Time has come to mention a few things about our next Bat species, devoted on "Batman Begins" OST, Tadarida.
The Mexican Free-tailed Bat (Tadarida brasiliensis) is a medium sized bat. Their bodies are about 9 cm in length, and they weigh about 12.30g 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. While being one of the most numerous mammals in North America, the whereabouts and status of winter populations of these animals is still largely unknown.
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.