THE HAWK OF THE OWLS

When you first encounter a Northern Hawk Owl (Surnia ulula), you will understand why it has two different types of raptors in its name. Clearly an owl because of that big head and forward-facing eyes, nevertheless it has the rakish look of a hawk about it, with long tail, rapid flight, and – of course – diurnal habits.

One of these birds spent the winter of 2010-2011 on Westham Island in southwestern British Columbia, delighting birders and nature photographers by the hundreds. Because of their open perching habits and tameness, Hawk Owls are readily detected where they occur, so it is likely that at least some of the few individuals that make it to peripheral wintering areas are found as observers scrutinize the winter landscape. In my case, it was a wonderful way to start the year - and on a beautiful sunny day!

In the Pacific Northwest, we don’t get veritable invasions in winter, with dozens of Hawk Owls showing up like they do in the Great Lakes region. Nevertheless, at least a few birds make it down to Washington in most winters, and with increasing knowledge of where to look for them, more have been seen in recent years. Breeding has been confirmed at Manning Provincial Park, just north of the border in British Columbia, and suspected at Harts Pass in Washington.

Hawk Owls perch, usually at the very top of a tree or other conspicuous perch (often on utility wires in this day and age), and survey the surrounding semiopen landscape for their prey. Their primary prey is voles, but they are willing to take anything they can subdue from a long list of mammals up to the size of hares and birds up to the size of grouse.

Hawk Owls are not modified like many other owls for auditory hunting. Their two ears are symmetrical, and they don’t have a well-developed facial disk. They must have good hearing, however, as they are occasionally seen to plunge into snow to capture a vole. With long tail and short, rounded wings, they hunt somewhat like accipiter hawks, detecting prey visually and dropping from a perch to move at high speed with rapid wing beats. Most prey is captured at fairly close range, but their distant vision is excellent.

There are other diurnal owls. Most pygmy-owls hunt during the day, small birds their primary prey. Snowy Owls and Burrowing Owls are conspicuous features of open landscapes, although both hunt at night as well. Short-eared Owls can be seen during the day, but much of their hunting is at dusk. The same is true for Great Gray Owls. Hawk Owls, conspicuous on their perches all day long, also tend to hunt more in the afternoon, so hunting in dim light seems to be hardwired in owls.

Bear in mind that owls of the Far North must be able to hunt both day and night, as the days are so long in summer, the nights so long in winter. Fortunately for them, voles are active day and night.

Like many other owls, Hawk Owls nest in natural cavities, for example at the hollow tops of broken-off snags, and holes abandoned by woodpeckers. Their clutch size varies from 3-13 eggs, with a mean of about 7. It is a large and variable clutch size, as is the case with several owl species that seem to depend on voles and lemmings for their reproductive success.

Keep your eyes peeled for the owl that acts like a hawk!

Dennis Paulson

Winter hummers

It's late September. Got a hummingbird in your yard?

Most people think of hummingbirds as tropical, and indeed most of them are. But a fair number of species have moved quite far north into the United States (including Alaska!) and Canada since the last glaciers receded. The Southwest has a great diversity of species, as many as 15 species breeding north of the Mexican border. But many of the border species migrate south for the winter, and all that occur north of the border region are migrants to Mexico and beyond, except one—Anna’s Hummingbird (Calypte anna).

This species was historically resident in southern and central California and northern Baja California, areas that remained warm enough in winter that the birds could remain through the cold season and find enough insects and winter-blooming flowers to sustain them. But that was then, and this is now. Over a half century ago, people discovered they could attract hummers to their yard by hanging out special feeders filled with sugar water, typically one part sugar dissolved in four parts water. It worked like a charm. People feed hummers all over North America now, and birders gather to watch these birds at southern localities with dozens of feeders and, sometimes, hundreds of hummers. These sites are especially rich during fall migration, as hummingbirds are streaming south through the western states on their way to Mexico.

All species may have benefited from the existence of these feeders, but none more than Anna’s. This species has extended its breeding range all the way north to southern British Columbia and east to the Arizona-New Mexico border, with occasional breeding attempts even outside this range. Nonbreeders have wandered east as far as Minnesota and Florida and north to southern Alaska.

Several other species of hummingbirds (Black-chinned, Rufous, Calliope) nest widely in the Pacific Northwest, but all except Anna’s leave in late summer and head for Mexico, not to return until the following spring. Anna’s is supremely adapted to live with people, taking advantage of nonnative plantings and feeders in a way the other species have not been able to do, and this has allowed it to overwinter in regions apparently too cold and/or food-free for the other species. All hummingbirds go into torpor during low temperatures at night, so why can’t the other species take advantage of feeders that are provided throughout the winter? Perhaps the fact that Anna’s was resident in the first place, with no genes for migratory behavior, allowed it to be perfectly adapted to take advantage of the changes we make in the natural world.

Dennis Paulson

where have all the birds gone?

I have perceived a lack of songbirds lately, and you probably have also. Not only did birds stop singing at the end of their breeding season, but most of them departed for parts unknown.

Where do these multitudes of birds go? You have to answer this question for each species, as each species has its own unique distribution. But we don't know where each individual goes, and when a Barn Swallow flies by me, I fantasize about it carrying a little flag that says "on the way to Bolivia." The great mobility of birds has long been recognized as one of the most characteristic things about them, and they use this mobility to good avail in their annual migrations.

By migrating north in spring, birds that have wintered in the tropics can take advantage of a seasonal flush of food resources, avoid competition with the great diversity of resident species, and get away from the nest predators—among others ants, snakes, kinkajous, and toucans—that are so common in the tropics. When winter comes at our high latitude, and insects and other primary sources of food are no longer available, they return whence they came.

Some of our breeders, for example Varied Thrushes that dig insects from the forest litter and Dark-eyed Juncos that subsist on weed seeds, may winter in the Washington lowlands, just downslope from where they bred. Seed-eating birds such as finches and sparrows often winter quite far north, as there is an abundance of seeds—the plant's dormant stage—at that season. So our backyard winter avifauna features seed-eaters, and many of our breeding sparrows winter not far away, in California and the Southwest.

But the majority of our small birds are insect-eaters. These birds—the thrushes, sparrows, vireos, warblers, tanagers, flycatchers, and swallows—head for warmer climes.

Many birds glean caterpillars and other insects from leaves. Leaf-eating insects become inactive at low temperatures, and leaf-gleaning birds can't find enough food to keep their metabolic furnaces stoked, so off they go. Most of our vireos and warblers winter in western Mexico and northern Central America, as do Western Tanagers, Black-headed Grosbeaks, and Bullock's Orioles.

Flying insects are even less likely to be active during winter, as they need real warmth to be able to fly. So those birds that eat flying insects can't make a living anywhere near these parts, and many of them are long-distance migrants. Western Wood-Pewees and Olive-sided Flycatchers head for the mountains of Central America, Bank and Cliff swallows and Eastern Kingbirds to the Amazon Basin, and Barn Swallows rarely make it all the way to Tierra del Fuego. These are long flights, but ones quite possible to long-winged birds such as swallows.

They’re gone but not forgotten, and they will return. Of course they leave behind many resident birds such as chickadees, jays, woodpeckers, and others, but that's another story.

Dennis Paulson

feeding birds

People often ask me whether feeding birds is good or bad. Perhaps it’s both. I feed birds because I love to have them in my yard, not because I think I’m doing them a great favor. In the lowlands of the western part of the Pacific Northwest, perhaps the only time we really aid birds by feeding them is when snow covers the ground, making it difficult for some species to find food. That’s when I see species at my feeders that I didn’t even know were in the neighborhood. Varied Thrushes and Fox Sparrows are two good examples.

Normally, natural selection eliminates the least capable individuals from a population during hard times, and by our feeding them this winnowing may not take place. It may even boil down to helping individual birds to the detriment of the gene pool of their species. So when we make bird populations increasingly dependent on our handouts, we may be obliged to continue feeding them. Birds that normally winter in the tropics may take up residence at a feeder in the fall and not migrate south; they will probably be in trouble if the feeding is discontinued. Many birds (for example, Anna’s Hummingbird in the PNW) have probably expanded their winter range because of dependable bird feeding.

However, there is also a downside to bird feeding. Cats haunt the shrubbery and accipiter hawks visit from time to time; birds kill themselves against windows; and disease spreads readily at feeders. All of these sources of mortality are there without feeding, but the concentration of birds at feeders exacerbates them.

And then there is our subsidy of introduced species. I live next to a green belt in Seattle, with a nice variety of birds, but starlings often dominate the suet in summer and House Sparrows the seed feeders all year until a recent and surprising decline in both species in my neighborhood (lack of nest sites?). 


When Rock Pigeons visit, all too frequently, they easily displace native Band-tailed Pigeons. Millet feeders attract cowbirds, which parasitize native passerines, although cowbirds have also declined dramatically in Seattle. And don’t forget the gray squirrels and rats that compete with the birds (and eat their eggs). I don’t know any way to avoid this when feeding birds.

The feeding of waterfowl at parks is even worse, leading to the proliferation of semidomestic ducks and geese, as well as pigeons and sparrows. Diseases transmitted by these birds will of course infect wild populations. Birds of the native species are quite able to find their own food, but some of them become virtual beggars, a far cry from the traits for which we admire them!

It sounds as if I’m arguing against it, but in fact bird feeding at our homes is probably benign for most birds and furnishes much pleasure, as well as personal education, for us. There is also greater knowledge of the birds when their occurrence is recorded on Cornell University’s FeederWatch (http://www.birds.cornell.edu/pfw/) or  ebird (http://ebird.org/content/ebird/). In any case, the real favor I think we can do for birds is to fill our yards with plants that attract insects (just the opposite of the gardener’s strategy), bear edible fruit and bird-pollinated flowers, and/or furnish good nest sites. And lay off the pesticides.

Dennis Paulson