veterinary diagnostic imaging: birds, exotic pets and wildlife || wild birds

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C h a p t e r 2

Wild Birds

III CROWS, MAGPIES, AND JAYS

Crows, magpies, and jays belong to the Corvidae family, within the order Passeriformes. Crows are rela-tively large black brassy birds that are equally at home in populated or wilderness environments (Figure 2-1). Their distinctive call reminds many of time spent hiking or camping in the woodlands. Crows are par-ticularly bold, feeding fearlessly on roadkill and seem-ingly impervious to the presence of passing vehicles. Their northern relative, the raven, is noticeably larger and considerably more diffi cult to handle in a hospital setting.

While in the care of veterinarians, crows may subsist comfortably on elements of their natural diet, includ-ing seeds, berries, insects, meat, or chicken. Eye protec-tion is a wise precaution when handling crows because of their large powerful beaks.

Magpies are somewhat smaller than crows, but they have a most attractive plumage comprised of a black cloak, white vest, and long dark blue-green tail (Figure 2-2). Like crows, magpies have a disproportionately large head. However, unlike crows, which have a conventional fl ight pattern, magpies often swoop from point to point, giving some the impression of a wing injury.

Jays are stunning, predominately blue and white birds with a distinctive collapsible crest atop their heads (Figures 2-3 and 2-4). When foraging for food, jays characteristically announce their presence with a sharp cry before beginning to feed (presumably a signal to other birds in the area). Commercial wild birdseed, supplemented by unsalted, roasted, unshelled peanuts, makes an excellent hospital ration.

III GEESE AND DUCKS

In western Canada, Canadian geese abound on rivers, lakes, and wetlands. Their annual arrival gratefully signals the coming of spring, but later and more omi-

nously, their departure forecasts winter freeze-up. Their overfl ights, which sometimes number in the thousands, are arranged in V-shaped, bomberlike for-mations often separated by only a few yards; their herringbone trails in the sky seem almost endless (Figure 2-5).

Geese with young goslings can be very aggressive (Figure 2-6). A large male once attacked my partner and me during a marathon canoe race when we inad-vertently got between it and its offspring. The gander hurled itself into my bowman’s chest, beating him with its large heavy wings (Figure 2-7) about the chest and head, nearly knocking him overboard and capsiz-ing our boat.

In the fall, hunters wait in ambush along the water’s edge, dressed in camoufl age and concealed in blinds, with their dogs fi dgeting nervously at their sides. Wounded birds that survive their fall to earth and are not retrieved usually are taken by opportunistic predators or die of starvation; however, some are discovered by hikers and taken to a veterinarian.

Although we have an equally large number of ducks in our region (Figure 2-8), comparatively few are brought to our hospital for medical attention. Con-scious ducks can be surprisingly aggressive when being handled, frequently biting those handling them (Figure 2-9). Both geese and ducks belong to the family Anatidae, order Anseriformes.

III BLACKBIRDS (COWBIRDS, GRACKLES, AND NORTHERN ORIOLES)

Cowbirds and grackles are ubiquitous in western Canada. The grackle is a particularly attractive bird, especially in bright sunlight where its bright metallic blue and lavender head positively gleams (Figure

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26 SECTION I III The Birds

Figure 2-1 • An inquisitive crow banks sharply, executing a low-speed turn, and avoids a stall by opening its wingtips to the onrushing wind.

Figure 2-2 • A magpie is profi led against a snowy backdrop as it leans forward and prepares to feed.


CHAPTER 2 III Wild Birds 27

A

B

Figure 2-3 • A, Frontal view of an adult jay, its characteristic dorsal crest collapsed as it dips beneath the arch of a moose antler to take a peanut. B, Roasted peanuts are an excellent, no fuss, short-term food source for hospitalized jays and magpies but should be unsalted.

Figure 2-4 • Portrait view of an adult jay with raised dorsal crest ready to take a peanut from a feeder.



Figure 2-5 • Canadian geese in formation.

Figure 2-6 • A gander oversees a small super family as they feed along the riverbank.



Figure 2-7 • An unconscious Canadian goose being examined before being radiographed. The size of its large, powerful wing compared with the size of the veterinarian’s hand helps one imagine how it might feel to be struck in the face by a bird attempting to defend itself while being handled.

Figure 2-8 • A pair of mallards swimming in the river (the drake is on the left).



Figure 2-9 • A duck clamps down on a radiographer’s fi nger.

Figure 2-10 • A grackle keeps a wary eye out.

2-10). Northern orioles are seen for a brief period during the spring in our part of Saskatchewan on their way to northern feeding and nesting grounds (Figure 2-11). These birds belong to the family Icteridae and are sometimes called blackbirds, although many, such as the oriole, are not truly black.

III EAGLES, HAWKS, AND OWLS

Eagles, hawks, and owls, so-called birds of prey, are spectacular creatures whether seen soaring in the sky or perched high in a wilderness spruce. Arguably the most magnifi cent of these, the bald eagle (Haliaeetus leucocephalus), is the national symbol of the United States and quite plentiful in central Saskatchewan (Figure 2-12).

Hawks are more morphologically diverse than many realize, featuring specimens nearly as large as eagles, such as Swainson’s hawk (Figure 2-13), or as small as robins, such as the kestrel (Figure 2-14). A Merlin may nest atop a downtown offi ce building, in a tree along a suburban bike trail, or on a power pole along the highway.

It has been said of owls that they are heard more often than seen, although their prey probably likely sense neither, only the bite of the owl’s talons a fraction of a second before being carried away (Figure 2-15).

III HERONS, LOONS, GREBES, AND KINGFISHERS

I group herons, loons, grebes, and kingfi shers together because of my experience on western Canadian water-ways rather than because of any taxonomical organiza-tion. I recall the slow-motion wing beat of the great blue heron or the distinctive call of the loon as it rever-berates across a northern lake at sunset (Figure 2-16).

III PELICANS, CORMORANTS, AND GULLS

Pelicans, cormorants, and gulls are grouped together here because of personal preference; I have frequently



Figure 2-11 • A startled Northern oriole makes for the protection of a nearby tree.

Figure 2-12 • An exotic animal resident holds a bald eagle recovering from gas anesthesia after being radiographed.



Figure 2-13 • A Swainson’s hawk, wings outspread, perched on the bare hand of its handler.

Figure 2-14 • A dead kestrel before being radiographed to see whether there is any evidence that it was shot. The examination proved to be negative.

observed these birds hunting side by side in a river near my home (Figure 2-17). The local pelicans and cormorants prefer to hunt the heavy, convergent hydraulics produced as water streams over and around a weir, just as it meets the reinforced riverbank (Figures 2-18 and 2-19). All prefer the shallows, especially the cormorants, which resemble otters more than birds because they pursue their prey only a few inches beneath the turbulent surface. Minnows, in their des-

peration to escape, often momentarily beach them-selves just long enough to be taken by a gull patiently waiting at the water’s edge (Figure 2-20).

III PIGEONS

Perhaps no other bird is more at home in cities than the pigeon. It perches on rooftops, beneath bridges, on



Figure 2-15 • Moving not a single feather, a great horned owl scans the ground for gophers.

Figure 2-16 • A spotted loon tracks along the outer edge of a weed bed in a central Saskatchewan lake.

Figure 2-17 • A pelican and cormorant hunt side by side in a river near my home.



Figure 2-18 • The shoreline near a hydraulic provides an abundant hunting ground for pelicans.

Figure 2-19 • A hunting cormorant surfaces in a heavy swell.



the heads and shoulders of heroic statues, along the backrests of park benches, and in squares and belfries (Figure 2-21). Somewhat of a catchall, the term pigeon (family Columbidae) refers to the larger, more statu-esque species but also includes the smaller, more deli-cate dove.

III SPARROWS, CHICKADEES, AND JUNCOS

Sparrows (order Passeriformes) are indeed the princi-pal residents of our urban bird feeders (Figure 2-22). These small but feisty birds regularly do mock battle with one another over food, females, and territory but rarely sustain substantial injury (Figure 2-23). Chicka-dees and juncos are also found in abundance but are far less aggressive (Figure 2-24). When hospitalized, these small birds thrive on commercial wild birdseed (Figure 2-25).

III ROBINS AND WAXWINGS

There is something electric about the sudden coming of a thousand cedar or bohemian waxwings as they fi ll every branch of a backyard maple and sound like the lead element in a prairie plough wind (Figures 2-26 and 2-27).

In our part of Canada, robins descend on our lawns in great numbers in the spring. They stay to raise their families during the summer (Figure 2-28) and then head south in the fall. Just before departing the north-lands, the birds form enormous fl ocks, sometimes numbering into the hundreds.

Figure 2-20 • A hopeful seagull watches from the shore as a cormorant cruises by just beneath the surface.

Figure 2-21 • Pigeons, disturbed by a passing train, temporarily vacate their roosts.



Figure 2-22 • A sparrow gathers dog hair for its nest.

Figure 2-23 • Sparrows “fi ght large.”



Figure 2-24 • A chickadee shares a peaceful meal with a Pine Siskin.

Figure 2-25 • Wild birdseed is an excellent way to observe wild birds in their natural environment and to nourish them when hospitalized.

Figure 2-26 • A solitary waxwing perches on a branch, puffed against the −35° F cold.



Figure 2-27 • Resembling passengers packed into a crowded subway train (except they are arranged vertically), a small fl ock of waxwings feed on what remains of last year’s apples.

Figure 2-28 • An immature robin attempts to maintain its perch in a stiff prairie wind.

Figure 2-29 • A Northern fl icker eats seed from a feeder.



III WOODPECKERS

The Northern fl icker (order Piciformes) is the most common large woodpecker in western Canada. Although insects are the staple of their diet, fl ickers are quite capable of eating from a cage fl oor while

recuperating from an injury, as evidenced by regular feeding from urban lawns and feeders (Figure 2-29). When performing an oral examination on a fl icker, the technician should remember that it has a highly spe-cialized, elongated tongue used for extracting insects from within trees.


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