Welcome to my zone 9a habitat garden near Houston, Texas.

Monday, July 22, 2013

Threatened wildlife

I found two disturbing reports in my inbox this morning. The first is from Journey North, the latest status report on this year's Monarch butterflies. The second was an announcement of the release of a new report from the American Bird Conservancy regarding the threat to wildlife from the world's most widely used pesticides, nicotine-like chemicals called neonicotininoids. Both are bad news for backyard wildlife.

First, the Monarchs. We've known for a while that the numbers are disastrously down this year. This is primarily a result of weather conditions in the past year that were unfriendly to the production of new butterflies. The drought and excessive heat last summer meant fewer butterflies produced, meaning there were fewer of them to overwinter in Mexico. The area of forest covered with Monarchs last winter was only 3 acres, compared to an average in the past of 17 acres. Obviously, that meant fewer of the colorful fliers heading north this spring.

But then the spring turned out to be unusually cool, even cold in the Midwest, which delayed the butterflies' migration northward. Some areas in the northern part of the butterflies' range are only now seeing their first migrants.

All of this, of course, has a domino effect. Fewer butterflies will be produced this summer. It is likely that the overwintering numbers again will be quite low. And next summer...?

The main enemy of the Monarch in all of this seems to have been unfavorable weather, but the role of pesticides cannot be overlooked.

The ABC's new report makes clear that the neonicotinoids have the potential to affect entire food chains. One of the co-authors of the report, Cynthia Palmer, emphasized that "the environmental persistence of the neonicotinoids, their propensity for runoff and for groundwater infiltration, and their cumulative and largely irreversible (my emphasis) mode of action in invertebrates raise significant environmental concerns."

These pesticides' toxicity to bees and other insects, including butterflies, has been well-documented and has received the most concern and attention from regulatory institutions worldwide. But the new report makes clear that this toxicity extends to birds and terrestrial and aquatic invertebrates as well as other wildlife. For example, a single kernel of corn coated with a neonicotinoid can kill a songbird. Even a tiny grain of wheat or canola treated with a neonicotinoid can fatally poison a bird.

Moreover, the report concludes that neonicotinoid contamination levels in both surface- and groundwater in the United States and around the world are already beyond the threshold found to kill many aquatic invertebrates. The report goes on to assert that part of the problem is that EPA assessments have greatly underestimated this risk, using scientifically unsound, outdated methodology that has more to do with "a game of chance than with rigorous scientific process."   (You can read the entire report here.)

The ABC is urging its members and other interested parties to contact their congressional representatives and ask them to support the Save America's Pollinators Act of 2013 as a first step in beginning to address this problem. Even if the act is passed and becomes law and neonicotinoids are better regulated, the persistence of these chemicals already in the environment does not bode well for the future of threatened wildlife like the Monarch butterfly. But we have to start somewhere.

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