HawkArtScience: Hawksaloft.com blog

(Archive: Science, straight up)

13 October 2009, Tuesday
"I'm locked in tight, I'm out of range
I used to care, but things have changed...

Dylan continues, "This place ain't doing me any good, I'm in the wrong town, I should be in Hollywood." See, Bob understands all... no matter the extralimital species. He won a Golden Globe and a Grammy for this musical science, albeit as part of the soundtrack for the terrifically terrific 2000 film, Wonder Boys starring Michael Douglas, Tobey Maguire, Robert Downey Jr., Frances McDormand, Katie Holmes, and Rip Torn. But I digress...

I engaged on a recent OneidaBirds listserv thread that I thought was a clear case of smelly old science. The old idea goes that extralimital individuals, say a Brown Pelican hanging out in upstate NY, are 'scouts' -- really meaning 'explorers' -- some how sent forth to find new territories and benefit the cosmic species. I dashed together a listserv-long email with some informative links to some newer ideas:

Sept 3, 2009
Re: Re: Fw: pelican [really really long]

First, I am not a geneticist in real life, but I play one online!

Gerry Smith wrote:
"I agree with Tony(Shrimpton) that wandering "scouts" can play an important role in species range expansion and change."

I have a problem with this old chestnut. Hoping for an update from the literature, or something, it was just tossed on the campfire. I will offer that it's no more true than any number of truisms that existed at the dawn of modern biology -- that would be, as Darwin went to sea.

Since WWII and the domination of molecular biology over fieldwork in terms of knowledge, and quite recently with evolutionary biology coming into its own through DNA analysis, geneticist are actually and seriously able to ask, investigate and begin to answer questions with more powerful techniques -- some new questions, and some old ones, anew in the context of studies near and dear to heart of any naturalist. After all the naturalist/ecologist/ornithologist receiving their education, until recently, involving identification and ecology of species, as conducted by the very best and brightest... has been, well, superficial -- literally working on the outside surface, and including the surface of the internal structures, hard and soft. Math was added, but still not a lot of data -- limited by available training and tools.

Think of science like crime solving as portrayed in books, movies, TV: until recently, the police detectives did most of the investigating. The brain power of one or two brought to bear on the very simple scene of the crime. This theme of the police procedural then evolved slightly to include an MD, the coroner or medical examiner, to add a touch of science. Now there's a crime-solving team and that team is dominated by crime scene investigation specialists [CSI] who work in the field plus others who can solve the whodunit without ever leaving their very well equipped labs... this is the molecular biology revolution, see above. Apparently this began in Las Vegas.

Junkin's Warbler is a recent example of what I'm talking about. An odd bird, seemingly a hybrid, is captured and photographed at a banding station in western NY. The images of the bird-in-hand are posted on the elite forum for bird ID. All fun breaks out.
[after reading the posts on this page, click 'next week' to see more educated guesses]

As luck would have it, the bird's recaptured and a single feather removed before releasing. Enter CSI Ithaca.
[follow the additional, tiny links at the bottom of the first page for more]

Like newspapers, we can lament the bygone day of the naturalist, but there's a reason for it -- things change, and for the better mostly.

Next let me work in some current events, raptor-related [surprise, surprise]. There is a difference between natural selection [a genetic mechanism for change] and an adaptation [a resulting change, physical or behavioral]. Very important distinction. In many, many raptor species, females are larger than males -- reversed sexual dimorphism [RSD]. A recent peer-reviewed study looked at over 200 species of hawks, falcons and owls. Looked at their molecular relationships and found compelling evidence that the evolution of RSD preceded the top-five reasons raptor biologists and hawkwatchers have been telling you causes female raptors to be larger than their mates! We are learning anew that it is a mistake to be too current, direct and alas superficial when thinking, or explaining the world around us.
Krueer, Oliver. 2005. Evolutionary Ecology 19: 467-486.

Now in addition to the off-course rock stars of the bird world -- pelicans, other hummingbird species, plus springtime passerines of bright colors and loud voices -- all kinds of birds seem to be going the wrong way at one time or another! From my own experience just in any Northeast summer, all manner of herons, gulls, and hawks head in the "wrong" direction making their migration longer than we think it should be. Makes me wonder about the existence of a "dispersal gene." One gene [or gene complex] you say?! Sure. It seems like a genetically hard-wired behavior common to many branches of our extant bird species tree. Makes me think it's been around for a while and therefore natural selection was working somewhere in a time and place and under selective pressures we can't guess at, to survive for a reason we'd never guess in a million years... without some of that science-y work, see above.

Interesting thing, the "Wanderlust Gene" might be just what we're looking for here. This allele [the gene that makes the difference] was reported this summer in stickleback fish. Two surprises here: this little fish is well-studied in terms of its speciation because they are very active in this department [famous as fruit flies]; second, the purpose of their wanderlust was there in the gene but hidden/misinterpreted... by a whole bunch of evolutionary biologists who spend careers looking for just this kind of thing in this tiny corner of our world.

Of course it all could be otherwise and that there are new/current uses for this behavior that might evolve further or faster. Okay by me. But let's set about investigating this with these new tools and younger eyes. Some of whom might only venture out for a little birding now and again.
A few afternotes:
The debate and/or lament regarding the loss of the naturalist gene [not a real allele, that we know of] has been ongoing for a decade. E.O. Wilson, preeminent Harvard evolutionary biologist, penned a book titled Naturalist in 1996. Last Child in the Woods [Richard Louv, 2005] was recalled just a couple of weeks ago in the NYTimes. And just out, is Naming Nature wherein Carol Yoon has the chapter, "Better Taxonomy Through Chemistry"!

Two completely readable books, on background, would be Neil Shubin's, Your Inner Fish. Here you'll quickly identify paleontology with birding as he weighs where to go for potential fossils, like you choose a locale for warblers or shorebirds. Also, there's The Reluctant Mr. Darwin by David Quammen. This is the best and shortest bio of basically our first biologist... that would be a naturalist who thinks scientifically.

And six letters for all you youngsters out there thinking about studying yourself some biology someday to make a difference: DNA & GPS.

Tom Carrolan
Nothing in biology makes sense
except in the light of evolution.
-- Theodosius Dobzhansky (1900-1975)

Furthermore, with the emphasis on more, today's Lewis and Clark of the bird world (Meriwether & William) are statistically more likely to be Mary and Kate: recent studies reveal that in Snowy Owls and Western Bluebirds (for a couple of diverse examples) juvenile females and females in general, move the farthest distances from their homelands... and do it most readily. Curiously then, last Winter when young male Snowies were occurring here, where were the females? Think about it, okay, think a bit more.

27 October 2009, Tuesday
Big box of birds, aka, Lab of Ornithology

CornellHeading down the highway, got Joni and Warren queued up on the iPod, but when I get in range, FSRN (Free Speech Radio News) will be coming in loud and clear from Ithaca, also known as, Cambridge with cows... my trademark anyway. That "Ithaca is Gorges" slogan can't last forever. Although I liked the "Ithaca is not George's" bumper stickers and t-shirts. Nowadays though people just ask, "George who?" But I digress...

Jeff Podos, UMass Amherst, spoke at Cornell Monday night on his bird song research including work with Swamp Sparrows and Galapagos finches. Don Kroodsma who penned The Singing Life of Birds is retired now, but this ornitho-lyrical office continues there. Don's book is a must read; there are links to Jeff's journal work at his page. Last night, Dr. Podos covered a lot of his cutting edge thinking before a hundred birders and biologists gathered in the expanded version of the old Lab room, as the Louis Agassiz Fuertes paintings and wood panelling have been faithfully forwarded along with the other traditions of the Monday Night Seminars. A extended question and answer session followed.

Charles Darwin established the importance of sexual selection after pondering the lavish expenditure of evolutionary energy into the Peacock's tail and other garish male appointments. Females make choices, driving this natural selection bus, he discovered (the males push it thru space and time?!).

Podos investigates the performance limits of bird song and by doing so has found out some groundbreaking stuff about its evolutionary importance (Here are a few notes of my own from Jeff's presentation):

  • Bird song is a demanding exercise: when young Swamp Sparrows are given their song to learn, but it's played way too fast for them to sing in real life, they attempt it, but when charted it shows gaps or rests due to performance limitations... the energetics, the difficulty inherent in song is visible
  • On the other hand, given an unnaturally slow version of their song to learn, they will ramp it up after they get it down; so while they need to practice their species' song to get it right, they do inherently head for their species' energetic edge of the envelope (this aspect of Jeff's work is unpublished)
  • From studying performance limits we learn that singing notes at a high frequency or singing very fast takes the most energy and therefore is most attractive to females; extra-pair copulation (EPC) studies show that the best singers also get the most (sparrow) tail
  • In head-to-head situations, males step up their game: singing higher and faster
  • In the Galapagos — the Darwin-Podos connection — Jeff has studied the song of Darwin's finches: one species in particular has a big beak and small beak morph; and guess what, true to form, the big beak guys sing a low, slow song [low performance] & the small-billed males sing high and fast... looks like you can invest in one thing or the other, evolutionarily speaking, but not both
  • In Chestnut-sided Warblers, ability to hit the highest frequency note gets the girl (again this is high performance in terms of the most energy to task)
  • In Black-capped Chickadees nailing the song is key: replicating the exact pitch of the fee and bee notes, over and over, gets her attention; this likely signals both good genes and experience... the chicks really digs that.
  • Work with Black-throated Blue Warbers in NH and NC is ongoing by new Cornell Macauley Sound Lab Director, Mike Webster: the northern and southern populations have some differences in their song & their response to the song of the other population; along the same performance limits: are we seeing speciation in the making or other selective factors in play(?); as you know by now: higher trill frequency in the male's song (the stud factor in warblers too, it looks like), produces the highest EPC rate.

On Monday, November 9th, Matt Carling (a postdoc at Cornell) presents, "Bird speciation: insights from Lazuli and Indigo Buntings":

Ever since Darwin penned 'On the Origin of Species,' birds have been at the forefront of speciation research. In fact, much of what we know about the importance of geography, ecology and behavior in the formation of new species has resulted from studies of birds. That said, we know relatively little about the genes important in bird speciation. This talk will discuss what we can learn about the processes of speciation by focusing on studies of Indigo and Lazuli buntings.

Who knows, catching this program just might do your personal EPC rate some good (in press).

28 October 2009, Wednesday
Sparrows vs. Plovers; winners face the Falcons

Hi sports fans! I'd take the Falcons and the points when it's all said and done, but that's just me.

Here's another bird song study involving sparrows, along with new and game-changing info on Snowy Plovers and Eleanora's Falcon. Three levels of entry into this science round-up post are available to you: read my snippets below and leave it at that. Continuing from there, click on the species name to view an easy-to-read press release. And if you have access to a college library, seek out the actual journal article — 'cause you're gettin' your science on, player. For most, the first two parts will do.

Song Sparrows are well-studied for their variety of song, hence the name. Jeff Podos, UMass Amherst, told me on Monday evening he had seen this current paper in preparation. It jumped out at me because the old story would have it that a young male focuses in on its father's songs to learn the trade. But it's more than that... the son especially wants to hear conversations...

[Young male Song Sparrows] generally moved closer, faster and farther when they heard recordings of two adult male sparrows interacting than when they heard recordings of a solo sparrow singing.

Kentish and (American) Snowy Plovers appear very similar in the field, and therefore lumping versus splitting them, species-wise, has been a question mark. But a DNA analysis of birds from the here, there, and Africa published in the October Auk concluded:

For the first time we've shown that these birds have been separated for a long time and evolved in different directions.

In addition to revealing the migratory route of the Eleanora's Falcon, using GPS tracking fills in other previous unknown facts about this extreme falcon.

The new discovery made by this study was that the falcons do not fly over the waters of the Mediterranean and along the East African coast, but instead cross straight over the African continent.


10 November 2009, Tuesday
"One of us, one of us..."

I don't know, I just wanted to quote the 1932 film Freaks on down the path to The Outermost House (1928). Henry Beston sought the rhythm of the sea and came away changed. "Us"...

We need another and a wiser and perhaps a more mystical concept of animals. Remote from universal nature, and living by complicated artifice, man in civilization surveys the creature through the glass of his knowledge and sees thereby a feather magnified and the whole image in distortion. We patronize them for their incompleteness, for their tragic fate of having taken form so far below ourselves. And therein we err, and greatly err. For the animal shall not be measured by man. In a world older and more complete than ours they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings; they are other nations caught with ourselves in the net of life and time, fellow prisoners of the splendour and travail of the earth.

For my early-in-the-week, new-science round-up we learn that a couple of old souls are not as primitive as we had imagined, and hopefully we can relate, even if we prefer to do so from a safe distant:

  • Great White Sharks from the northeast Pacific Ocean charted with GPS tags and passive acoustic pings — now can be seen to be leading a purpose driven life, shark style. In addition, studied genetically, we find this solitary eating machine (TV & science class cliche #273) is a regular homebody.
  • Alligators in Louisiana, and elsewhere likely, commit to long-term relationships, as revealed in this long-term study. Birds inherited this, maybe, rather than just making it up on the fly.

Rated NC-17 (for mature audiences), Short-nosed Fruit Bats lick each other in a way that, I think, is still illegal in a few states, were they us. The authors conclude their study with possible evolutionary reasons for this act. The link is through Jerry Coyne's Why Evolution is True blog/book site. A video for late night viewing is provided in the secondary link to the online article from, but still peer-reviewed journal, PLoS One... of us. Ah, the jokes, the jokes are so many, but let me conclude by saying, I don't think even Darwin saw this one coming.


26 November 2009, Thanksgiving Day
Power of the talon, explained

Raptors have made the pages of Wired magazine, online! It is a nice bit of visibility for the natural world to land there, even if their editors were maybe drawn to the image of dismembered talons, thinking of it as a hardware review — so many USB hubs or thumb drives. I was thinking mouse holders, but that's just me.

We're already fairly disconnected from the whole of stuff around us, so the components methodology of beaks/feets/wings, popular with old-timey nature centers and educators, doesn't need any encouragement in my view. In this case, however, the story goes that these paleontology grad students found a box-o-talons and the parts, looking odd and ancient, got them started down a road to some original research:

A journey that started with a box of bird feet carried three Montana State University graduate students into the gruesome world of raptors and led to their findings being published in a prominent journal.

Normally focused on dinosaurs, the students compared the claws and killing methods of four types of raptors and published a paper about their research in the Nov. 25th issue of PLoS ONE, a scientific journal published online by the Public Library of Science.

I've mentioned the online, peer-reviewed journal, PLoS-ONE, before and I've gotten feedback from both profs and students, so here it is again. It's open-source science in a way, while still rigorous, it is quick to e-press. At their site, you'll find the full and digitally sexy edition of this article, including reference links, with the tables and images in several formats for quick and slick use in your work or classroom. And then there's "recent molecular phylogenetic analyses suggest"... oh, be still my spiraling DNA.

The old joke goes, "Denial is not a river in Egypt." My sporadic mix-in of my concerns about the outright opposition to not only the scientific method, indeed science itself, along with the boring deniers has brought forth interests from high school educators, science and otherwise. Here the quest is the path of discourse, the pitfalls, and bounds of proactively bringing this into their work, formally and informally. I've come across two pretty good examples:

  • Kickin' it old school, here's a back and forth about Michael Specter's new book, Denialism over at Salon.com offered in a four-part dialogue between Specter and Chris Mooney, author of The Republican War on Science (2005) and Unscientific America, recently. Specter writes for The New Yorker... all kinds of civility breaks out, and that's refreshingly intellectual, accessible, and not at all emulating the food-fight premise that, unfortunately, kids bring into school from the media in general. In the first exchange, Mooney points us to one of the recent polling summaries on science and technology, this from the NSF. Again it's back and forth, richly and respectfully.
  • And connected to this holiday post about digesting things, I caught this interview with Randy Olson, author of Don't Be Such a Scientist, on Talk of the Nation. Taking direct action against the growing anti-science movement, this former UNH professor has now gone Hollywood. Here's both a book and a listen from an articulate scientist on the frontline of precision. A search over at the iTunes Store will turn up a couple of Dr. Olson's lectures on the university circuit (that would be through the iTunes app on your Mac or PeeCee).

11 December 2009, Friday
Science, Friday

Every freakin' thing we touch these days has its politics, most certainly when some talking head, elected or anointed, assures us their agenda is without. Whether art, history, science, you name it, it comes with politics. By politics, I mean ego and old ways. On the one hand conspiracies can be seen everywhere from the grassy knoll to climatologists' emails. The good news from my perch anyway, it gets messy for a while, then (to paraphrase Stephen Colbert of The Colbert Report), facts have a well-known liberal bias and things work themselves out. Basically, scientists are not in cahoots, but are in an infinity loop of proving and disproving each other (themselves too, in order to avoid others doing it to them). It's an intellectually exciting shooting gallery.

I have gathered up a few nice climate change science article abstracts that might interest hawkwatchers, plus a couple of sane summaries of the email kerfuffle. That will come next week as Copenhagen winds down. These lead in...

In songbirds, Blackcap evolution is happening right before our "eyes" (where eyes are genetic markers); more Sahara Desert crossings by raptors (wearing GPS transmitters); and science that contradicts... oh, science we hardly knew ye (see, it's not a belief system, it's science).

Blackcaps, an old world warbler, have been in the science news as they're evolving right now, over the last few decades. Not forming new and reproductively isolated species quite yet, but keep watching, especially if you have a birdfeeder in England. The BBC reports poorly by over-interpreting the study. They asked someone not involved in the research for their interpretation, this is not verboten in reporting, but here, mere activity and evolutionary change got confused in a hurry... and that got reported. NPR's Science Friday covered it — just the study, without getting into the BBC report — and here's the podcast conversation with the lead author only. Finally over at Jerry Coyne's blog, all this is summarized... especially, whether a student of biology or not, you might need a summary of the evolutionary science particulars. What's not to like: read a little , listen some, maybe read some more.

Another team of scientists has tracked how raptors handle the great desert, Sahara. The NYTimes has a quick look into this project that involves several hawk species, adults and juveniles. As can be the case, the authors mined their results for a couple of papers. Here's the full journal article with GPS maps for the various species they followed (can't get enough of those dots). Then they pulled out the Eurasian Hobby's course work and focused on their adjustments to reach the best and remnant wintering grounds.

I find the similarities between desert and water crossing fascinating. To be sure, not the same thing... wait for it... on the surface, unless studies from the desert reinforces what we see in hawks crossing water. When I suggest to folks interested in ideas, that there are no new ideas, I mean that one idea is often, dare I say always, building off another that came before. Even if you do the opposite.

Who couldn't go for a little old penguin and dinosaur info over the weekend? And in both papers, offered for your scientific consideration: we got it wrong. Where the "science we" is our colleagues who have studied and published before us. This will be both supported and challenged by investigations to come. In a look at Penguin DNA:

Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been routinely underestimating the age of many specimens by 200 to 600 percent.

In other words, a biological specimen determined by traditional DNA testing to be 100,000 years old may actually be 200,000 to 600,000 years old, researchers suggest in a new report in Trends in Genetics, a professional journal.

And there may be fewer dinosaur species than we thought! Been there, done that myself... well, when photographing Sonoran Desert lizards back in 80s and then trying to ID my images... there were fewer species than I hoped when I finished pouring over the field guides. This one just takes a taxonomist's eye and looks at the details too, old school:

"Juveniles and adults of these dinosaurs look very, very different from adults, and literally may resemble a different species," said dinosaur expert Mark B. Goodwin, assistant director of UC Berkeley's Museum of Paleontology. "But some scientists are confusing morphological differences at different growth stages with characteristics that are taxonomically important. The result is an inflated number of dinosaurs in the late Cretaceous."

If dinosaurs interest you or some young dino nut job spawn, as you read down the ScienceDaily.com digest, the full article with illustrations is published at the online journal, PLoS-ONE, the link is at end... DIY sci.

Previous science snippets along these lines are in a Hawk•art•science archive and pasted up here. The current list of archival topics is to the right, under the Redtails-in-cans image.


23 December 2009, Wednesday
Arsenic and old face

Venom in the animal world is like wearing orange (away from the Syracuse University area, that is): it stands out as unusual. Now with DNA work tracing this molecular orange around has lead us to see this oddity as much more pervasive, especially where we had only a hint before.

Recently, the world's catfish were in the science news for new info on their lineage and toxicology. Now, Sean Carroll — Professor of Molecular Biology and Genetics in Madison WI —has a fascinating NYTimes column on how species tolerate high levels of tetrodotoxin. This poison out-poisons arsenic and potassium cyanide, but the poisonous species that use it, from disparate lineages, are themselves immune.

This isn't even the best part! I will let the teller tell the tale, as Dr. Carroll is also an award-winning author and teacher, but we've learned that it's evolutionarily easy to get the drug "on the street" and not fall prey to the toxin once it's within. You just can't make this stuff up.

In addition to the primitive look coming at you from the inset image — a Goshawk showing off good old fashioned mechanical death — there's an even more primitive bird found fossilized in China, that in addition to some serious hardware, used chemistry to kill.

7 January 2010, Thursday
Anteater interview

Actually it's an interview with an anteater scientist. Well, maybe it's not quite that either, but there's said to be a grain of truth in almost anything... and this proves that theory.

In actual news both MSNBC and CBC covered the encounter between illegal Japanese whaling activity and Paul Watson's Sea Shepard activists. Rachel Maddow interviews Bob Barker, who when told by Watson that it would take five million dollars to curtail the latest Japanese whaling operations said, "The price is right." Barker made the donation and they named one of the craft after him!

On CBC Radio One, the great and true environmental activist Paul Watson is interviewed in the second hour of the program (it follows a folksy piece on the weekend's Nor'easter washing tons of lobsters onto people's lawns in New Brunswick). Using the CBC Radio app on your iPhone or iPod Touch, program segments can be listened to on demand.


13 January 2010, Wednesday
Science from the North Atlantic

Geolocators are used on smaller birds to see where they go and when. The bird needs to be recaptured (or the device recovered) so the data can be downloaded. It's not like the larger GPS transmitter used on a bigger species, like the Osprey, where the satellite shows the position of the organism in nearly real-time.

BBC science news had a piece today on the Arctic Tern, and our textbooks need an update.

The first surprise is that the terns do not make straight for the Antarctic when they leave the Arctic, but make a lengthy stop-over in the middle of the North Atlantic, about 1,000km (620 miles) north of the Azores. Here, they feed on zooplankton and fish to fuel themselves for the long journey ahead...

The birds then head south along the coast of western Europe and western Africa before making a choice, either to continue hugging Africa or sweep across the Atlantic from the Cape Verde Islands to continue the journey along the Brazilian coast.

About half the birds that were tracked decided to take the South American path. It is not clear why, but the researchers believe wind might make either route seem favourable to the terns.

More detailed info plus additional (insert neatogrooveykeen here) tracking maps are on the project's web site. This is also an article with the full PDF online, for viewing or downloading ("other-click" the PDF inset to pop up a menu).

A similar study, combining small trackers and other info, was reported this week for the declining Atlantic Puffin. And, like the terns, we find movements that banding returns and birders' observations have missed.

Since there was an unprecedented mortality of adult puffins over the 2007/2008 winter, the logger results suggest that conditions in the North Sea may have become less favourable for puffins in recent years, particularly during autumn and early winter, forcing many birds to move into the Atlantic. Here they have to travel greater distances and adapt to different habitats.

29 January 2010, Friday
Science, Friday

Over twenty years ago now, I was eagerly observing, enjoying, counting and reporting along with the hawks, "other things with wings" on the move: Crows, Blue Jays, Monarch Butterflies, and AJs (dragonflies). These are some of the volume generators, those Counter Culture skid marks, count everything today. Migration study holds no bounds (he clichéd).

Monarchs have an amazing story, just repackaged — Lincoln Brower, yada yada yada, Mexico — on NOVA. You can actually watch the thing online.

A little like reporting on the new Apple product before the official roll-out, Jerry Coyne, UChicago evolutionary biologist, author of Why Evolution is True and the blog of the same name, has read a ready-for-publication article on Monarch size, migration and the genetics behind it. On his blog, he also notes a pre-release article on the article over at BBC Earth News that covers the study by retyping the press release, after a fashion.

Dr. Coyne comments on the BBC reporting, but also on his questions about the study.

The BBC report, written by Matt Walker, echoes this conclusion in the report, titled “Supersized monarch butterflies evolved to fly far.” [:]

• These “supersized” butterflies have evolved to cope with the demands of long-distance flight.
• In contrast, monarchs that live in one place all year have wings that are up to 20% smaller, report scientists in the journal Evolution. . .

Is there anything wrong with that? Well, one thing: there’s another explanation for the results, not depending on migration, that neither the paper nor Walker considers. It is this: it has long been known that if you look at populations of insects from different areas of its range, those from colder locations tend to be larger (both developmentally and genetically) than those from warmer locations. In other words, they conform to Bergmann’s rule, an “ecogeographic rule” that states that the body mass of an animal is positively correlated with the latitude where it lives. In other words, populations from colder areas have bigger bodies.

The classic explanation of this “rule” involves mammals: if you’re living in a colder climate, it’s adaptive to have a larger mass, for the ratio of heat produced (proportional to the cube of a linear dimension, in other words body mass) to heat lost through radiation (proportional to the square of a linear dimension, in other words body surface area) is lower for larger animals. That is, it’s easier to stay warm if you’re bigger. Now this explanation holds only for warm-blooded animals (homeotherms), but we now know that the “rule” is also obeyed by many cold-blooded animals (poikilotherms). I’ve spent a lot of my career documenting this in Drosophila, and it’s clear that, regardless of the species, populations from colder areas evolve larger size. Why this is so in poikilotherms, who don’t produce body heat to keep warm, is an intriguing but unanswered question. But the phenomenon is real.

The apparent problem with Altizer and Davis’s result is this: all the “nonmigratory” populations live in warmer areas than do the “migratory” populations. Therefore, we expect nonmigratory individuals to be smaller than migratory individuals (i.e., have smaller wings), even if there were no difference in migration behavior. (This is aside from the fact that the authors draw sweeping conclusions about genetic differences from comparing only two migratory populations with only a single nonmigratory population.)

I just love this stuff. Coyne is questioning, yet respectful, but raises very interesting points, for both answering and further study... love that further study stuff.

BTW, the paperback edition of Why Evolution is True is on the shelves this week — public, commercial, virtual — and it is the best read and reference for any professional teaching biologist... semi-pro or amateur with an interest.

2 February 2010, Tuesday
Catbirds smell good!

But how do they taste? I think we'll leave that question for a panel of hawks and owls, meeting in a few months at a five-star forest near you.

In a study just released last week and conducted mainly in migration-rich New Jersey, biologists now think that birds experience their flyways by the various scents along the way. They learn this though over the course of the first journey.

Birds largely rely on their sense of smell to navigate on their long migration routes. Indeed, the “third sense” has been shown to be a more important for them than orientation based on the sun and the earth’s magnetic field. Exactly how birds navigate on their migration routes has not yet been fully clarified. How does a bird develop an “internal map”? How does it find its way back to last year’s nest?

... [A]dult migratory birds are able to remember routes that they have flown just once, and to correct their flight direction following a change of location and find their way back to their wintering locations. This is proof of real navigation performance and, based on this, scientists are trying to identify the factors and mechanisms that enable the animals to find their locations.

On the ancient side of things, it might be interesting to consider the long history of the migratory story. Both dragonflies and birds seem to follow the same rules.

"The dragonflies' routes have showed distinct stopover and migration days, just as the birds' did," said Wikelski, an associate professor of ecology and evolutionary biology. "Additionally, groups of both birds and dragonflies did not migrate on very windy days and only moved after two successive nights of falling temperatures. We saw other similarities as well, which makes us wonder just how far back in Earth's history the rules for migration were established in its animals."

Another ancient biological event, the virgin birth, might now be more believable to the non-believers... if they know that sharks can pull it off (or is it out). On the other hand, here's another case for the evolutionary unnecessity of another appendage, the male of the species. Plants have figured it out too.

There's a nifty little clip of foodite Michael Pollan talking real food with Oprah online over at Grist. And hoping this fast food quickie posting is fun, if not nourishing, I have a couple of longer weather-related ones in the works. Plus, I finally think I figured out why my all-time favorite Monty Python skit just gets funnier over the years... Dead Parrot Science — coming soon.

10 February 2010, Wednesday
The whole is greater than the sum of our parts

Of course it is, and well it should be. Whether it's a concert pianist, professional athlete or professional hawk, the whole is greater than the sum of its parts. A hawk is not the summation of talons, powerful eyes, wings on soar... it is more, whole, and because it is not less than us, equal partner. In wars ancient, and modern religions, it is important to make others less than us so we can either conquer or utilize them. More and more studies are showing us that this just doesn't have any basis in fact/science.

Got to love a bat study with "zen" in the title. That's what I'm talkin' about. And the photo with the article's release statement is worth the click. The art and science of bats, and probably all other hunters is examined through a simple study with high tech tools.

These bats emit paired clicking sounds and the researchers found that the sonar beam created by each click alternated to the left and right of a target. This alternating pattern effectively directed the inside edge, or maximum slope, of each sonar beam onto the target. As a result, any change in the relative position of the target to the bat reflected that large sonar edge back at the bat, delivering the largest possible change in echo intensity.

Seen any great tits lately? GoogleSafeSearch had reset itself this morning (to ExtraCensorshipMode... my term) and it took a couple of minutes of banging around to get search results for this species because of the its name. An impressive genetics study of Parus major looks into personalities and therefore behavior and adaptation, within but beyond this little chickadee. This stuff of behavior is more than just learned and lost (with an individual or within a family etc. that would be the case, where it not encoded... in advance).

Gene variation is the reason that some great tit populations are more curious than others. In humans and animals alike, individuals differ in sets of traits that we usually refer to as personality. An important part of the individual difference in personality is due to variation in the underlying genes. One gene, the dopamine receptor D4 gene, however, is known to influence novelty seeking and exploration behavior in a range of species, including humans and birds.

In both of these studies, and many more lately, we see our affinities to all life expressed through our DNA across space and time.

18 February 2010, Thursday
Size might matter...

Two studies reported out in the last week have looked at body size in two different ways. Both though have similar implications in a changing world.

Changes in body size for vertebrates are happening, but more rapidly farther North.

Changes are happening primarily in higher latitudes, where Prof. Yom-Tov has identified a pattern of birds getting smaller and mammals getting bigger, according to most of the species he's examined. The change, he hypothesizes, is likely a strategy for survival. Prof. Yom-Tov, who has spent decades measuring and monitoring the body sizes of mammals and small birds, says that these changes have been happening more rapidly.

His most recent paper on the topic, focused on the declining body sizes of arctic foxes in Iceland, appeared in Global Change Biology.

Next, in a fairly simple study using some high tech, biologists have shown that stopover times are effected by another factor, besides the weather. While the study is pretty basic and reinforced something you might have guessed at over a couple of beers, their conclusion and therefore the reinforcing hard science is important. There are also some interesting "related stories" in a sidebar.

Small migratory birds, like the garden warbler, must make stopovers on their journeys to their breeding grounds. When they have crossed extensive ecological barriers, such as deserts or oceans, they must land to replenish their fat reserves. A researcher from the Max Planck Institute for Ornithology in Seewiesen and a team of Italian colleagues measured the duration of the stopovers made by garden warblers on an island off the Italian coast. There they observed that fat birds usually move on the night of their arrival, while thin birds interrupt their journey for an average of almost two days.

Unrelated to today's sizings, but a prelude to tomorrow — Sean B. Carroll had a very nice birthday card to Darwin in Tuesday's Science section of the NYTimes. Darwin and Lincoln both were born on February 12, 1809, did you know?

Dr. Carroll's piece is about a slightly younger man, Henry Walter Bates, who upon reading Darwin's Origin of the Species realized his own explorations and collections supported Darwin's theory in a new way. Bates wrote to Darwin: "I think I have got a glimpse into the laboratory where Nature manufactures her new species." He was referring to mimicry.

When Bates published his idea, significant enough to be known to this day as Batesian mimicry, Darwin wrote back to say it was, “one of the most remarkable and admirable papers I ever read in my life.” Stay tuned.

19 February 2010, Friday
Darwin at the Lab, sort of

Last Friday, February 12th, was a birthday for Abraham Lincoln and Charles Darwin. Both were born on the same date in 1809, so both were two hundred and one years old. Celebrate.

Lincoln fought to bring an end to slavery and thereby hoped for an equality for all citizens, while Darwin, in his second major tome (toward the end of his life) made a biological imperative case for the equality of the sexes. This was the climatic message issued by Yale ornithologist Richard O. Prum at the Cornell Lab of Ornithology seminar last Monday night!

Prum works a lot with feathers: evo-devo; color, created both chemically and physically; and Darwinian courtship display. At the electron microscope level, his work with structure of melanocytes — black and brown pigment packaging — comparing the extant and the extinct (birds and dinosaurs), lead to the recent image in the mainstream media of small dino-bird with a brown crown and striking black and white wings. Old school coloration. This amazing scientific work, not guess work, was genius at work and likely caught the eye of the MacArthur Foundation leading to Dr. Prum receiving one of their famously unrestricted grants last year.

All this is a matter of teamwork for Prum and his brilliance shows up in all kinds of work on birds but also in some other fields. He works openly and generously with chemists, physicists, paleontologists, geologists... as you can see from Prum-online.

Now the birder turns aesthete, a "vagabond for beauty," but way more scientific than poetic. Still the sights and sounds of this stuff came Monday night as music to the ears of this hawk, art, & science guy (me: the dull end of the knife). Building his case through the evening and in the spirit of Darwin, with great energy and intellect, Richard Prum took up the mantle of Darwin's theory of sexual selection. Both Darwin and Prum theorize that the female sexual agency — female mate choice — drives evolution, and, pilots the course of change and speciation equally with natural selection. Not frivolously and not as a less than equal partner.

16 March 2010, Tuesday
Bart Simpson, Hummingbird behaviorist

While it's just too early for Ruby-throated Hummingbirds to be returning, on Sunday our eastern hummingbird species got some primetime facetime.
[Note: Double-click on the image above to play this QuickTime clip.]

Bart Simpson once wrote, actually more than once:
A burp in a jar is not a science project
A burp in a jar is not a science project
A burp in a jar is not a science project
A burp in a jar is not a science project
A burp in a jar is not a science project
[Opening chalkboard scene originally broadcast 18 November 2001]

For those keeping score, this may or may not be the first installment of Simpson Science. The show has used pretty good science on many occasions over its twenty seasons on the air. So instead of using it to mock something, it might pop up again when it works.... now, go ahead, play the clip again. You know you want to.

17 March 2010, Wednesday
Science, Wednesday

Adding to the other changing size studies, reported on here (18 February '10), this study comes from North America, and more precisely PA. As always with a BBC page, there are any number of other interesting articles allied with this one... all depends on how interesting you are.

Songbirds in the US are getting smaller, and climate change is suspected as the cause. A study of almost half a million birds, belonging to over 100 species, shows that many are gradually becoming lighter and growing shorter wings.

This shrinkage has occurred within just half a century, with the birds thought to be evolving into a smaller size in response to warmer temperatures.

However, there is little evidence that the change is harmful to the birds. Details of the discovery are published in the journal Oikos.

In biology, there is a general rule of thumb that animals tend to become smaller in warmer climates: an idea known as Bergman's Rule.

A brief note in yesterday's NYTimes Science Tuesday section links us to the State of the Birds 2010 report. There's a link from there over to the report's website. But the press release page is good destination with several bulleted points. From here you can back into the rest of this effort from many bird groups including National Audubon and the Cornell Lab of Ornithology.

• For bird species that are already of conservation concern such as the golden-cheeked warbler, whooping crane, and spectacled eider, the added vulnerability to climate change may hasten declines or prevent recovery.

• The report identified common bird species such as the American oystercatcher, common nighthawk, and northern pintail that are likely to become species of conservation concern as a result of climate change.


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