Downy Woodpecker

This female Downy Woodpecker fed at our suet feeder. If you look closely, you may notice that this bird is banded on her left foot, so she is probably one of my local birds. I took this photo because the woodpecker, with her bill pointed skyward, seemed frozen at the feeder. I have noted this behavior when predators are nearby. Curiously this strategy is not mentioned in Jackson and Ouellet’s (2002) definitive account of this species.

As I write this post, I am surprised by this woodpecker’s white nape. Previously I posted rhapsodically on the beauty of female Downy Woodpeckers—compare the black nape on the nape of the woodpecker at this link with the white nape on the present bird. None of my field guides show woodpeckers from behind. Clearly my identification is correct, the bill of the bird on the present post is too small to belong to a Hairy Woodpecker (which my guides also show with a black nape).

Jackson and Ouellet’s (2002) list a number of hypotheses for the Downy’s plumage patterns. They do not mention the possibility that the two spots on the upper back may act as cryptic eye spots, making a predator think the woodpecker is facing it. To me, this Downy’s back looks a bit like a face. Another unmentioned possibility is that the white stripe down the back camouflages these small woodpeckers as they climb about snow-spattered trees.

P.S. I received the following comments from Jerry Jackson: "While working on my dissertation eons ago, I examined and measured about 6000 Downy Woodpeckers -- presumably about half of those were females.  There is considerable variation in the extent of white on the nape.  The complete band is relatively common and a characteristic that is also variable in Hairy Woodpeckers.  As an aside, in Hairy males, birds in eastern North America can have either a complete band of red or a red spot on each side of the nape.  In western North America, males seem to invariably have a solid red band across the nape -- and that band is wider (anterior-posterior) than in birds from the east. 

"I think your idea about the eyespots is on target.  I've been doing a lot of work with eyespots lately and certainly this was one of the first birds I had noted. The "freezing" and "sky-pointing" in response to the presence of a potential predator (or an alarm call given by another bird) is common. While I failed to mention it, I believe it is in the literature."

Scarlet Ibis

The top photo is of three Scarlet Ibis deep within the Caroni Swamp in Trinidad. The Scarlet Ibis is a perplexing species. Many ornithologists consider them to be only a color phase of the White Ibis. Interbreeding occurs in captivity, when captive individuals are released in each other’s range, and among wild birds in South America. Scarlet Ibis that are seen in Florida are often escaped from zoos or racetracks or the offspring of these escapees and wild White Ibis. In south Florida (where I took the lower photo of a White Ibis), if you are not careful when you look up, ibis can also be perplexing.

Great Blue Heron

On this cold and snowy Minnesota day, I find myself dreaming about Florida. Audubon wrote that Florida birds were abundant and tame. Today the birds are less abundant, but they are often relatively tame—making Florida an an excellent photographic destination.

Great Blue Herons seem to have survived the onslaught of the 20th century despite plume hunters and widespread environmental degradation. One reason for their success is that heron rookeries are often located in areas that are difficult for predators to approach. They are also not picky eaters, preferring fish, but also consuming amphibians, rodents and other animals. Occasionally they even forage in fields, where unwary birders might mistake them for cranes.

Black-billed Cuckoo

In an American folk songwe are told “the coo coo, she's a pretty bird...she never says coo-coo ‘till the fourth day July…” There may be some truth here—Black-billed Cuckoos time their nesting to correlate with caterpillar, particularly tent caterpillar, outbreaks. Cuckoos consume up to a dozen caterpillars per minute. Cuckoo stomachs often contain several hundred caterpillars, so many that the lining of their digestive tracts become coated with caterpillar spines. When the spines obstruct digestion, “the entire stomach lining is sloughed off and is regurgitated as a pellet” (Hughes 2001).

Black-billed Cuckoos declined during the 1900s, with severe drops in the 1980s and 1990s. Caterpillar outbreaks are now controlled with pesticides. These poisons are probably detrimental to both insects and birds. In any case, cuckoos are now rarely seen but singly. Older accounts report flocks of cuckoos “descending on caterpillar-laden trees and not departing until every insect was consumed” (Hughes 2001). These photos are from Rice County, Minnesota—the Black-billed Cuckoo from Dundas and the caterpillars from the Carleton Arboretum.

Piping Plover

Piping Plovers are "threatened and endangered" shorebirds. They breed along the northeastern Atlantic Coast and in the northern Great Plains and winter along the coast from the Carolinas to the Gulf Coast and West Indies. Censuses in 2001 found fewer than 3,000 breeding pairs (Elliott-Smith and Haig 2004). The species' survival depends on conservation management, including fencing off nests, restricting off-road vehicles on beaches and dunes, water-level management both above and below Great Plains dams, and predator control.

The first photo is of a winter-plumaged bird, probably a female, taken on Sanibel Island, Florida.  The second is of a male breeding bird taken near Aberdeen South Dakota. You could guess that the second bird is from the Great Plains, since, unlike Atlantic breeders, inland Piping Plovers have a complete neck band. The two populations are recognized as being of different subspecies.

Chestnut-backed Chickadee

Chestnut-backed Chickadees are found along the west coasts of North America, from Alaska to southern California. Evolutionary studies suggest, although their crowns are black, they are closely related to Boreal Chickadees (Dahlsten et al. 2002). Although seeds and other plant materials are consumed, these chickadees specialize on insects and arthropods. They are particularly fond of insects on Douglas Firs. This photo was taken in Lacey, Washington.

Short-eared Owl

I flushed this Short-eared Owl along the shore of Sand Lake National Wildlife Refuge’s Mud Lake (in South Dakota). As the owl flew away, I noted the long wings that result in a bouncy, “butterfly-like” flight profile as seen in the second photo. Short-eared Owls hunt by day and in night. In North America, however, habitat loss has been attributed to declining numbers of this ground-nesting owl over the past several decades (Wiggins et al. 2006).

Short-eared Owls are widely distributed across the world. They even inhabit the Galapagos and Hawaii in the middle of the Pacific Ocean. In the United States, the species inhabits open country like grasslands and marshes. The owl’s numbers are controlled by vole and other mouse population dynamics—when voles are abundant, Short-eared Owls are often common. The last photo is of a bunch of tourists watching a Short-eared Owl in the Galapagos, where the owls hunt seabirds nesting in lava flows. (The relatively tame owl is in the lower right corner of the photograph).

Boreal Chickadee

After finding the Boreal Owl of the last post, Erika and I searched for Boreal Chickadees. These birds are restricted to the boreal forests of Canada and the northern-most United States (and, unlike the owl, not found south through the Rocky Mountains). Like other chickadees, the Boreal is territorial during the breeding season, but forms flocks when not breeding.

The species tends to be tame and will visit bird-feeders, such as within the Zak-Sim Bog in northern Minnesota, where we found this bird. During the winter, they consume seeds, fruits, and hibernating insects and/or their eggs and pupae. In the summer, they are opportunistic and omnivorous, seeking out insects and spiders, fruit and birch and conifer seeds (Ficken et al. 1996).

Boreal Owl

Boreal Owls inhabit spruce forests from Alaska and across Canada to the Atlantic. Scattered populations are also found in the Rocky Mountains, from the Pacific Northwest to northern New Mexico. The owls are also found across Siberia to northern Europe. In Minnesota, as in other areas of the United States, they are restricted to the far north.

They show irruptive cycles in Minnesota. They very rarely breed in the state, and then usually only after invasion years. These influxes appear to be caused by cycles in vole populations and or heavy snow cover. Females (which are the larger of the sexes) tend to wander further than do males. Males may remain in breeding territories to guard their nest-holes. Many Minnesota birders predicted a Boreal Owl invasion would occur this winter. All was quiet on state listservs until about three weeks ago, when dozens of owls began to be reported along Lake Superior north of Duluth.

Friday morning Erika and I slowly drove up the North Shore from Duluth to Two Harbors. Lake effect snow fell. We drove very slowly as we searched for owls. The problem was that, never having seen a Boreal Owl, we had a poor search image. We expected a bigger bird than a saw-whet owl, but, in fact, Boreals are only marginally larger birds. Some female saw-whets are as large as some small male Boreals. We also did not know where to look for them--deep within the spruces? On the tree tops? We saw nothing all the way up the lake, enjoyed lunch, and headed back towards Duluth. We were not optimistic.

We took a back road before coming out to the highway. We were warned in a listserv posting by local birder Sparky Stensaas "Note that looking for parked cars, birders, and photographers...is just as effective as looking for tiny owls!" At the highway, I looked right--nothing. I looked left, to see a line of about a half-dozen cars parked on the side of the highway. "Birders!" identified Erika, "I see scopes!" We pulled up and asked "Do you have an owl?" "Yes, right in front of us, at the tip of the closest spruce bough!" We photographed this bird for about ten minutes. The owl appeared to be actively searching for prey, as the bird repeatedly looked to the left and right.

Pronghorn Antelope

Pronghorns are not true antelopes, but examples of convergent evolution, wherein unrelated animals evolve in response to similar habitats so as to resemble one another. Rather than being an antelope of the Old World, the Pronghorn is the only surviving member of the family Antilocapridae (Wikipedia). Pronghorns are found in the Great Plains of southern Canada south into northern Mexico. Pronghorns rarely seen in western Minnesota are likely to be wanderers from South Dakotan herds. This photo was taken north of Fort Pierre along the western shore of the Missouri River.

In our region, Pronghorns become more common the further west you travel. Your chances increase when you cross the Missouri River in South Dakota and you can usually see them by the time you cross into Wyoming. In the 1920s, presumably due to overhunting, Pronghorn populations declined to about 13,000. They have now rebounded to about a million, and, in fact, may outnumber people in Wyoming (Wikipedia). East River populations in South Dakota were decimated (and perhaps extirpated) by blizzards in the late 1800s and 1940s. The animals have been reintroduced to these regions, but suffer from competition from livestock, sheep diseases, and prairie fragmentation.