HawkArtScience: Hawksaloft.com blog

16 October 2017

I like stories.
Homer Simpson, rumored taste-tester for Red Tail Ale and Peregrine Pilsner


Losing the old narratives of hawkwatching is important to achieve Eagle Enlightenment (patent pending). EE can be a way of life… or simply a better way to talk about hawk migration amongst hawkwatchers and those pesky tourists.

Here we have:
1. A recent long-term Golden Eagle study looks to widen the view from the hawkwatch by overlaying GPS onto the precise weather they are encountering to see the well-timed, persistent and knowing migratory movement of adults (professional hawks). The results are, "counterintuitive".
2. Another GPS study, following the migration of the new and the clueless… juvenile buzzards. This, telling a different windblown tale across Europe into Africa.
3. The best (and scientific) guesses as to where Golden Eagles glimpsed in the Northeast might both nest and winter based on snippets of their feathers.

And because August and September are just in the rearview -- NEXRAD from Big Days and radar out of the past, with some Little Days being more funner.

Next to NEXRAD
1. Professional hawks are never: "waiting", "delayed", and/or "late".
In The Auk's 2017, Counterintuitive roles of experience and weather on migratory performance, lead author Adrian Rus -- as both an undergrad and graduate student out of the Katzner Lab -- poured over GPS with that specific weather data on Golden Eagle migration. A ton of data points analyzed with several models in a dozen different ways… boiled down to thermals, good winds, timing, and all told, "migratory performance". But.

But, under ideal conditions with great solar lift and the best tailwinds, younger birds score high. Over time though, their scores worsen!? Guess what: favorable thermals and 'the right' winds are for beginners. With more finesse, adults start out from the wintering grounds for the homeland with an earlier idea of what Summer is, move under good, fair and even poor conditions because the goal is to produce more Golden Eagles, whose Fast and Furious (2001) mentality then matures into a four-wheel drive lifestyle. And so on, over miles and generations.

Because of the tremendous detail collected here, the paper also has air speeds for these Golden Eagles, Spring and Fall, by age. Also key weather conditions as they vary for age and season!

One wizened Golden, agreeing to be interviewed for this study commented on the record, "Hawkwatcher weather?! That's for amateurs."
Rus et al_2017_counterintuitive.pdf

2. Picture that airplane humming over the turning globe in the opening credits of Casablanca (1942), voice-over: "Honey Buzzards in transit encounter the Mediterranean Sea and then the vast Sahara seeking new lives as they are swept into sub-Saharan Africa where they wait and wait and wait."

A nice look at thirty-one juveniles in their first Fall migration coming out of Finland. While using GPS, this is a much more basic study than the Katzner Lab work, with the winds ("atmospheric conditions") remodeled-in over the tracking data. But still, we see new birds going-with-the-flow; ending up… where they end up. In other words, wintering and familiarizing themselves with a spot. Will they thrive there? Return there?

The Royal Society link above has this image, full-size, plus much more.

3. Back to Todd Katzner, his students and their Golden Eagles… matriculating. Stable isotopes of elements like hydrogen and nitrogen can tell a tale. Where someone has lived, or even just visited, can be told from an analysis of the water/soils in that place — and by extension, those who have been there, eating, drinking. Golden Eagles travel from nesting grounds seldom seen, over the hawkwatch occasionally, to wintering sites little known. Wouldn't you like to know more?

We have maps! From their field and (of course) lab work, eagles are captured and feathers are collected. The elemental chemistry of these are compared and contrasted with samples collected from far and wide, from nesting to wintering areas.

Some Golden Eagles travel farther, leapfrogging over their peers to winter. Dick Forsman in his Flight Identification of Raptors of Europe, North Africa and the Middle East (2016) notes this occurs in Old World GEs. Interestingly, this leapfrog-wintering is known too for Red-tailed Hawks via banding… 20th Century, old school. Makes banding and photo-banding a bit more interesting when we look closely at plumage patterns, molting progress, feather to feather, where everyone is not necessary on the same page.

Lab note, see manual for complete instructions: Remember to remove feather from eagle before inserting into the Cuisinart DrScience-462 (the whirring of the blender really freaks out the birds).

35mm transparency, Duluth 2001

From these Golden Eagles it's now easy to reimagine March — all those professional Redtails, Red-shoulders, and even Voldemort's Vultures* on track, in their season, heading home. Seen or un-. Detected or not so much. As neither waiting, nor delayed, nor late.
[* Voldemort's Vultures. Just trying to bring some of those Harry Potter Millennials into hawkwatching with a name change; Lord Voldemort commands the Death Eaters]

Hawks on NEXRAD
The root of all superstition is that men observe when a thing hits, but not when it misses.
— Francis Bacon, #bacon

Big Days and fallouts are impressive, but they can leave us with the wrong impression,

William John Swainson was an English ornithologist, malacologist, conchologist, entomologist and artist. And, John Stevens Henslow was a British priest, botanist, and geologist. He is best remembered as friend and mentor to his pupil, Charles Darwin.
Never met either, but I had Mr. Swainson's hawk and Rev. Henslow's sparrow at Derby Hill, in the county-countryside of Oswego, this August.

In the run-up to the August dispersal Big Day I had a nice two-hundred hawk Little Day, 13 August, with a bonus (Swainson's, light juv). On the Big Day, unseen until I checked NEXRAD, another surprise (Henslow's, loud & close). Then on Eclipse Day, nothin' hawk-wise, but an online image for the ages (In Other News, below).

Ideal Spring conditions in the notch on the 18th: behind the warm front and ahead of the cold front. This wedge and bubble worked fine for a dispersal Big Day.

Here's NEXRAD in motion, like a typical Spring day, dashes of raptor activity a bit in from the shoreline -- Sodus-Oswego-Tug Hill. Less than spectacular capture compared to other Augusts. Light-enough winds allowed for a more dispersed dispersal flight, and I unable to find any hawk-pixel-paths with Buffalo NEXRAD.

The Fall Broadwing flight initiates on a schedule, as tight as any Spring. On light winds, 13 September, strong inland lines head down in the Duluth area. The times indicated are on my iPhone, so eastern DST.

Biological Clockwork...
Light on the winds,

Heavy on the hawks.

In the Proceedings of the North American Hawk Migration Conference 1974, there's a paper on the use of weather radar for hawk migration study. This first such meeting had "275 hawkwatchers registered for the conference". Everything was new, in terms of discussion at this first forum. W. John Richardson opened his talk, Autumn Hawk Migration in Ontario Studied with Radar, with broad questions about where hawks might be and what they might be doing when not coming and going over the hawkwatch. He gives mention to the New England model where a couple dozen sites might be "manned" for a weekend in September, as a valiant one but not practical for a whole season.

Onto his study. Following much talk about radar units and their model numbers, he showed hawks on radar. Okay, I'm awake now! Confirming that they concentrate on approach to Big Water, but that they can just as easily fan out given the conditions to stay inland: "Furthermore, I frequently detected lines of echoes whose position changed continuously." Future me would concur in the 21st Century.

This radar image is a ten-second daytime sweep recorded a lot like Edison might have. Those blips are lines of hawks over Toronto ON (circles are 10nm).

These lines drawn are actual tracings of radar hawklines. Hands up: those of you who have actual used "tracing paper"? Seen it? Heard of it?

Two links on my site: first is John Richardson's 1974 paper closing with Q&A from conference attendees, with actual typewriter typing… not a typewriter font; second, with sources going back to the early 60s, is Jim Baird's well-told tale from the ornithology compilation, Gatherings of Angels (1999) -- his first thought and poetic reference to warblers on weather radar… just a great read!

NEXRAD Bonus Round: Dragonflies Swallows/Martins
Early AM in late August warms with huge hatch lift-offs from the north end of Cayuga Lake, out of the extensive wetlands. Below are two dragonfly swallows/martins dawn events.

The explosions of may flies and dragonflies swallows/martins (plus locusts) are large-winged enough that they can light up weather radar. Off the corner of a lake, as they emerge, a circle of activity rises. For mayflies that's it, just a blooming, round, mate, die. For the dragonflies swallows/martins in late Summer, there is a bloom with a conspicuous dispersal pattern from the hatch-bloom. In addition to mating, their rise includes movment away from the hatch site.
Here's a CNN video report on insect radar... one of many.

This lift-off flows NW from SW winds to the shoreline, staying inland.

Timed a little later, we see post-bloom both along the shoreline and blasting over-water. The flow of dragonflies swallows/martins at Derby Hill is from this center. On another day on N winds, the mass will about-face and head S depositing generations for next year.

Bonus Round: TLC's Book Club
Just now available in North America (I've been enjoying Where the Animals Go from Great Britain for almost a year). Coffee table-style, color, glossy GPS movements of vertebrates from around the world from scientific studies.

Killing two birds with one stone, twice: here are four nice sites that have reviewed the book, now that's it's available around here... each shows GPS map-meanderings of different species.
Enjoy the reviews, bookmark the sources, pair the book with a fieldguide for any birder who is young at heart and eager for the latest point of view!


In Other News...

Peanuts, 1955; Wingnut, 2017.



CanadaPost celebrates the Gyrfalcon in 2017.

We still think of events happening locally, in our lifetimes,
as significant in a way that is out of proportion with reality.

— Neil deGrasse Tyson, Astrophysicist and The Simpsons (as himself)

They've got the urge for going, and
they've got the wings so they can go.

— Joni Mitchell

Hawk•art•science blog
Truth and beauty. Art and science. Entries here will be on that flightline, although I will stray from the hawk-part on occasion, or will I? I aiming this beast at hawkheads and/or the young seasonal revolutionary biologists. It's for the flexible and young-at-heart too.
Comments, questions, excited utterances, and/or exasperated afterthoughts from you, dear reader, are welcome and will receive a reply. — Tom Carrolan
(Image above: "Recent self-portrait No.3, 2009")

Original recipe Hawksaloft.com
The Hawksaloft.com website was launched in 1997, following three years of printed handbills, plus numerous emails, all voicing my alt.hawkwatching ideas in New England. If you've been here before, the original site is archived in all its old-timey graphic glory. To navigate the old way, just click on Psychedelia the Hawk Owl and be transported back in time... trippy. Any bookmarks or links found anywhere online still work.

Not everything that counts can be counted and
not everything that can be counted counts.

— Albert Einstein