Motion-triggered cameras have captured at least four species of wildlife crossing the Robert L. B. Tobin Land Bridge, which opened to the public (and wild critters) last December.

Virginia opossum, cottontail rabbit, white-tailed deer, and a coyote were all captured making nighttime crossings over the bridge, which connects both sides of Hardberger Park over Wurzbach Parkway. San Antonio Parks and Recreation Naturalist Casey Cowan said that was the goal when placing eight cameras along the bridge’s 189 foot span.

“We want to know if the animals are using the bridge in totality,” said Cowan. “Are they actually crossing the bridge or are they simply using the space and then returning? We want to know if the bridge is doing its job.”

A Virginia opossum is spotted crossing the Robert L.B. Tobin Land Bridge. Credit: Courtesy / Phil Hardberger Park Conservancy

The bridge is part of a five-year research study of wildlife crossings in city areas. Staff with the Natural Areas Division of the parks department began collecting data in mid-April this year and will release a report on their findings annually.

With increased urbanization, it has become harder for wildlife to move from place to place and access food, water, and shelter, said Cowan. The Robert L.B. Tobin Land Bridge serves as a green corridor for animals to travel safely. 

What makes the bridge safe and inviting to the wildlife is its design: planted vegetation is native to the area and serves as food and shelter for wildlife. Two water bubblers, placed at the blinds, provide a year-round water source.

Its size also helps. A study of wildlife crossings by the University of Massachusetts, Amherst, recommends crossings be a minimum of 164 feet at the base and as little as 26 feet at the center to encourage wildlife to use it. The Robert L.B. Tobin Land Bridge is larger: 165 feet wide at the base and 150 feet wide in the center. 

The Robert L.B. Tobin Land Bridge is one of only two mixed-use — meaning it’s open to people and animals — bridges in the world. Apart from looking at the wildlife crossings, researchers want to analyze whether this type of structure is something that can be implemented in other cities. 

As vegetation establishes, more animals are expected to cross the bridge. Park staff will continue to document and track the process. Visitors and their pets are welcome to visit the landmark and the many attractions it has to offer. 

The $23 million land bridge was financed by the 2017 municipal bond as well as public and private funds raised by the Phil Hardberger Park Conservancy.

Polina Protozanova

Polina is a Shiner Editorial Intern for the San Antonio Report.