Grizzly Highway Encounter

Driving back from Windermere we spotted an adult grizzly walking along a path in the forest beside the highway. We slowed to a stop and watched as the bear continued down the path. We followed slowly on the shoulder and then stopped when the bear emerged from the forest and started to walk in the ditch. The bear disappeared from my view in the driver's seat but was still visible by Karen in the passenger seat. 

"Karen, I can't see the bear anymore."

"Dad, the bear is right next to us." 

A moment later the bear walked out of the ditch in front of the car, 
nonchalantly ambled across the two-lane highway,
started to browse the dandelions by the roadside, 
then continued to walk in the grass by the opposite side of the road. 

We decided not to let the puppy out for a pee. 

Hummingbird Nest

Hummingbird Nest

I found a hummingbird nest on my front porch a few weeks ago!

Likely the nest blew out of a nearby tree. The two closest trees are a cypress and a crabapple. The cypress was only four meters away. The crabapple was about 8 meters away. Likely the nest was in the cypress.

The most common hummingbird in my garden is the Rufous but Ruby-throated and Calliope hummingbirds also visit. For several years I have regularly heard and seen the typical territorial display of the Rufous Hummingbird, which might imply these hummers nest in my yard. I do not see displays of the Ruby-throated or Calliope Hummingbirds. Based on prevalence, likely the nest was built by a Rufous Hummingbird. 

The nest is made mostly of grass but there are some small wood chips or bark, and down is evident both on the inside and outside of the cup. The down is likely willow-seed from the Black-bud Willows in the garden. 

All three species use plant material bound with spiders' webs, are lined with down, and the outside is usually covered with flakes of lichens. Lichen is not common in my garden but is available in the forests down by the Elbow River. There was no evidence of lichen on the outside of the nest. 

Ruby-throated nests are described with a thick lining of down and the nest is bound smoothly and tightly with spiders' webs. Calliope nests are also thickly-lined with down. The nest in the photo was not thickly lined with down and was not tightly bound or smooth. Perhaps the nest was under construction when the wind intervened.

The dimensions of the nest (inches) and the reported dimensions of nests for the three hummers who visit my garden are shown in the table below.

	Diameter		Height
	Outside	Inside	Outside	Inside
Nest in photo	1½	1	¾	¾
Rufous	2	1	⅞	1½
Ruby-throated	1 - 1¾	¾ - 1	¾	1½
Calliope	1½ - 1¾	1⅛-1⅞	⅞	⅞

Reference
Baicich PJ and Harrison CJO. Nests, Eggs, and Nestlings of North American Birds. Princeton UP, Princeton, New Jersey, 2005.

Spruce Grouse

Spruce Grouse - Falcipennis canadensis

The boreal forest is the preferred habitat for the Spruce Grouse. 

These birds are common in closed (dense forest canopy) conifer forests. The birds are often solitary and unusually tame for a wild species.

Reference
Sibley David A. The Sibley Guide to Bird Life & Behavior. Alfred A Knopf, Inc. New York. 2001.

Hoary Marmot

Hoary Marmot - Marmota caligata

The name, "hoary," refers to the "mantle" of white hairs over the shoulders. These mammals are the largest marmot in Canada.

Hoary Marmots are colonial and live together in burrows where they share food. They often sun themselves in shallow depressions on rocks close to their burrow. They vocalize a loud, high-pitched alarm whistle when a predator is recognized.

Predators include Coyote, Wolf, Grizzly Bear, Red Fox, and Golden Eagle.

Reference

Naughton, Donna. The Natural History of Canadian Mammals. University of Toronto Press. 2012. 

Mule Deer

Mule Deer - Odocoileus hemionus

The larger ears and the black tip to the tail are two common clues that distinguish a Mule Deer from the more common White-tailed Deer. Both species live in the area where I hike. The hoof prints and the scat are similar.
  
















References

Gadd Ben. Handbook of the Canadian Rockies. Corax Press. Jasper, Alberta. 1986.

Naughton Donna. The Natural History of Canadian Mammals. U of Toronto Press. 2012.

Muskrat

Muskrat - Ondatra zibethicus

Muskrats are the largest and the most aquatic of the voles in North America. These rodents are not closely related to the beaver, although both mammals have evolved similar physical and behavioural adaptations to their shared environment.

Muskrats do not hibernate. The photo above shows a muscat feeding on the ice at the side of a slough (runoff pond) close to the Elbow River.

Muskrats usually feed within 60 meters of their burrow, which allows a high population density in an optimal environment. The population cycles with peaks every eight to ten years. Mink are common predators and the population of this carnivore tends to track that of the Muskrat.

The skull bones in the photos are likely muskrat. I found the bones in the grass about 20 meters from a runoff pond below my home. The muskrat was likely attacked by a predator either while swimming or while grooming or eating by the edge of the pond. The predator likely carried the muskrat into the tall grass to eat. 

The pond is home to muskrats. The average litter ranges from 5 to 9 kits. In the fall of 2008 I counted 9 muskrats in the pond at one time. The large number was likely the result of a successful spring litter. Since then I have never seen more than two at a time. Common local predators include coyote, domestic dog, bobcat, mink, larger raptors, and man. 

Reference

Naughton, Donna. The Natural History of Canadian Mammals. U of Toronto Press. 2012. 

Black-capped Chickadee

Black-capped Chickadee - Poecile atricapilla



Black-capped Chickadees are prevalent year round in the Calgary area. 

Specialized leg muscles enable these birds to feed upside down while hanging from a perch. They are adept at exploiting resources in difficult situations. Food is stored in caches and used during the winter when resources are meager. During very cold winter days chickadees are able to lower their body temperature (regulated hypothermia) from 42 C to 30 C to conserve energy.

Chickadees will pester predators (mobbing behaviour) that are in their territory.

In autumn the new chickadees leave their parents and join a flock with which they will overwinter. These chickadees will mate the next spring with a member of the flock.

The nest is often a cavity in rotten wood. In my neighborhood, the chickadees favor creating cavities in the exterior of a home. They choose a location under the eaves where they excavate into the soffit where the siding meets the roofline.

References
1. The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.
2. Baicich PJ, Harrison CJO. Nests, Eggs, and Nestlings of North American Birds. Princeton UP. 2005.
3. Sibley David A. The Sibley Guide to Bird Life & Behavior. Alfred A Knopf, Inc. New York. 2001.

House Finch

House Finch - Carpodacus mexicanus

House Finches winter in Calgary and are less common during the spring and summer. Purple Finches are usually not present during the winter and return in the spring. 

The two species can be difficult to differentiate. The finch below was near the top of a tall spruce tree and without my binoculars I was not able to identify the bird. Fortunately I had my camera and the identification was straightforward once I viewed the image on my computer.



The finch on the spruce branch above is a House Finch,

The red colouration in a House Finch is brightest on the forehead and over the cheeks (malar area). In a Purple Finch the entire head is red. 

The upper beak in a House Finch is curved. In a Purple Finch the beak is straighter. 

The tail in a House Finch is longer than the tail in a Purple Finch. In flight, the tail notch in a Purple Finch is more distinct. 

References
Sibley DA. The Sibley Guide to Birds. Alfred Knopf, New York. 2000.

Tracking Beaver

Canadian Beaver - Castor canadensis

The Canadian Beaver is the second largest rodent in the world.

Good beaver tracks are uncommon because the prints are usually wiped out by either the heavy flat tail or by the tree trunks and branches that the animal drags to the water.

The beaver has five toes on the front and hind feet but only three or four usually register. 

The impressions of the large broad nails are visible in the left hind print in the photo below.

The quarter-inch incisors of a beaver can cut down a five-inch willow in three minutes! Beavers strip the bark to access the nutritious inner cambium layer.

The protective wire placed around this aspen was not much of a deterrent for a hungry beaver.
  

The photo below shows the stumps of numerous aspen cut down last year and dragged into the water for use during construction of a lodge.

Once a beaver starts to cut down trees in a grove, these natural engineers tow the trunks and branches to the water over the same trail. This technique clears the pathway and forms channels with progressively lower resistance to drag, and makes the process faster and more energy efficient. The photo below shows a drag channel over the shore and a typical notch at the edge of the water.

References
Naughton D. The Natural History of Canadian Mammals. UofT Press. 2012.
Rezendes P. Tracking and the Art of Seeing. How to Read Animal Tracks and Signs. Firefly Books Ltd. Willowdale, Ontario. 1999.

Tracking Meadow Voles # 2

When the snow disappeared from the garden in my front yard, the bark at the bottom of my columnar crab apple tree was chewed off. 

The crab tree is located in designated garden area that is only a few meters from the driveway of my neighbour. You can see the pebbled pavement in the lower left of the photo above. My neighbour shovels his driveway and he throws the snow up on my lawn. Over this last winter, the snow was piled up about four to five feet high in this area. Moles choose to nest under deeper piles of snow. The grass above is filled with typical Meadow Vole runways through the grass and burrows.

A close up of the gnawed area shows tiny grooves that fit with the size of Meadow Vole incisors. Tiny chips of orange bark are strewn on the ground at the base. The vole chewed through the bark to reach the nutritious rich inner cambium layer. This layer of undifferentiated cells produces the bark.

Meadow Vole scat was piled around the base of the tree. There is enough scat in the photo above to confirm that the tree offered many meals for the animal.

There was another pile of scat on the other side of the tree. This scat has a slightly darker and different colour. Perhaps this poop was from a second vole with a slightly different diet. Another possibility is that the scat was formed by the same vole but during a time when the diet of this vole was otherwise different? Or perhaps this vole ate and digested more of the outer bark? 

Prairie Crocus

Prairie Crocus - Anemone patens

The Prairie Crocus is one of the earliest spring flowers. The flowers are prominent on southern exposed slopes. When the snow melt is delayed, the flowers can spring up through thin layers of snow or they appear within days after the snow disappears.

The ants in the photo above are likely attracted to calorie-rich nectar produced by specialised glands (nectaries). Ants are not efficient cross-pollinators. A protective chemical (antibiotic) produced by ants can inactivate pollen. 

The silky white hairs that envelope the stems and the leaves are visible under the lowermost flower in the photo above.

Anemone is from the Greek "anemos," which means the wind. These flowers propagate well in windy habitat. The fruit of the flower (achenes) develop attached to a long feathery tail, that helps with wind dispersal.

References
Cotter GW & Flygare H. Wildflowers of the Canadian Rockies. Hurtig Publishers. Edmonton. 1986. 
Phillips HW. Northern Rocky Mountain Wildflowers. Falcon Publishing. USA. 2001.

Thirteen-lined Ground Squirrel - Spermophilus tridecemlineatus

The cheek pouches of this Thirteen-lined Ground Squirrel are filled with the husked sunflower seeds I put out for the birds who prefer feeding on the ground. The seeds regularly attract red and black squirrels, chipmunks, and meadow voles. For several years, a Thirteen-lined Ground Squirrel has been a regular visitor. The squirrel turned up on April 2nd this year. The same day I found a hole at the base of the fence between my property and the meadow behind my home. I suspect the three inch diameter hole is the entrance to a burrow and winter nest for the squirrel. These squirrels emerge from winter hibernation in April, so the timing fits.

Thirteen-lined Ground Squirrels are solitary apart from during breeding season in early spring. In Canada the squirrels emerge from hibernation in spring and they disappear back to the nest in late summer. A home range is usually about two or three acres.

The sunflower seeds this squirrel scavenges over the spring and summer will help sustain the animal over the winter. 

References
1. Naughton, Donna. The Natural History of Canadian Mammals. University of Toronto Press. 2012.

Translucent Yellow Gelatinous Organic Mass in Elbow River

Last November I photographed this translucent yellow gelatinous organic mass on the floor of a shallow portion of the Elbow River. I walk by this location several times a week and the mass seemed to suddenly appear. The mass was several feet high.

Several days later the mass had deflated and was lying on the floor of the river. This implies the interior of the mass was filled with a gas.

The growth was located in a section of the Elbow River that is shallow and located between the mainland and a gravel bar about about 8 to 10 meters offshore. Until the flood in June 2013, the gravel bar was an island with a beaver lodge. The flood deposited enough dirt and gravel to connect the west end of the island to the mainland. This created a shallow blind inlet at the eastern end of the island. Since the river flows from west to east, the water movement in this newly created inlet is slow. The growth was close to the sun exposed southern shore of the river. Since the river is shallow, the temperature of the water in this location is higher. Slow water movement and a higher temperature likely favoured the growth of this organic mass.

By mid-March the snow had melted on this portion of the Elbow. Over the intervening four winter months the mass totally disappeared.

I spent research time on the Internet but was not able to identify the cause of the growth. Since the Elbow River provides the water supply for Calgary, I wondered about the toxic potential for this unusual growth. I sent the above photos to a provincial water expert to request assistance to identify the organic growth. I received a reply but no answers.

I will monitor the location this year to see if the mass redevelops. 

Tracking Meadow Voles

Meadow Vole - Microtus pennsylvanicus

Meadow Voles have the largest range of any North American vole and can be found in every province and in the Arctic.

Meadow voles do not hibernate and are active all year round.

The photo below shows the bounding gait of a Meadow Vole in the snow. The tail is responsible for the center line between the prints. 





































Winter nests are usually created in grassy areas on the ground and under a layer of snow. Burrows are connected to grassy runways which allow the vole access to feeding sites.

The photo below shows a snow tunnel created by a vole on an ice surface over a shallow portion of the Elbow River. The tunnel started by the land edge where tussocks of marsh grass served as the burrow. The vole likely abandoned this runway when continued ice implied that a feeding site was not close.


Below is a photo of a typical Meadow Vole runway through yard grass. The runways were created during the winter under the snow and are conspicuous once the snow melts in the spring.


In the photo below, the runway from the upper left leads to a nesting area towards the right.


Summer nests are similarly built as shallow burrows, often under debris, and are connected to a network of runways through the grass. 

Breeding starts in early spring while the burrows are still covered in snow and continues until autumn. Females are sexually mature as early as 25 days of age. Gestation last 21 days. The average litter is 4 to 6 infant voles. There are two to four litters a year in the wild. In captivity a female who mates immediately after every litter might give birth up to 17 times a year. Theoretically, with enough food and without any predation, illness, or injury, a pair of Meadow Voles could produce a million descendants in one year!!

Reference
Naughton D. The Natural History of Canadian Mammals. University of Toronto Press. 2012. 

Sun on Ice

River Reflections