Havard agaves of West Texas mountains have a beneficial relationship with bats, as well as birds and insects such as moths: The more pollinating critters, the more agaves that reproduce across desert mountains.
We recently did our bird-watching in Big Bend National Park by walking around blooming Havard agaves in the Chisos Mountains Basin.
Commonly called the century plant under the myth that it blooms once every 100 years, the Havard agave (Agave havardiana) is common in the Davis and Chisos mountains of West Texas at elevations ranging from 4,000 to 6,000 feet. The plant blooms between late spring and midsummer at the end of its 10- to 30-year life cycle.
The plant has a flower stalk reaching 6½ feet tall and a base spreading 3 feet wide. What attracts birds are the agave's approximately 2,000 nectar-generating flowers, with each flower containing 200 milligrams of sugar in its nectar per day. Compare that with the flowers in a garden penstemon that produce a mere 2 to 3 milligrams of sugar per day.
So we watched agaves for birds. One of the more beautiful was a Scott's oriole with a coal-black hood draped from its head down its back and onto its breast and with black wings and tail offset by a golden-yellow body. The bird's color fit perfectly with the bright yellow hues of the agave flowers.
The oriole perched in the center of a flower cluster and gulped down nectar from the blooms. Primarily an insect-eater, the bird was undoubtedly supplementing its diet with sugary nectar and deriving much-needed water from it.
Another bird we spotted was the tiny Lucifer's hummingbird, found outside of Mexico only in the Chisos and Davis mountains. I've taken many a hot summer's hike down mountain canyons while thinking the hummer got its name from being in places as hot as you-know-where.
But the name is Latin for "light-bearing" and refers to the hummer's bright iridescence.
The male Lucifer's hummer that showed up was so small his body didn't brush against the reproductive parts of the large agave blooms. He therefore got nectar free of charge because he didn't pollinate the agave in return for the nourishing juice.
Maybe there is a little Lucifer-the-Devil in him after all.
A surprise sighting was a Colima warbler. I've spent many knee-crunching hikes up steep mountains to see this bird, which nests only in Mexico's high Sierra Madre Oriental and in Texas in the high Davis Mountains and Boot Canyon high in the Chisos Mountains.
But there it was drinking nectar at a Havard agave at a much lower mountain elevation. Saved my knees.
Desert wildlife, including the Scott's oriole, are drawn to Havard agave blooms in the desert for their high nectar content.
