Thursday, July 12, 2007

Brightly Colored Birds More Affected By Chernobyl

On ScienceDaily today, a really fascinating report on how the Chernobyl meltdown has affected some bird species more than others. They studied 57 species, and found that those that have had the most drastic declines since the disaster fall into four groups:

1. Species that depend upon dietary carotenoids for their red, yellow, or orange plumage (orioles, blackbirds, blue tits, for example).
2. Species with relatively large eggs.
3. Species that migrate.
4. Species with wide dispersal patterns.

Apparently all of those groups have lifestyles that place a high demand on antioxidants (for plumage coloration, flight energetics, etc). The study suggests that high levels of radiation have a disproportionately negative impact on species that require lots of antioxidant compounds. Radiation levels in a normal (ie not post-meltdown) environment vary due to natural things like differences in isotopes between different geological features, and the researchers suggest that these new discoveries can be used to make predictions about species success in places where radiation levels can be quantified.

It is important to realize, from the data in their report, that some of the species studied fall into more than one of the high-risk groups: for example, orioles depend on carotenoids for their yellow plumage (see image above), and also migrate long distances.

Also, another thing I gathered from the report that I thought warranted a note: bird species that are taxonomically close might not be impacted to the same degree as less-related species with similar lifestyles (meaning, you can't necessarily predict the impact on a species by looking at stats on a sister species). For example, in the family Paridae, blue tits, which are highly dependent on carotenoids, have faced much sharper declines than coal tits.

I've always been fascinated with the Chernobyl meltdown (it's one of the landmark events in the year I was born, btw) and its impacts on the local wildlife. Despite my unabashed mammal and dino bias as far as interests go, the radiation-eating fungus recently discovered there is still definitely my favorite science story of 2007 (see my blog post on it here). One thing that is both interesting and sad is that some reports have shown that wildlife has actually benefited, in some ways, from the catastrophe, since human activities in the area have effectively ceased.

Wednesday, July 11, 2007

Quotes of the day

Carl Sagan in The Pale Blue Dot

Richard Dawkins in Unweaving the Rainbow

Monday, July 9, 2007

Worm-like jellyfish

There is a really fascinating article on Science Daily today about Buddenbrockia, a small organism previously that has long been thought to be a nematode worm, but now known to be most closely related to anemones and jellyfish. It has no gut, mouth, brain, or nerve cord, and although it was long thought to be a type of nematode, it has a very different body plan (the main distinction: Buddenbrockia is symmetrical).

Researchers from the University of Oxford compared 50 genes with a variety of organisms to determine where this enigmatic species fits into the animal kingdom.

There are practical implications for this as well: apparently Buddenbrockia is closely related to a parasite that causes trouble for salmon farms (I don't have time to go into my issues with salmon farming the first place, though...). Current and future studies of it will hoepfully shed light on how to conquer the parasite, although I think that the taxonomic revelations are pretty cool all on their own.

(Photo credit: University of Oxford)

Sunday, July 8, 2007

Could you solve it?

Scenario: You are shown a tall cylinder with a tasty nut in the bottom. How do you go about getting it out, assuming the cylinder is too tall and narrow for you to reach the bottom, and that it is fused to a tabletop (you can't dump it out)?

Could you create a strategy for getting the nut? Orangutans in one study showed amazing problem-solving skills to obtain the nut: they took mouthfuls of drinking water and spat into the cylinder, to make the nut float within finger-grasping range.

The five orangutans tested needed an average of nine minutes to realize that they could float a peanut to the top of the container, you can see an example here:

Pretty amazing, I think! Orangs are infamous for using tools and escaping enclosures in captivity (read about the legendary escapades of Fu Manchu here), which is interesting because in the wild they have not been observed to use tools to the same degree as other apes, or to captive members of their own species.

If I could pick one primate to study it would definitely be the orangutan, there is so much about the species that is unique from the other great apes. They are so imperiled right now, though, and often from places people wouldn't expect, like efforts to promote biofuels instead of fossil fuels. You can learn more about orangutan conservation efforts here, the statistics are very disturbing.