A sweet “zee-doo-zee-dee-ZEET” rings through the thick juniper forests as dawn breaks over the Hill Country of Texas. The golden-cheeked warbler is an endangered species that migrates from eastern Mexico to Texas to breed. Their breeding range is located solely in Texas, roughly in the center of the state. I had the opportunity to work with these warblers at Balcones Canyonlands National Wildlife Refuge.
The males show up first and roam the juniper forests looking for the best habitat. The older males usually get the best pick of the taller, thicker trees, while younger males are run off to the scrubbier juniper. When females arrive, the males have established their territories, and the conflicts over females begin. I witnessed a fight between a young and an older male who collided with one another and fell to the ground. Meanwhile, the female was happily chipping and foraging nearby.
After pairing up, the two birds mate for the season, producing one to two successful broods. The females will start to gather spider webs and strips of juniper bark for their nests, while the male continues to defend his territory. It usually takes a female about a week to build her nest.
Near the beginning of the season I happened upon a female with spider webs. I followed her to a group of tall juniper trees where she seemed to disappear. About five minutes later, she flew to a branch no more than 2 feet from me. She hopped along the branch as I stood there, and it seemed like she was examining me. After a moment, she continued her search for nest material. I found her nest at the very top of one of the tall junipers. I could see only a small part of the nest, about the size of a half-dollar, with the rest obscured.
The female incubates the eggs for about 12 days until they hatch. After nine days, the young warblers will fledge from the nest. The fledglings cannot fly when they emerge, but are very good at climbing and gliding between trees. They are best described as small, grey, feathered balls that scream. A lot.
The number of young in a brood usually will be three or four. I had a family I believed had four fledglings, only to find out a month later they actually had five. In another territory, the female opted for a second brood while still feeding her first batch of young. So, between feedings, she was also collecting material for her new nest. Motherhood for the golden-cheeked warbler is exhausting!
While these birds seem to be thriving in their Hill Country oasis, they are in trouble. Habitat loss is a major problem and threatens the golden-cheeked warbler like so many other species. The beautiful Hill Country they call home is under threat from development for agriculture and suburbs.
Thankfully, places like the Balcones Canyonlands National Wildlife Refuge have bought some land for these birds to safely breed. Their newest threat is the Permian Highway Pipeline, a natural gas pipeline that would run straight through the warblers’ habitat. This would require the destruction of acres of the juniper forest, putting not only the warblers at risk, but also the Edwards Aquifer, a major source of drinking water for Texas. For now, the project has been halted because of its potential harm, but it might still resume.
This warbler is a precious species that has a special place in my heart, and I hope it now holds a small part in yours. If you want to see these birds, they can be found at Warbler Vista in the Balcones Canyonlands National Wildlife Refuge between March and June.