Shrikes are black and white (Chen geese too)

 Other birds are too, but first this bird from yesterday.  Northern Shrike is a bird I've found by surprise maybe only two other times in the LP.  The silhouette was a fun adrenaline rush when it popped up (just imagine if it's been April or May).  It moved around a lot and must have been attacking the local birds since the robins and chickadees were making a lot of alarm noises.  For a bird I would imagine that they'd never seen before they must have learned fast.

Haven't made a montage effort in a while...

Today's bird of the day was a Chen goose.  It was certainly mostly Snow, but when it landed had a bit of blue wartiness to the base of the bill.

The gulls chasing it are Herrings, so based on size it's at least mostly a Snow.

I have to admit I was kinda wondering how dramatic the pics would be if one of the local eagles had wandered by a little sooner than this one did, but the gulls flushed it first...

almost another Ross's Goose

I drove a bit of a central county route this afternoon.  Mary Jo and Marie were looking at a pair of White-fronted geese at the Scottdale Rd flooding when I drove up.

Four more white-fronts flew in, thought about landing, circled, and then landed across the road, drawing my eye to the Ross's that was sitting distantly close to some grapevines.

I tried a few more spots not finding much aside from Mute Swans and was heading toward home when I noticed a bunch of geese at the Anna Lane Flooding.  Not terribly surprisingly there was a Ross's type in with them as well.

It has some blue wartiness to the bill base...

but the head is less round than yesterday's Ross's Goose

And you can see that the bill base has a decent amount of curvature where it meets the face.

A curved bill base is generally accepted to indicate some Snow Goose in its not-so-recent ancestry; this bird is likely an integrade.
After finding this bird I actually drove back to Scottdale to make sure that the original Ross's was still there; it was.

lakefront Ross's Goose

After striking out entirely on geese in the Scottdale plains where Rhoda had found a Ross's Goose earlier I did the next best thing and headed for the beach.  I wasn't expecting very much, and indeed there were few birds by the piers given the amount of boat and foot traffic on a 60 degree January day.  I was just finishing my last scan when I picked up a distant Snow-type Goose flying off the lake.  It landed off Jean Klock and I drove up to get better pics.  My camera was giving me trouble and not auto-focusing or stabilizing so I went back to phone-scoping with the scope zoomed in to 60x.

I was pretty surprised to see it also was a Ross's Goose.

 Note the round head, vertical bill base with blue wartiness, and the pale bill tip.  In the above pic shadow gives it the hint of a grin patch which was much more shadow than real.

Here's the bird with the bill not shadowing.

The bird flew after about 10 minutes and headed inland right past me.  This was total spray and pray with the shutter as I tried to manually focus through the bird and hoped a few frames would be sort of in focus.

Digi-scoping ... not quite done yet?

Ginger recently got a new point-and-shoot style digital camera which actually works pretty well for digiscoping which I'd pretty much abandoned for the last 4 years or so.  It has it's moments though, and for distant stationary birds, can do better than an SLR.  Here's some of the white-fronted goose flock from this morning.

I've included pics of this flock in each of the last 2 posts, you can compare the results.  Certainly the SLR is a lot more consistent, but there's something to be said for starting with 60x magnification of the scope as opposed to more like 7x magnification of the 300mm lens.

The real reason I tried digi-scoping again was to try to document the Ross's type Geese in a little pond in the Scottdale plains.  If I'm correctly interpreting GoogleMaps they're about 500feet off the road.

 They look the same size as far as I can tell.  Both have pale tips to the bill and some blue wartiness at the bill base.  They both had fairly generous furrowing of the feathers of the neck.  The bird on the right/back has a bill base that's pretty straight and I think would have been acceptable if this were the bad old days when they were still review birds (here's an old post of submitted Ross's and Ross's type birds.).

Here's the right bird again.

The 2nd bird is a little tougher to evaluate.

Its bill was a little thinner, in most shots the bill base is more concave, and it has less blue wartiness.  The bird, however, is identical in size to the other.  I can't decide if there's a true difference in head shapes.  Last fall when we had a group of white geese at 3 Oaks the borderline bird was nicely intermediate in size between the Ross's Geese and the Snow Goose.  I've seen this shape of bill on first year birds and I wonder if this isn't just a younger bird.  Sometimes there's still some duskiness on wing feathers to prove the young age; it being mid April it's probably not surprising the bird seemed pretty white overall.
I think the take-home message is that White-fronted Geese are pretty.

Ross's ... Geese

We were pretty close to chasing the Iowa Ross's Gull yesterday and if it'd been seen on Thursday we would have.  It wasn't so we didn't.  Ah well.  We found Ross's Geese instead.

They were mixed up in the large Canada Goose flock.  Their body size is less than the young Glaucous Gull in the foreground.  There's one white morph Snow Goose as well.  After not a whole lot of time all the gulls on the berm flushed (we didn't see the responsible raptor), and the white geese followed them (the Canadas were unimpressed).

The Snow is obviously the larger upper left bird.  The bird trailing it associated more with it than with the other 5 when they uncertainly circled the ponds (the flock split a few times).  It seems like it might be just a bit bigger than the other birds and when in the water through the scope may have had a bit less vertical a bill base.

The bottom 5 birds had consistently vertical bill bases.  One is a first year bird with some dusky feathering in the lore and face.

This afternoon I made a few central and north county stops with the highlight being 10 White-fronted Geese at the LMC ponds.  I've actually seen White-fronted on fewer occasions than Ross's in the county.

Here's the other 7, they were segregated at the other end of the pond

Finally a mega-crop record shot of 2 Harlequins in the New Buffalo harbor from yesterday.

The White-fronts were 271 for the county for me, my personal best.  Don't be impressed though, that'll be good for at best second (and quite possibly 3rd) place this year!

Early spring waterfowl

It may be April but it's still cold out.  The Long-tailed Ducks continue to hang around the pier, contrary to what I wrote a week ago, the males do come in sometimes.

It was pretty windy and the bird was getting tossed about in the chop as evidenced by the splashes made by the wave cresting beneath it.

March generally means wild goose chases.  I was gone the weekend Whitefronts were in the county, but did have a Ross's Goose at 3 Oaks.

The extra pixels on the 7D makes it easier to document the straight bill base at longer distances.

Here's a size comparison with the Canadas when they flushed off the berm in front of me before I noticed them (in my own defense they were hunkered down pretty low trying to stay out of the wind).

People chasing the Barnacle Goose before its pinioning was proven found this Trumpeter Swan, also at 3 Oaks.

I've always had trouble appreciating the difference Sibley shows with the cheek pattern; I think the average Trumpeter has more curve down than he shows.  The pointed forehead pattern is easier to see (of course the lack of a yellow dot, long sloped bill, and salmon edge to the lower mandible is also usually easier to see).

This is the Lemon Creek Blue Goose, I think this bird has wintered in that area for at least a few years.  I saw at least one other Blue Geese at LMC this spring. You can get a sense of the difference in head and bill shape from the Ross's.

 

Finally a hen Wood Duck that swam out from the edge of the ditch along Avery and posed reasonably cooperatively.

The male swam out too but he never turned broadside.


Great goose round-up

There's been some decent year birds around lately though I haven't had a ton of time to write a lot about them. The goal for a Berrien year lister is always to find as much stuff out of the way in the spring so that a minimum of birding time can be spent away from Tiscornia in the fall when there's greater rarity potential (not that I didn't probably have a distant Black-tailed Gull a couple weeks ago).

It took an hour and a half of walking though the Sarett pines with my head cricked back before I found a Long-eared; owls and geese are among the earliest migrants though this bird could have wintered. This was at least my 4th trip into the pines this year though.
Speaking of geese, we've had some decent SW winds in the last few weeks which makes it a lot easier to find White-fronted and Ross's types.

Three Ross's types have been seen at a farm pond along Buffalo Road. Ross's are no longer a review bird in Michigan fortunately. I wrote a post a few years ago showing a range of birds and how they were viewed by the committee. I think these would be accepted if this was back then. What they actually are, may be another matter. Personally I think all eastern Ross's have at least some Snow in them given the massive population expansion Ross's underwent at a time when Snow Geese were moving into new areas both on the wintering grounds and in the arctic. That's not to say they're not Ross's Geese, I just believe that what a Ross's Goose is has changed. The other post reviews the literature I was able to pull off SORA regarding this.

I was somewhat lucky that I was delayed in being able to chase the Ross's Geese. Had I gone first thing in the morning I wouldn't have heard about these Cackling Geese in a holding pond in Sodus from another birder. There's another similarly sized group out of the frame. Note the vertical foreheads, stubby bills, and smaller size than the Canada Goose in the foreground. In life they were also slighly grayer than the Canada, but that doesn't come out that well in this distant backlit pic.

The other advantage of driving after these Cacklers was that a Mockingbird perched up in a fruit tree on the way back.

Finally a distant through-the-fence shot of 3 White-fronts at 3 Oaks.

"arbitrary standards"

that are now up to me! (insert evil mwa-ha-ha-ha laugh here).



With the turn of the year, Ross's Goose has completed its 3 year "probation period," maintaining regular occurance in the state and is now off the review list, transferring the headaches of what is and isn't a Ross's goose from the committee to the NAB and MBNH compilers.



Here's a review of my experiences with Ross's-type birds in Michigan.



First the "best" Ross's I've seen, a bird I found in Washtenaw in November of 2002 or so. It has a vertical bill base and the most blue wartiness to the bill of any I've encountered. It was accepted by a 6-1 vote.



Next are 3 birds from Paw Paw Lake in March of 2006. The first pic shows what I took to be the female of the pair, the smaller of the 2 adults. It has a little more black along the tomia, what I would term a vertical or irregularly vertical bill base and some blue to the bill base.

Next the slightly larger of the adults, I assume the male, whose bill is not quite as vertical.

The first winter/first spring bird (with a little duskiness to the lore and some duskiness in the wing not visible in this pic) does have a more convex outward bill base, though I believe this is more allowable in first year birds (though I haven't yet come by a couple papers that apparently discuss this based on their title)...

These birds were accepted 7-0, 7-0, and 6-1 (my assumption is that the 6-1 bird was the "male" though that's purely a guess - though if the assumption that this was a family group is correct then it's not possible for only one to have been a hybrid).

Now we move onto even shakier footing.

I submitted this bird from March of 09 as a Ross's. It went to a 2nd round of voting with the committee, based on the context from the meeting minutes (from July 09) probably entering with a 4-3 vote. The bill isn't quite as vertical as the first bird, though the bill is certainly much smaller than probably all but the first winter bird of the previous trio. The reported discussion of the bird by the committee ended with this gem of a statement: "All agreed that the distinction between hybrids and pure birds is a murky issue, with some birds hovering around what are certainly arbitrary standards for acceptance."

But, the committee's headaches didn't stop there, they continued with the flock Tim found from the same day:

Birds 6, 9, 10, 11, and 14 were apparently accepted on the first round of voting. The birds were really too distant to get solid pics and Tim and I never collated our pics to figure out which numbers some of the sub-group pics corresponded to. Ironically in the field I thought number 10 seemed a little bigger than the others, I thought all the others were within the limits of what most Ross's-types in Michigan look like. Apparently after the ensuing discussion (where some members were no longer sure they supported some of the original birds), the minutes reveal that the committee took a break.

Finally, here's a bird from Washtenaw that's a clear hybrid (there were 2 like this at a Galien farm pond in Berrien last spring) with an evenly convex outward bill base, though still with some blueness to the bill base.

What to make of all this? Some birds, such as the last one, are obvious hybrids and are indeed intermediate between Ross's and Lesser Snow Geese. In my last Ross's post I mentioned how one paper (Trauger et al) and Pyle present similar measurements for hybrids and yet come to different conclusions, Trauger feeling that F1 hybrids can very much overlap "pure" Ross's and Pyle leaving a person with the feeling that they're more intermediate.

Before we get to that I think it's instructive to review the more studied Lesser Snow Goose over the last century. At the beginning of the 1900's the bird we now call the "Lesser" Snow Goose (the "Greater" subspecies breeds even higher in the arctic and winters on the east coast) was thought to be 2 species, the Blue Goose and the Snow Goose. Blue Goose wintered on the Louisiana coast and bred on Baffin Island and eastern Hudson Bay whereas Snow Geese wintered on the Texas coast and bred along western Hudson Bay. There was apparently only a narrow range of overlap in the wintering range. However, during the period of 1910-1930, rice farming exploded in Louisiana miles inland from the former wintering areas and opened up a big new foraging area attracting both color morphs. The ensuing decades found that blue-type geese steadily appeared in the western breeding areas and snow-type geese started appearing in the east. Cooke et al, 1975, describes that in smaller breeding colonies this process was accelerated, as up to 50% of the birds were born in different colonies from where they bred. The birds pair-bond for life on the wintering grounds during their 2nd winter, with females usually returning to their natal areas to breed with their mate following. (The young birds making their first trip north apparently mill about the edges of the breeding colony as non-breeders). The bottom line is that in a relatively short period of time a fairly significant change occurred across the Lesser Snow Goose population. (For more reading see Cooke et al, 1988, though it's a lot denser).

What of Ross's goose in this period? Well, a pretty tremendous population explosion occurred. One online reference suggests that the Ross's Goose population went from 2500 birds to about 1,000,000 birds over the last 60 years (though I have no idea where that figure is pulled from). We know that different populations of Snow Geese have been moving about in the last several decades. The birds pair up on the wintering grounds and Ross's Geese families are observed to be less able to stay together in a cohesive unit in the wintering grounds than Snow Geese according to Jonsson and Afton 2008. Trauger et al 1971, describes how years with late thaws leave the arctic nest sites at a premium leading Snow Geese to usurp the nests of Ross's Geese. Rather than going to the trouble of destroying the Ross's eggs and then having to remove them to a remote location to avoid attracting predators, they simply add their eggs to the nest and if Ross's goslings hatch they imprint on the Snows! Weckstein et al, 2002 also describes some degree of shared mitochondrial DNA between Lesser Snow and Ross's Geese in Louisiana.

I think it would be an interesting study to go through hunters' bags in Arkansas/Louisiana, New Mexico, and California and see what would shake out in terms of measurements of the birds and how they would compare with the studies done 30 and 40 years ago. My guess is that "Ross's Goose" in the east is a different bird now than it was a hundred years ago. As to whether the appearance of these birds in the east will stabilize or just continue to degenerate over the next decades will be interesting to see.

References:

Cooke, F, CD MacInnes, and JP Previtt. Gene flow between breeding populations of Lesser Snow Geese. Auk 92: 493-510. 1975.

Cooke, F, DT Parkin, and RF Rockwell. Evidence of Former Allopatry of the Two Color PHases of Lesser Snow Geese (Chen caerulescens caerulescens). Auk 105: 467-479. 1988.

Jonsson JE and AD Afton. Lesser Snow Geese and Ross's Geese from mixed flocks during winter but differ in family maintenance and social status. Wilson Journal 120 (4): 725-731. 2008.

Trauger, DL, A Dzubin, and JP Ryder. White Geese Intermediate between Ross's and Lesser Snow Geese. Auk 88: 856-875. 1971.

Weckstein JD, AD Afton, RM Zink, and RT Alisauskas. Hybridization and population subdivision within and between Ross's Geese and Lesser Snow Geese: A Molecular Perspective. Condor 104(2): 432:436. 2002

more than chickadees on the CBC

Having your count area include Lake Michigan waterfront always makes for a more entertaining day.

The following is a photographic rendition of what the purple sandipiper that flew past us and landed for less than a minute each on Tiscornia Beach, and the North and South Pier, might have looked like if it had rested on say, an algae covered rock, instead of a concrete pier, and sat for an hour, instead of running around constantly, in nice morning light, rather than heavy overcast. Tim managed a few IDable frames with the SLR, but my digiscoping efforts were futile. The pic is from New Buffalo about 3 years ago.
Next is a Ross's type goose that was in the rivermouth. It would appear to be the same bird as Tim found at LMC about a week ago.

The bird's small size (check out the HEGU behind it), short bill, bluish bill base, and utter lack of a grin patch are apparent. The bird's entirely white plumage in winter (per Pyle II) indicate that the bird is an adult. Is it a Ross's goose though? If so, based on the Audubon Society homepage, it would be the fourth for a Michigan CBC in the last 50 years.

The bill is accepted as the best way to discriminate between Ross's, Snow, and hybrid geese. In the positive column, I think it has as little black on the bill as any Ross's-type I've ever seen in Michigan (admittedly the only place I've seen Ross's geese). On the other hand I've seen Michigan birds that have a lot more actual wartiness to the bill base, though this increases gradually as the birds age. Pyle II gives the culmen (upper bill edge) length of Ross's goose as 35-47mm (41mm on average). Olsen and Larsson give the bill length of Herring gull to be 44-62mm (53mm avg). When I take those measurements on the top photo, the goose's culmen is about 80% of the length of the Herring Gull's bill giving the goose's culmen an estimate of 35-50mm (~43mm), somewhat closer to the measurement Pyle gives for pure Ross's (41mm) than for hybrids (47mm). However, even if those rough measurements could be reliable, other sources (Roberson, 1993 and Trauger et al, 1971) indicate that F1 hybrids between Ross's and the smaller (Lesser) Snow Goose subspecies tend to be small birds, many of whose measurements overlap those of Ross's, and are outside the limits of most Lesser Snow Geese. The Trauger paper is an interesting one, accessible through SORA reporting measurements made on 24 "intermediate" white geese and comparing them with about 150 Ross's and about 130 Snow Geese. Culmen length, tarsus (leg) length, total body length, and flattened wing length in adults all overlapped significantly between (presumed) F1 hybrids and presumed pure Ross's geese and were outside the ranges of Lesser Snow Goose. He found weight to be more intermediate. Sibley describes hybrids as intermediate in size. Pyle's average culmen lengths for Ross's, Snow, and hybrid geese are generally within a millimeter of what Trauger came up with but calculated 95% confidence intervals where the culmen length of hybrids overlapped both Lesser Snow and Ross's.

Which brings us to the all-important, unmeasureable, and subject-to-position-and-angle bill interface. Pyle describes this as "malar feathering extending distally to the forehead feathers," in Snow and "malar feathering not extending distally to the forehead feathers in Ross's." Now we get to parse words Bill Clinton style and try to define "malar." Pyle claims to follow Sibley's definition of "malar" even though Sibley in one of the articles referenced by Pyle (Sibley, 2001) explains why Pyle doesn't follow Sibley's definition of "malar." Pyle defines "malar" as "pertaining to the feather group at the posterior end of the gape and extending back to the neck" whereas Sibley defines it as "originating at the base of the lower mandible below the gape and extending back along the sides of the lower jaw." If Pyle follows Sibley's definition then neither bird has malar feathers extending distally to the forehead, for a photo, here's one I posted in March of a bunch of Snows with a Ross's-type. The forehead feathers are more distal to the malar in every bird including the Snows. Pyle must mean the cheek feathering extends forward in Snow and not in Ross's. Here's where a picture is worth a thousand words. Unfortunately Sibley's picture of a hybrid is of a small-billed bird (admittedly with a much more prominent grinpatch than the absent one on this bird) with the upper base of the bill hooking back a little towards the eye, essentially what this bird's does. On the other hand, so do a decent number of the birds on Robert Royse's page photographed in New Mexico.

Interestingly, Trauger concluded in 1971 that intermediate birds comprised about 5% of the Ross's population and felt that it was possible that "pure" Ross's may in the future cease to exist as the population becomes swamped with Lesser Snow Goose genes. As an example, he reported data suggesting that Black Ducks were outnumbered by Mallards by about 6:1 in North America, whereas Ross's goose was outnumbered by about 27:1 making hybrid pairings even more likely. I'm not sure that these Arctic geese aren't any different from the Arctic gulls; who knows where Kumlien's stops and Thayers begins in many individuals, the same may be becoming true for these.

At least in a week they won't need to be reviewed in Michigan any more, right? Right? Hmmmm...

References

Sibley, DA. "What is the Malar?" Birding, 32: 448-451. Oct 2000.

Trauger DL, A Dzubin, and JP Ryder. "White Geese Intermediate between Ross's Geese and Lesser Snow Geese." Auk, 88: 856-875. Oct 1971