Northern Goshawk

Northern Goshawk - Accipiter gentilis

The Northern Goshawk is the largest of the accipiters, which allows the bird to take larger prey such as Snowshoe Hare and Ruffed Grouse.  

The Goshawk in the photos above and below was posing about half way up an Aspen at Inglewood Bird Sanctuary. The white supercilium is a good field marker.

The young are able to tear food up by end of the first month, start hunting at about 50 days, and are independent by 70 days. The talons are for stabbing and killing the prey; the beak is for plucking and feeding. 

The Goshawk in these two photos was hunting in Griffith Wood on March 24, 2013. The feathers at the wing tips separate into "fingers," which allows the birds to fly at slower speeds without stalling. Notice the "fingers" are wider apart in the photo above, while the hawk was slowing. 

Several years ago, while hiking Heart Creek, I came upon a Goshawk feeding on the ground. I startled the bird, which flew off down the trail, leaving these wing prints. 

References

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

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

Dunne P, Sibley D, Sutton C. Hawks in Flight. Houghton Mifflin Co. Boston. 1988.

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998.

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

Scotter GW, Ulrich TJ, Jones EJ. Birds in the Canadian Rockies. Prairie Books. Saskatoon. 1990.

Tudge Colin. The Bird. Crown Publishers. New York. 2008.

Tundra Swan

Tundra Swan - Cygnus columbianus

Lewis and Clark reported the bird near the Columbia river, which explains the species name.

Tundra Swans "stacked up" and ready to land on Frank Lake

Tundra swans winter in the United States, and during March and April, while there is often still snow on the ground, these majestic birds migrate through Alberta to the Arctic where they nest. Swans mate for life. 

This Easter long weekend I counted more than a thousand swans on the lakes and sloughs south and east of Calgary. 

Swans flew over Langdon slough but they didn't land.
I heard them approach from the north and tracked them with my Canon.  

They circled around me and flew southeast into the morning sun, which allowed these grey silhouette photos. 

Tundra Swans flying over Frank Lake March 2013

Swans encountered in Alberta during late spring and summer are more likely Trumpeter Swans, which are larger but otherwise almost identical, but which nest throughout Alberta.

References

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

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

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998.

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

Scotter GW, Ulrich TJ, Jones EJ. Birds in the Canadian Rockies. Prairie Books. Saskatoon. 1990.

Tudge Colin. The Bird. Crown Publishers. New York. 2008.

  

Bald Eagle

Bald Eagle


By 1963, courtesy of DDT and other organic pesticides, which thin egg shells, there were only 417 known nesting pairs of Bald Eagles in the lower United States!!!! 

Rachel Carson published Silent Spring in 1962, and this book turned the tide and ushered in the modern conservation movement. By 1993 the census was up to 4500 nesting pairs.

The white head and tail in this bird photographed at Frank Lake on March 22, 2013 implies the bird is mature and at least 4 years of age. 

There were at least two Bald Eagles at Frank Lake that day. likely feeding on ducks. Fish are another common prey. Bald Eagles are good foragers and in the early spring before the ice is off the rivers, I commonly see these raptors in fields, where I presume they are on the look out for small mammals. These large opportunistic raptors often take fish from Osprey. 

The five photos above were shot on March 23, 2013 in Griffith Woods behind my home. I saw the eagles from a mile away and managed to get close enough for these photos, which were taken from about a hundred meters away. I was on the northern bank of the Elbow and the birds were at the top of Spruce trees on the southern bank. The trees were about 40 or 50 meters tall. Just before the sequence above, the male tried to mate with the female but his overture was not accepted.

Over this last weekend of March 22, 23 and 24th, I saw Bald Eagles every day, including at least two at Frank Lake, one at Inglewood, and at Griffith Woods, I saw the perched pair above on the Friday, and two more on the Sunday. Clearly the Bald Eagle is thriving where I live!

Bald Eagles have the largest nest of any North American bird. Two eggs are usually laid but only one chick usually survives. These raptors live for over 30 years.                                                               

References

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

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

Dunne P, Sibley D, Sutton C. Hawks in Flight. Houghton Mifflin Co. Boston. 1988.

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998.

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

Scotter GW, Ulrich TJ, Jones EJ. Birds in the Canadian Rockies. Prairie Books. Saskatoon. 1990.

Tudge Colin. The Bird. Crown Publishers. New York. 2008.

Cooper's Hawk

Cooper's Hawk - Accipiter cooperii

The quick agile accipiters also include the Sharp-shinned and Northern Goshawk.

The bird is named after William Cooper, a hunter who supplied ornithologists with specimens during the early 19th century.

The female is larger than the male, an example of sexual dimorphism, an attribute perhaps related to the large size of the eggs.  

The short rounded wings of the accipiters are well-adapted for quick maneuvering in dense forests. Falcons and Buteos are not capable of the bursts of weaving flight through dense brush. If the prey is not taken after a short chase, the pursuit is ended. Surprise, not endurance, is the hallmark of an accipiter.  

Cooper's Hawks breeds throughout the southern half of the Rockies. The hawks migrate according to a timetable set by the movements of their passerine prey. Passerines are taken on the wing and the hawk usually takes the prey to a "plucking" site prior to eating. 

I have never identified a Sharp-shinned Hawk. However, I have identified a Cooper's Hawk on 16 occasions in my Discovery Rise backyard. Since differentiation of these two accipiters is notoriously difficult, perhaps some of the Cooper's, might be Sharp-shinned.  

The chart above shows the months when a Cooper's Hawk was identified in my backyard. Not unexpectedly, the most sightings were in May, a month with very high passerine traffic at my feeders. I have not identified a Cooper's Hawk in November, January or February. Perhaps their migration takes them south during the winter.  

References

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

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

Dunne P, Sibley D, Sutton C. Hawks in Flight. Houghton Mifflin Co. Boston. 1988.

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998.

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

Scotter GW, Ulrich TJ, Jones EJ. Birds in the Canadian Rockies. Prairie Books. Saskatoon. 1990.

Tudge Colin. The Bird. Crown Publishers. New York. 2008.

Canada Goose

Canada Goose - Branta canadensis 

There are at least 11 subspecies of Canada Geese and the largest is twice the size of the smallest. The largest, Branta canadensis maxima, nests in the prairie wetlands and the smaller races nest further north. 

Inglewood March 24, 2013        

Nests are mostly on the ground by water, but more interesting locations include old Osprey nests on poles and the tops of Muskrat and Beaver lodges. 

Canada Geese mate for life and survival is recorded for up to 28 years. Every spring, after scouting out a satisfactory nesting site, our local geese build a nest and lay eggs in April and May. The average clutch is 5 to 6 eggs (range 2 to 11). The nest is lined with down. The mother sits on the nest while the father stands guard and the goslings hatch about a month later (25 to 30 days). The young birds fly by about 9 weeks and remain with the parents until the following spring.

I came upon the clutch above last year during the first week of May. The nest was built among some low shrubs on a ledge above the Elbow River. I was unaware of the nest until I was about 10 meters away. The Mother goose and I startled each other and we both flew. I flew several inches straight up and the Mother flew to the other side of the river. I took a few quick photos and left, and for the rest of the season, I avoided the site.

There is a stone nestled in the center of the eggs. I suspect the stone is a heat sink and helps maintain the temperature. During cold winter nights on the prairies, the settlers heated up a stone on the fire place and placed the stone under the blankets at the foot of the bed to keep their feet warm. Perhaps they learned this from the Geese? 

Geese are great dry land walkers. Their legs are positioned in the  middle of the body to facilitate walking on land. Their bill is suited for clipping grasses and eating seeds on the ground.

The goose in the two photos above was in Mallard Cove, off the Elbow River, on April 22, 2013. There have been two geese in the cove on most occasions since, but I have not spotted a nest.

References

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

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

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998

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

Tudge Colin. The Bird. Crown Publishers. New York. 2008