Category Archives: Kodiak Wildlife

Wildlife of Kodiak Island including biology, behavior, and news

What Happened to the Pacific Grey Cod?

July 1, 2018Fish, Kodiak WildlifeCod, Cod Crash in Alaska, Cod in Alaska, Crash of Pacific Grey Cod, Grey Cod, Pacific Cod, Robin Barefield, The Blobadmin

In October 2017, the National Oceanic and Atmospheric Administration (NOAA) made a shocking announcement. Pacific cod (or grey cod) stocks in the Gulf of Alaska had declined 71% since 2015 and 83% since 2013. Cod, once one of the most plentiful fish in Alaskan waters, suddenly became a rare catch, devastating one of the most lucrative commercial fisheries in the state. Biologists scrambled to learn why cod were dying and why the few cod caught weighed less than normal and appeared malnourished.

While researchers yet do not have empirical evidence to support their theory, they have a good idea why cod populations have crashed. During the winter of 2013/2014, scientists mapped an unusually warm, large, circular body of seawater in the North Pacific Ocean. This mass of water didn’t cool as winter progressed but instead hovered several degrees above the normal winter temperature. Scientists nicknamed the mass of warm water the “Blob.” In February 2014, the Blob remained 4.5° F (2.5°C) warmer than the average February ocean temperature.

Warm water temperatures persisted throughout 2014, and oceanographers noted these were the warmest temperatures ever measured in the North Pacific Ocean since climatologists began recording ocean temperatures. Along with these warm water temperatures, a static high-pressure region in the atmosphere persisted throughout much of 2014, resulting in a lack of the normal wind-generated currents that stir the surface waters of the North Pacific.

This warm, calm mass of water produced far-reaching effects on the biology of the North Pacific. Without an upwelling of cooler water and nutrients, the surface waters of the warm Blob became stagnant, resulting in reduced phytoplankton production. Phytoplankton is the platform for the ocean food pyramid, and without a healthy supply of phytoplankton, the pyramid collapses. Zooplankton can’t survive unless they have phytoplankton to eat, and without zooplankton, many fish species, including the juveniles of most species, will starve. Plankton-eating fish provide the food supply for larger fish, and all fish, mammals, and birds dependent on marine life to survive will suffer from a reduction in phytoplankton productivity.

A lack of food was not the only problem Pacific cod faced, though. The increased ocean temperatures raised their metabolism while reducing the available food. With less food, the average size of the cod dropped. A 2015 NOAA survey showed cod were the skinniest ever recorded, and at this same time, mortality rates skyrocketed for the younger age classes of cod, an indication the cod population would not recover for many years. The warm water and lack of nutrients also negatively affected cod egg production.

Will the Pacific grey cod recover? Biologists don’t know the answer to this question, but even if cod populations begin to recover now, they will not be commercially viable until at least 2021. The crash of the cod fishery has had a negative impact on the economies of Alaska fishing ports, and the decline of cod is certain to impact the food web of the North Pacific.

Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

Mystery Newsletter

Chalky vs. Mushy Halibut

June 24, 2018FishAlaska halibut, Chalky Halibut, Fishing in Alaska, Mushy halibut, North Pacific halibut, Robin Barefieldadmin

How much does a pound of halibut cost in your neighborhood grocery store? If you can even find halibut for sale, it probably costs more than $20 per pound, and if you decided to buy it, you expect your butcher to hand you a perfect chunk of pristine, white fish. Pacific halibut is one of the most sought-after food fish in the world. When cooked, halibut has a subtle flavor and a flaky texture, but when fishermen report catching halibut with sub-prime flesh conditions, the news alarms sport and commercial fishermen, fish processors, chefs, and consumers. Chalky and mushy flesh conditions are the two biggest concerns for halibut caught in Alaska.

What is the difference between chalky and mushy halibut, and can a human safely eat the meat of a fish afflicted with either condition? The two flesh conditions might both look unappetizing, but they are very different from each other. One is caused by the rigors of an athlete trying to stay in the ocean and out of your boat, while the other is a sign of a malnourished fish. Let me explain in more detail.

Chalky Halibut

When an animal exerts itself, it uses oxygen to break down glucose and produce energy. During intense exercise, such as when a sprinter runs a race, he might not be able to breathe enough oxygen to complete the chemical process to produce energy. When the body does not have sufficient oxygen, it produces lactic acid, which your body can convert anaerobically (without oxygen) into energy. Producing anaerobic energy works great in the short term, but during prolonged physical exertion, lactic acid can build up in the bloodstream and muscles faster than the animal can burn it, lowering the pH of the muscle tissue.

The blood and muscles of a healthy athlete, as well as those of a healthy fish, will slowly dump excess lactic acid once the athlete or fish stops exerting and begins breathing normally again. When a fish is killed at the end of a long fight, though, the excess lactic acid stays in its flesh. Small halibut in the 10 lb. to 15 lb. range, caught during the warmest part of the summer, are the most susceptible to excess lactic acid in their tissues.

The meat from a halibut with a build-up of lactic acid often looks white and cooked as soon as you fillet the fish, but it sometimes takes several hours before the flesh turns chalky. Instead of the semi-translucent appearance of normal halibut meat, chalky halibut is white and opaque. Chalky halibut looks like raw halibut after the meat has marinated in lemon juice for several hours. Chalky halibut is safe to eat, but the meat often tastes tough and dry when cooked.

Mushy Halibut Syndrome

As the name implies, halibut with this syndrome have large sections of flesh which are soft instead of firm, and sometimes the flesh is so mushy, it feels like jelly. A mushy halibut is often obvious even before you fillet it because the fish looks emaciated, and indeed, biologists think malnourishment causes this condition.

Mushy halibut syndrome is most prevalent in halibut in the 15-20-lb. range. Although fish pathologists have yet to pinpoint the cause of this condition, they have not found parasites or infectious agents in affected fish, and they do not believe it is a disease that can be transmitted from fish to fish. Microscopic examination of the tissues of mushy halibut reveal a severe loss of muscle mass, and the affected muscles resemble those of animals known to have nutritional deficiencies of vitamin E and selenium.

The muscle atrophy in mushy halibut causes weakness in the fish and compromises the halibut’s ability to capture prey, leading to further malnutrition and weakness. This syndrome is most common in areas where populations of prey fish have declined, and the stomach contents of mushy halibut show many have consumed small crabs instead of the forage fish they normally eat. Researchers wonder if crab lacks some of the nutrients necessary for halibut to thrive.

Mushy halibut is safe to eat, but when cooked, it falls apart and resembles oatmeal.
According to the International Halibut Commission, neither chalky nor mushy halibut are common, but the prevalence of these conditions varies between years and locations. As the oceans warm, researchers worry these conditions will become more common.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

Interesting Facts About Sitka Black-Tailed Deer

June 10, 2018Kodiak Wildlife, Sitka black-tailed deerDeer eat poisonous plants, deer on Kodiak Island, Deformed deer antlers on Kodiak Island, How do deer survive on Kodiak?, How many deer were transplanted to Kodiak?, Kodiak Sitka black-tailed deer, Sitka black-tailed deeradmin

While I always smile when I see a Sitka black-tailed deer, I don’t always run for my camera because I see deer nearly every day. Last week, I wrote about the three deer that hang out in our yard. The other day, I stretched out on a sunny spot in the grass and closed my eyes. I felt something touch my face, and when I casually brushed it away, I heard loud breathing and hooves stomping. I sat up abruptly and looked into the eyes of a young buck. I’m not sure which one of us was the most startled, but after we recovered, the deer resumed grazing, and I laughed.

While they may be common, deer are fascinating animals, and I thought I would share a few interesting facts about Sitka black-tailed deer.

How did deer get to Kodiak Island, and how have they survived?

The most interesting fact about the Sitka black-tailed deer on Kodiak Island is that they exist and thrive here. The deer population on Kodiak stems from a founder population of fewer than 35 animals. Twenty-five Sitka black-tailed deer were introduced to the north end of Kodiak Island in three transplants from 1924 to 1933, and another nine deer were introduced in 1934. The deer population has since spread to most areas of the Kodiak archipelago, and despite the limited gene pool, the population appears to be healthy. The size of the deer population fluctuates from year to year, depending on the harshness of the winter, but biologists estimate when the population is at its peak, approximately 70,000 deer on live on the archipelago.

How can deer eat some poisonous plants?

After a long, cold winter, deer enthusiastically graze on the first green sprouts in the spring, and they often eat skunk cabbage, despite the fact the plant contains oxalic acid, a poisonous compound. Humans who have tasted skunk cabbage claim the plant burns their mouths for hours, but it doesn’t seem to bother deer. Deer are also able to tolerate other toxic plants, and it is possible their gut bacteria can neutralize the toxins in these noxious plants.

How do deer communicate with each other?

A couple of weeks ago, I wrote about how foxes communicate with each other. One of the ways deer communicate is with the aid of pheromones produced by the scent glands located on the lower legs. A gland on the outside of the lower leg produces an “alarm” scent, a gland on the inside of the hock produces a scent to help deer recognize each other, and glands between the toes leave a scent trail when a deer walks. Deer have excellent senses of sight, smell, and hearing. Their ears move independently of each other, allowing them to pick up on signs of danger from different directions.

Why do some deer have deformed antlers?

A certain percentage of deformed antlers are common in any deer population and may be produced as the result of an injury. Research shows that leg, pedicle, and velvet injuries can all lead to deformed antlers, and these deformities may be temporary or permanent. Some deer in certain areas of Kodiak Island, particularly the Aliulik and Hepburn Peninsulas on the southern end of the island, display abnormal antlers with a bizarre shape, sharp tips, and retention of velvet well into the mating season. Research on these deer indicates they are also sterile. At first, the problem was believed to be genetically linked due to the narrow gene pool of the small founder population. This theory, however, did not explain why the deer with the mutated antlers were mostly concentrated in one area of the island, even though there was nothing confining the deer to this area. A study published in 2005 carefully analyzed all aspects of the problem and concluded the sterile deer with the malformed antlers were not the result of inbreeding. Instead, researchers think the deer living in this area of the island are ingesting something such as kelp or grass laced with estrogenic molecules that alter antler growth, transform testicular cells, and block the descent of fetal testes.

The Sitka black-tailed deer on Kodiak Island experience the best and worst of nature. In the spring and summer, they enjoy an endless supply of food in this lush environment, but winters are often harsh, and nearly the entire deer population can be wiped out by a series of cold, snowy winters.
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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. If you like audiobooks, check out her audiobook version of Murder Over Kodiak. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

Mystery Newsletter

How do Deer Antlers Grow?

June 3, 2018Kodiak Wildlife, Sitka black-tailed deerDeer Antler Growth, Deer Biology, How Fast Do Deer Antlers Grow?, Kodiak Deer, Sitka black-tailed deer, Wildlife of Kodiak Islandadmin

Why do deer have antlers, and how do they grow so fast? Can you imagine having to walk around with a set of antlers on your head? I get a headache just thinking about it.

Last year in late May, we saw a Sitka black-tailed deer doe with two newborn fawns in our yard. They took up residence nearby, and we still see the trio nearly every day as they graze on our sprouting grass. The fawns are now almost the same size as the doe, and I wonder when they will wander off on their own. Will the doe have a new set of fawns this year? She doesn’t look pregnant, but we will know for certain in a few weeks.

Does between the ages of five and ten are in their prime and usually produce two fawns a year. Mating season on Kodiak occurs between mid-October and late November. The gestation period is six to seven months, so fawns are born from late May through June. Twins are the most common, although many young does only produce a single fawn, and triplets do sometimes occur. Newborn fawns weigh between 6.0 and 8.8 lbs. (2.7 to 4.0 kgs.). For the first week, a newborn fawn has no scent, allowing the mother to leave the fawn hidden as she browses for food to rebuild her energy reserves after giving birth.

The two young deer we often see in our yard are bucks, and they have little nubs on their heads. Bucks begin to grow a new set of antlers in the late spring because the increased daylight in the spring stimulates the hormones that regulate antler growth. During the spring and summer, antlers receive a rich supply of blood and are covered by a fine membrane called “velvet.” At this time, the antlers are fragile and vulnerable to cuts and bruises. By August, antler growth slows, and they begin to harden. A few weeks later, antler growth ceases, blood flow to the antlers stops, and the velvet dries up and falls off. Bucks then retain these hard, polished antlers throughout the mating season. After the mating season, cells start to de-mineralize the bone between the pedicle and the antler, weakening the connection between the skull and the antler, and the antler falls off. On Kodiak, deer normally begin dropping their antlers from mid-to-late December.

Sitka black-tailed deer antlers are fairly small compared to other species of deer and typically have three or four points on either side, including the eye guards. A very large buck might have five points on each side, including the eye guards.

Deer antlers grow at an amazing rate. Biologists have determined white-tailed deer antlers can grow as much as one-half an inch (1.27 cm) per day during their peak growth. Antler size is dependent on age, nutrition, and genetics. Antlers are made from bone, and they develop from the pedicle on the frontal bone of the skull. Male fawns produce “button” antlers at the age of four to five months, and they begin growing their first noticeable antlers the following year. A young buck’s first antlers may be only single spikes, but antler size usually increases with age until they reach a maximum size. Antler growth requires a great deal of energy, so antler size is dependent on good nutrition and environmental conditions. A buck may produce smaller antlers the year following an extremely harsh winter.

While biologists don’t know why bucks grow antlers, several theories have been proposed:

(1) A buck with large antlers may signal to a potential mate that he is healthy and possess good genes.
(2) Antlers may be used as a weapon during the breeding season to establish dominance between males.
(3) The size of the antlers alone may display age-related dominance without the males having to fight. Although, current research does not support this theory.
(4) Deer may use antlers

to defend themselves against predators. Although, this would only be beneficial for bucks since does don’t have antlers.

It is likely a combination of two or more of these theories point to the true purpose of antlers.

The Kodiak winter of 2016/2017 was very harsh, and biologists estimated as much as 80% of the deer population on the island died. We saw deer carcasses everywhere we hiked in the late winter of 2017. The 2017/2018 winter was mild, and the deer fared much better. The deer wandering through our yard this spring look fat and healthy, and I suspect we will see a bumper crop of fawns this summer.

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Next week, I’ll cover some interesting facts about deer.

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Mystery Newsletter

How Do Red Foxes Communicate?

May 27, 2018Kodiak Wildlife, Red Foxred fox, Red Fox on Kodiak Island, Red Foxes Communicate, Robin Barefield, Wildlife of Kodiak Islandadmin

You only need to hear the scream of a fox in the middle of the night to know foxes communicate with each other and with other animals. Like dogs, red foxes communicate through body language, vocalizations, and scent.

Most body posturing is either aggressive/dominant or fearful/submissive. A curious fox will rotate his ears while sniffing, and when playing, a fox might perk up his ears and rise on his hind legs. When afraid, red foxes grin in submission, arch their backs, curve their bodies, crouch their legs, point their ears backward and pressed against their skulls, and swing their tails back and forth. Submissive foxes maintain a lower posture when approaching a dominant fox. When two evenly- matched foxes square off, they approach each other sideways and display postures suggesting a mixture of fear and aggression, with ears pulled back, tails lashing, and backs arched. When attacking each other, a red fox approaches its opponent head-on instead of sideways. They hold their tails aloft and rotate their ears to the sides.

In addition to body language, red foxes use vocalization to communicate. They have a wide vocal range and produce sounds spanning five octaves. Biologists have divided most of these sounds into contact calls and interaction calls. Contact calls are used when two foxes approach each other or when adults greet their kits. Foxes use interaction calls either during courting or when dominant and submissive foxes interact or during an aggressive encounter. A call that does not fit into either of these categories is a long, monosyllabic “waaaaah” sound made during the mating season, and biologists think this vocalization is a female calling for males.

The red fox has extremely good hearing, and unlike other mammals, it can hear low-frequency sounds well, allowing it to detect small animals moving underground, so it can dig the prey out of the dirt or snow. Although not as acute as its hearing, the red fox has a good sense of smell and binocular vision that reacts mainly to movement.

A fox’s sense of smell allows it to use scent to communicate. A fox urinates to mark its territory and food caches. A male raises one hind leg and sprays urine in front of him, while a female squats and sprays urine between her hind legs. Then, anal and supra-caudal glands, as well as glands around the lips, jaws, and on the pads of the feet, aid another fox in detecting the scents marking the first fox’s territory or food cache.

As with most mammals, foxes have developed an elaborate array of means to communicate with each other. Just because we don’t understand their language, doesn’t mean they don’t have one.

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For those of you who enjoy audio books, the audio version of my novel Murder Over Kodiak is now available. Check it out here. Also, you can download a freed digital version of one of my novels by watching my webinar about how I became an author and where I get my ideas for my novels.

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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.

Mystery Newsletter

The Kodiak Red Fox

May 20, 2018Kodiak Wildlife, Red FoxKodiak red fox, red fox, Red Fox Life Cycle, Robin Barefield, Wildlife of Kodiak Islandadmin

The red fox (Vulpes vulpes) is a member of the Order Carnivora and the dog family Canidae. Red foxes occupy the largest geographic range of any member of the Carnivora, across the entire Northern hemisphere, Central America, and Asia. There are currently 45 recognized subspecies of Vulpes Vulpes, and one of these subspecies is Vulpes vulpes harrimani, the Kodiak red fox.

Red foxes are one of only six mammals native to the Kodiak Archipelago, and like most other Kodiak mammals, Kodiak red foxes are very large. They have a huge tail, coarse, thick fur on the lower back and tail, and a thick ruff around the neck and shoulders. Most Kodiak red foxes are either cross foxes with a black/brown cross on their back and shoulders, or they are a solid reddish-orange in color. Silver foxes make up a smaller percentage of the population and are striking with black fur, silver-tipped guard hairs, and yellow eyes.

Red foxes breed in February and March in Alaska. Soon after mating, the female will begin preparing a den for the arrival of her kits (babies). She may dig her own den, but often a fox just enlarges the home of a smaller burrowing animal. The litter is born after a gestation period of 51 to 54 days. An average litter consists of four kits, but litters of ten are not uncommon.

The kits open their eyes at eight to ten days after birth and leave the den for the first time at five to six weeks of age. By the time the kits are three months old, they begin to hunt on their own, and the leave their mother when they are seven months old.
In the summer, we see young foxes dart out of their dens, playing, chasing each other, and learning to hunt. Kits are curious and will often sit and watch us as we cruise past them in our boat. Even adult foxes are curious, but as they age, they learn to be wary.

Most red fox populations are considered stable. Red foxes are adaptable, and while they seem to prefer a wild setting, they can thrive even when living near urban populations.
Humans are fascinated by the beautiful, curious, intelligent red fox, and the red fox has been the subject of many songs, fables, and parables. In certain areas, foxes are trapped or shot for their furs, and in the early 1900s, fox farms, to supply pelts, were established on many of the small islands around the Kodiak Archipelago and off the Alaska Peninsula.

In addition to man, red foxes have several other natural enemies, including wolves coyotes, lynx, wolverines, and possibly bears. Eagles may prey on young foxes. The mite Sarcoptes scabiei causes mange in red foxes, resulting in hair loss, wasting and death. In the wild, red foxes live about five years, but in captivity, they may live as long as fifteen years.

We often see red foxes on the beaches at low tide, feeding on mussels, starfish, sea urchins, worms, and other intertidal animals. Foxes are a part of the Kodiak landscape, and I smile whenever I spot one.

Next week, I’ll tell you how foxes communicate with each other.

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The audiobook of Murder Over Kodiak is now available, and you can buy it here. If you want a free digital copy of one of my books, watch my webinar, and you can download the book for free at the end.

Please leave me a comment if you have any observations, questions, or suggestions

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Mystery Newsletter

When Do Eaglets Leave The Nest?

April 29, 2018Bald Eagle, Kodiak WildlifeBald Eagle Chicks, Eagle growth in Alaska, Eagles on Kodiak Island, Eaglets, Growth of eaglets, Robin Barefield, When Eaglets leave the nestadmin

Three weeks after hatching, eagle chicks, or eaglets, molt to a thicker, darker down which remains until the first set of feathers develop. At this stage, one of the parents remains near the nest to shelter the chicks from direct sunlight, inclement weather, and anything else that can harm them.

When an eaglet first hatches, its bill and eyes are dark-colored. Over the course of three to four years, the bill lightens to a swirl of shades of brown, then to yellow-brown, and finally to bright yellow. The eyes lighten to buff yellow by one-and-one-half-years, light cream by age two-and-one-half, and pale yellow by three-and-one-half.

As the chicks develop feathers and grow, the parents spend less time at the nest and more time hunting for food. The eaglets grow very rapidly as long as the parents can provide sufficient food. If the parents are unable to find enough food, the smallest chicks might die.

At one-and-one-half to two-weeks, most young eagles weigh one to two lbs. (500 to 900 grams). Between 18 – 24 days, chicks gain four ounces (100-130 grams) per day, a faster weight gain than at any other stage of their development. Eaglets begin feeding themselves around the sixth to seventh week, and by eight weeks, they can stand and walk around the nest. At sixty days, eaglets are well-feathered and have gained 90% of their adult weight. Large nestlings consume nearly as much food as adults.

Chicks remain in the nest for ten to twelve weeks. A week or two before they fledge, they can be seen on the rim of the nest exercising their wings and holding onto the nest with their talons. They flap their wings and may even lift off the nest. A chick can fall or be blown off a nest while exercising, and if it can’t make it to another branch, it might fall to its death. Biologists estimate one in seven eaglets fledges prematurely, either falling or jumping from the nest before it can fly.

Once their muscles and wings are strong enough, eaglets are ready to leave the nest. What prompts the chicks to fledge is a matter of speculation, but at some point, the parents cut back on the amount of food they provide their young, and they may even use food to lure the chicks away from the nest. Males fledge at an average of 78 days, and females fledge at an average of 82 days. Research in Southeast Alaska shows fledging there occurs on average in mid-August.

The first several flights of a fledgling are very clumsy, and their first few landings are usually crash landings. Juvenile birds have longer wings and tails than adults, and this makes learning to fly easier for them. As an eagle matures, its wings become shorter and narrower, and the tail gets shorter with each molt.

Immature eagles usually stay within a half-mile radius of the nest for the first six weeks after fledging, and they may even continue to receive food from their parents during this time. Eight to ten weeks after fledging, they seem to develop a stronger instinct to move further away from the nest.

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Mystery Newsletter

When do Bald Eagles in Alaska Lay Their Eggs, and When do the Eggs Hatch?

April 22, 2018Bald Eagle, Kodiak WildlifeBald Eagle, Bald Eagle Chicks, Bald Eagle Eggs, Bald Eagle Eggs Hatching, Bald Eagles in Alaska, Bald Eagles on Kodiak Island, Robin Barefieldadmin

Bald eagles lay their eggs in mid to late May in southern areas of Alaska, although one study in Southeastern Alaska indicated that they might lay their eggs as late as early June. The female lays between one and three off-white-colored eggs in a span of one to three days. The eggs range in size from 2.76 inches by 2.09 inches (70mm by 53 mm) to 3.31 inches by 2.36 inches (84 mm by 60mm).

The eagle pair begins incubating the eggs as soon as they are laid. The male and female share the incubation duties, and each mate hunts for its own food. Studies show that for 98% of the day, either the male or female sits on the eggs. The incubating bird stands up about once per hour and may change positions. A study at several nesting sites on Admiralty Island in Southeast Alaska found eggs were incubated for 95% of the daylight hours with females sitting on the eggs 53% of the time, and males tending the eggs 42% of the time. Brooding time dropped to 79% of the day for the first 10 days after the eggs hatched and by 41 to 50 days after hatching, the brooding time decreased to only 6% of each day. Brooding time increased when it was rainy and decreased when it was sunny. The incubation period takes 34 to 36 days. Since individual eggs may be laid a few days apart, they will not all hatch at the same time.

The hatching process is slow and arduous. It takes chicks twelve to forty-eight hours to fully emerge from the egg. The chick makes the first crack in the shell with its egg tooth, a small, hard bump on the top of the bill. After resting awhile, it then chisels around the large end of the egg. It eventually pushes off the end of the egg and wriggles out of the shell. The egg tooth dries up and falls off four to six weeks after hatching.

During hatching, a chick must undergo several physiological adaptations. Before it hatches, a chick absorbs oxygen through the mat of membranes under the shell. During the hatching process, it must cut the blood supply to these membranes and trap the blood within its body. At the same time, it must also inflate its lungs and begin breathing air once it has cracked the shell. The chick must also absorb the yolk sack into its body and seal off the umbilicus.

Newborn chicks are wet, exhausted, nearly blind, and extremely needy. Since a newly-hatched chick can’t regulate its body temperature, the parents must keep it warm. The chick is covered with pale gray down. The skin and scales of the legs are bright pink, the bill is a grey-black with a white tip, and the talons are flesh-colored. After the first week, the legs begin to turn yellow.

Eagles lay one to three eggs, but usually, only one or two chicks survive. Survivability is directly correlated to age. The first chick to hatch will be one to two days older than its siblings, so it will be larger and stronger and able to out-compete its nestlings if food is limited. If a brood has three chicks, the smallest chick usually dies within a week of hatching. Death is not normally caused by injuries from fighting with its siblings, but the chick simply starves to death because the older nestlings get all the food. The older chicks peck the young chick into submission to prevent it from eating enough to survive. By doing this, the older chicks ensure they have plenty of food.

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Mystery Newsletter

Bald Eagle Nest Building

April 15, 2018Bald Eagle, Kodiak Wildlife, UncategorizedBald Eagle, Bald Eagle Nesting on Kodiak Island, Eagle nest, Eagle Reproductionadmin

Spring is a time for nest building; whether it’s a new nest made from twigs or a hollow spot in a rock needing only a fresh supply of moss for padding, birds know they must prepare their homes for the eggs and chicks that will soon follow.

Our weather is slowly warming here on Kodiak Island. Most days we creep into the forties, but then we drop back into the low thirties at night. I see a few sprouts popping through the ground, but mostly, it still looks like winter here.

Animals are the one, true indication spring is right around the corner. I hear whales exhaling in the pass near our lodge, signaling they are following the krill and small fish into the bay. In turn, the krill and fish are here to feed on the phytoplankton which blooms as the water warms. Yesterday, kittiwakes arrived in a big swarm to repopulate the rookery in front of our lodge. Puffins and arctic terns should be here soon.

The surest promise of spring, though, is the circling eagles high in the sky as they perform their mating ballet. Soon, they will begin repairing their homes as they prepare for their young to be born.

Bald eagles build the largest nest of any North American bird. The nest may be as large as 8 ft. (2.44 m) across and weigh one ton (907 kg). An eagle pair often uses and adds to the same nest every year, causing the nest to grow over time.

Bald eagles build their nests in large trees near the water. In Alaska, nests are usually found along saltwater shorelines or rivers, and in many parts of Alaska, eagles nest in old-growth timber. On Kodiak Island, eagles prefer to nest in black cottonwood trees, but in areas where black cottonwoods are not available, nests can be found on rocky cliffs or at the bases of alder trees on cliffs along the coast.

The nest is usually built in the crotch of the last set of branches one-third to one-quarter of the way down from the top of the tree. Eagles tend to nest in trees with sparse foliage near the edge of a habitat, so they can fly to and from the nest without having to navigate through a canopy of trees.

The nests are built of sticks, and each year the eagle pair adds new branches and other vegetation to the nest to cover over food remains, feathers, and other debris left from the previous year. Branches and twigs are placed on the edge of the nest, while softer vegetation such as leaves, grass, and moss are placed in the center. An eagle pair continues to add branches, moss, and grass to the nest all summer until the chicks are nearly grown. Researchers believe the reason for this may simply be to keep the nest cleaner. Waste, rotting fish, and even the bodies of chicks that have died in the nest are not tossed out of the nest but are buried by moss, grass, and other greenery. It is important to keep the nest clean, so parasites don’t infest the chicks.

An eagle pair usually uses a nest until either the eagles die or something happens to the nest or the tree holding the nest. Mates may build two, three, or even four nests in their breeding territory, and scientists are unsure what the purpose is for these multiple nests.

The average distance between occupied nests is usually 1 to 2 miles (1.6 – 3.2 km), but nest sites are often closer to each other in areas where food is plentiful. A 2007 nesting and productivity study on the Kodiak National Wildlife Refuge identified 1141 nests with 439 (38%) of those nests active. This was down from a 55% occupancy rate found in a 2002 study. Of the 439 active nests in 2007, 208 of the nests (48%) were successful in producing young. The researchers suspected the harsh spring weather in 2006 and 2007 might have contributed to the reduction of nesting effort.

Nesting and breeding bald eagles are territorial and defend their nests from other animals, including other eagles. Adults spend much of the day perched in prominent trees near the nest, perhaps to make themselves more visible to intruders. A resident eagle will warn an approaching eagle with a loud call consisting of grunts followed by a high-pitched screech. Sometimes the resident eagle quietly escorts an intruder out of the area, but occasionally, one of the two birds will attack the other, resulting in a display known as cart-wheeling, where one eagle descends on the other eagle, and the other bird rolls onto its back while both eagles grasp talons. The two birds then tumble toward the ground, separating just before they crash.

I welcome the birds back after a long winter. They are often noisy neighbors, but their cries herald birth, life, and spring!

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Mystery Newsletter

Kodiak Bear Management

April 8, 2018Kodiak Bear, Kodiak WildlifeBrown Bears, Hunting, Kodiak bear Management, Kodiak Islandadmin

Wildlife management most often involves managing humans. Research allows biologists to understand the needs and habits of wildlife, and this research hopefully leads to management policies to enable human populations to better coexist with wildlife. Wildlife management is never easy, and Kodiak is no different from anywhere else. Various user groups attempt to pressure wildlife managers into making decisions to further their particular interest, and managers struggle for a balance to try to accommodate a variety of users while protecting the wildlife and the habitat.

On the Kodiak Archipelago, I am proud to say the management of bears and their habitat is not only done well, but it is done so well, it is considered one of the best models of wildlife management in the world. The Kodiak National Wildlife Refuge managers, the Alaska Department of Fish and Game, the native corporations, and the citizens of Kodiak work well together to safeguard bears and protect their habitat.

History has shown us that protecting wildlife habitat is often the most difficult aspect of wildlife management, whether there is oil to be drilled, copper to be mined, trees to be cut, or roads and houses to be built, economics often wins while wildlife loses huge chunks of critical habitat. Brown bears require large tracts of wilderness to survive, and as the human population grows, it becomes more and more difficult to protect the bears’ home from economic and residential development.

The Kodiak National Wildlife Refuge is the largest intact, pristine island ecosystem in North America. The Refuge encompasses 16 lakes, 117 salmon streams, wetlands, grasslands, shrublands, Sitka spruce forest, tundra, and alpine meadows. This habitat supports 250 species of fish, birds, and mammals, including 400 breeding pairs of bald eagles. It supports 3000 bears, and an estimated 3500 bears live on the Kodiak Archipelago.

One of the stated purposes of the Kodiak National Wildlife Refuge is to conserve fish and wildlife populations and habitats in their natural diversity, including, but not limited to, Kodiak brown bears, salmonids, sea otters, sea lions, and other marine mammals and migratory birds.

The Kodiak National Wildlife Refuge was established in 1941 in response to concerns by bear hunters for the health and survival of the Kodiak brown bear population. The original mission of the Refuge was “to protect the natural feeding and breeding range of the brown bears and other wildlife on Uganik and Kodiak Island.” Without the strong lobbying efforts of hunting groups, it is doubtful the Kodiak National Wildlife Refuge would have been formed. The sale of bear hunting licenses and bear tags on Kodiak generates over $250,000 annually, and much of this money is used for research and habitat protection.

Bear hunting on Kodiak today is very tightly regulated. Each year, 4500 people apply for the 495 available bear-hunting permits. Of these 495 hunters, approximately 175 are successful, and 75% of the bears killed are male. All hunters must check in with the Alaska Department of Fish and Game office in Kodiak before going into the field, and they must check out with Fish and Game before leaving the island. Every bear killed must be inspected by an Alaska Department of Fish and Game biologist before it can be taken off the island. Because these strict regulations have the overwhelming support of guides and residents, illegal bear hunting on Kodiak is rare.

Perhaps the most telling fact proving the Kodiak bear and its habitat are well managed is the 3500 brown bears currently living on the Kodiak Archipelago. Biologists believe this is the largest the Kodiak bear population has ever been.

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