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Sunday, February 19, 2012

Solving the riddle of the raven

No, that title is not some poetic reference (I am not well-rounded enough to have such things at my fingertips). Rather than quoth the raven, I just want to know where she lives.

OK, so on March 15, 2009 (, I was hiking in the Rogue River SGA when I heard a Common Raven in flight deep within the Game Area. I tried to call it in, but never saw the bird. Then on August 7, 2010 ( I drove Red Pine Dr. through the Game Area on a hot summer afternoon, I encountered a silent Common Raven flying right over my car, along the roadside. This one never called, and despite my many playback attempts never came back to check me out.

These two happenstance encounters have proved to be my only sightings of this rare species for Kent County. The timing of it all really made me believe that these birds are likely to be breeding somewhere in the Game Area, and were not transient non-breeding visitors, but despite some effort hiking the remote areas of the Game Area for Northern Goshawk surveys, I have never been able to nail down their location, or that of a potential nest.

Fast forward to today. The clear skies really helped build up some quality thermals by noon, and so I decided to spend a little time at Fisk Knob, the highest point in Kent County, to see what raptors might be riding them. Fisk Knob is about 3 miles due NE of the NE corner of the Rogue River SGA, and offers a complete panoramic view of the south horizon, including the skies above the SGA. Pretty quickly into my survey I spotted a Bald Eagle about a mile to my south, heading west. I lost him for a while, then respotted the bird when it was more like 2.5-3 miles to my southwest, much farther out in the heat haze, but rather high up. It was being mobbed (or attended in its thermal?) by two other birds: the first was obviously an American Crow, and the 2nd bird, clearly intermediate in size between the two. I assumed it was going to be a Red-tailed Hawk, but was shocked up putting the scope on it to see that it was indeed a Common Raven! The bird was actively soaring (ravens love this), and had an obviously wedge-shaped tail and much thinner wing proportions than the crow. It harassed the eagle briefly, then worked its way south steadily.

I got one crappy video of the bird by digiscoping with my point and shoot, which is here:
But this isn't going to do much other than show a large black bird. I eventually lost the bird to the south of its initial position, as it headed further south.

So, to me, this is a pretty clear indication of local breeding and presumed resident pair of Common Ravens, somewhere in or near Rogue River SGA. I spent the remainder of the afternoon driving the roads I thought the bird to have been soaring above, but predictably came up empty-handed. Man I want to solve this riddle and find out where these things are nesting (they are early nesters, starting as early as January I believe, so chances are they're on eggs as we speak).

Here is the current status of my estimate as to where this territory might lie. First, I estimate the bird to have been at least 3 miles from my position at Fisk Knob when I took the video. I actually scoped Fisk Knob from Albrecht and 20 Mile, a distance of 2.5 miles, and based on the heat distortion estimated that the bird was farther than 2.5 miles from Fisk Knob when I saw it. Here is what 3 miles from Fisk Knob looks like:
The N-S road just east of the endpoint is Albrecht Rd. Now combining the approximate vectors of my sightings (ie. just north of due SW at its northmost, and to a point well south of SW at its southmost) with the ~3 mile distance gives:And finally, given that my hunch is that the bird was possibly upwards of 4-5 miles (estimating distances up there is extremely difficult!), I added this green area. The heavily forested sections of both the red and green polygons, and to their west, is the Rogue River SGA. Indeed, here are the locations of my 2 prior sightings in relation to the polygons from today:So, who's going to be the one who solves this riddle? Birding is all a big game of puzzles, in my opinion. Ravens have a home range of 5-40 km squared according to one source I have. This is 1.5 - 15 square miles, depending on the available resources in the territory and competition from other ravens. This is the extreme southern limit of the range of this species in Michigan, so competition shouldn't be heavy, but perhaps resources are more limited here than in the northern haunts. In any event, these birds are quiet around the nest and likely to be moving around a lot, so detecting the 1 Raven in this area which isn't sitting on a nest is not a trivial task! I will be trying hard to nail down this bird and get a good photo once and for all.

Since almost all of the other listers in Kent County still need this species, I am sure they are cheering for me.

Postscript (added Feb 20): Additional research has now led me to the conclusion that this species was last documented nesting in the southern lower peninsula on March 18, 1890, in Almena Twp., Van Buren County (Barrows 1912, p. 418 [Michigan Bird Life]) by "Mr. Sikes", of a nest 60 t up in a broken sycamore top containing 2 small, noisy, youngsters. This location is somewhere within a swamp several miles long and 2 miles wide, along the N. Branch of the Paw Paw River, so likely here, just north of the current day Wolf Lake Fish Hatchery:
Anyway, the point is that according to both the first and second breeding bird atlas accounts, this species does not seem to have any territories south of the tension zone, or more specifically, south of Newaygo, Mecosta, Oceana and Midland Counties: Co.
If there is a nesting pair of ravens in Rogue River SGA, they will be the first documented nesting pair for the southern lower peninsula in about 122 years! Needless to say, my motivation to document a nest is rather large now. More soon....

Saturday, February 4, 2012

Hoary time

On December 6, 2007, several years before I became interested in Kent County listing, I received a call from a friend who had a frosty adult male Hoary Redpoll in with 200 Commons about 10 minutes away. I rushed over to the scene just to see a rare bird, only to find that only 75 redpolls remained, not including the one I was looking for. I searched for several days and never saw more than 75 birds nor the Hoary.

A similar scene played out at the DeBruine residence in eastern Kent Co. yesterday, and was even more painful now that I am interested in the species for my county list. Minutes before I arrived, the flock of 120 Commons with 2+ candidates for Hoary departed, and only 50-60 Commons remained. Oh, the agony. I assumed the flock of over 100 would never return, but was pleasantly surprised by the appearance today of about 200 Commons (many thanks to the DeBruine family for their amazing hospitality and birding ardor- there are a LOT of birders in that household!). Upon arrival today at about 11:15AM I was treated to two very good Hoary Redpoll candidates. Let's get right to the field marks:

Individual 1. This bird, like the other, was extremely frosty white, and stood out amongst the Commons very clearly, at distance, by naked eye. Neither bird had red on the breast/underparts, making them both NOT adult males, I believe. The flank streaking on bird 1 was very sparse and fine, quite delicate (and beautiful!). Its undertail coverts had but one streak on the longest coverts, and its upperparts and crown were very frosty white. The uppertail coverts and rump were not seen. Like the second bird, its bill was small, nasal tuft large, and the bird had a small red cap and bull-headed appearance. This changed with angle somewhat:
Frosty upperparts and single undertail covert streak:
Bird 2 was similarly frosty to the first bird, and stood out naked eye just as much as bird 1. This bird was more streaky on the flanks (immature female?), but was very frosty overall, especially on the scapulars, mantle, and crown. Its rump was completely white and unstreaked (pics below), the undertail coverts again had 1 streak on the longest feathers, and it had an even more pronounced bull-headed appearance. This is shown well in my photographs:
Rump looked like a white sugarcube:
This photo shows how well the bird stood out from the many Common Redpolls.
The nasal tufts were prounced, giving it the bull-headed appearance:
Frosty upperparts and single undertail covert streak:

In terms of grading these 2 birds using Sibley's index I scored these birds like this:

Bird 1
Undertail: 5
Flanks: 5
Rump: not seen
Score: Tough with rump not being seen, but rump was presumably not 1-3, making the total score at least 14. Sibley mentions that for female/immatures, 11 would be enough to qualify as Hoary, so even if it had a 1 (the lowest value), it would still be so.

Bird 2
Undertail: 5
Flanks: 4
Uppertail: 5
Score: 14
Sibley says no female/immatures scored higher than 13, so presumably I have incorrectly assigned these values, but since 11 is enough to make it a Hoary, I believe this ID is fairly conservative.

What a fun and strange winter it is! Over 50 degrees, in shorts, and have seen a Hoary Redpoll all in the same day.