Sunday, January 20, 2013

Fenner Nature Center's Townsend's Solitaire: continuing since January 15


For the past several days, I have spent a cumulative total of at least four hours at Fenner Nature Center watching the now-famous Townsend's Solitaire and helping visiting birders view it.  I have already done one blog post about this bird, but that was only a brief description of the bird.  This post is the information and observations that I have collected over several hours of observation and through reading others' accounts of their visits.
   
TOSO_small 


This record is extremely remarkable because as you can see from this animated map of eBird sightings, usually when a Townsend's Solitaire--or any vagrant bird from the west--shows up as a vagrant to Southern Michigan, the first land it sees as it completes its crossing of Lake Michigan is, well, the shore of Lake Michigan, and the first land a vagrant sees is typically where it lands.  Fenner Nature Center, though, is pretty much as far inland in Michigan as it can get. 

The Bird spends a lot of time within a small area of the prairie, but also wanders into adjacent Mount Hope Cemetery--presumably to eat juniper berries--and very infrequently near the central pond.  Within the prairie, it spends most of the time feeding at the western edge of the field pond, or resting--often with a flock of four or more bluebirds--in the apple trees, brush pile, and other small trees and shrubs in the northwestern edge of the prairie. It has also been found several times in the chestnut trees closest to the field pond and at least once in the sumacs east of the field pond.  

All of the spots to my knowledge where the solitaire has been seen, based on my observations as well as others' reports.  The bottom oval encases where it feeds on the buckthorn berries, the top one surrounds the area where it rests and hangs out with bluebirds.  Notice the two spots in the cemetery across the road.
The solitaire and the bluebirds here have an interesting relationship.  When the bluebirds are not near the buckthorn berries, the solitaire is quite often amongst them and very amiable towards them.  In fact, whenever the solitaire is not near its food source, the bluebirds, far more conspicuous than it, are a very handy way to locate it.  When any bluebird tries to get ahold of one of those berries, though, the solitaire turns into a little demon, raising all its feathers and spreading its tail.  Terrified, the thief quickly turns tail and runs.

Interestingly, one of this bird's distinctive field marks--the white eyering, is very noticeable on one side, but smaller on the other side.  All of its other distinctive characteristics are fully there, though. It does have a very long tail, contributing to its larger appearance in comparison to the bluebirds.  It also shows the classic buffy wing bar and black "shoulders", and the upperparts are slightly darker than the underparts.  The tail is all black with white outer feathers.

The side of its head with a noticeabe white eye ring.  The other side has a thinner eye ring.  I need to work on getting a photo of that.
A good view of its really long tail.
 All-black tail with white outer tail feathers.
Buffy wing bars.
An amazing look at all of the wing markings: black"shoulder",
light wing bar, thin black wing bar, and gray flight feathers.
The solitaire's plumage suggests that it is an adult:  A young bird would have more barring on its underparts.  The sexes are inseparable in the field, so no one knows whether it's a male or a female.
The lack of darker barring on this bird's underparts suggests that it is an adult.
When the solitaire decides that it is time to eat a berry, it flies up to and perches on a buckthorn tree, and surveying the pickings decides which berry it will eat, and then launches itself off the branch into a stationary hover directly below its berry of choice.  Then it grabs the berry in its bill and twists its head, which in turn twists the berry off the stem.

Surveying its territory.                                      
Taking off toward its berry of choice.
Hovering in place under its future meal.
Grabbing the berry in its bill.
Twisting its head to loosen the berry.
Got it!!
After the solitaire has the berry, it settles down on a branch, swallows the berry and then usually just sits for a few minutes.  It is during these times that it is the easiest to get a really nice photo.  This is because not only can a photographer get close to it as mentioned below, but it spends a lot of time preening and stretching as well, and when it's not doing that, it has its feathers all puffed out to conserve heat.  These behaviors make for really neat action shots and some very cute portraits.

Preening.
Strrretch...
Another good time of to get good photographs of the solitaire is when it is obtaining its food (because of the hovering behavior, this can make for some great flight shots).  There is one potantial drawback to trying to photograph Fenner's Townsend's Solitaire, especially if you have limited time to do so:

When it takes off and you don't see where it lands, it can blend in really well!
Otherwise, this bird is quite easily photographed.  Besides, this is not that much of an issue, because as mentioned above, the solitaire is usually hanging out with bluebirds when it's not near the buckthorn berries, which makes it much easier to find, even without a clue as to where it is or where it landed.  

While it is digesting a meal, the solitaire seems content to let birders get quite close,
just so long as there are only one to five people approaching it at one time. 
When approaching this bird, the safe distance is about eight feet.  It has been known to come within arm's length, but the important thing to note here is that the solitaire comes within arm's length of people, not the other way around.  When photographing, it is helpful to use a technique that my good friend Mike Boyce taught me:

1) instead of raising your camera before each shot, keep it up the entire time.
2) once you are at a distance that the bird is obviously comfortable with, take some "just in case"photos.
3) keeping your camera up, take three SLOW paces towards the bird and take a few more shots.
4) keep pacing slowly towards and photographing the bird as out lined above until you feel like you are satisfied with your photos or until the bird is obviously feeling uncomfortable, or until it flies off.
5) once it flies off, it is safe to follow it and repeat steps 2-4, but stopping farther away than last time, so as not to get too close to it again.
6)  if you want to get a better angle, take three slow paces at a time until you have the angle you want
.


Using this strategy cuts down on the ways that a photographer can scare the bird, plus it allows extra opportunities if the bird flies off before you get a satisfactory shot.

I hope that this amazing bird decides to spend the rest of it's winter at Fenner Nature Center, and that all who come to see it while it's here are successful.

Wednesday, January 16, 2013

Townsend's Solitaire--three miles from my house!



Today (January 16) my mom and I went to the nature center near my home, Fenner Nature Center (my favorite birding spot in the whole wide world!), to see a staked-out Townsend's Solitaire.  It didn't take long to find it; no more than 5 or 6 minututes after we got there, I spotted it in a buckthorn near the field pond.  I was thrilled to be seing a rare bird at my favorite birding spot, and perhaps even more thrilled about the publicity Fenner was getting in the birding world because of that very bird.  It was teed up perfectly and not at all shy, letting me get within 10 feet of it to take some photographs.

It was so cute!  About the size of a bluebird, its pale eyering, long tail, and habit of constantly fluttering its wings (below) were all so endearing.

The pale eye ring
The very long tail
Fluttering the wings

It was also really cool to watch the bird's behavior.  I thought that the behavior of hovering was restricted to hummingbirds, kingfishers, kestrels, and a few other select raptors.  No, it turns out, thrushes can hover too.  Every time the solitaire felt like having a berry, it would take off from its perch and hover in place under a branch laden with berries, grabbing on to a berry with its bill and twisting its head in order to get the berry loose. 

Hovering in place, showing the distitctive wing markings
Snatching the berry
Twisting the head to get the berry

THE CROW ROOST



Four winters ago, I was first treated to a sight that I have come to be very fond of: hundreds of crows raining down into the forest behind my house.  That winter and the winter after that, this tremendous gathering of crows spent all night (or so I thought) roosting in my backyard or close by.
About a year ago, in December 2011, I decided to count the crows that flew in to the roost.  I was shocked to find that, far from my original guess of hundreds of crows, there were actually thousands of crows flying in to roost every night!  The roost peaked in February 2012, with over 10,000 crows coming in to roost.  After further observation, I found that there was a problem with that statement: the crows were not actually roosting, but taking off just before sunset.

                                 
Crows near my home taking off at sunset.

So, the woods behind my house weren’t used for roosting after all.  What was going on?  Were the crows gathering just before sundown only to disperse again?  I didn’t think so, because when they all few off, they did so in one direction and with purpose.  I thought that the woods around me, instead of being a real roosting area, were a kind of “staging grounds” where all of the crows coming from a certain direction, a place for a flights of crows to gather, regroup, and fly toward the actual roost or even another “staging area.”
After studying up on the American Crow’s roosting behavior, I found that these woods were indeed a sort of “staging area,” called a preroost.  Crows from certain acreage of land take flight some time before sunset towards a designated preroosting area, with the birds farthest away from the preroost starting first.  As it gets later in the day, the flight picks up numbers.  Since the lowest density of crows is present in areas farthest away from the preroost, the flight gains size slowly at first, then faster and faster as it gets closer to the preroost site (Moore and Switzer 1998, Haase 1963).

Heading toward the roost.

            Every five to ten minutes or so, all of the crows, every last one of them, would suddenly rise out of the trees and instead of heading off to the roost, fly off in a single direction and then circle two or three times and land again.  I have come to nickname such an occurrence a “vortex” for the powerful swirling motion it creates.  It is absolutely amazing, sometimes even dizzying to watch hundreds or thousands of crows take flight all at once and land again, often on the same branch they were perched on before (Good 1952).
"Vortex" at a preroost.

            A true roost site is where flights from several preroosting sites converge to stay throughout the night. Compared to the preroosting sites, roosting sites usually hold incredible numbers of crows.  Un like a preroosting site, where most birds fly in from one or a few directions, crows fly into a roost site from all directions (Good 1952).

Crows flying in from all directions toward the roost site.

            About a week ago (January 6, 2013), my mom and I followed crows leaving a preroost site in the car.  We zigzagged through town until I had the luck to come up on the true roost site of the Lansing-area crows.  It was spectacular!  There were thousands of birds in the air, perched in trees, on buildings, and on the ground.   When they rose up into a “vortex,” they dwarfed any vortex that I had ever seen at a preroosting site.  The crows just kept streaming in in huge numbers.  At the roost site, I was able to count 11,100 crows, although there were definitely much more than that.  There were so many crows that sometimes it seemed that the noise was deafening.  The only way to communicate with my mom was to shout!

See all those black specks in the trees?  They're all crows.  This is just a small portion of the entire roost.

           Another notable aspect of this phenomenon is the behavior of the crows as they are about to land.  Some veer up and circle around before they land.  Although this usually occurs during a “vortex,” a bird will sometimes veer up and away to circle around for no apparent reason.  Usually, a crow about to land goes into a stoop, diving headlong towards the middle of the roost, and going into a glide when it presumably knows where it will land.  In the photo below, the birds labeled "A" are in a stoop, the birds labeled "B" are gliding, and "C" has veered off and will circle once or twice before landing (NOTE: the perspective in the photo is warped so that it looks like the birds are going up, but they really are going down).


          Often, a crow will gain altitude before diving and gain tremendous speed on the way back down.  When this happens, the behavior is usually repeated once or twice more.  Are these crows climbing to such heights just to have fun on the way down?  One might argue that they are especially since corvids, among birds, are well known for their intelligence.  At any rate, it is sure fun to watch their free falls.
          Occasionally, two or three crows will beat their wings in perfect unison.  I cannot tell if this is a purposeful behavior or a coincidence, like the stride of humans walking together.  I have never seen it happen with groups of more than three birds.  I have come to call this “synchronized flying” because of how perfectly in unison the wing beats are.
            Finally, as a crow gets closer to the trees, it abruptly veers off from its downward course and lands on whatever branch, building or parking lot suits its fancy.  Eventually, the entire flock settles down for the night, in a tightly packed group as the sun’s light completely fades.

These two were flying in perfect unison.  Coincidence or not?  I don't know.

            Although I have attempted to use photographs and words as a means to portray the wonder and sheer size of crow roosts, neither pictures nor words can do a crow roost, or even a preroost, justice.  To really experience it, you truly have to be there for the real thing.




References:

Good, E.E. 1952. The life history of the American Crow Corvus brachyrhynchos Brehm. PhD Thesis. Ohio State Univ. Columbus.

Haase, B.L. 1963. The winter flocking behavior of the Common Crow (Corvus brachyrhynchos Brehm). Ohio J. Sci. 63: 145-151.

Moore, J.E. and P.V. Switzer. 1998.  Preroosting aggregations in the American crow, Corvus brachyrhynchos. Can. J. Zool. 76: 508-512.

Sunday, January 13, 2013

The Crow's Roost


Why did  I name my blog "The Crow's Roost?"  Unlike many people, who say that their favorite bird is the one they are looking at at the moment, I definitely have a favorite bird-- the American Crow.  I like crows so much because first and foremost, they are fascinating and often highly amusing to watch. Second, crows gather in huge numbers, something that Common Ravens don't tend to do.  Last but not least, American Crows are extremely abundant and so are easy to find and observe.

My interest in crows started four years ago when for the first time, a huge group of crows started dropping into the trees near my property every night.  Since then, I have come to learn a lot more about crows and their habits, and all the time I have come to like the American Crow more and more.

My birdwatching is certainly not limited to watching crows.  I try to watch every bird that I can get my eyes on, be it a Bald Eagle on the ice of a frozen lake or one of those pesky European Starlings (they are really pretty not to mention fun to listen to.  And how should they know they're invasive?)   In fact, the American Crow has not always been my favorite bird.  I have switched from Hooded Merganser to Sandhill Crane to Ruddy Duck to Ruffed Grouse to Common Loon to Magnolia Warbler until most recently  I permanently decided on American Crow as my favorite bird.

I don't only watch birds, either.  I like plants (especially trees, fruits, and wildflowers), watch butterflies, Odonates, and herps, hike a lot, and love to write.  I sing in a young men's chorus, play the cello, take lots of photos, and draw birds.  I volunteer often at the local nature center.

So, future posts on this blog will run the gamut from what kind of wildflower I found at the nearest county park, to the rarity I saw the other day, to (of course) updates on the local crow roost.

Enjoy!