Digiscoping

I saw Max sitting on the lighting post on the garage as soon as the elevator doors opened this morning. Ah HAH! Got you! I set up quickly and quietly. Unlike Hercules, who sat on that very same light post for three solid minutes so that I could easily (mis)read her leg bands, Max gave me all of 5 seconds.

The look was long enough to see black over green. So, he’s a Midwesterner. I could not identify the bottom letter/number, but I did get a good look at the top – a very clear “5”. So, Max is b/g, 5/?. That’s something! I just need the bottom number and I’ll have him!

Like yesterday, the wind and rain made falcon viewing difficult. To top that, today it was very cold. After Max left the light post and flew out of sight to the east, I scanned the ledges. No Hercules. Something new, however, was on a ledge. In fact, it was something that had appeared yesterday.

Hercules and Max nest in the 3rd niche from the left. The first day Mary brought me up to the roof, before we went to see the Wacker chicks, she pointed out something on the ledge of the 1st niche from the right – a long-dead and partially mummified American Woodcock propped up against the wall of that niche.

On caching prey – Mary explained that peregrines often have spots where they “cache” food. I did some further research and found that these caches appear more frequently used during breeding season.

The male caches birds before the female arrives at the start of the breeding season. These birds are often used in courtship feedings. During the incubation period, the female will sometimes eat birds from the cache if the male is slow to deliver food. After chicks hatch, the parents sometimes cache prey that the chicks do not finish completely. The consumption of cached food also has been observed when the weather is stormy for a number of days. Interestingly, cached birds are often whole, without even the head missing.

I noticed yesterday that a new bird had appeared next to the woodcock. On of my goals for today was to get a picture of this “mystery bird” in the cache. I did snap some pictures yesterday, but the cache is too far away for my camera to capture anything but a tiny dot – I don’t think even John, Dave or Mary could identify this bird from that scant information. So, last night, I did some web searching and found an article on “digiscoping”.

On Digiscoping – Digiscoping is a form of photography practiced mainly by wildlife photographers. I read about it on a birding website. Basically, you take a digital picture through the eyepiece of your spotting scope. This requires an extremely steady hand and very still conditions. Any movement of either the scope or the camera renders uselessly blurry photographs. To battle this problem, intense rigs have been invented which lash the camera to the scope so that the whole apparatus stays steady enough to get a picture. The picture itself presents a problem, even if it is crystal clear. Because it is taken through an eyepiece, the bulk of the picture is simply black, with the subject in a circle in the center. This requires some diligent work editing the photo after the fact.

So of course, I decided to practice digiscoping today sans any sort of mamby-pamby digiscoping apparatus and in less than ideal conditions. The rain lashed at my back and the wind gusts threw me forward as I excitedly set up my tripod, screwed the spotting scope on top and turned my camera on. My teeth chattering and my body shaking uncontrollably as I shivered, I trained my spotting scope on the mystery bird and held my camera up to the eyepiece.

I took 20 pictures just to make sure I had at least one that would turn out. As a “just in case” measure, I decided to also record my observations of the cached bird. Lucky.

Peregrine Falcon's Food CacheJournal entry: “M.B. about same size as woodcock, maybe 25-30cm. Yesterday, in completely different position. Wind? Yesterday, wing extended out nicely. The shoulder, back and secondaries were all a solid, dark olive-gray. The primaries beautiful russet color with dark gray tips. Today, blown so that head is more exposed. Crown and head also solid dark olive-gray. There might be a dark gray eye ring. Seems to be a dark band of feathers forming a stripe from the corner of the beak to the back of the head, but that may be blood. Throat and underbelly solid white. Beak top black, bottom yellow. Legs dark gray-black.”

I could not wait to see the fantastic digiscoped images I had, undoubtedly, captured. I arrived at the museum still freezing cold and wet from the rain, but excitedly turned my computer on, plugged my camera into the USB port and started the files downloading before even turning on my space heater. I guess that’s me – willing to court hypothermia for pictures of dead birds.

I had about 15 pictures of a white blob in the middle of a fuzzy black field. Hmmm. Perhaps the mamby-pamby set-ups were invented for good reason, eh? Five of the pictures yielded some barely usable footage. The one at the top of this post was the best. I sighed. Drat.

However, using my observation notes and the picture, John Bates easily identified the mystery bird as a Yellow-billed Cuckoo, because, well, that’s just how good the bird people are here at the museum. He told me that while not a rare bird, the cuckoo used to be much more plentiful here in the Midwest, but its numbers are in decline. John told me that Mary has noticed that peregrines are rather fond of cuckoos. He seemed pretty excited about the find.

I found this interesting tidbit on the Birds of North America Online’s peregrine entry: ” At site in downtown Milwaukee, food including cuckoos (Coccyzus spp.) was cleaned from cache several hours after civil sunset; then cache again contained cuckoos 2-3 h before civil dawn, indicating nocturnal hunting, perhaps aided by city lights (Wendt et al. 1991).”

So, peregrines are cuckoo for … cuckoos.

Advertisements

~ by Steph on May 12, 2006.