Wednesday, August 30, 2006

Fascinating foraging behavior...


© USF&WS

Here's a fascinating account of foraging behavior observed by myself and several other birders yesterday that I thought you might enjoy:

A Black-throated Blue Warbler was foraging in thin twigs protruding from the side of a tree about 10 feet from the ground. We were about 20 to 25 feet away so we had great viewing in good light. We became somewhat alarmed when it appeared the warbler was stuck on a twig. Then it began to bounce on the twig...at first without beating its wings but sometimes fluttering a little with its bill raised upward. In all sincereness, it looked like it was exercising on a trampoline. Upon closer observation the warbler was using the bouncing motion to systemically disconnect an orb spider web from the surrounding twigs. Once the web was disconnected, it reeled it in with its bill and then consumed the enswathed insects from the spider's cache.

From Cornell's BNA online (Black-throated Blue Warbler):

The most frequent prey capture method is to snatch prey from a substrate, usually a leaf, while hovering or flying past (65%); secondly (35%), they glean prey from nearby substrates while standing on the vegetation (Robinson and Holmes 1984). Unlike other species in northern hardwoods forests, they do not change their relative use of foraging maneuvers or search tactics among tree species or strata, suggesting more stereotyped foraging behavior (Robinson and Holmes 1984). In laboratory experiments, however, their foraging behavior changes with leaf shape and position in relation to available perches (Whelan 1989b, 2001), suggesting that plant morphology influences their foraging success.

Warbler activity at Pheasant Branch Conservancy yesterday was fantastic - 17 warbler species!

Monday, August 28, 2006

Gone Birding!



No time for writing! Yesterday we had 13 warbler species at Pheasant Branch Conservancy and it's only going to get better in the next week or two. So, for now...I'll take time to blog only if the news is more important than being out in the field watching the birds.

Have a great fall migration!

Mike M.

Wednesday, August 23, 2006

An alternative to field notes?


Yellow-throated Warbler - Record Early for Wisconsin

I've been reading with interest the discussion thread "An alternative to field notes?" on the ID-Frontiers listserv. At debate is the question (or impression) that digiscoping/digital photography may be replacing detailed note taking in the field (if that's the case then there are more digiscopers than I thought):

"Let's face it - note-taking and field sketching are a matter of personal priority/interest. I got into birding as a photographer and have at various times over the past 30 years resolved to keep field notes. After a few (days/weeks/months) those good intentions always returned to hibernation. Now I digiscope." - C. Taylor

"Not all reports need detailed field notes. If there are great photos of the thing, which are diagnostic, well many people on a committee will look at the photos and go no further before accepting." - A. Jaramillo


Red Pharalope - WSO Record #2005-072

Even an aesthetically good photograph won't guarantee that a records committee will accept a rare bird sighting. I've only ever had one rejection - the December 24th mystery swallows of 2001 at Nine Springs. Though I had fairly nice close-up shots (not digiscoped) of two nearly frozen juvenile swallows, they were back-angled views that didn't reveal quite enough to separate Tree from Northern Rough-winged or Bank Swallow. And whoopsie...I didn't make any field notes of their behavior! One member of ID-Frontiers seemed quite disappointed writing, "Do you mean a lone observer photographed two out-of-date-and-place swallows and took no notes of the sighting...just these five photos?"


Mystery Swallows - NOT ACCEPTED!

The pictures were submitted in early 2002 and believe or not, it took until just this past spring for WSO to reach a consensus, or rather lack thereof. Jim Frank, WSO Records Committee chair, closed his letter to me with the following paragraph:

"Bottom line, there just doesn't seem to be a consistent match of the field marks we have from the photos. If you have access to Birding, Vol. 28, No. 2, pp 111-116, from April 1986, some of the information there as well as the photographs may help you see we were left a bit confused. Even though the photographs were amazing, sometimes there just isn't enough to go on."

In a few ID Frontiers posts I began to detect a purist mentality when it comes to taking field notes. There's quite a bit of rhetoric about honing the skill, elevating it to a seemingly infallible capability when it comes to making an identification. The obvious implication to me was that digiscoping/digital photography doesn't quite match up as a potential bird identification discipline:

"I had in mind - the practice of note-taking improves and strengthens ones ability to see, describe, and communicate details with the wider community of birders. I'm not the best or most diligent at notes. Nevertheless, steadily practicing it, forcing myself to 'see' more and to see more accurately only came with note taking. This improvement in ability means that one's contributions are more lasting and more valuable. As humans, we all have extraordinary perceptual capacity. But it takes time and practice to hone those senses and to hone our ability to see and describe birds. More importantly, it takes time and experience to learn when those sense fail or fool us. Many people bird for their own enjoyment, and that is fine. Any photo or video is better than nothing in that case." - L. Bevier

"What I've come to realize, however, is that most birders will never take field notes, not on paper, not into a recording device. Note taking is data collection and data collection is just too sciency. Most folks just don't approach the hobby the way the great amateur naturalists of the 19th and early 20th century did. Most folks don't recognized the participatory possibilities in contributing data to the commons." - M. Patterson

"If you really want to ratchet up your skills at observation and recollection of what birds look like, take notes. If you want to ratchet it up two notches, draw pictures. Nothing forces you to look as closely as by drawing." - A. Jaramillo

Sure, I really blew it on the 2001 December swallows and I vowed something like that would never happen again. But the dedicated photographer cannot afford to divert his/her attention to writing things down in a notebook as opportunities can be fleeting. This was the case with the Midwest Cave Swallow invasion last fall. I had only seconds to get a shot off under very challenging circumstances and logistics, but I got my bird and it was clearly identifiable:


Cave Swallow - WSO Record #2005-084

"Mike, thank you for the very identifiable shot of the Cave Swallow! I was there last Monday and had good looks but the little buggers never perched. Glad you were able to get the shot that should help establish the first state record. " - M. Korducki

Documenting and submitting a written report of a rare bird sighting from field notes is a form of persuasive writing - you're building a case for an observation. But anyone reviewing the report begins from that impression and bias. With a photograph, each person who studies the picture can start from the exact same raw data - a physical representation of the observation.

Naturally, the quality of a written report (or image) will be reflected by the skill and talent of the observer (or field craft of the photographer) thus rendering a strong/weak report or a great/poor image. But all the salient points made with regard to accurate and skillful note taking cited by various seasoned ornithologists and birders - time, dedication and experience - are not unfamiliar notions to high-level digiscopers and bird photographers.

All images © 2006 Michael McDowell

Tuesday, August 22, 2006

Zeiss takes a step...



We get a lot of digiscoping questions each day at Eagle Optics, but I still lack a keen sense for how big or small digiscoping actually is. Are birders really embracing it as a viable method for bird photography? I wonder how many people never call with questions concerning connectivity or adapters and simply hold the digital camera up to the eyepiece.

The 2004 Birdwatcher's Companion has a brief entry on digiscoping that closes with a prediction to "expect rapid evolution." Digiscoping has been around for almost a decade now and I would opine that digital camera and spotting scope manufacturers remain in a period of stasis. To be fair, there have been a few attempts to branch from the trunk of the digiscoping evolutionary tree, but neither the Nikon P1 System or the Kowa TD-1 seemed to catch on with consumers.

Ever since the discontinuation of the Nikon Coolpix 990, 995 and 4500, it seems digiscoping remains a proverbial crapshoot - buying a high-end spotting scope, the manufacturer's digiscoping adapter and pray you can find a point-and-shoot digital camera that will connect to it and deliver the goods. Credit to the conventional methodology, Bill Thompson III recently featured a nice overview connecting a Canon PowerShot A520 to a Swarovski scope on his birding blog.



Now it appears Zeiss will attempt to punctuate the equilibrium with an evolutionary step of their own design - a veritable digital eyepiece. So far this integrated digiscoping eyepiece/digital camera only shows on their German website. Here's the product specification detail:
  • 4 megapixels.
  • 1.8" LCD display.
  • SD card data storage.
  • Rubber-armored/waterproof housing.
  • Integrated observation eyepiece with 30x(65mm)/40x(85mm) magnification.
  • Display can be viewed via eyepiece and integrated monitor simultaneously.
  • Wireless remote control avoids vibration during image capturing.
  • USB + AV interface for PC and external TV monitor.
  • Power supplied via batteries or external power supply.
Zeiss states, "Designed for the Zeiss Diascope spotting scope, the innovative DC4 camera eyepiece is expected to be available in the fall of 2006. Production is limited to 1000 units."

Is it good? Is it bad? I'll keep you posted...

Friday, August 18, 2006

Switching to Songbirds...



The Ashton K Pond has dried up and shorebird reports from Nine Spring have been rather sparse. This morning I decided to switch over to songbirds. I birded along the stream corridor of Pheasant Branch Conservancy, where this time of year it looks, smells and feels like a tropical rain forest with plenty of mosquitoes to render truth to such a notion. Still lush and green, a careful observer will note some leaves have already changed to fall colors. Well, September is only a few weeks away...



Most of the birds I saw or heard were residents like Tufted Titmice, Blue Jays, Northern Cardinals and Carolina Wrens and an assortment of woodpeckers. To my delight I found and watched a Northern Waterthrush foraging along the stream rocks. Given their recorded breeding range in Wisconsin I suspect it was an early fall migrant. The only other warbler was a lone Tennessee Warbler in the upper-story near an Eastern Wood-Pewee. Nearby but only heard was a Baltimore Oriole's cheerful song. A statuesque Green Heron at the duckweed pond demonstrated inordinate fishing patience, but I let it be without disturbance.

The perfect moment of the morning came when a Carolina Wren perched about 20 feet away on a branch, threw its head back and belted out its fantastic “tea-kettle” notes. I froze. Though I had my scope and camera along, it happened too fast to document. Instead, I spent those few moments admiring the wren through my binoculars. Without warning, the bird dashed back into the thicket with a few scolding notes and then all the other wrens were quieted.

In another week or two, this place is going to be swarming with wood warblers.

All images © 2006 Mike McDowell

Wednesday, August 16, 2006

Early one morning at Horicon NWR...











All images © 2006 Mike McDowell

Sunday, August 13, 2006

Form

Great Egret



He walks the shallow with an antic grace.
The great feet break the ridges of the sand,
The long eye notes the minnow's hiding place.
His beak is quicker than a human hand.

- Theodore Roethke





Great Egret images © 2006 Mike McDowell

Tuesday, August 08, 2006

Close Encounter...



Visiting the Ashton/K-Pond for a quick shorebird count after work, I checked another drainage pond along Woodland Drive before heading home. Successful bird portraiture combines a mixture of elements that come together by way of opportunity and recognizing when conditions are ideal. Being in the right place, the right time with great light and having a cooperative subject – knowing when it’s going to work even before the camera is turned on.



On this particular evening an opportunity came in the form of a Least Sandpiper foraging in duckweed. Viewing a Least Sandpiper from dozens of yards away, it’s easy to think it’s just another one...it’s just another Least Sandpiper.



But now the bird is right at the edge of my close focus and I see something that transcends the name we’ve given it. I admire the pattern of its intricate feathers in the warm light. I appreciate how its wet belly feathers and duckweed cling to its tiny legs. I study its complex bill with nostrils drawing in invisible breaths - it’s breathing...this living critter before me. We both pause...my world completely alien to it, and again I contemplate the unattainable – what is it like to be this bird?

People must have renounced, it seems to me, all natural intelligence to dare to advance that animals are but animated machines. It appears to me, besides, that [such people] can never have observed with attention the character of animals, not to have distinguished among them the different voices of need, of suffering, of joy, of pain, of love, of anger, and of all their affections. It would be very strange that they should express so well what they could not feel.”

- Voltaire, Trate sur la tolerance

All images © 2006 Mike McDowell

Monday, August 07, 2006

One Pond serves Thousands...



Yesterday Andy Paulios wrote to the Wisconsin Birding Network:

"Just to show you what a difference a day can make for shorebirding, I visited Mike's spot on Saturday and had no Stilts. I did have 3 at the pond on Hylsop road."

I replied with a few thoughts about my observations...

As Andy mentioned, it is sort of interesting how quickly shorebird activity changes at a particular isolated pond in Dane County. This morning on my way to work I stopped at the Ashton/K-Pond and all the STILT SANDPIPERS (there were 20 of them) and DOWITCHERS were gone. So too were the dozen or more SEMIPALMATED PLOVERS that were there the previous evening and the overall shorebird numbers dropped over 75% in my estimation.

Since it's right on my way to and from work, I've been checking it twice each day. Consistently I've noted that activity, diversity and numbers are greatest early evening prior to exodus. In the morning it has been comparatively quieter. One evening there were close to 300 KILLDEER present (numbers were far lower that morning) that were virtually gone the following morning. During most visits I've witnessed a few arrival flocks between 5 and 20 individuals. I suppose it's only obvious that there is some level of movement/migration occurring during the day.


Short-billed Dowticher

I find the arrivals, departures, fluctuation in numbers and diversity of species intriguing and fascinating to ponder. I feel fairly certain that most days I'm looking at an entirely new set of shorebirds and each day there are roughly 200 to 400 of them there. So, one pond in a farmer's field is serving who knows how many thousands of shorebirds (and other birds, too) during migration.

All images © 2006 Mike McDowell

Saturday, August 05, 2006

The exhibit is up!



I spent three hours this morning hanging my photographs (not as easy as it looks) and I'm pretty pleased with the way the project turned out. If you can't make it to the Madison Public Library to see it, you can always look at the images in my online bird digiscoping gallery.



They said I could place an artist's statement with my exhibit (far right). Rather than blather on about the digiscoping technique, I thought I would pay tribute to the birds, so here's what I wrote:

The Natural Beauty of Wisconsin's Birds

Birds have captured our intrigue and imagination with their freedom of flight since the dawn of civilization - symbols of birds are featured in ancient Egyptian hieroglyphs and Greek myths. Their sprightly behavior, elegant feathers and exquisite songs have inspired art and poetry across the ages.

With their innate and uncanny ability to use celestial navigational strategies, birds might be thought of as the first astronomers. They can detect the Earth's magnetism, sense the circumpolar movement of the stars and use the solar photoperiod (length of day) as cues that tell them when it's time to leave and how far they should fly.

Many of the birds pictured in this exhibit are migratory - they do not stay in Wisconsin during the winter and travel south to warmer climates where food can be found. They will fly hundreds or thousands of miles each year between their breeding and wintering grounds as a matter of survival. The Solitary Sandpiper (pictured in this exhibit) flies from near the Arctic Circle where it nests to as far south as Argentina and Uruguay.

The 1993 Monroe and Sibley checklist puts the number of bird species worldwide at 9,702 and over 300 can be observed right here in Wisconsin. Birds have ruled the skies for over 80 million years, but they base their homes closer to the ground on diverse habitats that include desert, prairie, forest, wetland, tropics, lakes and oceans and sometimes even your backyard.

Throughout the world many bird populations are in decline because there is less habitat for them to survive. According to a study by Standford University up to 10 percent of bird species are likely to become extinct by the year 2100. Their way of life often collides with ours as millions birds perish each year during migration. Great efforts in conservation are helping to tip the balance back in their favor, but there is still much work to be done.

All images © 2006 Mike McDowell

Thursday, August 03, 2006

Lesser and Greater



There hasn't been much news to report as of late. I'm running a little behind on preparations for my exhibit and plan to install the photographs at the Madison Public Library this Saturday. The only birding I've been doing is checking out a drainage pond for migrating shorebirds near Ashton on my way to and from work. The pond generally has the greatest number of shorebirds during the evening - around 200 individuals, mostly Pectoral Sandpipers, Killdeer, Least Sandpipers and Lesser Yellowlegs. But there have also been Semipalmated Sandpipers, Baird's Sandpipers, Solitary Sandpipers, Greater Yellowlegs, Spotted Sandpipers and a few Semipalmated Plovers.

The lone Lesser Yellowlegs can fool you. Though about half the mass of a Greater Yellowlegs, the two species have very similar plumage characteristics. Without a side-by-side comparison, I've been inclined to call a few lessers as greaters over the years. I've also noticed this seldom seems to work the other way - a Greater Yellowlegs is generally more obvious with its gawky appearance. You can see what I mean in this photograph when I was fortunate enough to have both species in the same frame. Notice that the bill length of the Greater Yellowlegs is almost twice the length of the bird's head, while the Lesser's is only just slightly longer than its head.



It's interesting checking this pond twice each day and noticing how the numbers fluctuate. Though I've been seeing the same 10 species each outing, the numbers shift. For example, one morning I found only two Solitary Sandpipers but when I returned that evening there were over a dozen. Yesterday there was a substantial increase in the number of juvenile Least and Semipalmated Sandpipers. I also get a kick out of watching a flock of sandpipers vacate the pond and take to the air. There's the somewhat ruckus call to flight that precedes an exodus. It almost seems like they're saying, "Come on, let's go!" in order to get the group motivated for another several hundred mile leg of their journey.

All images © 2006 Mike McDowell