Bonnie Arbittier / Rivard Report
A bird expert’s comprehensive survey of the San Antonio River’s Mission Reach has drawn an encouraging picture of how efforts to restore natural habitat in the area are progressing.
The study is the first long-term bird study done after the restoration of the Mission Reach, completed in 2013. That section of a massive $384.1 million improvements project introduced a mix of native prairies, savannas, woodlands, and forests to what was once an eight-mile drainage channel.
“We knew that if we found certain birds, we could say that the restoration was successful and we were providing the habitat,” said Lee Marlowe, a sustainable landscape ecologist for the San Antonio River Authority.
Created by the Texas Legislature in 1937, the River Authority is the official steward of the San Antonio River and brings in roughly $30 million each year in revenue from a property tax of 1.73 cents per $100 of assessed value in its territory in Bexar, Karnes, Wilson, and Goliad counties.
To identify the bird species using the Mission Reach, River Authority officials put out a request for proposal and ended up hiring veteran birder Martin Reid.
Twice a month from December 2015 to April 2018, Reid and a couple River Authority staffers visited points on the Mission Reach and recorded the birds they were able to find within a specific time limit. They also logged those they just happened to see while in the area to comprise a less rigorous data set.
“I was with Martin when we saw a peregrine falcon, and I’ve never seen one before,” said Katie Peche, a River Authority data specialist who often rose before sunrise to join Reid in the field. “That was pretty cool.”
The team ended up identifying 186 different species and more than 56,000 individual birds.
“I was expecting we would get pretty good diversity even this early in the restoration process," Reid said. "But I would say there were more species, more unusual species especially, that we recorded than I was expecting."
One example was Cassin’s kingbird, a species native to the southwestern United States and northern Mexico that’s “extremely unusual this far east,” Reid said, adding that his record was the first sighting of this bird in Bexar County.
Flitting through the long grass, scattered bushes, and trees, Reid and the others also found some of that bird’s close relatives – the scissor-tailed flycatcher, eastern kingbird, western kingbird, and tropical kingbird, a species that’s more common in the Rio Grande Valley.
“None of them like really open habitats,” Reid said. “Prior to the restoration of the river, you would probably have seen maybe one or two on the very edges, sitting on the trees, but not down using the river area. They like long grass and areas with scattered bushes, varying heights of trees.”
Reid also spotted an interior least tern, an endangered species that frequents midwestern rivers and the Gulf Coast.
“It did spend at least a morning being able to find forage and food on the river, which indicates the good health of the river,” he said.
Like other experienced birders, Reid can identify birds by their calls, a skill he first picked up from a mentor in his native England.
“We’d go out in predawn or at night and listen to birds flying around, and he’d tell me what they were,” Reid said. “I couldn’t see them, so I had to learn just to rely on their voices.”
Over the years, he honed his skills using audio records and field time in around 40 countries. He’s good enough that he can tell the difference between a genuine bird call and a mockingbird mimicking its song, Marlowe said.
The bird diversity he found marks a transformation of the river, which was once a uniform channel lined with concrete, surrounded on both side by slopes of mowed grass, with no trees or shrubs.
Reid is familiar with surveying birds in that kind of waterway, which is still prevalent in San Antonio, especially on the Westside. Before the Mission Reach survey, Reid did a bird survey of the Westside creeks for the River Authority.
“You would expect to get lots of grackles,” he said. “There’d be a few snowy egrets feeding along the river. You’d get the occasional sandpiper, maybe a greater yellowlegs once in a while on the river. In migration you may get small flocks of least sandpipers that stop briefly wherever the cement bottom of the river is shallow. … You would occasionally see one or two native sparrows.”
Starting only two years after the transformation, Reid found a much greater diversity of birds using the Mission Reach. He turned up 14 species of sparrow, 15 species of warbler, and 16 species of flycatcher.
“It’s pretty remarkable,” he said. “The variety of habitat gives you the variety of birds.”
The River Authority has incorporated Reid’s study into a checklist that birders can download and print when they visit the river.
His data will also serve as a baseline the River Authority can use to gauge its progress five, 10, or 20 years from now, Marlowe said.
“The plants are supporting insects, insects are supporting the birds, and we do have seed- and berry-eating birds,” she said. "All of them working together, they help us understand that we are actually providing habitat.”