The Hudsonian Godwits of Churchill

After all of the posts about Churchill that I've written, I realized that I've written very little about the bird that has taken me here for the past two summers: the Hudsonian Godwit, Limosa haemastica. The Hudsonian Godwit is a mid to large sized shorebird, and is a well known long-distance migrant. The godwits' breeding distribution is still not entirely understood, but is known to be found in isolated pockets across the sub-arctic and arctic of Canada and Alaska. They typically breed in fens, bogs, and marshes with abundant sedge cover as well as a few trees (such as Larch, Larix laricina and spruces, Picea sp.) and shrubs (in Churchill, mostly Dwarf Birch, Betula glandulosa). Hudsonian Godwits are particularly famous for their long-distance migration, which takes the birds from Churchill first to staging grounds around James Bay. From there, many godwits make a direct flight from James Bay south to South America, perhaps stopping off for a day or two somewhere in the Amazon before finally making it to the southern coast of Argentina and Tierra del Fuego. Godwits that breed in Alaska winter mostly on the island of Chiloe. On the northward journey, godwits again make very long flights, some flying all the way from Argentina to Texas and Nebraska before stopping.

In Churchill, godwits typically return to the area sometime between May 20 and May 25, however there can be variation in this depending on local conditions. For example, the first godwits in 2009 did not show up until June 3, and even then were restricted to a limited number of locations due to snow conditions. In a typical year, after the birds arrive, males usually spend almost a week establishing territories and displaying. Its during this period when we start walking through the breeding grounds, looking for returning birds from previous years, and getting an idea of where territories are so we know where to look for nests.

Upon arrival, godwits will hang around, perhaps going to areas where they will later breed. In these pictures, a female Hudsonian Godwit is loafing around the Fen with a Short-billed Dowitcher

In addition to inspecting the breeding grounds, godwits also spend a lot of time feeding when they first arrive. Often they will feed in areas close to their future territories. This male, feeding in a roadside pool, later nested about 300 meters away in the marsh.

During the first week or so after arrival, male godwits spend a lot of time displaying and setting up territories. This male, banded 2 years ago is seen here displaying in the top of a tree. The display flight of godwits consist of a slow, "butterfly-like" flight over their territories, calling consistently "god-wit, god-wit, god-wit."

Beginning sometime during the first week of June, godwits will begin nesting. During the summer of 2008, the first nest was found June 5, while this year, the first nest was found June 8. In any particular year, most nesting is fairly synchronous, and within about a week, most birds that are nesting will be on eggs. Incubation of eggs does not begin full time until a full clutch (usually of 4) is laid, although males will incubate sporadically even when two eggs are laid. Males incubate for the entire day after the last egg is laid, while females feed. After that first day, males and females share incubation tasks, with females typically incubating during the day, and males incubating at night (although there is considerable variation in this schedule).

A Hudsonian Godwit nest with a full clutch of 4 eggs. While 4 eggs is the maximum clutch size, and also the most typical, complete clutches of 3, and occasionally 2 eggs are also laid. If a godwit renests after losing the eggs to a predator, the replacement clutch is more frequently smaller.

Female Hudsonian Godwit incubating eggs. Godwits are very reluctant to flush from their nest, which can make nests particularly difficult to find. Their cryptic coloration allows them to hide incredibly well among the sedges.

Female godwit sitting very tight on her nest.

After about 17 or so days of incubation, the eggs begin to get star cracks, which are the first signs of hatching. The appearance of star cracks usually indicate that the eggs are within 3 or 4 days of hatch. The day before hatch, the chicks begin to pip the eggs, making small holes in the wider end of the egg. Hatching of all the eggs occurs on the same day, although there can be several hours delay between the first and last chick hatching. Oftentimes, the first chicks to hatch will disperse from the nest site by the time the last chick hatches. During this entire period, both adults stay very close to the nest, and incubating birds sit very tight on the nest, and are very reluctant to flush from the nest. Since chicks leave the nest only a couple of hours after hatch, it is very important for us to get to the nest at hatch if we want to band all the chicks. Otherwise, it can be very, very difficult to find all of the chicks of a brood once they have dispersed.

A godwit nest that is getting very close to hatching. If you look closely, all the eggs have fine "star-cracks" around the wide end of the egg.

A detail of "star-cracks" on an egg.

A godwit chick in the final stages of hatching. This particular chick hatched right in front of us while we were banding his siblings, which had already hatched. It was quite incredible.

Recently hatched godwit chick, this bird is still not completely dry.

Hudsonian Godwit chick that is less than one day old. It's difficult to see, but this chick has a tiny radio transmitter on his back, which we use to track them as they grow. This allows us to determine what habitats they use to feed in, how far they wander, and also check survival.

When chicks are very young, the parent godwits are very aggressive. This pair was constantly attacking us and yelling at us while we were banding their newly hatched chicks. Notice the white flags on the legs of each of these birds, as well as a plastic color band beneath the flag. The orange color band on the male indicates that he was first banded in 2009, while the blue color band indicates this female was banded this year. Also note the brightness of this female, compared with the female pictured in the first 2 pictures of the post.

Male Hudsonian Godwit brooding his recently hatched chicks while we finish banding the last of the brood.

After hatch, chicks and adults wander very far from the original territory. Just three days after hatching, we tracked one family over 2 kilometers from the original nest site. Parents stay with the chicks until they can fly, which is about 24 days after hatching. Females may leave before the chicks are fledged, but males stay with the chicks. Parents will defend their chicks vigorously against predators, and will brood them for the first several days after hatching, but do not feed them.

A godwit chick that is about 2 weeks old. Notice the wing feathers which are in pin, and the back feathers which have come in on this bird.

A 3-week old godwit chick. Notice the wing feathers are growing in nicely, and have already started breaking out of their sheaths. This is likely the latest age that we can capture godwit chicks, since after this they run too fast.

A 3-week old godwit chick running away from us after we banded it. In another 5 days, this godwit chick will be able to fly. At 26 days after hatching, godwit chicks are able to fledge. It is at this point when the adults leave the chicks.

After fledging at about 26 days after hatch, godwit chicks are completely on their own. Adult birds leave the chicks once they have fledged. Adults will continue to the staging grounds around James Bay, and the chicks will remain around Churchill for a little while longer before continuing to James Bay. If all goes well, 2 years from now, we will see "EC" return to Churchill. Young birds will spend their first "summer" on the non-breeding grounds in South America.

To see pictures of Hudsonian Godwits on their winter grounds in South America, see my posts from Chile, where I was able to see and catch some godwits.

Sanderlings in Molt

This past August I spent a few days birding Long Island getting my shorebird fix for the year (yes, I am just now putting something together to post). One of the best reasons to visit the Long Island beaches is to see the big flocks of Sanderling playing in the waves.


When taking big flock shots of birds, I like to zoom in afterwards and look for things I missed. When I took a look at the big Sanderling flock, I noticed a large number of birds in primary molt. I thought it unusual for a migrating flock of shorebirds to be molting flight feathers on a staging ground. Upon review of The Shorebird Guide and the Sanderling Birds of North America account, it seems this is not unusual at all. Adult Sanderling should be undergoing a complete prebasic molt into non-breeding plumage, replacing all of their flight feathers in late summer and early fall. Since the staging areas along the Long Island coast are also wintering areas for at least some Sanderling, they are not necessarily even going anywhere. In contrast to the adults, juvenile birds undergoing molt into their first, incomplete, basic plumage retain their juvenile flight feathers and should not be showing this condition in August. So, this neat little factoid I noticed after the fact is actually a roundabout way of aging Sanderling. Fancy that.

Migration and the Great Lakes

Check out how birds largely avoid moving over the Great Lakes. It's most apparent in birds moving across the Niagara Peninsula between Erie and Ontario. It's not a problem of coverage, you can see weather moving across Superior and Michigan.

Migration and weather

The migration pattern on radar is a lot different tonight than several nights ago. Take a look at tonight's radar:

Tonight, migration is weak in the eastern US, except in front of the storm front in the northeast, where there are strong returns that we haven't seen much of yet this spring. There is decent movement up the Great Plains. Take a look at the wind map for the explanation - strong winds from the south carrying migrants up the plains, with strong northwest winds impeding birds behind the storm system in the northeast:

Compare these patterns with several nights ago, when there was strong movement across most of the country. Note generally weak winds in most areas where birds are moving, and strong south winds off the Gulf coast to get them started:

As another influence of weather on migration, I noticed a neat effect here in NY. There are strong migrant returns at the Binghamton, Syracuse, and Albany radar stations where the storms haven't reached yet, but as the rain approaches the birds drop off Binghamton and Albany's radar. Perhaps birding could be good there in the morning?

More migration

Here is an animated version (source) of tonight's migration, which is moving pretty heavily up the central states. For those who weren't sure what represented migration versus weather in the previous images I've posted, this animation should make it abundantly clear - watch the movement pop up in an east-to-west wave as night falls. For a primer on radar birding, see here.

Compare with tonights winds. Strong northward winds all along the golf coast, and weak winds up the central flyway - good movement conditions. (Source).


This is a fun way for me to "watch" birds while I'm up late writing essays for finals...

Crowded Skies Tonight

It's that time of year again - when migrating birds clutter radar screens across the country during night migration. Check out previous posts on the subject for review here. For good radar loops see Rutgers Weather Center.

Before nightfall

11:00PM Eastern Time - the wave reaches the Great Plains

Click to animate

Update: migration spreads farther west

Migration winds down in the morning - 5am Eastern time

8am Eastern time

Migration, Radar, and Stadium Birding

This past spring, I posted some animated .gifs showing songbird night migration erupting northward on radar. That season has returned, with a southbound trend. Here are some collection of links to help you get acquainted with radar birding (these were originally posted to cayugabirds-l by the very helpful Chris Tessaglia-Hymes, thank you Chris!):

Clemson University Radar Ornithology Lab
CUROL Introduction to Radar Ornithology

Christ T-H's page on recording flight calls over his house.

Migration liftoff from Montezuma NWR on Youtube.


Monday night (Sep 9th) was a particularly strong night for migration (click to animate):


Even better, the big bank lights at the Cornell football stadium were on. Conditions weren't perfect - there was little cloud cover and birds were flying by high up, but the call quickly went out on cayugabirds-l and on our cell phone network of friends - there was a heavy fallout at the stadium. In less than half an hour, a dozen birders had assembled in the bleachers of the stadium while the football team practiced on the field below. Tom Johnson reported our findings on cayugabirds-l later:

Last night's light south winds and high clouds still produced a large
flight of birds over Ithaca... I suppose it is just that time of year
when migrants are moving. The lights were on at Schoellkopf Stadium
for football practice, and so of course the birders swarmed the
bleachers from 9:30 PM until nearly 1 AM. We experienced a flight
mostly composed of Common Yellowthroats, Savannah Sparrows, and
Rose-breasted Grosbeaks. This year, perhaps more so than the flight
of 15-16 September 2006 (the last large flight), we saw quite a few
warblers in the trees at the edges of the stadium. Savannah Sparrows
again blanketed the turf of the football field, and an American Pipit
(perhaps the first of fall for the Cayuga Lake Basin) briefly joined
them.
We collectively recorded 42 species (same species count as the big
night last year, though overall numbers were much lower this time),
some counts of which I've estimated below. Some counts might be off,
but it is interesting to note that at the elevation of Cornell on the
hill, we get very few thrushes in September in contrast to
Rose-breasted Grosbeaks. However, several hundred feet higher out in
Dryden, Jay McGowan recorded a heavy flight of thrushes before heading
over to the stadium. Veeries have started to taper off for the fall,
and were almost nonexistent at the stadium. The highlights of the
flight were 2 Ruddy Turnstones, one of which flew low through the
lights and afforded visual identification in addition to plaintively
calling for several minutes. A distant Dickcissel was also worthy of
note. It seems clear that Dickcissel can be recorded overhead pretty
much any night with a decent flight in Ithaca - this was the 7th I've
heard from campus in the past two falls.

Cheers,
Tom

Location: Cornell--Schoellkopf Field
Observation date: 9/10/07

Green Heron 10
Killdeer 1
Solitary Sandpiper 2
Ruddy Turnstone 2
Common Nighthawk 1
Ruby-throated Hummingbird 1
Northern Flicker 1
Eastern Wood-Pewee 2
Eastern Phoebe 1
Gray-cheeked Thrush 15
Swainson's Thrush 60
Veery 2
American Robin 1
Gray Catbird 1
American Pipit 3
Tennessee Warbler 2
Nashville Warbler 2
Northern Parula 2
Yellow Warbler 6
Chestnut-sided Warbler 1
Magnolia Warbler 8
Black-throated Blue Warbler 8
Black-throated Green Warbler 4
Blackburnian Warbler 5
Pine Warbler 1
Palm Warbler 3
Bay-breasted Warbler 5
Blackpoll Warbler 5
American Redstart 5
Northern Waterthrush 4
Ovenbird 1
Common Yellowthroat 400
Wilson's Warbler 4
Canada Warbler 4
Scarlet Tanager 3
Savannah Sparrow 200
Lincoln's Sparrow 1
Rose-breasted Grosbeak 800
Indigo Bunting 10
Dickcissel 1
Bobolink 30

Empidonax sp. 1
Thrush/ Grosbeak sp. 75
Warbler/ Sparrow sp. 200

Almost all of the warblers were confirmed visually, as they fed in the trees near the stadium lights. It was an incredible experience - birds were flying all around above, just visible in the darkness above the lights. We were lucky enough that the lights remained on until nearly 1am, despite the football team finishing up practice before midnight.

It was the best stadium birding night I've yet experienced, but it pales in comparison to the 'big night' two years ago, when stadium birding as a phenomena was discovered by Cornell students. You can check out my classmate Mike Harvey's page on that infamous night of 17 warbler species in October (I missed it) here, and you can hear Ray Brown's Talkin Birds interview Mike about it here. There is even a publication out of it:

Lebbin, D. J., Harvey, M. G., Lenz, T. C., Andersen, M. J., & Ellis, J. M. 2007. Mixed-species flock of fall migrant birds foraging at night by artificial light. Wilson Journal of Ornithology 119:506-508.

This event is incredible to experience. If you have a stadium or other suitable bank of lights, get out there and start looking for night migrants - if you hit a fallout you will never forget the experience.

Here they come!

It really is the doldrums of summer (even if it's been unseasonably cool for a few days). Herping this past weekend in some prime habitat on the local hilltops, I heard maybe ten birds in two hours. When a single goldfinch flew over calling per-chick-o-ree, I started, because it made me realize how silent the woods were.

Don't let this news keep you down, however. The last straggling migrants passed through just a few weeks ago, yet here come the southbound shorebirds! From cayugabirds-l and geneseebirds-l:

Subject: Shorebirds in Region 5
Date: Tue, 24 Jul 2007 23:18:42 EDT

An increase in shorebird numbers and diversity is being noted in Region 5.

Tony Shrimpton and I made a late-day trip to Delta Lake. New (and more) birds from Sunday were noted.

1 STILT SANDPIPER
~5 SHORT-BILLED DOWITCHER
1 SANDERLING
1 WHITE-RUMPED SANDPIPER
lots of LEAST & a few SEMI-PALMATED SANDPIPER
plenty of LESSER YELLOWLEGS & 1-2 GREATER
1 WILSON'S SNIPE
2-3 SOLITARY SANDPIPER
a few PECTORAL SANDPIPER
lots of KILLDEER and a few SPOTTED SANDPIPER

1 GREAT EGRET
1 MERLIN
1 unidentified accipiter, packing a lunch, a peep I'm guessing
1 BALD EAGLE (adult)

The White-rump, looking like the same bird as Sunday, is early (7/22 date is possibly record-early based on what I've been able to find for Region 5). Somewhat better looks were had today and it does seem to be a White-rump.

Most of the birds are distant, but there's a ton of habitat for phalaropes and other goodies.

---David Wheeler

Bird Migration on radar

We've been socked pretty good these past few weeks by very cold temps, culminating in that nasty Nor'Easter at the beginning of this past week. Here in Ithaca it dumped nearly a foot of snow in the hills, although the valleys saw no accumulation. Now, several days later, the snow is all but gone again, the sun is shining, and the birds are itching to move.

It's been a very weird spring. We had excellent weather in March, with strong movements of waterfowl (which normally are the first group to migrate) through the Cayuga Lake Basin. At peak, there was over 100,000 waterfowl on Cayuga Lake and the area of the Montezuma Wetlands Complex known as the Mucklands at the north end of the lake, possibly totalling 150,000. The numbers were staggering. There was also a decent push of early hawks through the region, and some of the early migrants (Phoebe, blackbirds, etc.) arrived. Then the cold hit, and very little new birds trickled in. Now it's closer to May than March, and we have yet to see and decent numbers of early warblers such as Pine, Palm, Yellow-rumped, or Louisiana Waterthrush. That's going to change shortly.

Here's a few images pulled from regional radars tonight on www.wunderground.com. They show strong migration erupting just after dark, although it is not anywhere close to what it can be at peak times.

This one is the coolest... swarms of birds moving in over the Gulf. I did check the current conditions in Houston - this isn't rain.



To give you the idea of directionality, I downloaded the animated gif from wunderground. Click to animate:



And now, the best one, from the Rutgers Weather Center. You can clearly see birds rising to the air across the nation, in a sweep from east to west as night progresses (click to animate):