What Birders Need to Know About GMO Products in Bird Food

As a responsible buyer, I began to wonder about the effects of genetically modified crops on the environment and whether GMO crops are sold in bird food, such as tallow. From this year, certain genetically modified foods sold for human consumption must be labeled as such, but not those marketed and sold for consumption by wildlife.

Roundup Ready crops do not make their own glyphosate, but are genetically engineered to withstand heavy applications. Like most pesticides, this weed killer has important uses, as land managers trying to eradicate invasive exotic weeds know. Rachel Carson did not argue that pesticides should never be used; she simply warned that it is wiser to use them as a last resort, both because of potential toxicity issues for humans and wildlife and because pests (weeds, insects, etc.) develop resistance to pesticides much faster than other plants and animals, resulting in spiraling pesticide applications.

A McGill University study published in March in the journal Nature ecology and evolution found that heavy use of Roundup can lead to loss of biodiversity. Since the 1990s, when the agriculture industry embraced Roundup Ready crop seeds, use of the herbicide has skyrocketed and researchers have found that glyphosate has seeped into surrounding areas, including rivers and streams. Some plankton and algae adapt, but others do not, reducing biodiversity at the bottom of the food chain of aquatic life. Aquatic insects such as dragonflies and mayflies are essential food for purple swallows and swallows, nightjars, whip-poor-wills and other insectivorous birds. The distressing loss of 3 billion birds in recent decades coincides with both falling insect and spider numbers and increasing pesticide use. Glyphosate has also been implicated in cancers in animals and humans.

Glyphosate kills insects indirectly by killing the plants they need. another pesticide, Bacillus thuringiensisOr “BToutright kills insect larvae. The form called BtK appears to be safe for birds and mammals, but kills caterpillars of all moths and butterflies, not just gypsy moths and other pests.

“BT maize” has been genetically modified to produce the insecticidal proteins naturally present in BT. Few beneficial insects feed on maize, but pollen from BT-corn can be blown over milkweed, where it is known to kill monarch caterpillars. This question, however, is complicated. BT is produced and stays in genetically modified plant tissues, so the vast majority of the pesticide stays in the corn field, and the farmers using BT maize rarely needs to apply more harmful insecticides to its crops. This is a good thing.

More than 90% of all corn and soybeans grown in the United States are genetically modified, and Roundup Ready corn is almost always exposed to heavy applications of glyphosate. Although I was not concerned, corn is also susceptible to fungi which produce extremely dangerous aflatoxins. Maize sold for human, animal and animal consumption must be certified aflatoxin-free, but not that sold for wildlife consumption. And GMO labeling laws simply don’t extend to wild bird food. I don’t know how to make an informed decision on most suet cake ingredients, but when it comes to corn, I just say no.

Study shows neonicotinoids threaten survival of wild birds