Ross's Goose...or ?

Ross's Goose has been considered for a long time as one of the rarest species of breeding goose in North America. The first evidence of this species breeding in Ontario was in 1975, when two of my former MNR and now retired colleagues (Paul Prevett and Fred Johnson) observed flightless young at Cape Henrietta Maria along Hudson Bay while they were working out of Moosonee. The population has continued to expand. During the second Ontario Breeding Bird Atlas, it was recorded with breeding evidence in 6 atlas squares.

While it is still a rarity, it has been seen much more regularly in the last couple of decades than before. One just has to look at the number of reports in Ontario on eBird, Ontbirds or other rare bird reporting sites to see just how much more frequently it occurs. Of course part of that is due to many more birders being out in the field and with higher quality optical equipment than several decades ago.

Ross's Goose nests in Snow Goose colonies, and as the latter species has expanded considerably in Ontario over the last few decades, it isn't all that surprising that Ross's Goose has expanded as well.

Nesting 'blue' phase Snow Goose, from scan of 1990 slide taken in Polar Bear Prov Park

Waterfowl are known to hybridize with regularity when the opportunity arises. Hybridization between Snow Goose and Ross's Goose may occur relatively frequently since they nest in the same colonies. With Ross's Goose looking like a smaller version of Snow Goose, it is possible that the two species think that as well, which facilitates hybridization. And that presents a problem for birders who want a clear cut species in order to put that check mark on their lists.

Recently two small white geese have been present at the Keith McLean Conservation Area, just outside of Rondeau Provincial Park. The high water levels and greater snow melt than usual allowed a fairly large but shallow pond to form at the south end of the CA, much of which was easily viewable from the adjacent road. There has been a typical mix of waterbirds present which vary from day to day, including Canada Geese (of course!), Northern Shoveler, Northern Pintail, American Wigeon, Gadwall, Mallard, Green-winged Teal, and others.

This next photo shows one of the birds observed by several folks. The photo was taken with a lens magnification of about 14X, so it is magnified a little higher than the average 8 or 10 power binocular view would provide. At first it looks good for a Ross's, being a small goose (that is a Ring-billed Gull out-of-focus in the foreground), with a round head, no obvious grin patch, a bluish area to the base of the bill and a fairly straight feather line at the base of the bill. Ross' Goose...check.

A few other shots, including the two of the birds.

Being chased by a probable Herring Gull

Next is a bit closer look, zoomed in. But with this closer view, questions start to arise. The bill looks a bit longer than a pure Ross's Goose, which normally has a short, stubby bill. And there is a hint of a grin patch, which Ross's should not have.

Zooming in even closer, the bill clearly does not look good for a pure Ross's Goose. If birders had viewed the birds with a 'scope and not just binoculars, they might have had the same questions come to mind.

After careful consideration, I changed my initial conclusion of Ross's Goose on eBird to a hybrid between Ross's and Snow Goose. I'm not sure how many others who checked off Ross's Goose will do the same, but the fact is that neither bird is a pure Ross's and to be accurate, should be recorded as a hybrid.

A few years ago I had taken photos of what I was initially convinced was a Ross's Goose out near St. Clair NWA and posted it as such along with a photo. I was contacted by a waterfowl biologist who had considerable experience with Ross's and Snow geese, among others, and he pointed out some of the less obvious characteristics that indicated the bird in question definitely had a mix of both species. Since that time, I have tried to be more careful when indicating on my lists which species I am reporting, as in many cases, the bird(s) show hybridization.

Does it really matter? It is apparent that this bird is 'mostly' Ross's....not 100% but still a beautiful bird. Nonetheless many checklists on eBird will likely remain as Ross's, and therefore muddying the true picture of Ross's vs hybrid.

With this in mind, it is likely that many Ross's Geese reported on eBird and other reporting sites are actually hybrids.

One of the rarest plants in Canada

Walpole Island First Nation is a fabulous place, full of rare, threatened and endangered species of flora and fauna. Of course to host all of these rarities, there is an abundance of significant habitats as well. Walpole is renowned for its tallgrass prairie, and I have had the privilege of spending a lot of time exploring the wonderful natural areas there over the years, dating back to about the mid 1970s.

One plant I am always excited to see is one of Canada's rarest: the White Prairie Gentian (Gentiana alba). It is a striking yellowish/white flower with fine green markings along the fluted edges. It will partially open, so as to allow pollinators access. This species, at least on Walpole, is in some of the best quality tallgrass prairie/oak savanna habitats.

White Prairie Gentian

It occurs in three known places on Walpole, all of them which are somewhat out-of-the-way. It is interesting to note that even historically it was only known from two other locations in Canada: Northumberland County and Essex County. Those two sites are considered historic, not having been seen for several decades, in spite of searches at known historical locations.

A recent survey of the populations at Walpole totalled 50 plants, with about 40 of them having flowers. That is it...... the entire known Canadian population is just 50 plants, and some years there are even fewer recorded. It is legislated as an Endangered species both provincially and federally, not surprisingly. The localized spots where it occurs are reasonably well protected, although the original population, first found in 1984, is quite shaded and the single surviving plant has not been seen in flower for several years.

At one point during the survey, I only had my point-and-shoot camera, and I got a few shots including this next one. It was the freshest looking of all of the ones we encountered. Most others had at least a bit of brown showing on the petals.

What makes this species toehold in Canada even more precarious is the fact that it sometimes hybridizes with the much more common Bottle or Closed Gentian (Gentiana andrewsii). As its name indicates, it remains closed, and the only way for pollinators to pollinate it is to be a rather robust insect, such as a medium to large bee, having the capability to force its way through the side of the petal.

Bottle Gentian

Clearly the two species are quite different looking, at least in colour, and those hybrids make for some unusual colour combinations.

Gentiana alba X andrewsii

 Some hybrids are mostly closed, with others being at least partly open.

White Prairie Gentian typically flowers in late August, whereas Bottle Gentian typically flowers after mid-September. Of course there are sometimes early or late ones of either species, and if the flowering period overlaps where they both occur, hybrids are more likely.

Ross's Goose, not a hybrid

Today I was at Rondeau hoping to locate the Summer Tanager that had been seen the previous couple of days. Check out Blake Mann's blog if you haven't already seen it.

I couldn't make it to Rondeau yesterday, so today was the day, I was hoping....But in spite of several hours of searching both where it had been seen the last two days as well as just as likely spots elsewhere along the cottage community, I was not able to find it. It may still be there, or the relatively clear night last night and the colder temperatures may have been enough impetus for the lingering bird to decide enough was enough, and it was time to leave.

Giving up on the tanager, I stopped to check the lake front area at the traffic circle at the north end of the park to see what was in the relatively sheltered waterfront. I immediately noticed two small white geese mixed in with several hundred Canada Geese that have been occupying this part of the park which is off limits to hunters. I first thought 'Snow Goose' but then quickly realized that the combination of the short stubby bill, the bluish-purple base of the bill, the lack of a grin patch and the fairly straight, not sloping, feathers from the top of the bill to the bottom, all signalled Ross's Goose!

Note first the size comparison with one of the typical Canada Geese.

Next note the other features of the base of the bill as described above.

It looks pretty convincing to me. But Ross's Geese are known to hybridize with Snow Geese, and if they do, the characteristics aren't so clear. Note these next two images of the small mostly white goose which was associating with Tundra Swans. I took these photos last year near St. Clair National Wildlife Area, fairly late in the day, so the images aren't quite as sharp as the ones I took today.

The bird in question is small, no doubt about that. But the beak is not as short and stubby as the ones I saw today. It does lack the grin patch, and it has a fairly straight slope to the base of the bill. The bluish-purple area at the base of the bill isn't very obvious. So some goose biologists familiar with northern geese advised me that this bird probably has some Snow Goose genes in its makeup, and would more likely be considered a hybrid. Interestingly another goose biologist suggested that it was a good example of a Ross's Goose, and yet another excellent birder indicated it was more likely a good example of a Snow Goose! So even the experts gave different opinions. Admittedly to be completely fair, it is hard to be definitive when only seeing a single photo, not watching the bird from different angles and picking up subtle nuances of the way it appears in real life. And when a bird shows some characteristics of a species or a hybrid, but not all, it adds to the challenge.

So I learned from the experience of last year, and I consider myself a bit more careful in calling out 'Ross's Goose' when I see something that appears to be one. And in that vein, I am fairly confident that the birds of today are good examples of pure Ross's Goose.

What kind of bird is this.....are you sure?

I've been a little behind in posting this. It all started about a week ago, when I posted some shots of swans and geese taken in the fields of the former Dover Township, between Chatham and Lake St. Clair. A couple of shots showed what I determined to be a juvenile Ross's Goose. The photos weren't definitive, but in combination with what I saw in addition to the photos, I was convinced (and still am) that it was a Ross's Goose.

A former MNR colleague who specializes in, amongst other things, northern geese and swans, sent me a message making some comments on it. I wanted to get some additional photos to be more definitive, and indicated that I would be going out again to see what I could find.

This past Wednesday, December 3, I returned to the scene. However things had changed in the several days between visits. Once the corn fields were harvested, farmers set about to plow or disc them. So instead of the 15 or so fields I had seen on Nov 28 with swans and sometimes other assorted waterfowl. the choices were limited. I only saw 3 fields with swans, although one was in fine condition and had upwards of 1000 birds. This was right along Belle Rose Line, a bit east of St. Clair NWA.

I looked and looked over the swans, but did not see any small white goose.

It was quite windy, and small flocks of swans were arriving steadily while I watched.

But after awhile, I decided to see if there were other fields harbouring my target small white goose. So I moved on.

As mentioned, there were only a couple of other fields with swans, and even then only a few, so I didn't have any greater success at those fields.

But I did notice other white birds.....Snowy Owls.

One field alone had three Snowies, with yet a fourth only a few hundred metres away across the small creek. Yet another field well away from this concentration had another individual. All were sitting tight close to the ground. Perhaps the very windy conditions caused them to sit low and tight, and I likely missed others.

None of them were as close as I wanted them to be....they never are! While I was watching one individual, it got up and flew a short distance farther into the corn stubble, heading into the sun. I got a record shot, but the light was poor as was the angle of shooting from the car.

Eventually, I decided to meander on back to the main field of swans. The days are just too short! And there were even more birds arriving. Usually at the end of the day, swans that have been feeding in the fields return to the lake to spend the night. But presumably the 40-60 km/hour winds were keeping the lake surface a bit riled up, and so the swans were heading inland for the night.

I watched and watched, and was about to pack up and head for home. The sun had already set, as one can see from the slightly rosy hue on the swans in the previous photo.

And then a small group of swans arrived, with a small white goose with black wing tips out in front!

This is a fairly heavily cropped photo, and again, one can see the pink in the sky indicating the lateness of the afternoon. The fading light made it more challenging to get the photo I was hoping for. To keep the shutter speed to an acceptable level of 1/640 sec, I had to shoot wide open at about f/4 and with an ISO of either 800 or 1600, certainly higher than I normally like on this particular camera body (7D). But at least they landed more or less in front of me, so I got some more distant shots which I could, and did, crop.

Clearly this was a different bird than the juvenile bird I had seen the previous week. This clean white bird is obviously an adult. It is small enough for a Ross's Goose. There is no 'grinning' patch on the bill, although it may not be really obvious from these two photos. The bluish base of the bill also fits Ross's Goose. The only thing that doesn't fit well for Ross's is the longer beak and more sloped forehead than one would expect. It isn't always easy to get all the salient features well represented in a photo. Ideally one needs to study the bird from different angles, especially when the characteristics don't fit nicely.

I sent three of the photos to a former MNR colleague, who has a Ph. D involving waterfowl, especially geese, of the far north. He in turn sent it to another former MNR colleague, who is an excellent field biologist and birder. He also sent it to another Ph. D. researcher with the American Museum of Natural History, who specializes in Snow Geese of the northern latitudes. I also sent it to another former MNR colleague who did his Ph. D. in researching geese both in the northern latitudes and also on their wintering ground. Two of the aforementioned individuals spent many years as the waterfowl biologist with Moosonee District. So clearly all of these gentlemen had a lot of first hand experience with this species and any other goose species of the northern latitudes.

It took a couple of days to get the responses, hence this post is a little later arriving on my blog than I would normally plan.

Their responses were interesting. They ranged from:
-clearly a hybrid between Ross's Goose and Lesser Snow Goose
-definitely a Ross's Goose
-strongly would consider it being a Lesser Snow Goose

In the face of the varied opinions of these experts, and they are very much experts, it pointed out something that I've known for quite some time: viewing one or two photos, if they don't illustrate all the important and therefore clinching features, makes it difficult to be 100% certain of a bird's identity. One needs to study a bird first hand to really get a true feeling of how a bird behaves and how it looks from various angles.

So what do I conclude?

Being the only person to have seen this bird in real life and under better conditions that the two photos show, I do feel that it shows a lot of Ross's Goose characteristics: the very small size (less than half the size of a swan), the lack of a grinning patch and the bluish base to the bill all nicely fit Ross's Goose (I saw several white Snow Geese just yesterday at Ridgetown Sewage Lagoon, and they were definitely larger and the grinning patch was evident even from a distance). However, and herein lies the difficulty in declaring it a pure Ross's Goose, this bird also shows some characteristics that don't fit, primarily the longer bill and more sloped forehead. A 'good' Ross's Goose has a stubbier bill, and a more abrupt forehead, not a sloping one.

Therefore, this bird is almost guaranteed to have some Snow Goose genes in its heritage, but there is no way of telling how many generations one has to go back to determine when that happened. And it is possible that those genes came into the mix on more than one occasion. Snow Geese and Ross's Geese are known to hybridize, so overall it isn't surprising that this bird shows some traits of both.

So there you have it....I think one can safely say this bird is a hybrid.