Daily Archives: May 23, 2011

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.


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.


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
Journey North
Operation Migration
National Geographic Animals Whooping Crane Page

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