November 14, 2002

Swan Song

Is Acid Rain Killing Off Wood Thrushes?
Robert Winkler for National Geographic News

Acid rain is old news, but it hasn't gone away. Going away may be one of the more ethereal songs sung outside the human voice...that of the Wood Thrush.

Acid rain, for example, can cause calcium to leach from the soil. The loss of this nutrient jeopardizes the breeding success of birdsto produce a clutch of eggs, a female bird may require up to 15 times more calcium than a pregnant mammal of equivalent size.

[...] In areas where acid rain is most severe, the supplementary calcium-rich foods that female songbirds depend onsnail shells, isopods such as pill bugs, millipedes, and earthwormsmay be in short supply. Lacking adequate calcium in their diet, females are more likely to lay eggs that are thin, brittle, and porous. If the weakened eggs can withstand the rigors of incubation, the parent birds will be hard-pressed to meet the very high calcium requirements of their growing nestlings.

[...]Aside from depleting calcium, acid rain in soil can promote increased levels of potentially toxic aluminum, cadmium, and lead. Polluted soil, moreover, may slow the decomposition of leaf litter, which reduces the diversity and abundance of prey.

There is a point of no recovery for entire ecosystems in jeopardy because of the impact of our various wastes. It seems to me that there is some of the same arrogant indifference or blatant disregard for 'the commons' by corporations and nations that we have discussed and condemned in individuals who are disposed to trash the commons... roadsides, parking lots, parks, forests... with litter. There is so much more to lose at the biosphere level if we continue in our indifference to and ignorance of the health of 'the meek'.


Posted by fred1st at November 14, 2002 07:29 AM
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Fred, do you write essays on nature/landscape, btw? Do you have any completed ones in hand?

Posted by: Artichoke Heart at November 14, 2002 11:30 AM

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