If it's alive and it lives wild, it's wildlife.

Kevin J. Cook                                              Kevin@WildlifeWindow.com

Dates for 2010 Tree Class field trips now available
on Schedules of Activities page.


 

A Naturalist's Daily Reader



Shadow Dance
Wednesday, 18 November 2009

    With each passing day, the autumn Sun rises ever lower in the sky, which makes the shadow of my house creep ever higher up my neighbor’s wall. Looking out my window, I see bird shadows dancing there.
    Particularly distinctive, Mourning Dove and Eurasian Collared-Dove silhouettes strut along the roofline, pumping their long slender necks in cadence with their steps so their small round heads with slender beaks keep rhythm with their strutting. And roosting in place, they lean their necks and cock their heads in coordinated motions so characteristically dovish.
    The brighter the day, the bolder the shadowy dove dance.


Quiet Time
Tuesday, 17 November 2009

    They’re still out there, the owls; but their silence fills the night with an emptiness.
    The same predators with the same appetites for voles, cottontails, and pigeons, they still hunt to appease their hunger; ever the lords of their individual domains, they still chase away interlopers.
    But late autumn is their quiet time, a span of weeks during which each owl, content with its own company and without duty to mate and offspring, need only live its own life. Sleep. Hunt. Eat. Preen. Rest. Repeat.
    All this with a mere rustle of twiggery. Despite their silence, they’re still out there.


Clinging: Life from the Lifeless
Monday, 16 November 2009

    Autumn’s leafless cold seems harsh for a mayfly on the wing. But this mayfly does not fly; it is an empty husk clinging to my fence. Perhaps a robber-fly or a crab-spider drained its life juices, but the husk’s tenacious clinging suggests other than a predatory end.
    This wisp of an insect alighted where textured wood provided purchase for its tiny clawed feet; and while the mayfly waited for something unknown, its life spark dwindled...flickered...and vanished.
    Wind will sever the clinging and cast the husk upon the ground where through bacteria and fungi life will reclaim the lifeless.


Impossible Name
Saturday, 15 November 2009

    Everything from dragonflies and spiders through hawks and squirrels uses this tree for escaping or resting, eating or nesting. Wildlife loves this hard-to-name tree.
    Some places, people call it "Sugar Ash"; it is no ash. Other places, people call it "Manitoba Maple"; it is a maple though its geographic range lies more outside Manitoba than inside. Most people call it "Box Elder," "Box-Elder," or "Boxelder," reportedly because it has wood like box trees and leaves like elder shrubs; it is neither box nor elder.
    Admiring the tree and its wildlife retinue, I wonder: How, exactly, does one spell an inappropriate name?


The Man That Isn’t There
Sunday, 14 November 2009

    The Steller’s Jay delivers its sooty-gray and medium-blue self with a flourish, tempering its curiosity with reserve, its boldness with restraint. I know this bird but not the man whose name it bears.
    An Eighteenth Century naturalist, Georg Steller was the first to collect an Alaskan bird unknown in Europe. Oddly, the diligence to describe the bird was never applied to the man: no photograph, sketch, painting, or written description. Short or tall, dark or fair, blue-eyed or brown-eyed, bearded or shaven – we can only imagine. And I do.
    In this bird I can see the man that isn’t there.


News of the Invisible
Friday, 13 November 2009

    Tiny paws crush snow creating a hoarse whisper like an old-time scrivener’s quill scratching across parchment. Large hooves pound snow creating a din like a modern writer’s keyboard clattering.
    Gathering like so many ink letters on newsprint, tracks, large and small, accumulate on snow where flowing like sentences they present stories. 
    Here the weasel ran, and there the vole hopped. The fox trotted; the mouse scurried.
    Though a wonderful tattletale, snow is also an insufferable tease. For all the life news the snow’s pages reveal, the trackmakers themselves – Martens and Southern Redback-Voles, Gray Foxes and Deer Mice – remain coyly unseen.


Bird on a Lamp Post
Thursday, 12 November 2009

    Standing atop the parking lot lamp post, the Herring Gull evokes a certain awe.
    Long before people spread Rock Pigeons, European Starlings, and House Sparrows around the world, Herring Gulls visited the coasts and lakes, islands and rivers of Iceland and Great Britain, Scandinavia and Siberia, Alaska and Canada. Reservoirs, agricultural waste, and garbage, made the Herring Gull’s world larger.
    And here it is, where Rocky Mountains and Great Plains merge, a thousand miles from the nearest sea.
    What looks like a gull on a lamp post is really a story of life adapting and succeeding, a story worth knowing.


  

 










 

 

 



A Naturalist's Way with Words



18a    phasenountraditional (becoming archaic): a genetically determined variability of coloration among individuals of the same species without being attributable to, associated with, or determined by subspecies, race, or geographic population.

18b    morphnoun – (1) biology: a recognizable group, distinctive for some specific attribute of form or structure, within a species; (2) an individual of a recognizable group within a species known for having two or more groups distinguishable by form or structure; (3a) ornithology: a group or an individual within a species known to vary by form or structure; (3b) an individual bird distinctive for a specific permanent plumage color within a species known for various genetically determined plumage colors that do not vary by age, season, breeding condition, or geographic subspecies status.

dimorphicadjective – descriptive of a species characterized by two groups distinguishable by some attribute of form or structure.

Example: Hawks and owls are sexually dimorphic because females are larger than males.

Example: Elk and Moose are sexually dimorphic species because males grow antlers and females do not.

polymorphicadjective – descriptive of a species characterized by three or more groups distinguishable by some attribute of form or structure.

Example: The Canada Goose is a polymorphic species because the various subspecies are distinctive by size and body proportions.

Example: The Red Crossbill is a polymorphic species based on geographically predictable differences in beak sizes.

18c    chromernoun – (Kevinism) an individual bearing a specific, permanent coloration that is one of two or more color variations typical of the species and not attributable to genetic mutation or defect or to age, season, breeding condition, geography, or subspecies status.

Example: That soaring bird is a dark chromer of Red-tailed Hawk.



The expression "color morph" exemplifies either linguistic naivete, hence error of scholarship, or a willingness to revise the vocabulary of scholarship downwards rather than to expect people to educate upwards. Wildlife Window policy is to reserve the term "morph" only for descriptions involving size, shape, form, or structure and to use the coinage "chromer" for descriptions of colors or color variations unrelated to seasonal breeding or nonbreeding condition.

 



 

 




For a complete explanation including chronology of word changes, go to the new "Naturalist Words" page.

 

A Hawk A Day Musings You Won't Find in a Field Guide



Northern Harrier Circus cyaneus (Linnaeus)

    Considering its year round distribution, the Northern Harrier occupies more of North America than any other hawk. As a breeding species, it occurs throughout Alaska and eastward through Yukon and Northwest Territories sweeping southeastward thereby missing Nunavak and on eastward through the southern half of Quebec plus Newfoundland, and Nova Scotia. The southern boundary of its breeding range includes extreme northwestern Baja and coastal California but excludes southeastern California then closely follows the Utah-Arizona, Colorado-New Mexico, Kansas-Oklahoma borders before arcing northeastward through central Missouri then eastward into Delaware. Wintering birds move as far south as Venezuela. Northern Harriers have been found in the Aleutian Islands, Hawaii, Bahamas, Bermuda, and Greater Antilles.
    
And this is just in North America!
    
The Northern Harrier also occurs in Eurasia from Great Britain through Scandinavia eastward to the Pacific Coast including Sakhalin and Kurile Islands. During winter, these Asian Harriers move south into northern Africa, India, Myanmar, and southern China.

    
Eurasian harriers had caught the attention of Eighteenth Century taxonomist Carolus Linnaeus. In 1758 he classified what is now called "Western Marsh Harrier" as Falco aeruginosus and "Montagu’s Harrier" as Falco pygargus. In 1766 he extended his work to include another Eurasian harrier, which he named Falco cyaneus, plus a North American harrier he named Falco hudsonius. To Linnaeus, if it looked like a hawk, it was a hawk; and all hawks were named "Falco."

    
But harriers bear two features that quickly distinguish them: their faces and their flight. Their facial feathers are stiffer, less pliant, and more open, less fully meshed together, than other head feathers. These qualities form a facial disk typical of owls but unique among hawks. The facial disk helps the harriers hunt by sound. When hunting, harriers stroke the air in a languid cadence that keeps them aloft in a buoyant, floating manner of flight. They hunt low to the ground and work tall grasses, rushes, and sedges that other hawks ignore. Though vision is vital to their hunting, being able to hear prey – voices, chewing of food, rustlings of movement – can make the difference in eating or not eating.

    
Acknowledging the distinctiveness of harriers, French naturalist, musician-composer, and politician, Bernard Germain Etienne de La Ville-sur-Illon, Compt de Lacepede, (basically, the Count of La Cepede, pronounced law-seh-ped), published a 1799 revision establishing the genus Circus just for them. The name is a New Latin adaptation of Greek kirkos, which meant "hawk" predating Aristotle. The species name cyaneus likewise originated in Greek: kyaneus meaning "dark blue," referring to the color of the male’s upper side. The genus has endured academic scrutiny for 210 years. Not so the species.
    
During the 1700s and 1800s, taxonomic scholarship used every nuance of detail to establish a new species or genus. This academic temperament completely reversed by the 1930s. Well into the 1970s, consolidation was the new drumbeat of taxonomy. Variability came to be regarded as well within the limits of both the species and the genus concepts. This explains the changes in historical documentation of birds in Colorado.
    
Wells Woodbridge Cooke (The Birds of Colorado, 1897), William Lutley Sclater (A History of the Birds of Colorado, 1912), and William Harry Bergtold (A Guide to the Birds of Colorado, 1928) all treated the harrier as Circus hudsonius and called it "Marsh Hawk," though Sclater hyphenated it as "Marsh-Hawk." (The issue of hyphenation in wildlife names in general and bird names in particular has evolved into a highly contentious issue with international implications. It is a story for another day.) Even Arthur Cleveland Bent, writing with a national scope (Life Histories of North American Birds of Prey, Part 1, 1937) cited Circus hudsonius and called it "Marsh Hawk." But when Alfred M. Bailey and Robert J. Niedrach published Birds of Colorado in 1965, North America’s Marsh Hawk had been reassigned as a subspecies, Circus cyaneus hudsonius. Only the American name remained to be tweaked.
    
During the 1970s, the Check-list Committee of the American Ornithologists’ Union revised many bird names including "Marsh Hawk." Citing the bird’s frequent use of vegetation types other than marshes and invoking the desirability of aligning American names with international standards, the Check-list Committee abandoned "Marsh Hawk" in favor of "Northern Harrier," a senseless name with no "Southern Harrier," "Western Harrier," or "Eastern Harrier" for meaningful context: "northern" relevant to what? Nevertheless, all 14 species in the genus now go by the name "harrier." Both Latin and American names have been stable for the better part of four decades.

    
Before Colorado was even a territory, Spencer Fullerton Baird included the Northern Harrier as part of the regional fauna in the ninth volume of the Pacific Railroad Survey (1858). As political boundaries formed and ornithological knowledge grew, the Northern Harrier took its place in Colorado’s avifauna.
    
The Colorado Breeding Bird Atlas (1998) reported Northern Harriers as confirmed nesting in 15 latilongs, 20 counties, and 30 priority blocks. They were documented as probably nesting in 13 additional latilongs (unreported in the four partial Utah-border latilongs), 24 other counties, and 277 more priority blocks (of 1,760 total blocks). Some combination of factors affected the ability of field workers to confirm nesting.
    
Northern Harrier colors differ between males and females, a condition widely but improperly called "sexual dimorphism" (see A Naturalist’s Way with Words, No. 18, to be posted Monday, February 16). Color differences also apply to differences between adult and immature birds. Young Harriers resemble females but differ enough the practiced eye can distinguish some portion of them. The similarity explains why females always appear to outnumber males. During migrations, males and females depart from and arrive at nesting grounds in pulses; watch and you will notice more males for awhile then more females.
    
Harriers hunt as they migrate; but when intent on covering distance, they abandon their low, languid flying and ride thermals with other hawks and even gulls. Sometimes they spiral so high they become indiscernible specks before they leave the column of rising air and point their beaks to a far horizon.

 

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