It was really starting to feel like spring last week, and I was looking forward to a pleasant day of birding this weekend. Then it got cold again and snowed about an inch on Saturday, but I figured that meant Sunday would be a great chance to do a tour de farm fields to look for longspurs and buntings. A little snow meant the roads wouldn't be unbikeable, but it was enough to push the birds out to the roads where they would be more visible. Well, then I saw the forecast for winds gusting over 40 mph - with what would have been a headwind my whole ride home - so I scrapped that plan!
Instead, I went back up to the quarry at the top of the bluffs where I spent New Year's Day. That location is conveniently close to my house for bad weather days (very cold on January 1st or very windy today); I know I can bike 4 miles in any conditions. After parking my bike, the quarry provides a good long walk through a variety of habitats that are relatively hard to find around here, including several birch patches, a stand of impressively large spruce, and some open scrubby stuff at the bottom of the quarry. The walk starts in mixed deciduous forest, which is not at all hard to find around here, but adds to the variety.
The wind wasn't bad when I started, and bird activity was good for the first couple of hours. On my way up the initial steep climb from the parking lot, I came across a mixed flock of birds (Downies and other woodpeckers, White-breasted Nuthatches, chickadees, jays - and a gray squirrel) scolding at something. I was hoping for an owl and the group was not far off the trail, just down a short steep embankment that I didn't want to navigate. I crept up to the top of the embankment and had great views of the agitated birds... but never saw what they were scolding. The birds were all pretty low to the ground and seemed to be watching something on the ground, so I decided it was probably a mammal rather than an owl. A few minutes later I saw fresh cat tracks, so that could have been it.
I continued up the trail and heard a Tufted Titmouse singing for #42. Titmice are not rare around here, but have only recently started singing for the season, and I generally seem to hear them much more often than I see them.
A little bit farther up I glimpsed a large wing-flap a short distance off the trail, through fairly open woods and next to a cliff. I got my binoculars on the bird and was pleased to see the back and shoulder of a Barred Owl (#43). The bird turned around, saw me looking at it, and slowly side-stepped until it was hidden from my view by the trunk of the tree. I went on my way to avoid disturbing it while it settled in for the day. Last year I never did find a Barred Owl in La Crosse County, and only had one Great Horned! Aren't there Barred and Great Horned owls everywhere?? Apparently not here. I heard both species hootin' it up on an overnight camping trip that I did last spring to neighboring Trempealeau County, and I'll probably do that again at least once this year, but it wasn't out of the question that I could have missed Barred Owl altogether with a bit of bad luck. So, it's nice to get that one on the list, especially with a chance encounter where I wasn't expecting one.
I took some of the trails less traveled farther up in the quarry, hoping to find a Northern Shrike that had been there a few days ago. That's another species I could happen to miss all year - I never found one last year, and while I'm planning some trips to/through better shrike habitat this year, they're so sparse that I can't count on finding one. Likewise, especially given the windy conditions, I was keeping an eye to the sky for Golden Eagles, which I could also easily miss this year. No shrike or golden today, but I did flush a pair of Song Sparrows (#44) from a sheltered patch of grass.
By then the wind had really started gusting, and I didn't see much else as I finished circling the quarry and headed back down to my bike. I was glad to have the wind at my back for most of the ride home!
Sunday, February 18, 2018
Sunday, February 11, 2018
10 February 2018: Chasing a species that might not exist...
Defining a species is notoriously tricky. There are various definitions, and exceptions to every one of them. Generally a biologist would say that one species is distinct from another when they do not interbreed, as a result of behavioral or morphological incompatibilities. If they occasionally interbreed, the hybrid offspring are supposed to be infertile. Usually, the two species also must seem different to a human observer (in appearance, behavior, range, song) for us to consider whether they are separate species in the first place.
So, what are the exceptions? Many species will interbreed. An extreme example - from a human perspective - involves the Golden-winged and Blue-winged Warblers. These two species look completely different:
and they have songs that are easily distinguishable to a human observer. But they readily interbreed, to the extent that hybridization is contributing to the decline of the rarer Golden-winged Warbler. Their offspring are fertile. But the two species look so different that there is no question that we should consider them to be two separate species. On the other hand, the races of Dark-eyed Juncos look very different from one another, but we consider them to be all one species because they readily interbreed.
Another interesting group is the large white-headed gulls. A recent high-tech study of 17 species that breed in the Northern Hemisphere found that these species are nearly genetically indistinguishable! Yet a human observer can reliably distinguish a Herring Gull from a Great Black-backed Gull from a Glaucous Gull. However, large white-headed gulls are notorious for hybridizing amongst themselves. Some will even hybridize with black-headed gulls, producing offspring like this beautiful putative Ring-billed x Laughing Gull. The offspring are fertile - unfortunately for gullers, because second-generation hybrids are even trickier to identify! But we consider pure adults to be sufficiently distinguishable to be different species.
Except in the case of Iceland and Thayer's Gulls. These used to be considered two separate species. Iceland has white or pale gray wingtips; Thayer's has black (among other, more subtle differences). In those "pure" plumages, the two are easy to distinguish in the field (at least as adults). But the two interbreed extensively, so that individuals with intermediate plumage are at least as common as the pure birds and span the full spectrum from white to black wingtips. Last year, the American Ornithological Society (formerly AOU), which is the taxonomic authority for the U.S. and Canada, decided to lump the two into a single species. Thayer's Gull no longer exists - it's just another Iceland Gull.
So why would we consider Iceland/Thayer's to be a single species, but not other species pairs like Western/Glaucous-winged, which similarly hybridize extensively where their breeding ranges overlap? Sometimes the decisions are somewhat subjective; otherwise the committee might feel that there is insufficient evidence (thus far) to change the status quo. I've heard the species concept described as a mountain range: the individual mountains are species, and while it's easy to tell which peak belongs to which mountain, it's harder to assign the area between the peaks one way or another. Sometimes there seems to be a distinct valley until you get closer (like with a genetic analysis), and then the terrain gets lumpy and messy and you really don't know where one particular lump (or individual bird) should be placed relative to the two peaks (species) on either side.
Another proposal that AOS considered last year was to lump Common and Hoary Redpolls into a single species. There's scientific evidence for this - no one has yet found a way to distinguish these two species genetically. Identifying them in the field is also tricky, as the differences are subtle and - like Iceland/Thayer's Gulls - an observer can find individuals that span the full spectrum between the two. However, as mentioned above, hybridization alone is not sufficient reason to lump other species pairs; and genetic distinctions can be difficult to pin down. AOS decided to retain two North American species of redpolls, pending further information on how the two species interact on their breeding grounds. It was a close decision, though.
I lived in Alaska for a little over three years, and saw both species of redpolls breeding at Utqiaġvik (formerly Barrow):
I frequently saw both species and didn't worry too much about identifying each individual, though if I were to go back now, that area would be a great place to study any segregation between the two - or whether they interbreed freely. Certainly the fact that both species breed there, while maintaining distinct characteristics, indicates that the differences between the two are not solely a result of the environmental conditions in which an individual hatched, as has been suggested given the apparent lack of genetic distinction between the two.
What does this have to do with Green Birding in Wisconsin in 2018? Well, Common Redpolls have been abundant in the area (and most of Wisconsin) this winter; I easily found a couple of flocks on January 1st. Hoaries are much less common here, but one or two show up in flocks of Commons every once in a while. The other day I heard that a pair of Hoaries has been visiting a feeder just 5 miles from my house. The homeowners put the word out to the local birding community and generously invited everyone to stop by and check them out. I biked up there today and enjoyed the convenient opportunity to sit on the front porch and watch and photograph the birds at the feeder from close range - perfect conditions for picking apart two similar species. The male wasn't around when I was there, but I had fun picking out the female as she came and went. The feeder was a riot of activity with perhaps 60 redpolls at a time on the feeder, ground, and nearby branches.
So, how Hoary is the female Hoary? Thanks to the excellent viewing conditions, I managed to get photos (not stellar photographic quality, but identifiable) of all the relevant field marks:
So, this bird ticks all the boxes for pure Hoary, putting Hoary Redpoll on my list for #40. I also added Merlin (#41) later in the morning when I was biking around Brice Prairie (again hoping for Lapland Longspurs or Snow Buntings or a Northern Shrike, but no luck on any of those).
Of course, there may be no such thing as a Hoary Redpoll. Hopefully last year's AOS decision will spark further study of these birds on their breeding grounds and provide further evidence one way or the other. In the meantime, Hoary is still countable on the ABA Checklist (which follows AOS taxonomy), and thus for my green year. I'm really excited to add this species to my list, as there was certainly no guarantee that I would find it this year, especially given the difficulty in distinguishing Hoary from Common under most field conditions. I'm grateful to the homeowners for generously sharing their birds! They weren't home when I stopped by, but I left a bag of thistle seed as a thank-you gift, which will go to good use feeding this large, hungry flock.
So, what are the exceptions? Many species will interbreed. An extreme example - from a human perspective - involves the Golden-winged and Blue-winged Warblers. These two species look completely different:
 |
| Blue-winged (left) and Golden-winged Warblers. Both were lifers for me last year, but there was no chance that I would confuse the two! |
Another interesting group is the large white-headed gulls. A recent high-tech study of 17 species that breed in the Northern Hemisphere found that these species are nearly genetically indistinguishable! Yet a human observer can reliably distinguish a Herring Gull from a Great Black-backed Gull from a Glaucous Gull. However, large white-headed gulls are notorious for hybridizing amongst themselves. Some will even hybridize with black-headed gulls, producing offspring like this beautiful putative Ring-billed x Laughing Gull. The offspring are fertile - unfortunately for gullers, because second-generation hybrids are even trickier to identify! But we consider pure adults to be sufficiently distinguishable to be different species.
Except in the case of Iceland and Thayer's Gulls. These used to be considered two separate species. Iceland has white or pale gray wingtips; Thayer's has black (among other, more subtle differences). In those "pure" plumages, the two are easy to distinguish in the field (at least as adults). But the two interbreed extensively, so that individuals with intermediate plumage are at least as common as the pure birds and span the full spectrum from white to black wingtips. Last year, the American Ornithological Society (formerly AOU), which is the taxonomic authority for the U.S. and Canada, decided to lump the two into a single species. Thayer's Gull no longer exists - it's just another Iceland Gull.
So why would we consider Iceland/Thayer's to be a single species, but not other species pairs like Western/Glaucous-winged, which similarly hybridize extensively where their breeding ranges overlap? Sometimes the decisions are somewhat subjective; otherwise the committee might feel that there is insufficient evidence (thus far) to change the status quo. I've heard the species concept described as a mountain range: the individual mountains are species, and while it's easy to tell which peak belongs to which mountain, it's harder to assign the area between the peaks one way or another. Sometimes there seems to be a distinct valley until you get closer (like with a genetic analysis), and then the terrain gets lumpy and messy and you really don't know where one particular lump (or individual bird) should be placed relative to the two peaks (species) on either side.
Another proposal that AOS considered last year was to lump Common and Hoary Redpolls into a single species. There's scientific evidence for this - no one has yet found a way to distinguish these two species genetically. Identifying them in the field is also tricky, as the differences are subtle and - like Iceland/Thayer's Gulls - an observer can find individuals that span the full spectrum between the two. However, as mentioned above, hybridization alone is not sufficient reason to lump other species pairs; and genetic distinctions can be difficult to pin down. AOS decided to retain two North American species of redpolls, pending further information on how the two species interact on their breeding grounds. It was a close decision, though.
I lived in Alaska for a little over three years, and saw both species of redpolls breeding at Utqiaġvik (formerly Barrow):
 |
| Hoary (left) and Common Redpolls, both nesting in large cages that were used decades ago for studying wolves. |
 |
| Hoary (left) and Common Redpolls - easier to see some of the field marks here. On the Hoary, note smaller bill, smaller red cap, white rump and undertail coverts (both hard to see on the Common but would be streaked with brown), more silvery mantle, and less streaking on the sides. There's no guarantee that either of these birds is pure, but they seem to be classic examples of the respective species. |
I frequently saw both species and didn't worry too much about identifying each individual, though if I were to go back now, that area would be a great place to study any segregation between the two - or whether they interbreed freely. Certainly the fact that both species breed there, while maintaining distinct characteristics, indicates that the differences between the two are not solely a result of the environmental conditions in which an individual hatched, as has been suggested given the apparent lack of genetic distinction between the two.
What does this have to do with Green Birding in Wisconsin in 2018? Well, Common Redpolls have been abundant in the area (and most of Wisconsin) this winter; I easily found a couple of flocks on January 1st. Hoaries are much less common here, but one or two show up in flocks of Commons every once in a while. The other day I heard that a pair of Hoaries has been visiting a feeder just 5 miles from my house. The homeowners put the word out to the local birding community and generously invited everyone to stop by and check them out. I biked up there today and enjoyed the convenient opportunity to sit on the front porch and watch and photograph the birds at the feeder from close range - perfect conditions for picking apart two similar species. The male wasn't around when I was there, but I had fun picking out the female as she came and went. The feeder was a riot of activity with perhaps 60 redpolls at a time on the feeder, ground, and nearby branches.
 |
| Busy feeder! Can you pick out the Hoary? It got easier as I became familiar with this individual. She's the paler bird oriented vertically at the bottom right of the feeder - you can see her white rump. She dug into this spot for a good while, refusing to be displaced by her hungry flockmates, though competition was fierce. The top horizontal bird also looks paler than the others and has a smallish red cap, but you can see brown on the rump, and another photo shows his bill as being too long for Hoary. Another bird had only a single brown streak on her undertail coverts, and Common rumps spanned the spectrum from very brown to nearly white. Hybridization or individual variation? |
So, how Hoary is the female Hoary? Thanks to the excellent viewing conditions, I managed to get photos (not stellar photographic quality, but identifiable) of all the relevant field marks:
 |
| Female Hoary at top. Note overall silvery color, limited streaking on sites, small bill (not entirely an artifact of the photo angle), small red patch on the poll, white rump, and white undertail coverts. |
 |
| Another view of the white rump |
 |
| White rump when perched, and white undertail coverts |
 |
| Good view of the small bill and small red patch - compare to the female Common on the feeder |
So, this bird ticks all the boxes for pure Hoary, putting Hoary Redpoll on my list for #40. I also added Merlin (#41) later in the morning when I was biking around Brice Prairie (again hoping for Lapland Longspurs or Snow Buntings or a Northern Shrike, but no luck on any of those).
Of course, there may be no such thing as a Hoary Redpoll. Hopefully last year's AOS decision will spark further study of these birds on their breeding grounds and provide further evidence one way or the other. In the meantime, Hoary is still countable on the ABA Checklist (which follows AOS taxonomy), and thus for my green year. I'm really excited to add this species to my list, as there was certainly no guarantee that I would find it this year, especially given the difficulty in distinguishing Hoary from Common under most field conditions. I'm grateful to the homeowners for generously sharing their birds! They weren't home when I stopped by, but I left a bag of thistle seed as a thank-you gift, which will go to good use feeding this large, hungry flock.
Monday, February 5, 2018
5 February 2018: A snowy Snowy!
I haven't been out to bird in a dedicated way recently, but today I lucked into two FOGYs. First I happened to glance out my office window (I bike-commute every day, so office birds are green birds) and saw some bird making a weird motion in one of the pine trees outside, sort of a longish tail of a medium-sized bird bobbing up and down. I got my binoculars on it and saw that it was an adult Sharp-shinned Hawk (#38) plucking its prey, which could have been a chickadee or a junco. Another chickadee in the same tree seemed completely unconcerned, so maybe it was more likely a junco. [Edit: Ha, just saw on eBird that a colleague reported a Sharp-shin that had captured a junco at the office!]
After work I followed up on a tip I'd gotten about a Snowy Owl at the airport (thanks, Gwyn!). My office is right next to the airport, and I'd checked the fields multiple times earlier in the winter before giving up. The owl had been seen on the opposite side of the airport from my office, but it had been snowing all afternoon and the roads were already kind of a mess from snow over the weekend - apparently no one sees a need to plow the roads around here until there's a lot of snow, so the snow plows just drive along spraying salt everywhere without plowing anything! - so I thought I'd see what I could see from the road that goes past my office rather than biking all the way over to the other side. I had a pretty clear (if distant) view of the light poles where the owl had been seen the previous day, and there was no owl on them. I went a little farther up the road and scanned all the other tall objects - light poles around another parking lot, various aircraft control devices, and a weather station. There was a big white lump on one part of the station... I biked around to try to get a better view, but it was pretty far out there. But the white lump looked an awful lot like it had a gray vest (i.e. the black speckles of a well-marked Snowy) with a white head. Finally I saw it stretch out a wing to preen a bit - definitely an animate object! You can even make out its face (just barely!) in one of my photos. Snowy Owl for #39!
I took a bunch more pictures from a different angle, where I was closer to the bird, but it was snowing harder and the light was fading. I stacked several images in Photoshop to get rid of the snowflakes and noise... at least a little:
In contrast, here's one of those images alone, without being stacked:
So stacking is definitely a handy trick - though you still sort of have to take my word for it that this is truly a Snowy Owl. =) At least you can rest assured that I was keeping my distance and not disturbing the bird! (Especially because the photos are from a 300mm lens and very heavily cropped!)
The central U.S. is seeing a pretty good irruption of Snowies this year, so I was hopeful that I would get one for my 2018 list. But the five that were seen in December have not made an appearance this year (at least not in the same spot, though that's not far from the airport as the owl flies), so I was starting to worry. Can't get much more convenient than a half-mile ride from my office, though!
After work I followed up on a tip I'd gotten about a Snowy Owl at the airport (thanks, Gwyn!). My office is right next to the airport, and I'd checked the fields multiple times earlier in the winter before giving up. The owl had been seen on the opposite side of the airport from my office, but it had been snowing all afternoon and the roads were already kind of a mess from snow over the weekend - apparently no one sees a need to plow the roads around here until there's a lot of snow, so the snow plows just drive along spraying salt everywhere without plowing anything! - so I thought I'd see what I could see from the road that goes past my office rather than biking all the way over to the other side. I had a pretty clear (if distant) view of the light poles where the owl had been seen the previous day, and there was no owl on them. I went a little farther up the road and scanned all the other tall objects - light poles around another parking lot, various aircraft control devices, and a weather station. There was a big white lump on one part of the station... I biked around to try to get a better view, but it was pretty far out there. But the white lump looked an awful lot like it had a gray vest (i.e. the black speckles of a well-marked Snowy) with a white head. Finally I saw it stretch out a wing to preen a bit - definitely an animate object! You can even make out its face (just barely!) in one of my photos. Snowy Owl for #39!
 |
| Snowy Owl sitting on the black tower. It really is an owl, I promise... although I have no idea what the ghostly red Y is over the red tower! |
I took a bunch more pictures from a different angle, where I was closer to the bird, but it was snowing harder and the light was fading. I stacked several images in Photoshop to get rid of the snowflakes and noise... at least a little:
 |
| Snowy Owl on the weathervane. I love the setting, even if you can still barely tell it's an owl! |
In contrast, here's one of those images alone, without being stacked:
 |
| More snowflakes than Snowy in this one... |
So stacking is definitely a handy trick - though you still sort of have to take my word for it that this is truly a Snowy Owl. =) At least you can rest assured that I was keeping my distance and not disturbing the bird! (Especially because the photos are from a 300mm lens and very heavily cropped!)
The central U.S. is seeing a pretty good irruption of Snowies this year, so I was hopeful that I would get one for my 2018 list. But the five that were seen in December have not made an appearance this year (at least not in the same spot, though that's not far from the airport as the owl flies), so I was starting to worry. Can't get much more convenient than a half-mile ride from my office, though!
Subscribe to:
Posts (Atom)