Mega-Bats in HD: Austin, the World's Largest Urban Bat Colony

Over the past few months, new HD video of Austin's 1.5million bats have been popping up on YouTube (watch'em full screen). For those not in the know, Austin is home to the world's largest urban bat colony.They migrate up from Mexico in the late summer and roost under the Congress Avenue Bridge.

The new HD footage really captures the drama of seeing such an enormous quantity of bats all air born at the same time. At points they look like a tornado about to form in the sky. The bridge is always crowded  with people watching (and filming), and the voices you hear in the background of the footage show just how much people enjoy the show.

But why are the bats there?
In 1980 the bridge was rebuilt and the new support beams were spaced roughly one inch apart.  That created exactly the size of crevice that bats roost in. Much wider or thinner and they won't use it. From what I can gather, it seems like this was done on purpose. What a simple and inexpensive way to integrate habitat into infrastructure and create an icon that captivates locals and visitors.

Even if green design is all the rage, the cities we live in have been built almost exclusively for human use. Architects past and present rarely, for example, stop to wonder if their next condo tower will provide good roosting spots for owls or help preserve local endangered species. It's a problem of specialization: Conservationists might ask those questions...but then they rarely design buildings.

The thing that I love about the Austin footage is that it makes you wonder: What if entire cities were built to work this way? An Urban Jungle of a different kind...

This one is not in HD, but I love the kids reaction at the end: "WOW!" 
That is definitely the best one word definition of "biophilic design" I've ever heard.


2 Responses to "Mega-Bats in HD: Austin, the World's Largest Urban Bat Colony"

LSzabo said... 21 March 2010 at 21:19

Alex, thanks for this post.

The design was actually unintentional, and in fact initially the reaction was to destroy the Mexican free-tail bat colony. Bat Conservation International prevented this by acting at a community level, educating locals with a mixture of ecology and aesthetic appreciation-- an ecofriendly aesthetics. Bats, marshes, or overgrown and weedy lawns rarely inspire odes of praise. BCI targeted the underlying assumptions and motivation for destroying the bat colony, namely fear and misperception (a common reaction toward "ugly" species). Ecofirendly aesthetics builds on the assumption that ecological understanding of, for instance, a bat's place in the urban environment will lead to aesthetic appreciation. In the case of Austin, BCI's efforts were facilitated by the city building aesthetic cues such as a "Bat Observation Area" and hiring "Bat Interpreters." See the BCI/Austin bat history here: For further reading on ecofriendly aesthetics with the Congress Ave. Bridge bats as a case study, see Sheila Lintott's "Toward an Ecofriendly Aesthetics" in _Beauty to Duty_.

Alex Aylett said... 21 March 2010 at 21:22

Thanks for the extra information Lisa. I like that phrase "an ecofriendly aesthetic."

Interesting too how something people initially wanted to get rid of has become a real local attraction.


This is a blog for news and views on the future of sustainable cites. A major revamp is in the works. Until then I am keeping this version up as an archive of my past writing.

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