Back from near extinction

British Columbia has a population of 20,000 to 30,000 bald eagles. Most of them can be found along our coastline. Counts in the Fraser Valley have gone as high as 7,362 bald eagles. Being top carnivores, that is an impressive number of these large, majestic birds. Topping that, Alaska boasts a population of some 70,000. The species seems to be doing well.

That has not always been the case though. Back in 1782, when the US adopted the bald eagle as its national bird, there was an estimated continental US population of 100,000 breeding adults. Despite that honour, war was unofficially declared on the species in the mid to late 1800s. Every conceivable method of eradication was employed, some intentionally and others not. This resulted in a tumultuous decline to the extent that, in 1963, there were only 487 nesting pairs known to be left (click here for more information). The greatest contributor to their demise was the nation's desire to control mosquito populations.

The insecticide DDT was used in vast quantities shortly after the end of World War II. The chemical is bioaccumulative and builds up in the fatty tissues of animals. It also biomagnifies up the food chain. Tissue concentrations in predatory birds such as the eagle and falcon reach critical levels. DDT, it turns out, affects calcium metabolism in avian species. If enough is present, it causes eggs to be produced with critically thin shells; the young never survive to become hatchlings.

With the extinction of the species and an environmental catastrophe in the making, DDT was banned in 1972. Education and environmental awareness allowed the slow period of recovery. Continental populations are still relatively thin, but they have rebounded nicely along the Pacific shoreline. Although healthy numbers now exist we have to be vigilant. As salmon populations plummet because of the unofficial war on aquatic ecosystems, there is the risk that the eagle may once again near extinction. If you don't think that is possible, consider the loss of the passenager pigeon, the Carolina parakeet, or the ivory-billed woodpecker (click here for more information).

The only way we can save the species, all species, is through education, awareness, and good environmental practice. The concept "It takes a community to raise a child" can be paraphrased. It takes a planet to save a species. And the sooner we start, the better.

Thanks for reading.     Ericspix     Eric Svendsen