a variety of species lists that can be examined, as well as historical records to be perused. As an example, the Kenai National Wildlife Refuge is currently compiling a list of all the species of organisms that have been identified from the refuge.
In some cases these records can be very old. For instance, there are extensive ship’s logs and records of the animals that were seen or collected by G.W. Steller during Vitus Bering’s voyages from Russia to Alaska in the 1700s. It was fairly common for early exploring ships to take a naturalist on voyages to record the biota that were encountered. Charles Darwin was such a naturalist on the famous voyage of the Beagle.
Museums throughout the world are repositories for ship’s logs and many extensive biological collections. If well-preserved, well-cared-for and properly documented, these collections can be used by researchers and specialists for a great many years. Darwin’s many biological collections from the early 1800s can still be examined in the British Museum. Most authors will spend considerable time examining the collections held in various museums.
Many authors will be well-versed in the specific biota of an area but will join with others who have collected specimens from additional areas. Professors Ken Stewart, of Texas, and Mark Oswood, formerly with the University of Alaska Fairbanks, have written a book on “The Stoneflies (Plecoptera) of Alaska and Western Canada.” Together they compiled a vast collection of stoneflies. They have both visited many parts of Alaska, collecting stoneflies wherever they went.
In addition, there are many other colleagues in Canada and the U.S. who have shared their Alaska collections with them. In the book, they describe all the specimens they have examined, list the hundreds of biologists who have collected them and list where the insects were found. I have personally been sending them stonefly specimens from Alaska for almost 30 years.
Because many book topics are so large, it is common for several authors to join together to create a book on a particular group of organisms. This is common when there are vast numbers of different subcategories within the overall group. The most authoritative book on identifying aquatic insects is “An Introduction to the Aquatic Insects of North America.”
It was put together by three specialists — Rich Merritt, Ken Cummins and Marty Berg. Instead of being listed as authors, they are described as “editors.” While each wrote a section of this 1,214-page book, they have invited a variety of other international experts to write a section (with identification keys) about a specific order or family of aquatic insects. The number of insect groups covered in this book is so large that it is almost impossible for any one author to know them all. In this case, it has taken a large team to put together one book.
One of the hallmarks of taxonomists — specialists who identify and name newly discovered species — is a willingness to work with others on identifying unusual, unknown or new specimens. There is a constant sharing of specimens between specialists as they collaborate to understand the scope of any particular group of organisms.
As a new graduate student many years ago, I found the aquatic insect taxonomists and the authors of many of the well-known identification books were some of the most gregarious, engaging and helpful scientists I met.
A highlight of attending international meetings on aquatic ecology is seeing the cooperative and collegial work among so many taxonomists, as they try to understand the great variety of life that surrounds us.
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
Tuesday, February 10, 2009
Something to chew on: Circle of life, beaver style
Every school-age child knows that beavers dam up streams, and it is a compliment to be described as being “busy as a beaver.”
These two thoughts are related, since beavers do spend long hours cutting down trees and then weaving the branches into a functional dam. Their impoundments require constant upkeep and additions of new branches. Along with the woody components, beavers scoop up mud from the bottom of the impoundment and pack it in between the stick framework.
Beaver dams vary in size and height but are frequently 2 to 3 feet high. The beaver dam I studied for my master thesis was more than 200 feet wide and created a pond of almost half an acre.
There are a couple important benefits for the beaver that justify the extensive energy output during dam construction. Perhaps the most obvious benefit is to raise the water level upstream of the dam. The deepened, backed-up water provides a quick escape when confronted with potential predators like cougars, wolves or bears. Besides the safety aspect, the water inundates channels that then provide safe access to feeding areas upstream. These upstream areas are where beavers cut down trees that are used for food or construction materials. While beavers will often take down larger diameter trees, they seem to prefer the young trees that are only a couple inches in diameter. The smaller trees are completely covered with tender and edible bark. It’s like a beaver’s version of a corn dog on a stick.
The beaver pond can provide a series of shipping lanes for moving tree limbs to the lodge or to the dam. Another major role the impoundment plays is as a food locker. Beavers will store hundreds of freshly trimmed limbs and branches underwater. During winter, they can swim from their lodge (or from tunnels into the bank) to the underwater pantry to retrieve a submerged limb. After feeding on the bark, the now-bare sticks can be used for springtime dam repair.
Ecologists often describe beavers as a keystone species in streams. This connotation refers to the major impact beavers have on a stream and the surrounding habitats. The presence of beavers can change many important aspects of the stream, as well as conditions in the surrounding riparian areas.
Beaver impoundments inundate large areas of terrestrial vegetation and will literally drown out most of the original vegetation. Virtually all the inundated trees and shrubs will die. This usually leads to an increase in solar radiation, which provides opportunities for new species of plants and algae to grow. Sometimes sedges and other wetland plants will appear along the edges or right on the breast of the dam.
Construction of a beaver dam immediately slows the stream water and that causes deposition of many materials being washed downstream. Organic materials like leaves, twigs, grasses and fish carcasses, as well as mineral sediments, will collect on the bottom of the dam. This accumulated material will eventually become very rich soil.
Because of the deepened water in the beaver pond, many fish will use these areas as an overwintering refuge. Many resident salmonids in Alaska move out of streams in the winter months and seek out areas like beaver dams where they can be assured of unfrozen waters. Given the opportunity, young silver salmon fry will use a beaver pond for a wintering area or may use it for a year-round place to feed and hide.
Because of the excavations by beavers and scooped-up mud for stabilization of the stick-built dam, there tends to be a fair amount of fine silt downstream of beaver dams. Those silty stream conditions cause changes in the stream’s invertebrate community downstream of the impoundment. These differences in turn can cause alterations in the downstream fish populations, too.
Beaver dams are ephemeral structures. After beavers utilize most of the available trees, they begin to prospect for greener pastures, or areas with more young trees. With no beavers to perform repairs and maintenance on the dam, it will eventually give way and drain out. When a dam washout occurs, those previously underwater areas become terrestrial habitats again. With all the deposited materials creating rich soil, the newly exposed pond bottom quickly becomes revegetated with herbs and woody vegetation.
The released stream cuts down through the deposited silt material and returns to its original physical flow patterns. Soon, the original stream and riparian biota return too. Several years later, when the trees have regrown, the stream section will once again be an attractive site for another beaver dam.
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
These two thoughts are related, since beavers do spend long hours cutting down trees and then weaving the branches into a functional dam. Their impoundments require constant upkeep and additions of new branches. Along with the woody components, beavers scoop up mud from the bottom of the impoundment and pack it in between the stick framework.
Beaver dams vary in size and height but are frequently 2 to 3 feet high. The beaver dam I studied for my master thesis was more than 200 feet wide and created a pond of almost half an acre.
There are a couple important benefits for the beaver that justify the extensive energy output during dam construction. Perhaps the most obvious benefit is to raise the water level upstream of the dam. The deepened, backed-up water provides a quick escape when confronted with potential predators like cougars, wolves or bears. Besides the safety aspect, the water inundates channels that then provide safe access to feeding areas upstream. These upstream areas are where beavers cut down trees that are used for food or construction materials. While beavers will often take down larger diameter trees, they seem to prefer the young trees that are only a couple inches in diameter. The smaller trees are completely covered with tender and edible bark. It’s like a beaver’s version of a corn dog on a stick.
The beaver pond can provide a series of shipping lanes for moving tree limbs to the lodge or to the dam. Another major role the impoundment plays is as a food locker. Beavers will store hundreds of freshly trimmed limbs and branches underwater. During winter, they can swim from their lodge (or from tunnels into the bank) to the underwater pantry to retrieve a submerged limb. After feeding on the bark, the now-bare sticks can be used for springtime dam repair.
Ecologists often describe beavers as a keystone species in streams. This connotation refers to the major impact beavers have on a stream and the surrounding habitats. The presence of beavers can change many important aspects of the stream, as well as conditions in the surrounding riparian areas.
Beaver impoundments inundate large areas of terrestrial vegetation and will literally drown out most of the original vegetation. Virtually all the inundated trees and shrubs will die. This usually leads to an increase in solar radiation, which provides opportunities for new species of plants and algae to grow. Sometimes sedges and other wetland plants will appear along the edges or right on the breast of the dam.
Construction of a beaver dam immediately slows the stream water and that causes deposition of many materials being washed downstream. Organic materials like leaves, twigs, grasses and fish carcasses, as well as mineral sediments, will collect on the bottom of the dam. This accumulated material will eventually become very rich soil.
Because of the deepened water in the beaver pond, many fish will use these areas as an overwintering refuge. Many resident salmonids in Alaska move out of streams in the winter months and seek out areas like beaver dams where they can be assured of unfrozen waters. Given the opportunity, young silver salmon fry will use a beaver pond for a wintering area or may use it for a year-round place to feed and hide.
Because of the excavations by beavers and scooped-up mud for stabilization of the stick-built dam, there tends to be a fair amount of fine silt downstream of beaver dams. Those silty stream conditions cause changes in the stream’s invertebrate community downstream of the impoundment. These differences in turn can cause alterations in the downstream fish populations, too.
Beaver dams are ephemeral structures. After beavers utilize most of the available trees, they begin to prospect for greener pastures, or areas with more young trees. With no beavers to perform repairs and maintenance on the dam, it will eventually give way and drain out. When a dam washout occurs, those previously underwater areas become terrestrial habitats again. With all the deposited materials creating rich soil, the newly exposed pond bottom quickly becomes revegetated with herbs and woody vegetation.
The released stream cuts down through the deposited silt material and returns to its original physical flow patterns. Soon, the original stream and riparian biota return too. Several years later, when the trees have regrown, the stream section will once again be an attractive site for another beaver dam.
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
Guest editorial: Joint effort needed to study belugas now, before it’s too late
Should belugas be protected as an endangered species? This is really several questions in one:
Do belugas warrant listing under the Endangered Species Act? Definitely. The population has little chance of long-term survival unless its size can be increased and kept above 1,000 whales.
Wouldn’t the problem disappear as soon as the last beluga dies? Wouldn’t we save a fortune and years of trouble by covertly killing all the remaining belugas? No! That’s like saying the way to way to cure liver disease is by cutting out your liver. That kind of “cure” can be worse than the disease.
Don't fall for the myth that ecological disruptions lack economic and social consequences. Perhaps the best-known marine example is impacts to commercial fishing when sea otter numbers crashed along the central Pacific coast. Without their predation on sea urchins, the urchins did so much damage to kelp forests that fish dependent on these forests crashed. A “balance” between predator and prey numbers is vital to the health of an ecosystem.
Hasn’t the decline in belugas actually helped fishermen? We don’t know. Granted, belugas compete with salmon for herring prey; and belugas eat salmon. But whether those losses outweigh benefits provided by belugas is still impossible to say. Ecological impacts of changing beluga numbers are largely unknown, despite decades of requests by biologists for funding to study this.
Failure of governments to provide adequate support hasn’t made the problem go away; it’s just gotten worse and more expensive to cure. Had we been working on this full steam for the past two decades, we’d have solid answers in hand and have been able to innovate minimal-cost technologies for keeping human impacts within tolerable limits.
Unfortunately, local and state governments waited to the 11th hour and their feet are still dragging. With every passing month, chances of success fall and potential costs rise.
Would the benefits of protection outweigh the costs? Cost-benefit ratios vary from person to person, and community to community, depending on who reaps the benefits vs. who pays the costs. Some costs could be felt very quickly, for instance if beluga protection were to preclude mining coal on the western side of Cook Inlet or require installation of more thorough treatment of sewage and other effluents from Anchorage. However, until we know a lot more about how our activities impact belugas, we will have little basis for identifying needed protections, much less for evaluating their costs.
It’s time to pull our collective heads out of the sand and quickly ramp up studies of beluga ecology and of how we humans impact them. The sooner we have this information, the more effectively and efficiently we can identify and implement protective measures that meet beluga needs with minimal economic and social impact.
What steps should we take? Identify legal requirements under the Endangered Species Act, the Marine Mammal Protection Act and other relevant statutes, court decisions and agency regulations.
We all know what a nightmare government red tape can be. This is partly a consequence of antiquated methods of educating ourselves about legalities. Invaluable aid has been provided by uploading legal information onto the Web where it is accessible to search engines. But even with that assistance, some laws, like the Marine Mammal Protection Act, are so convoluted that major sections defy logical analysis – a job I once attempted as an employee of the U.S. Fish and Wildlife Service.
Reading statutory law is just a first step. We also need to review case law and agency regulations. Some “laws” need to be clarified and/or made more user-friendly. It’s not enough to have the information available. You’ll never find the information you need unless you know enough to ask the right questions and how to interpret the answers. So-called “expert systems” employing artificial intelligence — way beyond that in search engines — could be of great assistance, and save folks a fortune in legal fees.
Business functions best in a climate where legal gray areas are minimized as much as possible so that we can anticipate with fair reliability which of our actions would be judged legal vs. illegal (as well as which conservation measures would be effective vs. ineffective). This may require being very proactive, perhaps in revising the MMPA.
For each municipality, business or other entity to tackle these challenges individually would be intolerably expensive. A far cheaper alternative is to do much of it collectively. For example, the Kenai Peninsula Borough might solicit donations from local industries and small businesses as matching funds for federal and state grants. Think of it as an economic stimulus package for Southcentral Alaska.
Every million dollars saved is another million dollars earned — tax free.
Dr. Stephen Stringham earned his master of science degree at the University of Alaska studying moose, and his doctorate degree studying bears. He is the author of five books on Alaska’s wildlife.
Do belugas warrant listing under the Endangered Species Act? Definitely. The population has little chance of long-term survival unless its size can be increased and kept above 1,000 whales.
Wouldn’t the problem disappear as soon as the last beluga dies? Wouldn’t we save a fortune and years of trouble by covertly killing all the remaining belugas? No! That’s like saying the way to way to cure liver disease is by cutting out your liver. That kind of “cure” can be worse than the disease.
Don't fall for the myth that ecological disruptions lack economic and social consequences. Perhaps the best-known marine example is impacts to commercial fishing when sea otter numbers crashed along the central Pacific coast. Without their predation on sea urchins, the urchins did so much damage to kelp forests that fish dependent on these forests crashed. A “balance” between predator and prey numbers is vital to the health of an ecosystem.
Hasn’t the decline in belugas actually helped fishermen? We don’t know. Granted, belugas compete with salmon for herring prey; and belugas eat salmon. But whether those losses outweigh benefits provided by belugas is still impossible to say. Ecological impacts of changing beluga numbers are largely unknown, despite decades of requests by biologists for funding to study this.
Failure of governments to provide adequate support hasn’t made the problem go away; it’s just gotten worse and more expensive to cure. Had we been working on this full steam for the past two decades, we’d have solid answers in hand and have been able to innovate minimal-cost technologies for keeping human impacts within tolerable limits.
Unfortunately, local and state governments waited to the 11th hour and their feet are still dragging. With every passing month, chances of success fall and potential costs rise.
Would the benefits of protection outweigh the costs? Cost-benefit ratios vary from person to person, and community to community, depending on who reaps the benefits vs. who pays the costs. Some costs could be felt very quickly, for instance if beluga protection were to preclude mining coal on the western side of Cook Inlet or require installation of more thorough treatment of sewage and other effluents from Anchorage. However, until we know a lot more about how our activities impact belugas, we will have little basis for identifying needed protections, much less for evaluating their costs.
It’s time to pull our collective heads out of the sand and quickly ramp up studies of beluga ecology and of how we humans impact them. The sooner we have this information, the more effectively and efficiently we can identify and implement protective measures that meet beluga needs with minimal economic and social impact.
What steps should we take? Identify legal requirements under the Endangered Species Act, the Marine Mammal Protection Act and other relevant statutes, court decisions and agency regulations.
We all know what a nightmare government red tape can be. This is partly a consequence of antiquated methods of educating ourselves about legalities. Invaluable aid has been provided by uploading legal information onto the Web where it is accessible to search engines. But even with that assistance, some laws, like the Marine Mammal Protection Act, are so convoluted that major sections defy logical analysis – a job I once attempted as an employee of the U.S. Fish and Wildlife Service.
Reading statutory law is just a first step. We also need to review case law and agency regulations. Some “laws” need to be clarified and/or made more user-friendly. It’s not enough to have the information available. You’ll never find the information you need unless you know enough to ask the right questions and how to interpret the answers. So-called “expert systems” employing artificial intelligence — way beyond that in search engines — could be of great assistance, and save folks a fortune in legal fees.
Business functions best in a climate where legal gray areas are minimized as much as possible so that we can anticipate with fair reliability which of our actions would be judged legal vs. illegal (as well as which conservation measures would be effective vs. ineffective). This may require being very proactive, perhaps in revising the MMPA.
For each municipality, business or other entity to tackle these challenges individually would be intolerably expensive. A far cheaper alternative is to do much of it collectively. For example, the Kenai Peninsula Borough might solicit donations from local industries and small businesses as matching funds for federal and state grants. Think of it as an economic stimulus package for Southcentral Alaska.
Every million dollars saved is another million dollars earned — tax free.
Dr. Stephen Stringham earned his master of science degree at the University of Alaska studying moose, and his doctorate degree studying bears. He is the author of five books on Alaska’s wildlife.
Tuesday, February 3, 2009
Malformed moose hit by vehicle — Hooves had abnormal growth
By Clark Fair
Redoubt Reporter
On Jan. 12, the story began ordinarily enough: Moose struck by vehicle on Kenai Spur Highway near Tesoro refinery. Family called to drive out and salvage meat.
Then the typical changed to the unusual: Family arrives to discover an oddity — dramatically elongated hooves. Family calls the authorities for an explanation.
According to U.S. Fish and Wildlife Service wildlife biologist Elizabeth Jozwiak, the moose — an older cow carrying a 2-month-old fetus — had “abnormal hoof keratinization.”
Keratins are a family of fibrous structural proteins that form hard mineralized structures in mammals: hair, nails, horns, claws and hooves.
On the Kenai Peninsula, some moose are believed to suffer from abnormal keratinization either because of a copper deficiency in their diet or an inability to process copper efficiently. The most visually pronounced evidence of this abnormality occurs in the hooves.
Whereas a normal, healthy moose of the same age might have hooves 3 to 5 inches long, three of this cow’s hooves were about six inches longer than that, and the rear left hoof was 10 inches longer.
According to Jeff Selinger from the Alaska Department of Fish and Game, local state biologists hear at least one report a year concerning such hoof abnormalities.
Despite the elongated hooves, which tend to be softer and more rubbery than normal hooves, he said, the afflicted moose seem to manage all right.
The deformity did not necessarily contribute to the moose’s collision with the vehicle.
Tuesday, November 25, 2008
Cold feet don’t foul up ducks — Waterfowl have several strategies for keeping tootsies toasty during icy months
Throughout winter, many Alaskans participate in various outdoor activities like skiing, skating, snowshoeing, ice fishing and snowmachining. A common problem for all participants is keeping their feet warm. There are a variety of possible solutions for cold feet: waterproof and breathable boots, extra socks, highly insulated boots and even heat-generating chemical or electric warmers.
But what about the waterfowl that remain along the rivers and streams all winter? Do they make Bunny Boots for ducks?
There are several species of ducks, mergansers and even swans that frequent the Kenai River watershed all winter long. They can usually be found in or near open water sections because that is where they can feed and it provides them protection from terrestrial predators like fox, coyotes, wolves and lynx. Nonswimming ducks can be found standing or lying on ice for long periods of time and they do not freeze. What’s their secret?
Waterfowl actually allow their feet to get very cold, keeping them just above freezing temperatures. Since their feet contain mostly bones and tendons surrounded by thick skin, there isn’t a critical need for the feet to stay any warmer. All of the muscles moving the feet are in the upper legs, and they are maintained at normal body core temperatures of 102 to 106 degrees Fahrenheit.
If we immersed our feet in icy water for any length of time, our body core temperatures would drop drastically. Waterfowl do it all day long and are easily able to keep their core temperatures fairly steady. How?
Physiologically, waterfowl have a special blood vessel system at the start of their legs called a “counter current exchanger” that warms the blood returning from the feet. Cold venous blood coming from the feet runs very close to warm arterial vessels carrying blood toward the feet. The blood leaving the body is cooled and the returning blood is warmed. This way, very little heat is actually lost to the outside world from the feet.
While it might appear that their feet could actually freeze, the supplying arterial blood vessels can be dilated or constricted to allow just enough extra warm blood into the feet to keep them from actually freezing.
There are also several behaviors that these birds can use to help keep their feet warmer or to reduce body heat loss. One method is to stand on only one foot. When on one foot, the other can be tucked up close to the body and kept warm within the insulating feathers. If you observe this one-foot stance behavior, watch to see that they will periodically switch feet.
Another common behavior is for the waterfowl to rest completely on the ice with both feet tucked up into the breast feathers. Their breast plumage provides amazing insulation, and they are able to maintain their body temperatures while sleeping on the ice. Their heads and beaks can also be tucked under a wing or buried in the feathers to preheat the air they take in and to retain some of the heat they lose during respiration.
This superb insulating quality of waterfowl breast feathers is well known and used in popular winter clothing filled with duck or goose down. Perhaps the very first down jackets were made by a number of Alaska Native populations. Dozens of waterfowl breast skins were sewn together to make very warm winter coats. Examples of these bird-skin coats can be seen in a number of Alaska museums.
In the case of waterfowl, they really do have “cold feet and a warm heart.”
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
But what about the waterfowl that remain along the rivers and streams all winter? Do they make Bunny Boots for ducks?
There are several species of ducks, mergansers and even swans that frequent the Kenai River watershed all winter long. They can usually be found in or near open water sections because that is where they can feed and it provides them protection from terrestrial predators like fox, coyotes, wolves and lynx. Nonswimming ducks can be found standing or lying on ice for long periods of time and they do not freeze. What’s their secret?
Waterfowl actually allow their feet to get very cold, keeping them just above freezing temperatures. Since their feet contain mostly bones and tendons surrounded by thick skin, there isn’t a critical need for the feet to stay any warmer. All of the muscles moving the feet are in the upper legs, and they are maintained at normal body core temperatures of 102 to 106 degrees Fahrenheit.
If we immersed our feet in icy water for any length of time, our body core temperatures would drop drastically. Waterfowl do it all day long and are easily able to keep their core temperatures fairly steady. How?
Physiologically, waterfowl have a special blood vessel system at the start of their legs called a “counter current exchanger” that warms the blood returning from the feet. Cold venous blood coming from the feet runs very close to warm arterial vessels carrying blood toward the feet. The blood leaving the body is cooled and the returning blood is warmed. This way, very little heat is actually lost to the outside world from the feet.
While it might appear that their feet could actually freeze, the supplying arterial blood vessels can be dilated or constricted to allow just enough extra warm blood into the feet to keep them from actually freezing.
There are also several behaviors that these birds can use to help keep their feet warmer or to reduce body heat loss. One method is to stand on only one foot. When on one foot, the other can be tucked up close to the body and kept warm within the insulating feathers. If you observe this one-foot stance behavior, watch to see that they will periodically switch feet.
Another common behavior is for the waterfowl to rest completely on the ice with both feet tucked up into the breast feathers. Their breast plumage provides amazing insulation, and they are able to maintain their body temperatures while sleeping on the ice. Their heads and beaks can also be tucked under a wing or buried in the feathers to preheat the air they take in and to retain some of the heat they lose during respiration.
This superb insulating quality of waterfowl breast feathers is well known and used in popular winter clothing filled with duck or goose down. Perhaps the very first down jackets were made by a number of Alaska Native populations. Dozens of waterfowl breast skins were sewn together to make very warm winter coats. Examples of these bird-skin coats can be seen in a number of Alaska museums.
In the case of waterfowl, they really do have “cold feet and a warm heart.”
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
Tuesday, November 18, 2008
Water works: Insects master submerged breathing
I remember as an elementary school student watching a classmate attempt to drown a grasshopper by holding its head under water. The grasshopper endured the insult long enough for the childish attention span to turn to some other endeavor, and the insect was released to swim another day.
While the grasshopper was in danger of being squeezed too hard and perhaps getting a bath it neither needed nor wanted, it was in absolutely no danger of drowning with its head under the water.
Insects take in their air by way of a special set of spiracles on the thorax and the abdominal segments. The many spiracular openings lead to a series of very fine, hollow tracheal tubules that repeatedly branch until they are about one micron in diameter (one micron equals 1/1,000,000 of a meter).
These very fine tubules are surrounded by insect hemolymph (insect blood) that can absorb oxygen from the tubules and give back carbon dioxide. In order to refresh the air in these tubules, insects simply stretch or move the abdominal segments. If you watch an insect for a while, it will periodically stretch the abdomen, much like you and I do when we elevate the chest and draw in a fresh breath of air.
So how do the many aquatic insects live completely under water if they use air-filled tracheal tubes for oxygen exchange? There are several interesting solutions to this problem. Many aquatic insects are so small that they are able to simply exchange gases from the water right through their thin exoskeleton.
Another approach can be found in several groups like the mayflies and caddisflies that have special gills as larvae. Some of these gills look like a miniature brush of fine tubes, while others resemble flattened footballs attached to each abdominal segment. These gills exchange gases that are then channeled into the tracheal tubes.
Mosquito larvae and some other dipteran (flies) larvae have a tiny tube that they extend above the water surface so they can take air directly into their tracheal tubes. This is like breathing through a straw while still completely submerged.
(While we now appreciate the damage that was done to our wetlands, this is why years ago oil was spread over swamps in attempts to control mosquitoes. The surface oil would plug up the mosquito respiratory structures and the larvae would die.)
The colder the water is, the more oxygen it can hold. Warm water, on the other hand, can hold much smaller amounts of oxygen. Most streams in Alaska are so cold that it is no hardship for insects to get all the oxygen they need. During the winter months, when the water is at its coldest, the insects are able to get all the oxygen they can use so they are very active feeding and growing.
In warmer waters the oxygen is limited so insects must resort to additional measures. Some insects use hemoglobin in their hemolymph that is the same bright red color as our blood. The insect hemoglobin, just like ours, helps hold onto oxygen and spread it throughout the insect body. In an effort to extract the limited oxygen from warm water, some insects flap their gills in the current to bring them in contact with more water. Yet others can undulate their bodies to create a current or even build little tubes that funnel water past their gills.
When these immature aquatic insects leave the water to become aerial adults, part of the emergence process involves shedding their gills. They then use the normal spiracular openings and tracheal systems for their breathing as adults. When we consider that many insects can fly nonstop for hours, the insect’s simple breathing system apparently works quite efficiently.
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
While the grasshopper was in danger of being squeezed too hard and perhaps getting a bath it neither needed nor wanted, it was in absolutely no danger of drowning with its head under the water.
Insects take in their air by way of a special set of spiracles on the thorax and the abdominal segments. The many spiracular openings lead to a series of very fine, hollow tracheal tubules that repeatedly branch until they are about one micron in diameter (one micron equals 1/1,000,000 of a meter).
These very fine tubules are surrounded by insect hemolymph (insect blood) that can absorb oxygen from the tubules and give back carbon dioxide. In order to refresh the air in these tubules, insects simply stretch or move the abdominal segments. If you watch an insect for a while, it will periodically stretch the abdomen, much like you and I do when we elevate the chest and draw in a fresh breath of air.
So how do the many aquatic insects live completely under water if they use air-filled tracheal tubes for oxygen exchange? There are several interesting solutions to this problem. Many aquatic insects are so small that they are able to simply exchange gases from the water right through their thin exoskeleton.
Another approach can be found in several groups like the mayflies and caddisflies that have special gills as larvae. Some of these gills look like a miniature brush of fine tubes, while others resemble flattened footballs attached to each abdominal segment. These gills exchange gases that are then channeled into the tracheal tubes.
Mosquito larvae and some other dipteran (flies) larvae have a tiny tube that they extend above the water surface so they can take air directly into their tracheal tubes. This is like breathing through a straw while still completely submerged.
(While we now appreciate the damage that was done to our wetlands, this is why years ago oil was spread over swamps in attempts to control mosquitoes. The surface oil would plug up the mosquito respiratory structures and the larvae would die.)
The colder the water is, the more oxygen it can hold. Warm water, on the other hand, can hold much smaller amounts of oxygen. Most streams in Alaska are so cold that it is no hardship for insects to get all the oxygen they need. During the winter months, when the water is at its coldest, the insects are able to get all the oxygen they can use so they are very active feeding and growing.
In warmer waters the oxygen is limited so insects must resort to additional measures. Some insects use hemoglobin in their hemolymph that is the same bright red color as our blood. The insect hemoglobin, just like ours, helps hold onto oxygen and spread it throughout the insect body. In an effort to extract the limited oxygen from warm water, some insects flap their gills in the current to bring them in contact with more water. Yet others can undulate their bodies to create a current or even build little tubes that funnel water past their gills.
When these immature aquatic insects leave the water to become aerial adults, part of the emergence process involves shedding their gills. They then use the normal spiracular openings and tracheal systems for their breathing as adults. When we consider that many insects can fly nonstop for hours, the insect’s simple breathing system apparently works quite efficiently.
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.
Tuesday, November 11, 2008
Bears visit airport — Soldotna pilots find tracks inside fence
By Jenny NeymanRedoubt Reporter
Two brown bears apparently took an interest in aviation Thursday night and led themselves on a tour of the Soldotna Airport.
Pilots found bear tracks around their planes Friday, and the city maintenance department was called to investigate. Doug Schoessler, maintenance manager, followed two sets of what he figures were brown bear tracks, one large and one small, but didn’t see the bears. He thinks it’s a sow and cub.
“I saw two spots where they came under the back fence. They’d kind of dug through the trees under the fence,” he said.
An Enstar crew has been working on a gas pipeline outside the fence. They also saw bear tracks but didn’t seen the bears, Schoessler said.
The smaller tracks stayed mostly out by the fence, while the larger bear was bolder.
“They definitely walked through some of the planes right by the hangers there, but were mostly in the spots that were not populated by anyone. But the bigger one definitely walked around by some the airplanes and didn’t seem too shy,” Schoessler said.
No damage was reported to planes or other equipment. There aren’t any food sources or garbage left out at the airport to attract bears, Schoessler said. They may have been looking for game.
“I saw a lot of rabbit tracks. That was what I kinda wondered, if they were coming in looking for rabbits or not. But I didn’t see any kills or any anything other than tracks,” he said.
Whatever enticed them, the bears seemed to have let themselves out the same way they got in — by making a hole under the back fence.
“They walked right by that one gate that had a big gap under it, but they didn’t even try to get under it. I think they try to find their private areas,” Schoessler said.
There’s a stand of trees in the roughly 200-acre fenced enclosure, but maintenance workers didn’t see any sign of the bears.
“We tried to make some noise over that way to drive them out, but it they were in those trees at the east end, they were just sitting tight. But I don’t think so. I think they got out.,” he said.
Moose occasionally find their way into the airport fence in the winter and have to be driven out, but bears are uncommon.
“A long, long time ago they had some issues with bears, but I’ve been there five years and I’ve never had anything since I’ve been there,” Schoessler said.
Bears could pose a threat to humans at the airport, but the larger concern with any sizeable wildlife is the hazard they pose to planes landing or taking off.
“Moose or bears or any of those things, if a plane hit them, it’s not a good thing,” Schoessler said.
Wednesday, October 1, 2008
Cook Inlet beluga numbers flatline — Decision on endangered listing due this month
By Naomi Klouda
Homer Tribune
The beluga whale population in Cook Inlet remains troubled, with numbers hovering at about 375 members of a genetically distinct group that formerly numbered at about 1,300.
In response, marine mammal experts and conservation groups have renewed their calls for the Bush administration to immediately list the Cook Inlet beluga whale as endangered under the Endangered Species Act.
John Schoen, senior scientist at Audubon-Alaska, said he’s expecting a decision after Oct. 20.
“At that point, the National Marine Fisheries Service could rule whether the beluga in Cook Inlet should be listed as threatened or endangered.”
An endangered or threatened status would put three advantageous factors to work for the beluga, Schoen said.
NMFS would be required to do a recovery plan and spell out exactly what research and monitoring would be involved. The agency would be required to develop a recovery plan.
“The second factor is that if critical habitat is defined, then any activity will require consultation with NMFS, and the third issue is that being listed will bring more money for research and monitoring,” Schoen said.
Only the science and protections offered by the endangered status would provide a safety net to help this group of beluga escape extinction, stated marine mammal scientist Craig Matkin of the North Gulf Oceanic Society, in a press release.
Cook Inlet is the most heavily used waterway in Alaska. It is the route for major shipping freight coming into Anchorage and communities beyond. Oil rigs and spills have stressed the waterway, Schoen said.
“It’s no one cause, but an accumulation of activities with all the things going on in Cook Inlet,” he said.
Other factors threatening beluga whales are not manmade problems, but stress that can put the population in danger, such as strandings in Turnagain Arm.
“Any kind of a natural catastrophe, like a killer whale predation or a stranding, plus all the human-caused issues, can push the beluga population to the brink,” he said.
After conservation groups petitioned to list the population as endangered, NMFS had one year to determine whether to do so. NMFS extended that deadline six months (until Oct. 20) at the request of Gov. Sarah Palin’s administration, which claimed the 2007 survey data showed an upward increase in the population. That, therefore, made the listing unwarranted. NMFS’s recent survey results demonstrate there is no upward population trend.
Beluga concentrate in the Susitna and Chickaloon Flats during the summer. Up to 90 percent of them can be in those places, making it “habitat we would want to be very cautious of,” Schoen said.
Beluga populations in the Bristol Bay and the Beauford Sea are healthy, but the Cook Inlet mammals remain distinct from them and geographically isolated. If more protections aren’t put in place, scientists are concerned it won’t take long for the beluga to become extinct in Cook Inlet.
The aerial surveys were taken June 3-12 by National Oceanic and Atmospheric Administration fisheries service scientists, where the belugas had congregated by the Susitna and Little Susitna Rivers, Knik Arm and Chickaloon Bay. They also took photographs and video. After examining the images, and from the manual count, observers said the population estimate remained the same as last year — about 375.
Alaska Native groups have been allowed to hunt the whales under co-management agreements with NOAA’s Fisheries Service, with restrictions on how many can be taken. Between 1999 and 2007, hunters took five beluga whales for subsistence, down from 308 in 1995 and 1998. There was no subsistence hunt for belugas in 2008.
Schoen said he expects there will be opposition to listing Cook Inlet beluga whales as endangered by Gov. Palin, similar to her administration’s actions against the polar bear listing. The effort to deny the need for an ESA listing, “is part of a larger trend in Alaska government to overrule science that contradicts political ideology,” Schoen said.
Schoen said that listing belugas as endangered won’t stop industry along Cook Inlet.
“But it takes a good look at that activity and tries to mitigate harm. It most certainly won’t stop all economic development in Cook Inlet,” Schoen said.
The organizations listed as petitioning to place the beluga as endangered are: Cook Inletkeeper, Alaska Center for the Environment, the National Audubon Society, the Kachemak Bay Conservation Society and the Natural Resource Defense Council, among others.
Homer Tribune
The beluga whale population in Cook Inlet remains troubled, with numbers hovering at about 375 members of a genetically distinct group that formerly numbered at about 1,300.
In response, marine mammal experts and conservation groups have renewed their calls for the Bush administration to immediately list the Cook Inlet beluga whale as endangered under the Endangered Species Act.
John Schoen, senior scientist at Audubon-Alaska, said he’s expecting a decision after Oct. 20.
“At that point, the National Marine Fisheries Service could rule whether the beluga in Cook Inlet should be listed as threatened or endangered.”
An endangered or threatened status would put three advantageous factors to work for the beluga, Schoen said.
NMFS would be required to do a recovery plan and spell out exactly what research and monitoring would be involved. The agency would be required to develop a recovery plan.
“The second factor is that if critical habitat is defined, then any activity will require consultation with NMFS, and the third issue is that being listed will bring more money for research and monitoring,” Schoen said.
Only the science and protections offered by the endangered status would provide a safety net to help this group of beluga escape extinction, stated marine mammal scientist Craig Matkin of the North Gulf Oceanic Society, in a press release.
Cook Inlet is the most heavily used waterway in Alaska. It is the route for major shipping freight coming into Anchorage and communities beyond. Oil rigs and spills have stressed the waterway, Schoen said.
“It’s no one cause, but an accumulation of activities with all the things going on in Cook Inlet,” he said.
Other factors threatening beluga whales are not manmade problems, but stress that can put the population in danger, such as strandings in Turnagain Arm.
“Any kind of a natural catastrophe, like a killer whale predation or a stranding, plus all the human-caused issues, can push the beluga population to the brink,” he said.
After conservation groups petitioned to list the population as endangered, NMFS had one year to determine whether to do so. NMFS extended that deadline six months (until Oct. 20) at the request of Gov. Sarah Palin’s administration, which claimed the 2007 survey data showed an upward increase in the population. That, therefore, made the listing unwarranted. NMFS’s recent survey results demonstrate there is no upward population trend.
Beluga concentrate in the Susitna and Chickaloon Flats during the summer. Up to 90 percent of them can be in those places, making it “habitat we would want to be very cautious of,” Schoen said.
Beluga populations in the Bristol Bay and the Beauford Sea are healthy, but the Cook Inlet mammals remain distinct from them and geographically isolated. If more protections aren’t put in place, scientists are concerned it won’t take long for the beluga to become extinct in Cook Inlet.
The aerial surveys were taken June 3-12 by National Oceanic and Atmospheric Administration fisheries service scientists, where the belugas had congregated by the Susitna and Little Susitna Rivers, Knik Arm and Chickaloon Bay. They also took photographs and video. After examining the images, and from the manual count, observers said the population estimate remained the same as last year — about 375.
Alaska Native groups have been allowed to hunt the whales under co-management agreements with NOAA’s Fisheries Service, with restrictions on how many can be taken. Between 1999 and 2007, hunters took five beluga whales for subsistence, down from 308 in 1995 and 1998. There was no subsistence hunt for belugas in 2008.
Schoen said he expects there will be opposition to listing Cook Inlet beluga whales as endangered by Gov. Palin, similar to her administration’s actions against the polar bear listing. The effort to deny the need for an ESA listing, “is part of a larger trend in Alaska government to overrule science that contradicts political ideology,” Schoen said.
Schoen said that listing belugas as endangered won’t stop industry along Cook Inlet.
“But it takes a good look at that activity and tries to mitigate harm. It most certainly won’t stop all economic development in Cook Inlet,” Schoen said.
The organizations listed as petitioning to place the beluga as endangered are: Cook Inletkeeper, Alaska Center for the Environment, the National Audubon Society, the Kachemak Bay Conservation Society and the Natural Resource Defense Council, among others.
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