Spring passerines

I did really well from a numbers standpoint this May, tallying every warbler, vireo, and flycatcher that could reasonably be expected.  I took a lot fewer photographs though, but I'll put a few here.

And what says May migration like pics of flycatchers???

Eastern Wood-pewee actually was one of the more cooperative birds this spring.

I saw Yellow-bellied Flycatcher a few times.  While lighting matters for a lot of birds, it really matters for this one...

above in dull early morning overcast, and below in bright mid morning sun...

This (silent) one is probably a Willow.

Ok, ok, a couple warblers.  It is May after all!

Solitary Birdathon

Last week in lieu of the Covid cancelled Team Birdathon many of us did individual big days on the day Birdathon would have been held, a Solitary Birdathon.  It felt really weird to see 2 of the 3 people who would have been on the team all take up separate positions at daybreak fifty yards apart.  Big days always dawn with a ton of promise (well the ones that aren't already hamstrung by wind and rain), but I really missed sharing that excitement.  I didn't stay long at the beach.

Ironically a Solitary Sandpiper, the day's emblem, was in the first 20 or so birds of the day; I'm not sure the sun was quite up when this was taken.

With many of the southern warblers not really singing in the bare canopy at the time I didn't have to worry about being the last to hear Yellow-throated Warbler as I seem to usually be; there wasn't one to be heard at all!  I did manage to see a silent one, but Cerulean eluded me (as did a bunch of canopy birds like Acadian Flycatcher).  There were birds about though, I don't usually take a ton of pics on big days, but anything in a flowering red bud is fair game.

This was a really good spring for Gray-cheeked Thrush, to the point that I started photographing them just to prove to myself that I was ID-ing them correctly.

I pressed pretty hard in the morning.  There were a lot of downsides to lacking teammates, I was on my own to find and keep track of everything, but I tried to capitalize on what small advantages I could find.  Windows were rolled down a lot more than usual since I didn't have to worry about creating a wind tunnel for others.  I literally ran in and out of Pine and Worm-eating territories to score those birds while it was still cool and still hit Floral by 9am.

I didn't find a ton of birds at Floral, though White-eyed Vireo was still singing away.

I left after one loop and went up and birded Grand Mere and environs, finding more early warblers before returning to the hawkwatch dune.  It was a SE wind and I did manage Broad-winged, as well as my only hummingbird of the day.  A Summer Tanager pitty-tucked and then teed up for a distant phone-scope.

The afternoon of Birdathon can be a bit of a slog as a person circles back around the county.  The camera turned into a scope for a Lesser Scaup at Brown, a more appropriate use of the camera on a big day.

It was certainly a more relaxed day (I also had the most sleep before Birdathon that I've had in a few years with Covid cancelling the Friday work thing I've had to travel to the day before the last 3 years).  Without teammates there was no stress over getting on a bird others had found, or getting them on a bird in turn.  There was no worry about being the last to hear all the high-pitched songs.  And the competition were all my friends, so the urge to not lose was a lot less than usual. 

I ended with 142 birds, but I bet with a team that would have been high 150's.

Mute Pelicans

Had a very nice walk around Floral, hearing tons of warblers, and seeing good numbers as well.  Philadelphia Vireo and Olive-sided Flycatcher were the rarest migrants I found.  After a few hours, a conference call, and a walk in the nature area I was feeling ready to go home, but the overcast had kept it cool and I knew I had to check a few more places.  I decided on North Bay Park given it's a place I've had Clay-colored Sparrow before, and who knows, maybe a Yellow-crowned Night-heron might be teed up.  I didn't find a Clay-colored, and didn't see any herons as I scanned the treelines.

After walking down the little nature trail I headed back for the car and noticed two big white birds out in the middle of the lake.  The ducks migrated away weeks ago, what were the odds they were anything other than Mute Swans.  I'm glad I put bins on them...

Pelicans!  My first self-found ones in the county.

After sending a couple texts I started typing a listserv post, leading with the word "Currently..."

My heart sank as I noticed some motion and saw the birds had taken flight.

They circled a few times, once going right past me...

And disappeared.  (Check out that bill shield!)

Fortunately they returned (though landed farther away) about 10 minutes later.

migration at last

It's been SUPER slow in the midwest this spring; the birds are about a week late, if not more.  We'll see how much catch-up happens in the next couple of days.

The warblers are still dominated by early ones, Yellow-rumps and Palms are still common, with other early ones like Black-throated Green prominent sounds.  I haven't heard a Tennessee yet; usually they'd be dominating the sounds by now.  Black-and-White has also been pretty common at Floral.

 As have Nashvilles...

White-eyed Vireo isn't on territory every year in Berrien, and some years they're hard to find as overshoots.  I didn't get one at all last year.  This bird has been hanging out at Floral for about a week.

It basically has a new song each day.

But the middle of the migration may FINALLY be starting.  Here's the flagship May bird

With the canopy still minimally leafed out the upper level birds aren't recognizing their territories.  The downside is that they're silent.  The upside is that when you do find one, it might be quite low.

Hoatzins!!!

Ok this bird is cool.  And with travel restrictions making the planet feel bigger as international ares become inaccessible it feels a little bit surreal that I've recently seen them.  They're really like nothing else, enough that I was motivated to pull up some papers on SORA to learn more.

It turns out that they're giant cuckoos.  They're bizarre enough though that they were originally put in the cracid family (turkeys/guans/etc), then moved to rails (!), before egg white protein studies carried out by the elder Sibley showed them to be cuckoos.  Sibley speculated that their foot structure (3 toes forward, 1 back) probably played a big role in their original assignments (cuckoos typically have 2 forward and 2 back).

They eat leaves.  Lots of leaves.  And take a completely different approach than any other bird.  Geese eat grass, and the grass, well, passes through the goose in proverbial fashion.  Since there isn't a ton of nutrition in leaves geese pass them through the digestive track quickly to get what they can, move it along, and eat more, ignoring the energy that is stored in the hard-to-break-down plant cell walls. 

Hoatzins take the opposite approach and ferment the leaves in a crop that's so big that it takes the place of some of the breastbone and pectoral muscles, leaving the hoatzin a very weak flier.  The crop is big enough that it makes the bird front heavy when full and the birds develop calluses on the skin atop the base of their breastbone from leaning against branches.  And that process takes time.  Some grad students (not sure how you'd pitch this study to someone ... hey!  want to join our lab?  We do Hoatzin Poop Studies!) fed captive hoatzins some undigestable tiny plastic pellets in their feed ... and then counted how long it took the pellets to end up on the floor of the cage.  It took 4-5 days to pass them all (maybe we have a replacement for watching paint dry?), a rate that's much more analogous to some of the herbivorous cud-chewing mammals than to a bird.

A likely offshoot of trying to raise young on a diet of fermented leaves is that hoatzins often will have helpers at their nest since the younger adults may not be able to produce enough leaf malt on their own to raise young and may help their parents in raising the next year's brood.  Young at nests with helpers grew faster and fledged at higher rates than those without

and this doesn't even touch on the babies having wing claws that are useful to clamber about the foliage when young (I forgot to ask Fito or Jason when the young Hoatzins are about).  I guess I'll just have to go back...

References
Grahal et al.  Structure and Function of the Digestive Tract of the Hoatzin:  a Folivorous Bird with Foregut Fermentation.  Auk 112(1): 20-28. 1995.

Grahal et al.  Passage Rate of Digestive Markers in the Gut of the Hoatzin, a Folivorous Bird with Foregut Fermentation.  Condor 94(3): 675-83. 1995.

Sibley and Ahlquist.  The Relationships of the Hoatzin.  Auk 90(1): 1-13. 1973.

Vanderwelf et al.  Effects of Unit Size and Territory Defense on Communal Nest Care in the Hoatzin.  Auk 107(3): 626-28.  1990.

On to Sani

After 3 or 4 days at Shiripuno we moved one river north and arrived at Sani Lodge.  After working our way down the Napo our guides canoed us down backwater channels that I don't think actually connected to the river.

And there were birds, Great Potoo (again!), and a little flock we couldn't really catch up to, though an Olivaceous Woodcreeper bailed out somewhat dramatically.

 Lineated Woodpecker put on a show

Jason recognized the call of an Orange-crowned Manakin.  I cautioned the group that it wouldn't look like a manakin ... and then still didn't believe when the bird popped out that it was one until it flashed the crown a couple times.

Shortly after this pic was taken Guillermo (paddling in the front of the kayak in the top pic) attempted to re-position the canoe while standing ... and tipped himself right out of the boat!  The other guides and lodge personnel were giving him grief for the rest of the trip.

These White-winged Swallows paid no attention though.

This was another place where I should have taken more scenery pics...

Crane Hawk!

Our final morning at Shiripuno was spent ... leaving Shiripuno.  It was a 3-4 hour boat trip back upstream (and given we had about that in trucks and then about that in a boat down the next river to the next spot) we left before the sun was up.  It was a little unnerving to be going upstream basically in the dark, but the sun rose quickly.

I really should have taken more scenery shots on this trip.

The early morning light was perfect for getting a decent exposure for a black and white bird like the Wattled Piping-guans. 

I saw a perched hawk and was having trouble shoe-horning it into something I knew.  Fortunately it flew behind some trees before appearing directly overhead.

Crane Hawk is a bird that's been theoretically possible on most trips I've taken that reached lowlands in the tropics (heck there's at least one record for S Texas), and the contrasting white underwing comma is pretty unique (though I was once fooled by a Yellow-headed Caracara), so it's a bird that's been on the wish list so long that they kind of felt like a myth.  But the myth appeared overhead (and a second one did about 20 minutes later as it turned out) so I was pretty happy.

Blue-and-yellow Macaw also generally makes me pretty happy.

We had more flyover Red-bellied's as well.

Sunbittern on the other hand I've had a lot better luck with.  This is my 3rd country with a sunbittern (though I'm still missing Sungrebe everywhere).

A pic of a Squirrel Monkey

Finally the last lifer of the boat trip, Greater Yellow-headed Vulture.  I've got a bunch of pics that are almost pretty good, but all have some combo of a wingtip cut off, or the eye shadowed, or a weird angle, but ah well.

The orange head was a really neat contrast to the TV's we're used to.