Monthly Archives: May 2011

How Birds Migrate

i-76891fc7febc8891ce44d8624c2b0bcd-howbirdsmigrate_altnernativecover-thumb-250x397-65213.jpgAs part of Migration Week (inspired by this post), I’m covering migration related books (mainly having to do with birds). How Birds Migrate by Paul Kerlinger (with Illustrations by Pat Archer), Second Edition, is an affordable, up to date (2009 publication) comprehensive and intelligently written book. It is written for the general public but is not dumbed down.

The thing about bird migration is that there are many facets to the behavior. There are different kinds of birds, with respect to the nature of their flight, body size, etc (think albatross vs. hummingbird). There are many kinds of landscapes across which birds migrate (terrestrial regions of varying degrees of habitability vs. open ocean). Migrations may vary in length or even fidelity to the process, with some birds in a given population doing it, others not. And, of course, there are numerous mechanisms involved in the process, with some subset of those mechanisms being used by any given bird species.

The best way to think about migration is probably as a collection of strategies using a collection of tools by a diversity of bird species.

This book does a good job at slicing and dicing the problem of migration up into bite size bits, and presents this information with numerous case studies that personalize (or should I say, birdize) the discussion.

The book is available on the Kindle but I’m not sure I would like that version, given the importance of the excellent illustrations.

Summer Reading Suggestions: Science

Here is a short list of what you should read this summer in science and science related topics. Some are old, some are new. There is a lot missing from this list, I’m sure, but the summer is short here in Minnesota and we’ll be busy with the corn, so there is not much time.

What am I missing?

I’m working on my Summer Reading Suggestions: Fiction list but I think I’ve only read one fiction book since last summer so this may be a short list. I may ask my facebook friends to come up with some suggestions that I’ll compile. Feel free to join in on that.

Extinction rates have NOT been over-estimated

ResearchBlogging.orgThere are several things that cause extinction, but ultimately it is always the same: The last individual (or small number of individuals) of a species die. That may sound like a trivial explanation for extinction but consider what happens when you work backwards from that tragic moment in time. Well, you have more individuals in a population that was once much larger but was reduced in size somehow, which then dwindled to the last few, the last one, then zero. But how did that small population go from hundreds to a few then to zero? Most likely for no particular reason other than this: The number of individuals in a population can be made to vary in roughly absolute terms, as well as relative terms. Say there is a population of a rare rabbit, Bugs bunnii living in a region the size of Yellowstone National Park. If you introduce 1,000 coyotes to this area, they will eat rabbits indiscriminately, all species, and along the way they may consume almost all of the B. bunnii leaving maybe three or four. Then, those wemaining wabbits die off because they are all males, or for some other totally dumb and tragic reason.
Continue reading Extinction rates have NOT been over-estimated

The Marvelous Migrating Whooping Crane

They used to hunt whooping cranes. Between that and habitat loss, the number dropped from nearly 20,0000 to a mere 1,400 during the first half of the 19th century, and continued to drop to an all time low of 15 birds in 1941.

Fifteen birds, in 1941, represented the entire species.

All those birds were members of a single flock that migrated between the Aransas National Wildlife Refuge in Texas, USA and Wood Buffalo National Park in Canada.

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Most people know the story, or at least, the vague outlines of the story. Much has been written about them, including several books such as Cranes: A Natural History of a Bird in Crisis, which is about cranes in general (most cranes are threatened or endangered), and a few ~ A few ~ their rescue ~ and comeback. There are also academic works on the whooping crane story, including a study of what happens to their genetics when their population undergoes such a bottleneck. They’ve even been sullied by economists.

With considerable effort from numerous private and government agencies, in both Canada and the US, the whooping crane population has soared, bird-like, from about one tenth of one percent of their normal population to almost 2 percent of their normal population (from 15 or so, depending on which source you like1, to between 300 and 400, of which only half live in the wild) over a period of about 60 years.

One of the things that had to happen to save the cranes was teaching new chicks where to go, and this was accomplished by getting them to imprint on humans. Then, the specific human to which the bird had imprinted was attached to a lawnmower engine with a propeller on it and flown along the migration route. More or less.

As it turns out, the future of the whooping cranes was tied to a small plane. Creating a new migratory flock of whooping cranes required teaching young chicks how to migrate without the assistance of adult birds. The International Whooping Crane Recovery Team decided to use an ultralight aircraft as a teaching tool to show the young whooping cranes how to fly from western Florida to Wisconsin. The program has proven very successful and as of October 2009, there are 77 whooping cranes that follow a plane from Florida to Wisconsin and back each year.

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Once the cranes were imprinted on humans they needed to undergo the crane version of dating, which involved an elaborate mating dance, with human rather than crane partners. Or at least, that’s what the crazy scientists such as Dr. George Archibald, who engaged in this … activity, insisted to be necessary.

Saving the whooping crane from extinction certainly required a great deal of effort. And dancing and flying.

wcrane_Tex&Geo.dancing.jpgYou will see, occasionally, verbiage such as “whooping cranes have come back from the brink of extinction.” That’s not true. They are still very much on the brink of extinction. Although there have been efforts to split the slowly growing flock into different geographical distributions, it is still the case that the wintering grounds could all be affected by a single bad hurricane year (and we do have them now and then). And, with several states attempting to bring back crane hunting, some will surely be shot while migrating. (I assume there is no effort to bring back hunting of this species, but given the way things operate there will be collateral damages if Jeeter and Bubba are in fact allowed to legally shoot at crane-like birds).

Internet resources and photo sources:

Cornell Lab of Ornithology Whooping Crane Page
National Wildlife Federation Whooping Crane Page
Wikipedia
Journey North
Operation Migration
National Geographic Animals Whooping Crane Page


1National Geographic says 16; Wikipedia says 21; The National Wildlife Federation says 15.

Live blogging a tornado

Well, that was interesting. We are having turbulent weather here in Minnesota. The current low pressure system passing across the US is sitting on us like a bullet on a bull’s eye. Almost every line of storm activity is breaking into small blobs which in turn are spinning up wall clouds and twisters, mostly small, mostly only on radar, mostly not touching down.

Except the one that is currently bearing down on Coon Lake Beach and Forest Lake. It was spotted on a traffic cam earlier, seen by some spotters, damaged a shopping mall, and hit the small airport we have down the road from here. But what happened here, at our house, was kinda cool.

A large cloud which I believe contained the tornado to our east sat over head dropping one or two inch an hour rain (but no hail). However the wind velocity was zero. The leaves on nearby trees were quivering lightly from being rained on. I heard the freight train but the air did not move.

Then, just as the sound of the tornado going by faded into the distance, with the wind still at zero, leaves started to fall. I could see them way up in the air, two or three times higher than the tops of the perfectly still trees all around me, and the leaves fell, spinning or wavering a bit, but not much, straight down to the ground. And, when they hit the ground I could see that every one of the green falling items was a small fragment of a leaf or other vegetation. Debris carried high into the air, spread out from the tornado, and gently dropped on it.

As I write this I’m hearing that dozens of homes in one area have been damaged, people are using their own axes and chain saws to cut through trees sitting on people’s houses to rescue those trapped inside. No reports of injuries from that locality right now. I don’t know where the heck the breathless reporter was calling in from … oh, wait, North Minneapolis. People are trapped in their homes and cars. We’ll keep an eye on that.

UPDATE: They’re showing traffic cam film of a twister on the ground in Forest Lake now, a few miles away from the camera, which in turn is in the sun.

Three Academic Books on Bird Migration

These are the kinds of books you get if you are either a scientists studying bird migration and related issues, or a very serious bird geek. The first two can be obtained at very low prices used, but the third will set you back at least 50 bucks US$ if you want a used copy. Note the spread of publication dates. It is not the case that the oldest book is out of date in all respects: Quite the contrary. Alerstam reviews theory and ideas that have not been revisited or revised to any great degree. Also, it is interesting to see how changes in the field develop over a decade or so. In any event, I’ve labeled the books by year of publication to make it very clear that I’m not showing you hot off the press items here.

1993: Bird Migration by Thomas Alerstam is a general overview of bird migration with an excellent overarching discussion of the context in which migration has evolved followed by a focused study of nine different ecologically defined categories of birds. There is also a detailed discussion of what was known about navigation at the time of publication.

2001: Bird Migration: A General Survey by Peter Berthold covers similar topics as Alerstam but with more focus on the evolution of migration, methods of study, bird physiology and threats to migratory species.

2005: Birds of Two Worlds: The Ecology and Evolution of Migration, Edited by Russell Greenberg and Peter P. Marra is different from the above mentioned book in that it is an anthology of scholarly papers on bird migration, covering the full range of migratory syndromes and the evolution of migration.

Ark Park Gets State Funding

The separation of church and state is dead in Kentucky Governor Beshear says he would welcome a “Mecca Theme Park” as well. He also says the Ark Park will be required to not discriminate in hiring. We’ll see.

From the Courier-Journal:

A state contractor concluded that the proposed Ark Encounter biblical theme park will draw enough visitors to qualify for state incentives, prompting the Kentucky Tourism Development Finance Authority to grant final approval for up to $43.1 million in sales tax rebates over 10 years.

The state tourism law spells out several requirements, including the number of out-of-state visitors, that must be met for developers to recover up to 25 percent of the project’s cost through a return of the sales tax paid by visitors on admission tickets, food, souvenirs and other expenses.

Ark Encounter, which will feature a 500-foot wooden model of Noah’s Ark and the Tower of Babel from the Bible, is projected to cost as much as $172.5 million and create 500 full-time and 400 part-time jobs.

Here’s the governor trying to make it sound like he couldn’t care less about the way our system of democracy is supposed to work:

(If the video is invisible, watch it here.)

Hat Tip: Joe

I shall build it and I shall call it gregBook

Both my desktop and my laptop started working more slowly a few weeks ago. This indicated that something about the operating system (some version of Ubuntu Linux) changed in a bad way. Or, perhaps, since the slowness was mostly noticed in the web browser, the newer version of Firefox was somehow borked. It turns out that the latter is true to some extent because the developers of Firefox left Linux out in the cold with hardware acceleration (and despite the excuses for that I’m still annoyed … had the same issues applied to, say Windows, they would not have left Windows out in the cold). But that is a digression. It turns out that the cause was related to something I had installed that was related to the system. This little problem has been solved, but it brings up another issue, which has also been addressed on the blog Linux in Exile. This is what I wanted to talk about.
Continue reading I shall build it and I shall call it gregBook

On the Wing: American Birds in Migration

On the Wing: American Birds in Migration is a children’s book suitable for up to Middle School or thereabouts. Remarkably, this ten year old volume is actually fairly accurate and comprehensible, covering most of the major aspects of bird migration, discussion ecological patterns, mechanisms, and methods used to study the phenomenon.

It is written and illustrated by Carol Lerner, who has prodcued well over a dozen anture related books of similar (high) quality including Butterflies in the Garden and Backyard Birds of Summer. Since these books are all at least ten years old you can find them at very low prices in used bookstores (in meatspace or on line). They’re all good.

More books on birds.

More on migration.

More book reviews and notices.

See also this post at 10,000 birds on migration.

Japan Nuclear Disaster Update 24: Reactor 1 did melt down, fission and cooling remain issues, worker dies, sarcophagi in Fukushima’s future.

The worker’s death was probably unrelated to the nuclear disaster, but it can’t help moral much at the crippled site. Fission and cooling still remain issues at the Fukushima plant. Although fission is not happening to any large degree, or possibly at all, there has been fission more recently than many expected, and there is still concern that the reaction could restart. Various attempts at introducing long term cooling solutions at the site have been less than successful. It is clear that at least two of the reactors will have to be covered by a protective overarching structure.

The reactor in unit one, which is now known to have experienced a meltdown several hourse after the earthquake, has shown no recent evidence of criticality and the engineers and regulatory authorities are fairly satisfied that the reaction in this unit is under control. However, stable and reliable has not been achieved at this reactor. Although nitrogen is still being injected at a precaution, H2 buildup is not happening and the pressure of the reactor vessel is being maintained at a safe level. The reactor vessel, however, is leaking radioactive material presumably through breaches in the container via the pump system’s connectors, and possibly from small holes that formed at the base of the vessel during the meltdown (there is concern, though this has not been verified, that some of the radioactive material from this vessel actually breached the foundation structure of the reactor building). Further leakage of radioactive material is expected and engineers and authorities are concerned about this.

Fission reactions are not occurring in Reactor 2, and overall the situation is more serious than that of Reactor 1, though cooling is more of a concern here. It is thought that the March 14 hydrogen explosion, thought at the time to have been a harmless and expected event, damaged the containment vessel, resulting in leaking. Containment of radioactive material at Reactor 2 has not been achieved. It appears at this point that the only way to achieve containment here is to cover the reactor area with a superstructure.

Fission reactions appear to be continuing at a low level in Reactor 3. Cooling in this reactor is not achieved, and pressure varies unpredictably. There is a crack in the primary containment of this unit. Aside from this crack the reactor pressure vessel appears to be leaking via broken seals at pipes. Radioactive material continues to be released from this reactor, and as with REactor 2, it appears that the only way to stop this is to build a super structure over the reactor.

It is not entirely clear that fission reaction are totally stopped or limited in Reactor 4. The fuel rods are thought to be intact and in position but there is some conflicting data suggesting otherwise. While the fuel assembly seem to be covered by water and cooling achieved make-shift, there is also a lack of data from this reactor via TEPCO.

Quite a bit more information is to be found in Ana’s Feed (below).

Regarding exposure to radiation in the vicinity, the International Atomic Energy Agency has this statement:
Continue reading Japan Nuclear Disaster Update 24: Reactor 1 did melt down, fission and cooling remain issues, worker dies, sarcophagi in Fukushima’s future.

On the Move

On the Move: How and Why Animals Travel in Groups, edited by Sue Boinski and Paul Garber is a compendium of academic research on … well, on how and why animals travel in groups. Notice of this book is a fitting start to a series of reviews of migration-related books that is part of Migration Week on GLB. (For an overview of the Bigness and Vastness of bird migration in particular, see A Question of Migration.)
Continue reading On the Move