Cackling and Barnacle Geese and hybrids (Feb 23rd)

Despite rainy conditions I decided to go goose-watching in Jamesburg at Thompson park just south of town.  I located a few large Canada Goose flocks and was digging the scope out of the car when a local birder drove up and point me in the direction of a Barnacle Goose at the far end of the field.  I'd seen a report of a Barnacle and three hybrids in the NJ RBA and so it turned out: what he couldn't pick out in his binoculars but was clearer in the scope was that the Barnacle Goose was accompanied by three Barnacle X Canada/Cackling Geese hybrids, which looked rather Cackling-like in stature, but were grayer on the back and flanks and with Brant-like dark breasts.  A small amount of white above the eye that was separated from the white cheek also indicated mixed parentage.  I snapped a couple of bad pictures in bad light and heavy drizzle.

On the way out of the field my eye caught something a couple of 'scope scans had not: a Cackling Goose in one of the Canada flocks.  This one had the square head and even a little white collar at the bottom of the black neck sock.

Barnacle x Canada hybrids are center and right in this photograph and the parental influence is most clearly shown in this photo with the feather coloration and the extra white in the face.  More pictures on Flickr.  Upon reflection the goose at left is a likely Cackling Goose but the head profile is not "classical" Richardson's - it's approaching that of Lesser Canada - but there's a fair amount of gray in the feathers, suggesting Cackling.

Cackling Geese in NJ

A slower start to Jan 2nd had me in search of yet more winter special birds to pad the year list. I picked up Common Merganser at Mercer County Park at the marina but not much else was there. Then I wandered north to Negri-Nepote Grasslands and saw almost nothing there except a large extended flock of American Robins headed south - several hundred of them spread over many miles in loose association.

Then it was time for geese, albeit via an unsuccessful search for Sandhill Cranes in Franklin Twp (they're there, but often elusive). At Dukes Island Park in Bridgewater the large flock of Canadas at the pond and adjacent field held a lot of Cackling - I was scanning for the Greater White-fronted but kept coming up with Cacking: first one, then two, then a group of 6, then 4 more etc. I figured out I had at least 12 and perhaps 15 or more. A total of 33 was reported from that site during the day, and they were pretty much every where I looked. Finally the Greater White-fronted was found.

2pm now, and there was just enough light to sprint for the final special bird of the day: Snowy Owl in western NJ that I found in it's usual roosting place on the dam as the light started to fade. Combined with a few fly-by Snow Geese at an otherwise quiet reservoir this propelled the 2012 year list to 46 in the first two days. Not a bad total.

Cackling Geese

I found singles of Cackling Geese at North Branch Park and Dukes Island Park in Raritan on Sunday morning amongst flocks of Canada Geese, as had previously been reported. I didn't find the Greater White-fronted Goose at Dukes Island (I was there before it was reported) but there were enough Canada Geese milling around in the air that it might have flown in after I left.

En route home for this short birding day I stopped at the Stony Brook-Millstone Watershed property off Titusville Road to check out the pond trail. The pond itself held four Mute Swans, several Canada Geese and a few Mallards. The area around the pond looked promising for sparrows but held only a few White-throated Sparrows - their numbers have been low this winter and it would not surprise me if they have stayed further north courtesy of good food crops and mild temperatures this November. Once the snow comes perhaps they will drift south.

The Cackling Goose quandary

Cackling Geese are somewhat sought-after in these parts, being relatively rare and a very small proportion of the often massive Canada Goose flocks that dominate inland ponds and lakes. There are big wintering flocks around the Princeton-ish NJ area. This is rather different from e.g. the Katy Prairie area of TX where Canada/Cackling are in the distinct minority amongst other geese.

On Thanksgiving morning I headed out to Etra Lake, south-east of Hightstown in search of both Greater White-fronted and Cackling Geese, and found one of the latter but no GWF.

Picking out Cackling from Canada requires a certain comfort with the variation within Canada, which can be quite considerable within a flock. In particular the cheek patch and breast color are rather variable. Cackling is sometimes hyped as being a grayer-frostier colored bird, especially on the back, but there's quite a range of variation just within Canada. When I finally found the Cackling - identified by square head structure, bill size and small size - it was a similar color as a Canada next to it and well within the range of color variation of the flock. In fact I had one bird pegged as a Cackling by color until it raised its head and proved me obviously wrong.

In this mix there's also the big question of Lesser Canada Goose, which shares many of the attributes of Richardson's Cackling Goose and the separation of which is a potential nightmare. At the moment I'm (mostly) sweeping that under the rug but there have been some "Cackling" Geese that have certainly got me to wondering, in particular last winter's Rahway River Park birds.

A recent post by Sibley on Cackling vs Canada goose bill structure is pertinent here. The whole ID morass is still being worked out. While that effort is ongoing I rather suspect that Cackling Goose in eastern NY and NJ is really a bit bucket for all sorts of small outlier White-cheeked Geese. Which is why I still seek out reliable locations to study them further.

Jan 2nd - Mercer County Parks

To start the year out, I decided to head to Florence NJ to view the gulls in the river that accumulate there when the dump was in operation. Of course, on Friday the dump wasn't operating at all and there were very few birds to be seen, only the three species of gulls, and in the light snow not a great deal else.

While contemplating this debacle I decided to visit Mercer County Park in Lawrenceville/Hamilton to see if I could at least find a Common Merganser. I did, almost immediately, and there were a few small flocks flying around. Most of the lake was frozen but at the marina a decent size Canada Goose flock had accumulated. In the midst of it I found a Cackling Goose - classical in petite structure with a paler and pale-fringed mantle. Then while looking for more of them I came across a Greater White-fronted Goose in the same flock. After I returned with my scope I couldn't find the GWF but finally tracked it down after the flock decided to leave the lake and feed on the ball fields behind the ranger station near the marina. Two nice geese and not a bad consolation for Florence.

Near home I decided to check out the other version: Mercer County Park North West i.e. Pole Farm. The snow had stopped and the weather was starting to clear as I made it to the park. Almost immediately I saw a pale phase Rough-legged Hawk - rather unexpected - and then a few Northern Harriers (including two males) and an American Kestrel. A rather nice mix of raptors, padded by one of the local Red-tailed Hawks. After sprinting home to get the camera to see if I could get photos of the Rough-legged I returned just to watch the pale phase decided it had had enough action for one day and perch on the far side of the field. The icing on the cake was a dark phase Rough-legged that flew over the park toward dusk, ultimately ending up roosting on the far side of the other field I was monitoring.

I waited around until dusk and after the sun went down the final bird of the day was a single Short-eared Owl. Not as prolific as last year in terms of owls, Pole Farm still has some nice birds hunting the grassland this winter.

Interesting invasion patterns related to food supplies in northern wintering areas: last year was a Short-eared Owl invasion year, at least at Pole Farm but also in general; this year the numbers are low but in turn Snowy Owls and Rough-legged Hawks are having some of the best invasion numbers in years. I'm always conflicted about this - I love these birds but invasion years always correspond to years in which food supplies crash and the birds are starving. Many will not make it to return to breeding grounds.