Yellow-bellied Sapsucker

Last spring I found this Yellow-bellied Sapsucker gleaning insects in the treetops at the Cannon River Wilderness Area near Northfield. Sapsuckers are famous for drilling sap wells, and often damage trees in the process. In the spring, the wells harvest upward moving sap in tree xylem. Later wells capture downward-flowing phloem sap. Insects trapped in the sap wells are also consumed.

Sapsuckers also glean and probe for insects from tree bark and leaves. They sometimes capture insects in the air, in the manner of flycatchers. They also dine on tree buds. But most of their time is spent drilling and maintaining their wells. This dependence on live trees obliges sapsuckers to be our most migratory woodpecker.

Turkey in a Crabapple Tree

Turkeys are known to be “catholic” in their diet (McRoberts et al. 2014). These birds will eat almost anything—mostly vegetable matter, but also small animals. The turkeys that Erika and I found at the University of Minnesota Landscape Arboretum on 5 March 2016, gorged on crabapples.  The aforementioned authors list a variety of tree fruits that turkeys enjoy, but they do not mention crabapples. Oaks are a staple of their diet.

The turkeys we watched flew up into the trees to feed. This behavior is not unexpected. Turkeys usually spend the night in trees. Our turkeys looked ungainly in the delicate apple branches, but the birds proved to be adept acrobats.

Wild Turkey Track

On 5 March 2016, Erika and I discovered a turkey track at the University of Minnesota Landscape Arboretum. In short order, we found a flock of 15 birds.

Turkey behavior is complex and variable. Both males and females may form separate flocks, which can be composed of up to 40 individuals. Some winter turkey flocks exceed 200. 

Males form leks, strut about, and try to attract the attention of females. Dominant males mate with multiple females. The females then leave their female flock and raise their young. Young males remain with their mother until they exceed her in size. Males then join independent male flocks. (McRoberts et al. 2014).

Greater vs. Lesser Scaup

Greater and Lesser scaup are closely related ducks that are hard to tell apart.  Greater Scaup, like in the first photo, have large, black, bill nails and rounded heads. The head may be slightly highest in the front, but head shape often depends on what the duck is doing (diving, resting, etc.). The head often shows a green sheen, but this field mark depends so much on light conditions that color is not a dependable trait. The back is finely barred, making it appear brighter white than in the Lesser Scaup. Finally, the sides of the Greater Scaup often appear to be brighter white.

Compare the Greater Scaup to the duck in the second photo. The bill nail is much less prominant, barely visible from the side. The head is slightly crested behind the head. The black back barring is more pronounced, and the sides are not as bright white. The head sheen appears to be purple, not green.

So what is this last scaup? The bill nail is not pronounced and the head is clearly purplish. On the other hand, the head is not crested and appears to be highest in front. The back and side seem to be very pale. I have an opinion about this bird’s identity, but I welcome reader input. Perhaps the correct guess may be “unknown species of scaup.”

I took the first and the last photos at the Minnesota Valley National Wildlife Refuge’s Bass Ponds last Friday, 11 March 2016. I do not recall where I took the Lesser Scaup photo. All these ducks are drakes. Identification of the hens requires even more finesse.

Yellow House Finch

On 8 March 2016, Erika and I walked in the neighborhood. We heard the clear, complex notes of an House Finch from a nearby treetop. Despite its being a common bird, I looked up at the singer. To my surprise, this male was bright yellow.

I assumed that these yellow variants are the result of their having high levels of beta-carotene or with low levels of echinenone (either because of what they are eating or because they are unable to metabolize these hormones). See my 2012 post on a yellow House Finch in California.

The situation may be more complicated. LaBarbera (in Toughlittlebirds.com) has an interesting blog post. She writes that red males often hold the richest territories. Younger females are attracted to these wealthy birds. Red males, however, do not raise their young as fastidiously as do yellow males.

Yellow males breed later and and take better care of their young. Older females prefer to mate with these more stalwart males. I have simplified LaBarbera’s report, which includes further variables in this hypothesis. For example, it may be advantageous for a younger male to be red and then become yellow in subsequent breeding seasons. You will find LaBarbera’s post to be fascinating.

Black-capped Chickadee

Last Saturday, on 5 March 2016, Erika and I encountered a Back-capped Chickadee giving a “gargling” call, with which we were unfamiliar. Gargles are poorly understood calls. They can be complex and variable, containing up to 23 syllable types. Gargles are components of aggressive displays and are often given in winter (Foote et al. 2010).

We are not sure if this chickadee was being aggressive towards us or to other chickadees. Perhaps the bird was defending sap dripping from a nearby branch. The chickadee made repeated visits to the branch, where it drank the sap. Curiously, the above-cited authors do not mention that chickadees drink sap. The behavior is well-known. Bazilchuk (in nasw.org) mentions that chickadees feed on sap icicles. Undoubtedly sweet sap contributes to the high energy needed to survive our cold and often barren winters.

Horned Lark

This Horned Lark fed along the snowy roadside during Erika and my drive home last Friday. The bird appeared to be eating weed seeds.

Horned Larks are found around the world, from the Arctic sousth to central Asia and Mexico. They also inhabit Columbia and Morocco (Beason 1995). In Europe, they are known as Shorelarks. Horned Larks are common in prairies, deserts, and agricultural areas. With deforestation, Horned Lark populations increased in eastern North America. During the past 50 years, however, much abandoned land in the east has reverted to forest. As a result, eastern Horned Lark numbers have declined.

Gulls and eBird

On Friday, 4 March 2016, Erika and I enjoyed a lunch date at the San Pedro Cafe along the St. Croix River in Hudson, Wisconsin. As we ate, a heavy snow began to fall. After lunch, we scanned for birds at the Hudson Lakefront Park. Several gulls flew over the river.

Gulls are confusing. One of the advantages of using eBird is that this listing app asks you for confirming details when you try to report a rare bird. I thought I saw a Ring-billed Gull.  “Rare,” proclaimed eBird.  “OK,” I replied, “How about Herring Gull?” “Rare,” snarled eBird.

Rather than capitulating to eBird and not reporting these gulls, I pulled out my camera and took photos. That first bird proved to be a Herring Gull.  Note the red spot on the bill and the pink legs. A few minutes later, a second gull flew overhead. This one was a Ring-billed Gull! Note the yellow bill with the broad black band. This gulls back is pale compared with the Herring, and its inner primaries are even paler than the back.

Although they let you know when records are questioned, eBird is not very good at letting observers know when rare observations are accepted. I await their verdict.

Pileated Woodpecker

One of the delights of Minnesota birding is the relative abundance of Pileated Woodpeckers. Yesterday, I took this photo out our back window. I am excited every time I see one of these woodpeckers, and I have recently posted on the species.

In many areas Pileated Woodpecker populations are increasing. Forest management favoring older growth forests and retaining large-diameter trees—both alive and dead—contribute to this woodpecker’s survival. In some eastern areas, however, Pileated Woodpeckers are declining due to general habitat destruction (Bull and Jackson 2011).

Blue-gray Gnatcatcher

On 19 May 2015, Erika and I watched two Blue-gray Gnatcatchers forage at the edge of the forest in the Carleton College arboretum. Gnatcatchers are active little birds, often hard to see in the dense foliage in which they feed. You often hear their high-pitched, nasal songs. They will often come close and investigate if you make squeaking or spishing noises.

Gnatcatchers are monogamous.  Males contribute to most aspects of breeding. They help build their intricate nests, incubate eggs, and feed young. In the past 25 years, Blue-gray Gnatcatchers have increased in numbers and expanded their range northward (Kersner and Ellison 2012).