Friday, November 30, 2018

Mallard

A drake Mallard from our 21 November 2018 stroll around a Northfield pond. Mallards are the most abundant of North American Ducks. Note the “duck-tail” curls above its tail, a trait shared by Mallards and Elvis. In Mallards, these are actually upper tail feathers.

Tuesday, November 27, 2018

Canada Goose

On 21 November 2018, Erika and I checked for waterfowl at a Northfield pond. All we saw were a few mallards and 900 Canada Geese. One reason for this concentration was that this pond tends to be ice-free longer than other area ponds. It must be spring-fed. Among the geese swam an odd individual with a broad white face patch and a broad eye-brow. I have noted other Canada Geese with similar markings, but never quite this extensive. I wondered if we stumbled upon a hybrid Canada and Barnacle Goose. As you can see, this bird’s breast is white—that argues against the hybrid hypothesis. Among the various races of Canada Geese, some birds occasionally sport white eye-brows and/or white foreheads. It is unclear to me as to whether or not these traits are indicative of some young birds. I have concluded, therefore, that what we found was a Canada Goose.

Sunday, November 25, 2018

New Dragonfly Book

Just out—The 7th edition of my dragonfly book! Hardcopy books are regrettably expensive, but a .PDF file, which can be read on most computers and cell phones, is now available for a mere $7.99. Furthermore, the .PDF format is e-mailed to you immediately. Previews of the first 15 pages of this 300-page book can be seen by following the link. In all, the book includes 133 color photos of North American dragonflies and Damselflies.

Saturday, November 24, 2018

White-throated Sparrow

White-throated Sparrows are common migrants in our part of Minnesota. For some reason, however, we seldom find them in our backyard. Perhaps our woodland does not have enough brushy cover. In any event, this bird poked around under our feeders on 12 November 2018. Elsewhere in this blog I have written about their calls and about their fascinating color morphs.

Tuesday, November 20, 2018

Purple Finch

A Purple Finch appeared at our bird feeder on 12 November 2018. Because these finches take two years to become purple, this bird could be a female or an immature male.

Purple finches used to be classified in the genus Carpodacus, along with European rosefiches. European ornithologists even called our bird the American Rosefinch. Numerous genetic studies, however, conclude that Purple, Cassin’s, and House Finches are not closely related to the European birds. The American finches are now placed in the genus Haemorhous. These studies also indicate that Purple and Cassin’s Finches differentiated about 3 or 4 million years ago. This stock arose from House Finch ancestors about 9 to 10 million years ago (Wootton 1999). 

Sunday, November 18, 2018

Dark-eyed Junco

A Dark-eyed Junco by any other name. Image taken at our Northfield bird feeder on 12 November 2018. Actually, due to their confusing and often controversial systematics, juncos go by a bushel basket-full of names. Until relatively recently, this race was thought to be a distinct species, the Slate-colored Junco. An old folk name used by Audubon and still by many non-birders is Snow Bird. The word “junco” is Latin for “rush,” an odd name for a bird that prefers woodlands to marshes.

Saturday, November 17, 2018

Horned Lark

I am surprised by how pink Horned Larks are. This one guarded a dirt road in Goodhue County on 6 November 2018. I pulled sideways to get this photograph, but, unfortunately on-coming traffic obliged me to move. (There are laws agains texting while driving in Minnesota, but I am unaware of prohibitions against bird photography.) Horned Larks are extremely variable in coloration, with some 21 races described across the continent. 

Thursday, November 15, 2018

Cedar Waxwing Snow Drinking

In the Carleton College campus, on 13 November 2018, I came upon a Cedar Waxwing that appeared to be drinking snow. Never have I seen this behavior. I was surprised, because I have always thought that drinking snow is a metabolically foolish behavior for warm-blooded animals—certainly a fast track to hypothermia. A quick Google search sent me straight to Witmer et al. (2014), in Birds of North America, who write “Cedar Waxwings often drink water or eat snow in winter, since the sugar in their fruit diet can dehydrate the birds.” 

Wednesday, November 14, 2018

American Goldfinch

So I finally capitulated and seriously read the directions that came with my new camera. This image of an American Goldfinch is the first post-reading result. I still have a way to go, and I look forward to next year’s dragonfly season with a mixture of excitement and apprehension.

I have previously posted about why American Goldfinches are late-season breeders. They apparently wait until June or July, when thistles flower and go to seed. These birds are almost exclusively granivorous. Unlike most other birds, they eat and feed their young almost no insects. One curious result of this diet is that Brown-headed Cowbird nestlings do not survive in goldfinch nests. Without insect protein, cowbird nestlings’ growth is retarded, and almost all die before they fledge (McGraw and Middleton 2017).

Tuesday, November 13, 2018

Eurasian Collared-Dove

Eurasian Collared-Doves have spread across most of North America. Just exactly where to find them in southern Minnesota is a bit hard to predict—usually near small town grain elevators. For the last several years, Dennison, Minnesota, has been a reliable location to find these doves. I found them near bird feeders there on 6 November 2018.

Monday, November 12, 2018

Mourning Dove

Have you ever had a Mourning Dove wink at you? This one did along a cornfield near the southwest shore of Lake Byllesby, Goodhue County, on 6 November 2018. What gorgeous blue eye shadow! Mourning Doves breed from southern Canada to southern Mexico. In the United States, southern birds tend to be year-round residents, while northern ones migrate south in the winter. Most leave southern Minnesota; only a few attempt to survive our winter—usually near bird feeders or areas of leftover or stored grain.

Friday, November 9, 2018

Red-breasted Nuthatch

2018 is a Red-breasted Nuthatch invasion year. Nuthatch influxes are caused by winter food shortages in their coniferous breeding grounds. When the nuthatches invade, they are not very particular about their habitat. They often visit bird feeders and can be found across most of the United States. Individuals have even been recorded in Iceland and Great Britain. In large flight years in some locations, over a thousand Red-breasted Nuthatches can be seen in an hour (Ghalambor and Martin 1999). On the other hand, during non-invasion years, these nuthatches may be completely absent outside their breeding range.

Thursday, November 8, 2018

White-breasted Nuthatch

White-breasted Nuthatches are among the most common birds in our backyard woods.  Due to their frequent feeding upside-down on tree trunks, this species is often one of the first birds beginners learn. White-breasted Nuthatches also visit bird feeders. Pairs hoard large quantities of food, caching it piece by piece across their territory. These nuthatches form permanent pair bonds and defend territories all year. Some northern birds may migrate, but not much about these movements are known (and I have no evidence from my banding).

Tuesday, November 6, 2018

Bald Eagle

Erika and I took this photo of a Bald Eagle perched above the Cannon River in Dakota County, Minnesota, on 23 October 2018. Throughout the year, one of the pleasures of living in Northfield is the abundance of eagles. They even fly over town. It is hard to pass by an eagle without taking a photo, so I have plenty of previous posts about them. Now I am still exploring my new Nikon P1000 camera and its 3000 mm lens. Even with the camera’s suite of image stabilizers, at the high magnifications you really need a tripod. Erika proved to be an excellent bipod. 

Sunday, November 4, 2018

Cedar Waxwing

On 23 October 2018, Erika and I happened upon a large flock of Cedar Waxwings in the Carleton College arboretum. The first is a rather motley immature bird. The second is a more elegant adult. If you look closely at the adult, you will notice a few of the red feather tips for which waxwings are named. Both adults and immatures have variable numbers of these feather tips, although immature birds often have fewer of them. The immature in my photo lacks red tipped feathers.

Friday, November 2, 2018

Hairy Woodpecker

Elsewhere in this blog, I have commented on ways to tell Hairy (above) and Downy (below) woodpeckers. In these images, taken of the Downy on 30 October and of the Hairy on 21 October 2018, you can clearly see the difference in the bill size—despite the fact that the Downy is a large male and the Hairy is a relatively small female. But there is another difference evident here. At least at our feeders, Hairy Woodpeckers seem more gluttonous than Downys, as evidenced by the Hairy Woodpecker’s often carrying large chucks of suet away from the feeding station.