Monday, December 23, 2013

The Winter Kinglet

Although it is over two weeks into the month of December, only now may one finally say that winter has truly arrived.  Today is December 15, 2013, and up until now it's either been really cold and not snowing, or just below freezing and snowing. The immense snow storm that rolled in from the Southwest a few days ago marked the first time this season that snow coincided with decidedly colder temperatures.  As I walk under a dense stand of pine trees at Fenner Nature Center, I am awed by the beauty of the untouched blanket of white powder that covers every available surface, from the ground I tread on to the tops of the trees.  I can't help but think how lucky I am to live in a place where I can be part of scenes such as this.  
Suddenly, a chorus of barely audible, high-pitched trills off to my right sets my thoughts on another, altogether more marvelous course.  How can these treble voices be part of this winter landscape, covered in seven inches of snow and nightly reaching subzero temperatures?  The Golden-crowned Kinglet, to whom these sounds belong, is nothing short of an avian miracle. These diminutive birds, whose average body size is barely bigger than the top half of your thumb, somehow manage to find enough food in temperatures as low as -40° to sustain their exceedingly hyperactive lifestyle, day after day after day.

© Janine Russell
They survive each day against a set of overwhelming odds that works constantly against them, for a body that small, unaided, in the middle of winter, would die in a matter of not minutes but seconds at such cold temperatures. Their metabolism is so high that they must eat more than their body weight in food every day.  And that's assuming that their diet is as rich in protein as it is during the rest of the year.  Surely that is impossible given the lack of insect life in the middle of winter.  And what of the nights?  How would such a tiny creature stay warm without constant sustenance through the long hours of a cold winter's night?
Their secret to survival lies in the tiny "inchworm" caterpillars of Noctuid moths—mostly those of the One-spotted Variant (Hypagyrtis unipunctata). They lay perfectly camouflaged against the twigs and branches of maple and birch trees all winter long, no matter how low the temperature drops.  The caterpillars themselves are truly phenomenal.  Just before their host trees shed their leaves, they stop feeding and, with a few strands of silk, loosely fasten themselves the outer tip of a branch. Now their bodies go through a chemical change that saturates their body fluids with high concentrations of glucose sugar, to be used as an antifreeze in the winter months.  After a number of weeks, the substance has permeated each caterpillar's every cell.  Packed with antifreeze, they are now equipped to survive even the coldest temperatures that the coming winter has to offer.  The very same glucose that allows a caterpillar to survive the winter simultaneously provides an energy-packed meal for a kinglet.  Thus, the kinglets' "hyperactive" behavior of hovering or hanging at the ends of branches, picking off seemingly invisible prey.
The Golden-crowned Kinglet's winter mainstay--
the caterpillar of the One-spotted Variant. © Canadian National Collection
Another common winter feeding behavior coincides with the range of the Sack-bearer Moths (Family Mimallonidae).  In August, the larvae of Sack-bearer moths construct open-ended sacks of silk and leaves where they will overwinter and pupate in the spring.  They also ensure that their shelters will not fall off of the tree with the rest of the leaves by enforcing the leaf stems with countless strands of silk.  In the winter, flocks of chickadees and kinglets take advantage of this by locating these surprisingly inconspicuous clumps of leaves and poking their heads inside to make a meal of the luckless caterpillars.
After a day of foraging, the members of each small flock find their way back to the dense conifer whose interior they have been roosting in at night since the first night that the temperature dipped below freezing.  Once there, they may settle down close to the trunk of their tree and cuddle close together to form a fluffy ball of feathers.  (One morning last winter, I was lucky enough to find one of these clusters roosting in the pine tree in my own backyard!)  More often, perhaps, the flock returns to settle into a carefully constructed, globular, down-lined nest.  Constructed by the flock during mid to late October, this structure is used solely as a roosting shelter on long winter nights.  This apparently gives the Golden-crowned Kinglet the distinction of being the only North American bird to deliberately construct a nest for purposes other than incubating and raising young.  
Bernd Heinrich's sketch of a kinglet cluster.
© Bernd Heinrich 2003

So, next time you see a Golden-crowned Kinglet on a cold winter's day, perhaps you can stop to ponder the miracle of the winter kinglet.  Think of the staggering odds that the bird has beaten each and every day that the temperature has dipped below zero.  Remember that you are witness to an incredibly unlikely scene: a tiny bird flitting about in lively manner in a frigid, hostile environment.

© Michael Murphy 

For an excellent read and more information on nature's ingenious winter survival strategies, see Winter World by Bernd Heinrich.

Saturday, December 7, 2013


Ugh.  Gulls.   Watching them is no fun--gull watching requires hours of standing miserably on a lakeshore or seashore, or visiting a landfill.  They're just not worth the effort, and you only ever get distant, unsatisfactory views of them. surprises me how many birders resort to this point of view.  Yes, some gulls are difficult and  take a long time to learn (I readily admit that I am still very much in the process of learning the details of several gull IDs), but that's not the case with all gulls.  It's easy to start out: you just need to get to know the species that are the most common in your area.  Here in Michigan, I started out by learning Herring, Ring-billed, and Bonaparte's Gulls inside and out (obviously, the set of gulls that you must get to know will vary based on where you live).  This enabled me to recognize anything that wasn't one of those two species, which allowed me to focus on the odd birds out.

As with the practice of birding in general, a field guide is essential.  The very best, in my opinion, is the Field Guide to the Gulls of the Americas by Steve N. G. Howell and Jon Dunn.  Though I only first laid my hands on it just over a month ago, it has done me an infinite amount of help in furthering my gull identification skills.   Another important facet of gull identification is being okay with leaving a bird unidentified.  No one can always identify every single bird.

The more you learn, the more FUN gull watching becomes!  So finally, here are a few of my best gull experiences:

The first time I had a cool gull encounter was in April of 2011 at Pointe Mouillee SGA.  They were a couple of adult Great Black-backed Gulls loafing with hundreds of "normal" gulls in Cell 3.  I could not get over how huge they were--I kept on exclaiming that they "looked like eagles, they were so big!"  Seeing two adults black-backs at close range left a strong impression on me, such that my heart still skips a beat whenever I see one.

From then until almost the end of 2012, I focused on getting to know the common gulls.  In November that year, my dad took me up to the Upper Peninsula to see Gray Jays at Hulbert Bog and winter finches at Whitefish Point .  After watching over 50 Pine Grosbeaks and hundreds of Common Redpolls (a single Hoary among them) at the Whitefish Point feeders, I went down to the beach and BOOM!  An enormous, all-white gull was the first thing I saw.  It was struggling against the wind, going nowhere despite its powerful wingbeats.  It was a stunning second-winter Glaucous Gull, and I watched it hover close above me for half a minute before it gave in to the wind and rocketed way from me.  It didn't take long for its pale form to blend into the cloudy sky.

Later that day before driving home, we stopped at the Whitefish Harbor Breakwall.   Just as I started to look through the hundreds of gulls on the breakwall, a rather pale juvenile gull flew in and landed not far away.  This was the first time my familiarity with the common gulls kicked in:  it was similar to a Herring Gull but with several important differences. It had gray outer primaries and secondaries that contrasted slightly with paler inner primaries.  The lack of black on its flight feathers was something I thought was odd.

When it landed, I saw that overall it was a monotone gray, instead of brown or tan with a paler head.  Its primaries were only slightly darker than the rest of it, with pale edges. Its feathers were intricately patterned and gave the bird's back a very "scaly" appearance--this bird was clearly still in juvenile plumage.  It also had a smaller, rounder head and a smaller bill than any of the juvenile Herring Gulls nearby.  After observing the bird for a good long while, I finally got into the car and, looking at a field guide, easily saw that it had been a "classic" juvenile Thayer's Gull.  To top things off, my observation was confirmed when, an hour later, a couple of more experienced birders saw the same bird at the same location.

My next awesome gull experiences came much more recently: both within the last month, in fact.  The first of these was on November 10th, at the Fennville Sewage Ponds (restricted access) in Allegan County, Michigan.  As part of an Allegan County field trip that he was leading for the Capital Area Audubon Society, Rick Brigham took us to these restricted-access sewage ponds, where we watched the close-up flocks of waterfowl until my brother and I saw a small gull amongst the 130 or so Bonaparte's Gulls with an interesting wing pattern.  Elijah said, "is that a young Bonaparte's?"  I, reluctant to believe what I thought I was seeing, frantically called Rick over so that he could look at it through his scope.  It wasn't long before he confirmed my suspicion by exclaiming that it was a juvenile SABINE'S GULL!! Were able to watch the beauty for over an hour while it fed in the water at close range.  NOT your typical Sabine's Gull zooming past a lakewatch in high winds!

My last cool gull experience was just a few days ago on November 23rd.  After finishing the Lake Erie Pelagic out of Cleveland (which was also amazing!), many of those who had been on the boat ride drove to Edgewater Marina in order to see the Little Gull that had been present there for a while. It was practically the first thing that I saw upon getting out of the car!  It was seriously RIGHT THERE, approaching us within six feet as we stood poised with cameras and binoculars.  It was accompanied by 300 Bonaparte's Gulls, which were also approaching within arm's reach of us.  I had never seen anything like it; the flock of Bonaparte's alone would have made my day.

Part of the flock of Bonaparte's:

After five minutes or so, I saw this and yelled "Guys!! GUYS, there are TWO!!" as I snapped the photo.

It was absolutely unreal to be standing so close to not one, but two of these beautiful, rare birds!