Friday, September 27, 2013

Grizzly Bear

Grizzly Bear
 The grizzly bear is the largest predator in North America. Males can get up to 1200 lbs or more. They are omnivores eating a diet of fruits, berries, nuts, seeds, grasses, rodents, fish and larger mammals. During the fall they go into hyperphagia in preparation for hibernation. During hypephagia the bear do little else other then eat and sleep. An adult bear can put on up to 400 extra pounds during this time, which is important because they do not eat during the 5 - 7 months that they hibernate.
Grizzly Bear
Grizzly bears are related to brown bears or Europe and Asia. It is believed that they traveled to North America across the Bearing Strait around 50,000 years ago. When European settlers came to North America Grizzly bears were found through out much of the western half of the continent. Unfortunately because of hunting and habitat loss the grizzly bear has been extirpated from over half of it's original range. The largest concentration of grizzly bears is in Alaska where they estimate the population at around 30,000 bears. The population in Canada is estimated at between 15,000 to 20,000. In the continental U.S. the population is only about 1500. Most of the bears in the lower 48 states of the U.S. live in Montana, Wyoming, and Idaho. With the majority of them living in Yellowstone National Park, where we photographed these, and the Grand Tetons.
Grizzly Bear Sow and Cubs
Part of the problem with the grizzly bear population is that they have a low reproductive rate. Grizzly bears do not reach sexual maturity until they are at least five years old. Mating occurs in the summer but the embryo goes into stasis until the female is in hibernation. If the female is not in good health and sufficient weight her system will abort the pregnancy. If she is healthy she will have the one to four cubs in the den while she sleeps. The cubs will stay with their mother for a couple of years, hibernating with her over two winters. During this time the main predator that the cubs need to fear is a male grizzly. Males will kill the cubs hoping to put the female in estrus so that they can mate with her. After a couple of years she will chase her offspring away and the cubs will be on their own. She may mate again that year if a male finds her while she is in estrus but grizzly bears are solitary and have large territories so it is possible that she may not find a mate for a year or two.

Tuesday, September 24, 2013


Golden-crowned Kinglet

Kinglets are small passerines (songbirds) that are found in North America, Europe, Africa and Asia. They are called kinglet because all seven species have a crest or crown. There are two species of kinglets in North America, the golden-crowned kinglet, pictured above, and the ruby-crowned kinglet, pictured below. The golden-crowned is similar in appearance to the goldcrest kinglet which is found in Europe and Asia.

Ruby-crowned Kinglet
The ruby-crowned kinglet is the largest of all species of kinglets. The ruby crown is often not visible, usually depending on the mood of the bird. This may be because it is the only kinglets whose crown is not lined with black. Both species of North American kinglets breed mainly across northern Canada, although some birds also breed along the northern Atlantic and Pacific coasts of the US, and in the Rocky Mountain region. Most of these birds migrate to the US and northern Mexico for the winter.

Saturday, September 21, 2013

Red-shouldered Hawk

Red-shouldered Hawk
 The red-shouldered hawk is a medium sized hawk that is typically found in the eastern half of the United States and along the Pacific coast in California. They are forest hawks that typically ambush their prey, located on the forest floor, from a perch in the trees. Their main prey is small rodents, such as mice, voles, rats, moles, chipmunks, and ground squirrels. They will also take other prey such as tree squirrels, rabbits, reptiles, amphibians, birds and larger bugs, when available. They stay on territory all year long through out most of their range, with only the birds in the farthest north regions migrating to central Mexico for the winter.
Red-shouldered Hawk
There are five different subspecies of red-shouldered hawks. The subspecies with the largest range is the lineatus subspecies. Often called the northern red-shouldered they are found from Kansas to the Atlantic Coast, in the south, up to southern Canada. These red-shouldered hawks are larger in size then the other subspecies. The top photo is a northern red-shouldered hawk photographed in Minnesota. There are 2 subspecies in Florida, alleni and extimus. the extimus subspecies is found only in the southern parts of Florida. The Florida subspecies are smaller and usually lighter in color especially around the face. The bird in the photo above was photographed in Florida. The last eastern subspecies is texamus and they are found in eastern Texas and northeastern Mexico. There is one subspecies, elegans, found along the Pacific coast mostly in California. Their breast and belly are more orange and have less barring then the other subspecies. This subspecies used to be called the red-bellied hawk. 
Red-shouldered Hawk
Red-shouldered hawks breed once per year, typically between April and July. They often sue the same nest year after year with both male and female helping to refurbish it. The average clutch size is three to four eggs which are usually laid with in two to three days. The eggs are incubated for a little over a month before they hatch. It is around six weeks before the chicks are ready to fly. After they fledge the young will hang around for another three to four months before they will leave their parents territory to find a place of their own. This last photo shows the different coloration of an immature Florida red-shouldered hawk.

Tuesday, September 17, 2013


 Dark-eyed Junco (Slate-colored)
 There are only two types of Juncos found in North America. There is the yellow-eyed junco, which is found in Mexico and southern Arizona, and the dark-eyed juncos, which are found almost every place else across the continent. Dark-eyed juncos have several different color variations which is fun but can be confusing to people who are new to birding.
Dark-eyed Junco (Pink-Sided)
 Even through they look different all 4 birds in this post are dark-eyed juncos. The most common coloration is the slate-colored, which is pictured on top. These juncos breed in Canada, the north eastern United States and the Appalachian Mountain region. They winter through out most of the US. This is the only junco that is regularly found in the eastern half of the continent. These are the type that we see here in southern Minnesota during the winter. Many of them breed in the northeast portion of the state.
Dark-eyed Junco (Oregon)
 The second photo is an example of a pink-sided. The pink-sided breed in the Wyoming, Idaho, Montana area and winter from Colorado south down into northern Mexico. The bird in the photo above looks similar to the pink-sided but it has a darker head and pinkinsh brown flanks. This is an Oregon dark-eyed junco. They breed in western Canada and the west coast. Birds that breed in Canada migrate to the western half of the US for the winter.
Dark-eyed Junco (Gray-headed)
 This last dark-eyed junco is an example of a Gray-headed variety. They breed in Colorado, Utah, Nevada, and New Mexico and winter in southern Arizona, New Mexico and northern Mexico. They look very similar to the red-backed variation which is found in a smaller range in Arizona and New Mexico. There is one last variety, the white-winged dark-eyed junco which I still have left to photograph. They are found around eastern Wyoming, western South Dakota, Colorado and New Mexico.

Sunday, September 15, 2013

Orange-barred Sulphur

Orange-barred Sulphur
The orange-barred sulphur is a large sulphur butterfly found in Florida, south Texas, Mexico, Central America and northern South America. There are usually 2 to 3 brood per year in Florida and the butterflies can be seen year round. Occasionally they migrate north, and in those cases usually have only one brood. The larval host plants are Cassia species in the pea family.

Tuesday, September 10, 2013

Indigo Bunting

Indigo Bunting
 The indigo bunting gets its common name from the color indigo which is a deep bright blue. However the feathers of the indigo bunting are not really blue. Just like the sky appears blue because particles in the air that reflect the blue light rays, microscopic structures on the buntings feathers reflect and refract blue light.
Indigo Bunting
Indigo buntings breed primarily in the south western and eastern United States. They are omnivorous and eat a variety of seeds, berries and insects. During the winter they migrate down to Mexico and Central America. 

Sunday, September 8, 2013

Great Horned Owl

Great Horned Owl
 The great horned owl is the top raptor predator where I live. These efficient hunters are considered a border species because they nest and live in a wooded area that is usually adjacent to an open area that is used for hunting. They eat a variety of prey including rabbits, squirrels, rodents, frogs, skunks, and birds. They are crepuscular which means most of their hunting occurs around dusk or dawn. Their large eyes have many rods which are cells that assist in seeing things in black and white. The rods help them to see in very low light. The facial disks, flat spots, on their face help to direct sound to their ears, which are on the side of their face underneath the feathers. The ears are at different heights allowing the owl to use asynchronous hearing to locate their prey by sound. This is especially helpful when the owl is hunting prey that is burrowing under the snow, which happens often here in Minnesota during the winter.
Great Horned Owl Chick
The great horned owl is one of the first bird species to nest each year. They are often on the nest beginning at the end of January. Great horns do not make a nest, they borrow a nest from another bird that has not yet returned from their winter migration. Typically they will use a nest from another large bird such as a hawk, heron or crows. They may also use a tree hollow or a squirrel's nest, if they are desperate. Clutch sizes vary from 1 to 4 eggs. The female incubates the eggs which take 4 to 5 weeks to hatch. The female continues to sit on the nest after the eggs hatch to keep the bald and helpless chicks warm. As the chicks grow and are able to keep themselves warm the female will join the male in hunting for the family laving the chicks alone. At around 5 weeks of age the chicks begin to get adventurous and start branching, climbing along the tree branches of the nesting tree. It is not unusual that a chick may fall out of the tree at this age. The parents will continue to watch over and feed the chick on the ground until the chick can climb back up into the tree. Unfortunately this is when people often find the chick on the ground. Often they will take the chick home, usually out of concern, but they are not a good substitute for the chicks real parent and during this developmental stage of the chicks life they can really mess them up. It is called human imprinting and it usually leads to an owl that can no longer survive on their own in the wild. SO what should you do if you find a chick? If the chick does not appear injured or in danger the best thing to do is leave it for its parents to care for. If it looks like the chick is hurt or in danger, especially from domestic cats or dogs, then you should take it to a facility that cares for injured raptors or birds.  

Tuesday, September 3, 2013

Harris Hawk

Harris Hawk
 The Harris hawk is a medium sized hawk that is found in North and South America. They typically live in hot arid climates and as such do not migrate. In North America they are found primarily in the southwest, south Texas and Arizona, and Mexico. Harris hawks are some times found well outside their range. This is typically due to falconry birds that escape and become feral, since Harris Hawks are very popular falconry birds.
Harris Hawk Immature
 Harris hawks nest in small trees, scrub bushes or cactus. The female usually builds the nest which is sticks and plants and lined with leaves or moss. Clutch size is usually 2 to 4 eggs which are incubated primarily by the female for 30 to 36 days before they hatch. When the chicks hatch they are bald, blind and helpless. It will take about 45 to 50 days before they are able to fledge. Since Harris hawks breed in climates that do not change much in the winter the females will sometimes breed two to three times a year.
Harris Hawk Family
The Harris hawk is more social then most other raptors. Typically raptors are loners tolerating other raptors only when breeding but Harris hawks often live in small social groups. Often breeding groups consists of a couple of adult males and one female. Immature birds will sometimes stay with their parents for two to three years helping to feed and raise new broods. Since there are not a lot of trees in the habitats in which they are found they will often perch on each others backs, called stacking. They will also hunt in a group using some of the same pack hunting techniques as lions and wolves. Harris hawks that hunt in a group are much more successful then those that hunt on their own.

Sunday, September 1, 2013

Atlantis Fritillary

Atlantis Fritillary
 The Atlantis fritillary is a brushfoot butterfly that is found in Southern Canada, and the northern and eastern United States. They usually have one brood per summer and can be identified from other fritiallry butterflies by the black border on the upper side of the wings. Their larval host plants are violets. This year the number of butterflies that I have seen has been way down. It most likely has something to do with the late winter that we had this year.