Brown-headed Cowbirds

Brown-headed Cowbirds have a bad reputation. A lot of birders don’t like them because they seem to be shirking their parental duties. Because they are obligate brood parasites—they don’t build their own nests, and only lay their eggs in the nests of other species—we accuse them of taking advantage of other species by forcing them into doing all the work of feeding a hungry nestling. It’s unfair. We’re indignant.

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Vampire Plants

Humpback_anglerfishWhen I think of parasites, I typically think of creatures such as tapeworms, fleas, ticks, and leeches—nasty invertebrates that drain the life out of us humans. Then, I might recall that some higher animals can also be parasites, such as the deep sea anglerfish. You’ve likely seen pictures of anglerfish, with their huge, pointy teeth in a large head, followed by a tapering body. When these fish mate, the male permanently attaches itself to the female and lives off her bloodstream for the rest of his life, his sperm his only contribution.  (See National Geographic’s video of a particularly beautiful anglerfish species.)

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Castilleja miniata Paintbrush

Castilleja - Indian Paintbrush__SpruceGrove-Tarryall_20090626_ 0038)The scarlet blossoms really do look like bushy paintbrushes dipped in red paint; they’re hard to miss, even in a meadow crowded with wildflowers. Most of us easily identify these iconic perennials, although we may be a bit confused by the species that bloom in pink, white, and yellow.

Here along the Front Range of Colorado, the most common species of paintbrush is Castilleja miniata, more familiarly known as Giant Red Paintbrush. The one- to two-foot plant is easily identified by its long, unbranched stems lined with lance-shaped leaves. They’re topped with colorful bracts, which are usually divided into threes. These bracts are typically red (miniata means “colored red”) but you can also find blooms in shades of orange, salmon, and pink. The actual flowers are yellowish-green tubes that grow to become more visible later in the season.

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Mistletoe

Dwarf mistletoe on Ponderosa
Dwarf mistletoe on Ponderosa

“You don’t want to buy that lot—the trees have mistletoe!” Our realtor pointed at a shrubby mass growing among the branches high in the Ponderosa pine.

It didn’t look anything like the mistletoe I was familiar with, coming from California. There, the live oaks often support huge masses of mistletoe. And neither plant resembled the old plastic “mistletoe sprig” I inherited from my parents, that we hung in our doorway at Christmastime to encourage kissing. Curious, I did some research. It turns out that there are hundreds, if not thousands of barely-related species of parasitic plants called mistletoe.

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Dwarf Mistletoe is not for kissing

Sparse foliage and a witches' broom indicate a mistletoe infection.
Sparse foliage and a witches’ broom indicate a mistletoe infection.

Mistletoe is a holiday tradition. We decorate our doorways with it, where tarrying under a spring might bring you a kiss. Unfortunately, the kind of mistletoe growing along Colorado’s Front Range isn’t so romantic. Five different species of dwarf mistletoe infest pines, spruces and firs. Given enough time, an infected tree will eventually die.

All mistletoes are flowering plants that have given up a life of self-sufficiency to become harmful parasites. Dwarf mistletoes lack leaves, so they have little ability to make their own food from sunlight. Instead of extending their roots into the soil, they have root-like structures that penetrate under the bark, where they siphon off both water and nutrients from the host tree.

The female mistletoe plant produces sticky seeds. When the seed capsules are ripe, usually in late summer, they explode, expelling their contents at speeds up to 60 mph! The seeds can travel up to 60 feet, although 30 feet is more common. Wherever the seeds hit, there they stick.

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