Bird-a-thon 2009

Dear all of you avid blog followers,

If you have enjoyed the various blog posts this season, now is your chance let us know by pledging to our staff Bird-a-thon. This is a great way to ensure that there will continue to be blog posts in the future to amuse and amaze you.

This is the 3rd year for the WPBO spring Bird-a-thon fundraiser. Last year the Bird-a-thon pledges were the single biggest contributor to the summer owl research project. The total amount of funding required for this program is $8,000. In the last month, we have raised $7,060 towards our goal, mostly through Bird-a-thon pledges. We are so close, please consider becoming a sponsor!

At the end of May, WPBO staff known as the “Northern Saw-whats” team will record the number of bird species seen in the Whitefish Point Peninsula area during a 24 hour time period. We hope to see about 100 species. You can choose to pledge per species or donate a fixed amount. All pledges collected will directly support the summer owl research at WPBO. Sponsors will receive a written account of our day, a species list and information on our summer research. Anyone who donates over $150 will receive a juvenile saw-whet adoption package, including a photo of your owl, banding information, and adoption certificate.

Be the first to pledge from this blog post! Send your name, address and phone # along with the amount you would like to pledge to wpbostaff@gmail.com, or send by snail mail to:
WPBO Birdathon
16914 N Whitefish Point Rd
Paradise, MI 49768

Swainson's Hawk

High winds today did bring a surprise in the form of this adult intermediate (rufous) morph Swainson's Hawk. Conditions were not exactly favorable for photography, and the bird never got very close, so these two pictures are the best I have. I think you can see that it's a Swainson's Hawk (dark flight feathers, long 'hand'), but as far as age and color morph are concerned, I guess you will have to take my word for it.

Just before the start of the count, I said to my coworker Sarah that today's high winds might bring a surprise. Swainson's Hawk, was her reply. Nah, I said, you need west winds for that. Guess I was wrong!

Yesterday's 'vacuum cleaner' metaphor didn't exactly pan out either. A few new arrivals (Eastern Kingbird, Savannah Sparrow, Bank Swallow) but nothing in any great numbers. The hawk flight too was fairly modest today, with really only good migration of Peregrine Falcon (5), and Sharp-shinned Hawk (97). In the case of the latter, I have to wonder just how many of those birds actually went through, and how many were flying in circles. Other raptor sightings today include 6 Turkey Vultures, 1 Bald Eagle, 4 Northern Harriers, 3 Broad-winged Hawks, 3 Red-tailed Hawks, 4 Rough-legged Hawks, 1 American Kestrel, and 1 Merlin.

The Whitefish Point hawk count usually gets one or two Swainson's Hawks each spring. I thought the window of opportunity on that species had closed last weekend, but evidently I was wrong, and indeed recent records show sightings even later than May 13. In 2006, for example, a Swainson's Hawk was sighted on May 20, and again the very next day. Last year also had two birds, one on April 22 (also the date one was seen in 2007!) and another one on May 8.

Yesterday we looked at some redshoulder and redtail pictures. I have a few more pictures of redtails from yesterday to further illustrate the age / molt story.

This is of course an adult redtail. The wings have an obvious dark trailing edge, and there is no primary panel visible in the hand. The tail is a little shorter than on immature redtails, while the wing is broader, with more of a bulge on the secondaries.

Compare that adult bird with this juvenile, and note the absence of the dark trailing edge on the wings, the light primary panels, and the subtle differences in tail and wing shape, resulting in a slightly different overall shape.

Here's a juvenile bird molting its first primaries. P1 and P2 on this bird are growing in at the same time. Note the dark tips on the new incoming feathers: once they have all been replaced, the bird will have a dark trailing edge on its wings.

Then finally take a look at this bird. As far as I can tell, it's not missing any flight feathers in the wing (maybe a secondary in the right wing, although that could just be some feathers that need reshuffling). Most flight feathers are adult-type, but there are a few retained juvenal feathers here and there. Note that one of the 'fingers' is darker (adult) than the others (juvenal), and that some of the secondaries do not have a dark tip. The bird appears to be missing (i.e. molting) its central tail feather, resulting in a w-shaped tail end.

Fickle weather

I guess it goes without saying that the hawk flight predictions here are completely dependent on the accuracy of the weather forecast. Yesterday I thought today was going to be great, but instead it ended up being merely good. There was some SE wind in the morning, but by afternoon this had shifted to E and eventually even NE. Winds also were lighter than forecast, and on those light winds birds got high, for a while even so high that they were barely visible in 10X binoculars.

Tomorrow's forecast is now for less rain than initially thought, and even stronger winds than previously predicted. It'll be an interesting day, for sure. With SE winds 15-25 mph, gusting to around 40 mph (!), you have to wonder how many birds that will dump over the northeastern UP. Think of a giant vacuum cleaner sucking up birds and blowing them our way.

Today's sightings include 5 Turkey Vultures, 9 Bald Eagles, 4 Northern Harriers, 95 Sharp-shinned Hawks, 2 Cooper's Hawks, 2 Northern Goshawks, 1 Red-shouldered Hawk, 218 Broad-winged Hawks, 40 Red-tailed Hawks, 13 Rough-legged Hawks, 1 American Kestrel, 1 Merlin, and 3 Peregrine Falcons.

Let's do a bit more hawk ID workshop. Most readers probably identified the hawk at the top of this post. If you don't know what it is, no worries - I'll walk you through it.

It should be immediately obvious that this is a buteo, not a falcon, harrier, eagle or accipiter. Medium-sized bird, rounded wings, relatively short tail: buteo. We can see part of the left underwing, and on it we can see the beginning of a dark marking on the leading edge of the wing, the so-called patagial bar. Red-tailed Hawk is the only one with this field mark, and all age groups show it, so we really don't need to look for additional field marks. (Most people know about the redtail's 'belly band', but that particular field mark is invisible in this photo.)

Remember from a few days ago, that Rough-legged Hawk with the light panel in the primaries? Most young buteos show this field mark, and our bird today also shows it: observe on the (right) upperwing the contrast between the darker secondaries (i.e. flight feathers in the 'arm' of the wing) and the lighter primaries (i.e. flight feathers in the 'hand' of the wing). Observe also how on the (left) underwing, there is no terminal band on the trailing edge. Both these items - light primary panel and absence of dark trailing edge - indicate a juvenile Red-tailed Hawk. Most people know about the difference in tail color - red for adults, grayish-brown for juveniles - but that is usually not visible on a closed tail from below. But as I've demonstrated here, we don't really need it.

Here's one that's more difficult. If you know at first glance what this is, you're good. If you don't know what this is, then again let's review what is visible on this bird, and see if we can work it out. This bird is also a buteo. Now, based on what I said earlier about that patagial bar, we can rule out Red-tailed Hawk, because all redtails show that while this bird doesn't. We can also eliminate Rough-legged Hawk, for this bird has no carpal patches (i.e. big dark markings on the wrist). Virtually all roughlegs have them, although they can be less obvious on some males, where the carpal patch blends in with the rest of a heavily marked underwing. These underwings are very lightly marked, without a carpal patch, and only a very faint 'hook' on the underwing primary coverts.

It's not a Swainson's Hawk either, for that bird has darker flight feathers.

So, we're left with Broad-winged Hawk and Red-shouldered Hawk, both of which are quite distinctive in the adult plumage. Obviously - no dark trailing edge on the wing - this is a juvenile, and these two species are surprisingly similar in the juvenal plumage.

Matters are further complicated by the fact that the bird is in a glide, with half-folded wings. Both adult and juvenile Red-shouldered Hawks show light crescent-shaped panels in the 'hand' of the wing, but that feature is hard to judge on a bird with folded wings.

This is where subtle differences in shape and plumage start to become relevant. Shape: fairly long tail for a buteo (but note that juvenile buteos have longer tails and slimmer wings than adults do), and fairly slender body. These are both better for redshoulder. The dark throat and the evenly blobby markings on the body are also better for redshoulder, and this is indeed a Red-shouldered Hawk, as the following photo - with spread wings - will confirm:

Now the light crescent is visible in the hand, just where the darker 'fingers' of the hand start. Beware of buteos molting their primaries, which sometimes can create a similar impression of a crescent-shaped lighter panel. Our bird here has just started molting its flight feathers, and two feathers in each wing are missing. Red-shouldered Hawks have 10 primaries, which are usually numbered from the innermost (P1) to the outermost (P10). This bird appears to be molting P1 and P4 in each wing.

Another field mark that works well on distant birds: if you're not sure the bird is a buteo or an accipiter, it is probably a redshoulder. The basic shape is still buteo, but on the 'accipiter end of the spectrum', with a relatively long tail (for a buteo) and a slender body. Broadwing is stockier, and has pointier wings.

Upward trend continues

.Light NW winds and blue skies make for pleasant hawk watching, albeit with birds mostly distant on the southeastern end of the Point. Monday was again an improvement over the previous day, both in quality and quantity. Especially mid-afternoon was nice, with 6 Peregrine Falcons in about an hour's time. Other raptors counted include 10 Bald Eagles, 4 Northern Harriers, 27 Sharp-shinned Hawks, 1 Cooper's Hawk, 1 Red-shouldered Hawk, 118 Broad-winged Hawks, 22 Red-tailed Hawks, 6 Rough-legged Hawks, 3 Golden Eagles, and 1 American Kestrel.

A little flock of four Magnolia Warblers were seen as flyovers over the platform. Also seen as flyover a breeding plumage adult male Lapland Longspur. Heard singing today was a Black-throated Green Warbler. Two Caspian Terns flew by in the afternoon.

The next two days look very promising, weatherwise. I'm gonna go out on a limb here and predict 1) that the hawk watching - and the overall birding for that matter - will be outstanding on Whitefish Point those two days, and 2) that Tuesday will probably have the greater numbers, but Wednesday possibly the bigger surprises...

For Tuesday, conditions will be downright good. Expect birds to be directly overhead and probably not too high right over the platform (as opposed to 'over the harbor', where most of the flight has been of late). It looks like we're in for a lot of rain Wednesday, but also very strong SSE winds, and who knows some southern rarities... Everything will depend on how much rainfall we will get, and in which part of the day. I guess Tuesday is more or less guaranteed to be good, while Wednesday is more of a coin flip: it may turn out a dud, or it may just be fantastic...

Hawks bounce back

It wasn't exactly epic, but the raptor flight did pick up a bit after yesterday's low point of 14. Today, the count reached 82, with a couple of Osprey, 2 Bald Eagles, 2 Northern Harriers, 23 Sharp-shinned Hawks, a juvenile Northern Goshawk, 25 Broad-winged Hawks, 19 Red-tailed Hawks, 7 Rough-legged Hawks, and 1 American Kestrel.

Based on current weather forecasts, it seems reasonable to expect this upward trend to continue over the next few days. For Monday, sunny weather and light winds are forecast - which will be nice with or without birds - but the best hawk days are likely to be Tuesday and Wednesday.

Windy!

Saturday was a windy day at Whitefish Point, with fairly strong north winds in the morning and even stronger northwest winds in the afternoon. Temperatures didn't even make it into the forties today. There was very little active hawk migration visible today, although a few raptors could be seen hunting or just hanging in the wind for most of the day, like this adult Bald Eagle. Birds that were added to the count as migrants included 2 Osprey, 3 Sharp-shinned Hawks, 1 Red-tailed Hawk, 4 Rough-legged Hawks, and 3 American Kestrels.

The forecast for Sunday is only marginally better. A more substantial improvement, with once again favorable conditions for a hawk flight, is now forecast for Tuesday.

Strange buteos

This top bird is not a strange buteo, but - on the basis of just this side view - it's probably not an easy ID for most birders. If you don't know what this is, then let's review what is visible on this bird and see where that gets us.

It's a hawk with rounded wings and a medium-short tail - in other words: a buteo. We see some kind of light panel in the primaries, a light buffy bar across the upperwing coverts, and - for a hawk at least - a small bill. Let's take a look at another photo of the same bird, with more field marks visible.

Here we have a clear view of the bird's upperside. It would probably be easier if we had a view of its underside, because that's just how we see buteos most often. But we can work it out with this upperside view just fine. What else is visible that wasn't earlier? Exactly, the tail. Brown tail with wide dark terminal band and smaller bands on the rest of the tail. That wide dark terminal tail band should suggest Rough-legged Hawk to us, and the earlier noted small bill would confirm that ID. Those light panels in the upperwings are quite characteristic of juvenile Rough-legged Hawk. Juvenile Red-tailed Hawks have primary panels too, but usually not this exaggerated.

Here then finally a photo of the underside of the same bird, and it should be quite clear now that this is a juvenile dark morph Rough-legged Hawk. Those big dark carpal patches are what most birders think of when they think of Rough-legged Hawks, and most of them indeed show that field mark.

I'll admit, this is a rather contrived and elaborate - OK, far-fetched - way to get to my real topic, i.e. 'strange buteos'. What I really mean is strange redtails. Two days ago there was that "Krider's-type" bird, which hasn't been seen since. For those of you who have back issues of Birding on their shelves: that bird was a spitting image of the bird illustrated in the October 2001 issue of that publication, in figure 20, showing a bird captured at a raptor banding station in Braddock Bay, NY. Jerry Liguori, author of that article, suggests that the bird in that photo is an adult Eastern Red-tailed Hawk, probably a Krider's intergrade but not a true Krider's. The head on that bird, like on our bird of two days ago, is pale, but not whitish. I think Wednesday's bird was most likely also an intergrade, not a true Krider's. There are still things to be learned about sub-specific variation in the Red-tailed Hawk; the more you look into it, the more variation you will find.

Today, another pale redtail showed up, but this was a different individual from two days ago. It had a little more spotting on the sides of the belly (still unspotted mid-belly), the head was a fraction darker (but still quite blonde), and the tail was all-red, with a narrow black subterminal band. (The tail on the earlier bird was half-white.) The back on today's bird was extensively speckled with light markings.

Then also today there was an adult 'rufous' intermediate morph redtail, and a juvenile 'rufous' intermediate morph redtail, possibly the same bird that was seen yesterday and the day before of a similar description.

But the real mystery bird was seen in the first hour of the count only. I don't have photos but I followed the bird for a while in the scope, and made extensive field notes:

• all-dark buteo, shape like redtail
• slightly smaller and shorter-winged than roughleg, with which it soared for a few moments
• dark tail with wide dark terminal band, smaller bands on rest of tail (not unlike bird pictured above!)
• remiges (flight feathers) quite dark! almost as dark as on Swainson's Hawk
• dark trailing edge on wings (i.e. adult)
• jizz not like Swainson's, also undertail coverts dark (not light, as in Swainson's)
• jizz not like Short-tailed, also wingtips not upturned when soaring
• structure essentially like redtail

So what's an adult dark redtail whose tail is not red? Is that a Harlan's, or is it yet another dark redtail variation?

Good. So much for that 'familiar' buteo, the Red-tailed Hawk, which shows so much variation. Other raptors added to the count today were 7 Turkey Vultures, 3 Bald Eagles, 6 Northern Harriers, 11 Sharp-shinned Hawks, 2 Cooper's Hawks, 3 Northern Goshawks, 196 Broad-winged Hawks, 14 Red-tailed Hawks, 7 Rough-legged Hawks, 1 Golden Eagle, 4 American Kestrels, 2 Merlins, 3 Peregrine Falcons, and one unidentified buteo. Also seen from the platform today an adult female Rusty Blackbird, sadly a bird rapidly plummeting toward extinction. Good sparrow variety at the feeders, with American Tree, Chipping, Song, Lincoln's, White-throated, White-crowned, Vesper and Clay-colored Sparrows present today.