The Edwards Plateau Savannas ecoregion (NA0806), largely one and the same as “Texas Hill Country”, is famed in the North American birding world for two bird species. The Black-capped Vireo (Vireo atricapilla) is an endangered skulker breeding here in oak scrub and thickets and in nearby areas to the north and in Mexico to the south. The gorgeous Golden-cheeked Warbler (Setophaga chrysoparia) (GCW) is a virtual endemic to this ecoregion, in the breeding season, and its ornithological specialty.
Although cohabitants of the juniper-oak forests/thickets of this ecoregion, one can imagine that evolutionarily, these species took very different paths to end up in central Texas. The Black-capped Vireo winters in the hot arid scrub and low forest of the Pacific slope of Mexico (southern Sinaloa to Colima). On the other hand, the GCW winter in a completely different area – the coolish high-altitude (1000 m+) pine-oak and coniferous ecoregions of Guatemala, Honduras, and Nicaragua.
A great deal of this ecoregion looks to the untrained eye (see photo below of Friedrich Wilderness Park) as heavily forested and wild and natural terrain. The original habitat of the ecoregion was however very different – much more open, extensive grassy areas (with grazing bison) with patches of mature juniper-oak forests. Fire played an important role in maintaining the habitat. This was the habitat GCW evolved in; they depend on mature junipers with shedding bark that they pick at for nesting material. Over the last hundred years or so, fire has been suppressed, the bison are gone, and mature forests have been felled, and in their place has grown up dense brushy thickets of juniper-oak with few open areas, poor habitat for this endangered species of warbler.
It is indeed one of the rarest of the North American warblers. The post-breeding population in 2004 was estimated at only 21,000 birds (Handbook of Birds of the World). It is an example of how the US Endangered Species Act can both help and hinder. Just prior to its federal listing in December, 1990, a sudden loss of its key habitat was triggered as landowners rushed to rid themselves of the warbler rather than suffer land use restrictions imposed by the Act. Since 1990, protection as an endangered species has undoubtedly helped it maintain its precarious numbers.
While we were in Texas however this month, a news items emerged about a major push by a certain Mr. George P. Bush, Texas Land Commissioner, to remove the endangered species listing. The Austin Statesman of July 7 2015 reported:
“We now know the golden-cheeked warbler should never have been listed in the first place based on actual science,” Bush said in a news release that also announced the support of private property and business groups. He continued: “Its listing devastated private property owners across Central Texas and even limited military training at Fort Hood. With so much at stake, the federal government needs to get this right and de-list the Warbler.”
Not so sure about that “actual science” part because the last careful 5-year review of its status by the Fish and Wildlife Service, just concluded in August 2014, determined that no change in its listing status was warranted. Mr. Bush is the son of Florida’s Jeb Bush, whose name you might have seen in the news these days!
On many occasions in the last 30 years, I have fruitlessly looked for GCW in Texas and in all the countries of their wintering range. Visiting Jim and Joan down in San Antonio this early July, I made one more try but was told not to get my hopes up since by July they might already be Guatemala-bound. But as luck would have it, France spotted us a stunning male in Friedrich Park just outside of San Antonio! Now, just need to find a Black-capped Vireo during our planned trip down to Puerto Vallarta this winter…