Tag: invasive species

Posted on in Conservation, Gardening

Noxious Weeds

Toadflax is on Colorado’s Noxious Weed List “B”
Toadflax is on Colorado’s Noxious Weed List “B”

There are aliens among us. They didn’t come from outer space. Instead, they invaded our country from their native lands around the world. Some hitchhiked in bales of hay or on unsuspecting travelers. Others were brought here deliberately, perhaps for their beauty or stalwart endurance in the face of adversity.

Once here, they took advantage of our hospitality and spread far beyond their original destination. These invaders are plants: grasses, flowers, even trees that are taking over our country. It’s time we fight back.

When aggressive plants arrive in a new environment, they upset the delicate ecological balance that sustains birds and other wildlife. We call them “noxious weeds” because they tend to take over the landscape, are difficult to control, and out-compete more useful natives. They are frequently useless as wildlife forage or shelter, while replacing plants on which wild creatures depend.

(more…)

Posted on in Bird Profiles, Birds, Conservation

House Sparrows

You see them everywhere… singing outside your bedroom window, eating squashed bugs off your car windshield, cleaning up spilled crumbs at sidewalk cafes. They mob bird feeders full of millet and take up space in nest boxes intended for other species. I’ve even found them in a tiny town in the middle of the Utah desert, miles from anything wet or green. One would think that House Sparrows are one of the most successful species ever to populate planet Earth.

house-sparrow-denverzoo-20090527-lah-093
Male House Sparrow

Not closely related to North American sparrows, House Sparrows are relative newcomers to the Western Hemisphere. They were deliberately introduced during the latter half of the 19th century in repeated attempts to establish a breeding population in the U.S.

While the story is a bit foggy, apparently the birds were imported to eat insects that were damaging crops. If so, it was an egregious error. House Sparrows are primarily seed eaters, and according to one study, 78% of those seeds come from agricultural crops intended for livestock or human consumption.

(more…)