Sunday, February 26, 2017

Yellow-shafted Flicker

This woodpecker is the eastern, yellow-shafted race of the Northern Flicker. I have recently posted on this species in this blog, but I was happy to be able to share with you this species’ yellow-shafted tail feathers. The wing shafts are similarly colored. The flicker flashes this color during courtship and for territorial defense.

Northern Flickers are common and often visit bird feeders. Nevertheless, significant declines in flicker populations have been noted in Breeding Bird Surveys. The cause of this trend is not known. Habitat loss and competition with European Starlings for nesting holes have both been suggested Wiebe and Moore (2008). Indeed, years ago in South Dakota, we watched breeding flickers displaced by starlings in a dead backyard tree. The woodpeckers won’t be back. The new home owners long ago removed our flicker hotel.

Saturday, February 25, 2017

Tulips

 
Five of the last six days have been temperature world records, in the low 60s F.  Now it is 17 and we have a foot of snow. It looks like it is going to be a bad year for Erika's tulips.

Friday, February 24, 2017

Eared and Western Grebes


Eared Grebes and Western Grebes look quite different. Ornithologists place them in different genera. Their similarly plumaged young, however, argue for their close evolutionary relationship. It was Ernst Haeckel (1834-1919), German zoologist and philosopher, who hypothesized “ontogeny recapitulates phylogeny.” In other words,  species’ biologic development parallels their evolutionary history. This dictum proved to be influential but is no longer widely held.

Grebes are among the oldest kinds of birds. They arose in Antarctica or southern South America. Half the 22 species of the world are found in the American tropics. Grebes do not appear to be closely related to other bird families. Their similarity to loons appears to lack genetic evidence. DNA studies suggest that they belong to the evolutionary lineage that also led to storks, shearwaters, pelicans, and penguins (del Hoyo et al 2017).

These photos were taken years ago at Sand Lake National Wildlife Refuge in northeastern South Dakota.

Wednesday, February 22, 2017

Bald Eagle

Ornithologists decree that all birds’ birthdays are on the first of January. This eagle is a second-year bird. Bald Eagles do not acquire their striking white heads and tails until their fourth year. The uneven wing and tails feathers are typical of second-year birds. They retain some of their longer juvenile feathers. The speckled white sides of this bird’s body are also typical of second-year Bald Eagles.

We photographed this Bald Eagle on 21 February 2017 at Lake Byllesby Regional Park in Dakota County, Minnesota.

Monday, February 20, 2017

House Sparrow

House Sparrows are a world-wide invasive species. These Old World sparrows were first introduced to New York in 1851 and 1852. With their preference human-altered habitat, the species quickly spread across eastern North America. These introductions were augmented by subsequent releases in the western United States. 

Although House Sparrows remain common, I do not think I see as many as in my youth. Breeding Bird Surveys demonstrate a general population decline across the United States and Canada—a decline of about 2.5% per year. European numbers are also going down. Hypotheses for these drops in numbers include increased use of pesticides, which reduce insect numbers that adults feed to their young, and efficient farming practices that result in both less grain spillage and fewer weed seeds that used to support huge sparrow populations (Lowther and Cink 2000).

Saturday, February 18, 2017

Bald Eagle on Nest

Bald Eagles nest early in Minnesota. I suspect they try to match egg hatching with ice-out. The consequent bounty of winter-killed fish probably helps assure survival of the chicks. More landlocked eagles probably do the same, but hope for the emergence of spring rodents.

Bald Eagles nests are among the largest of all birds. One nest in Ohio, used for 34 years, weighed almost 2 metric tons. A Florida nest was 2.9 meters in diameter and 6.1 meters tall. Typical nests are just over 1.5 meters around and about a meter tall (Buehler 2000).

We photographed this nesting eagle yesterday at the Carpenter Nature Center in nearby Washington County, Minnesota. The frozen St. Croix River is in the background.

Thursday, February 16, 2017

Wilson’s Snipe

A Wilson’s Snipe yesterday at the Old Highway 77 Bridge across the Minnesota River south of Minneapolis. Birders have reported here for several weeks, and birders pointed it out to us as we walked across the bridge. The bird appeared unhealthy. The eye looked to be half-closed and the feathers on its left side appeared ruffled. When the snipe flew a short distance, its flight seemed a bit crippled. Our warm winter has kept a patch of muddy water open for the snipe to survive.

Wilson’s snipes are one of North Americas most common shorebirds. They are interesting birds. Briefly they were thought to be a race of the Common Snipe of Europe. Recently ornithologists re-elevated its status to species-hood, and once again it is named the Wilson’s Snipe. The word “snipe” refers to the bird’s long bill, which it uses to probe its muddy habitat. Snipe eyes are set towards the back of their head. The bird can see to both sides, and it can see what is coming from behind Mueller (1999).

Tuesday, February 14, 2017

Review: Illustrated Checklist of the birds of the World, Vol 2. Passerines.

Illustrated Checklist of the Birds of the World, Vol 2. Passerines. Josep del Hoyo and Nigel J. Collar. 1013 pp. Hardbound. $240.

We have had a long wait for this book, the final volume of The Handbook of Birds of the World. In August 2014, I reviewed the first volume of the Illustrated Checklist, which covered the non-passerines. Like the first volume, this book will be enjoyed by all birders. At over a thousand pages, it is large and expensive—about $240 at current exchange rates. Libraries should be encouraged to obtain both volumes. The book is available from the publisher, with free shipping, or from Amazon.

The checklist is not meant to be an identification guide, but rather a review of avian diversity. The color plates each contain about two-dozen birds and show species and many subspecies. Small range maps are included on each plate. Opposite each plate is a page giving alternative names, taxonomic notes, population status, subspecies and species' distribution.  A reference is given to the 17-volume, Handbook of the Birds of the World, thus serving as an index to that monumental work.

This passerine volume contains 446 plates containing 6649 small illustrations of the world’s songbirds. These drawings are generally very good, but tend to be in a cookie-cutter style, with birds often in identical poses. I cannot imagine the technical challenge to produce this work. It seems almost nitpicking to criticize occasional slight errors in bird shapes or colors. Critically look at the odd shapes of many of the antbirds and North American thrushes, the color of the Scarlet Tanager is completely wrong. The checklist follows a European and occasionally idiocentric taxonomy, briefly discussed in a short introduction. According to the publisher, this volume has 41 lumps and 628 splits from even their Handbook of Birds of the World series. Some ornithologists have questioned whether these books are the appropriate venue for new taxonomic science. These slight flaws and the taxonomic changes, however, do not critically affect the glory of this book.

The checklist contains almost 3000 bibliographic references. Readers are left with a wonderful overview of bird diversity. Almost as interesting as the colors and patterns of the planet’s birds are their range maps. The maps clearly show the intriguing distribution of birds and, along with the portraits, give us a snapshot of avian evolution.

Sunday, February 12, 2017

Dark-eyed Junco

Dark-eyed Juncos are common breeders across almost all of Canada and Alaska, also nesting in eastern and western mountains of the United States. They breed south to New England, Minnesota and Wisconsin, and through most of the Rocky Mountains. The species winters across the United States south to central Mexico. Another name for the species in Snowbird. Audubon wrote “there is not an individual in the Union who does not know the little Snow-bird” (in Nolan et al. 2002). The same might be said today.

Not surprisingly, with such a large range, juncos show much geographic variation Up until the 1970s, ornithologists recognized 5 species of what is now called the Dark-eyed Junco. Now these former species are lumped into a single species, with 15 subspecies. Several of these have been recorded in Minnesota. But the most common eastern form, which used to be named the Slate-colored Junco, is the most abundant here. This form is what Erika and I photographed last week in the University of Minnesota Landscape Arboretum.

Friday, February 10, 2017

Black-capped Chickadee

A Black-capped Chickadee from the University of Minnesota Landscape Arboretum. The sharply defined black bib suggests a Carolina Chickadee, but the pale wing coverts are typical of Black-caps. The two species do hybridize where their ranges overlap. Minnesota, however, is well north of the Carolina’s range. The hybrid zone is moving north—about 20 km from 1986 to 2003 and 100 kim from the 1930s to 1980s. Carolina Chickadees replace Black-caps as the hybrid zone moves north  (Foote et al. 2010).

 During our cold nights, Black-capped Chickadees lower their body temperatures, even entering “controlled” hyperthermia (Foote et al. 2010). These chickadees also break down organ proteins to generate heat. Our cold nights appear to be becoming warmer over time. Today we are heading for a possible 50 degrees F in Minneapolis. The all-time record low for the state on this day was -49 in northern Minnesota.