A viewing platform for visitors with signage

No, it is not a bus stop, although I saw a greyhound recently inspecting the area.

The City of Houston, with a grant from Lyondell Chemical, built this platform so visitors could have a level place to stand apart from the bikers and joggers using the trail by the bridge.

From the platform you can view the bats dropping from crevices under the bridge to begin their nightly exodus.

Signage, thanks to donations from the Hershey Foundation, Houston Endowment, Bat Conservation International, Texas Parks & Wildlife.

BUFFALO BAYOU looking East towards downtown

Looking from atop the Waugh Street bridge, Buffalo Bayou flows east towards the Gulf Freeway.

The bats generally fly out from the bridge and hug the south bank for about 200 feet before the column rises up and fly over the trees towards the dandelion fountain and then disperses to fly over the city and beyond, looking for prey.

ANATOMY OF BATS

The bat's wing, which provides both lift and thrust, incorporates the same basic arm and hand bones found in humans and most other mammals, except that in bats the hand and finger bones are very long and slender and they have fewer digits. One of the forearm bones, the ulna, is reduced in size.

Flight membranes are very thin sections of the skin stretched between the arms, fingers, body, legs, and feet. Rather delicate-looking, these membranes are more resistant to tearing by sharp objects than rubber gloves.

The muscles that move the wing are located on the chest, back, and shoulder rather than on the wing. This allows the bat to fly with less expenditure of energy. Bat legs are used more for flight than for moving about on land. The pelvis and legs are reduced in size, which contributes to a slender body figure.

WAITING FOR THE SHOW

Spectators sit and wait for the bat flight at a 3rd Friday Family Night presentation. Many visitors are just passing thru on a visit to Metro Houston.

This is a maternity colony with about 1100 baby bats among the 250,000 Mexican Free-tails inhabiting the bridge.

The nearest large bat colony to Houston is the Congress street bridge in Austin, Texas.

Mexican Free-tails begin to emerge - Photo by Diana Foss, tpwd

Information about MEXICAN FREE-TAIL BATS Bat information from Wikipedia: Scientific classification Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Chiroptera Family: Molossidae Genus: Tadarida Species:T. brasiliensis Binomial name: Tadarida brasiliensis The Mexican Free-tailed Bat (Tadarida brasiliensis) a medium sized bat. Their bodies are about 9 centimeters in length, and they weigh about 15 grams. Their ears are wide and set apart to help them find prey with echolocation. The fur color varies from dark brown to gray. The Mexican Free-tailed Bat is widely regarded as one of the most abundant mammals in North America and is not on any federal lists. However, its proclivity towards roosting in large numbers in relatively few roosts makes it especially vulnerable to human disturbance and habitat destruction. Documented declines at some roosts are cause for concern. It is considered a Species of Special Concern due to declining populations and limited distribution in Utah. Mexican Free-tailed Bats live in caves in the western and southern United States, Mexico, Central America, the West Indies, central Chile and Argentina. Their colonies are the largest congregations of mammals in the world. The largest colony is found at Bracken Cave, north of San Antonio, Texas, with nearly 20 million bats; research indicates that bats from this colony congregate in huge numbers at altitudes between 600 and 3,200 ft (180-1000 m), and even as high as 10,000 ft (3000 m). It is believed that these bats are feeding on migrating cotton bollworm moths, a severe agricultural pest. When the baby bats are born, their mothers leave them behind in the cave while they go out to hunt insects. She remembers where she left her "pup" by recognizing its unique "cry" and smell. The species is very important for the control of pest-insect populations. But its populations are in an alarming decline because of the pesticide poisoning and the destruction of their roosting caves. A population decline in Eagle Creek Cave was documented from over 25 million in 1963 to just 30,000 six years later, and the famous Carlsbad Caverns population, estimated to contain 8.7 million in 1936, had fallen as low as 218,000 by 1973. In addition, the bats lose roosting habitat as old buildings are destroyed. Human disturbance and vandalism of key roosting sites in caves are likely the single most serious causes of decline. Grossly exaggerated media stories about rabies have led to the intentional destruction of large colonies. One of the most cost-effective ways to help this highly beneficial bat is through key roost protection, public education, and provision of "bat-friendly" bridge designs and other artificial roosts. In Austin, Texas, a colony of Mexican Free-tailed bats summers (they winter in Mexico) under the Congress Avenue Bridge just ten blocks south of the state capitol. It is the largest urban colony in North America with an estimated 1,500,000 bats. Each night they eat 10,000 to 30,000 pounds of insects. Each year they attract 100,000 tourists who come to watch them. One of the largest Mexican Free-tailed bat populations inhabits, during the spring and summer, Cueva de la Boca, a cave near Monterrey, Mexico. In 2006, the Mexican environmental conservation NGO, Pronatura Noreste purchased the property due to a reduction of more than 95% of the original 20 million bat individuals population, as a result of vandalism, pollution, and uncontrolled tourism, the organization decided to buy the property in order to place it under conservation. Other species of high ecological value that inhabit the cavern are also being protected.

HOW WE COUNT BATS CREVICE COUNTS: We conduct the "crevice count" at least once every a month. We try to limit this type of count so as not to disturb the bats. Three trained bat teams of 3 members each work together during the mid afternoon using 1 million candlepower spotlights to briefly illuminate the bridge crevices. They record which crevices have bats present and amount of space per crevice filled. This is done quickly so as to reduce disturbance. From that information, we can estimate the number of bats filling the spaces. EMERGENCE COUNTS: Bat teams conduct an "emergence count" normally at least twice a month at dusk. From June to September 2006 we had emergence counts 3 times each weekend. During October 2006, as of the 24th, we've had 12 presentations at the bridge for visitors and interested groups. Teams time the emergence, as well as take valuable observations about bat behavior and flight patterns. They record the date, sunset time, temperature at sunset, precipitation at time of emergence, cloud cover, moon phase, relative humidity, barometric pressure, wind speed and direction, predator sightings and bat behavior as well as time of emergence, length of emergence and volume of bats emerging by the minute, plus number of visitors, and their hometowns. THUMB COUNTS: (very general estimates) We have a couple of team members who conduct their own "thumb" counts of the bats, using hand-held counters to estimate the bats flying overhead. While the "thumb" count can't give us data for the entire population, it gives us interesting bat rate figures for that portion of the column. For example, on October 14, 2005, the team counted 34,500 bats in a 40 minute period, resulting in an estimate of 862.5 bats a minute flying over their viewing location.

VOLUNTEERS COLLECTING DATA

Gulf Coast Master Naturalist Scott Keister, with volunteers Bonita Pernell and Bill Foss, check and compare data on their weather instruments.

OUR VOLUNTEERS Data is currently being gathered by Texas Parks & Wildlife, urban wildlife biologist Diana Foss with volunteers from the Texas Master Naturalist Program's local chapters: Galveston Bay Area chapter, Gulf Coast chapter, Heartwood chapter. Many volunteers are from these organizations:: Bayou Preservation Association Buffalo Bayou Partnership, City of Houston Parks & Recreation Dept,, Houston Zoo staff and docents, Texas Parks & Wildlife Urban Wildlife program, Texas Parks & Wildlife Dept., State Bat Biologist, Volunteers from the public in the City of Houston and local area communites. NOTE: Most of the bat facts used in this web site is from a draft titled "Houston Bat Project, Bat Fact Sheets" written by Diana Foss, urban wildlife biologist, tpwd

Web site created & maintained by Odie Asscherick, Texas Master Naturalist, Galveston Bay Area Chapter. To email Webmaster use WaughStreetBats@webtv.net or @aol.com This web site was created to highlight volunteer efforts to collect data for Texas Parks & Wildlife about Bats in Bridges. At the time of its creation in July of 2005, there was no web site in the Houston area set up exclusively with information about the Mexican free-tail bats currently inhabiting the Waugh Street bridge over Buffalo Bayou. Bats are not new to Houston, only media about bats. Bats have resided in the Waugh Drive bridge since 1993. Texas Master Naturalists have studied the bats under the Waugh Drive bridge since June 2000.