Counting Free-tailed Bats in Bridges

9/10/18
By Merlin Tuttle

Merlin inspects Brazilian free-tailed bats (Tadarida brasiliensis) moments after removing them from their bridge crevice roost for counting.

For many years we’ve wondered just how many Brazilian free-tailed bats (Tadarida brasiliensis) could cram into a single 18-inch-deep bridge crevice. Accurate counts of large colonies are difficult no matter how they’re made. However, when estimating bridge colonies, it would help if we knew the number, using an average horizontal foot of crevice.

The solution seemed easy. Two years ago, Glen Novinger, an MTBC member and I, inserted two, three-quarter-inch-thick wooden frames, each encompassing a square foot of interior space, into bridge crevices of the same width while the bats were out feeding. The idea was to later slowly remove them, forcing those roosting inside to exit into a cloth-lined bag from which we would count them.

However, the bats were full of surprises. The first night we waited patiently till half an hour after we’d seen the last ones leave—or at least that was what we thought! But when we approached to install our devices, roughly half remained inside. I couldn’t help but wonder how many emergence counts had missed those that, for whatever their reasons, didn’t emerge at sundown. (more…)

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Response to Inappropriate Coverage of Bats and Ebola in Smithsonian Publication

Response to Smithsonian story, “Can Saving Animals Prevent the Next Deadly Pandemic?”
Merlin Tuttle
5/9/17

 

Lorraine Boissoneault’s story, Can Saving Animals Prevent the Next Deadly Pandemic?, is clearly well intended. However, when it comes to fruit bats and Ebola it is based on outdated speculation that threatens serious harm to a group of mammals that is already in alarming decline. For a summary of current knowledge of bats versus Ebola and other rare, but so-called emerging diseases, and their speculated association with bats, I refer you to my article in the current edition of Issues in Science and Technology, titled “Give Bats a Break.”

Diseases that are millions of years old, but that are just now being discovered due to their rarity, are being referred to as “emerging” as an apparent public relations ploy to make them sound more dangerous. And speculating associations with bats makes them even more scary, since many people already fear bats. This has proven unprecedentedly effective in gaining hundreds of millions of dollars in grants to support so-called virus hunters, who must continue speculating about potentially dire threats from bat diseases to keep their grants flowing.

Bats historically have one of the world’s finest records of living safely with humans, first in caves and thatched huts, then in log cabins.

Hundreds of thousands of Straw-colored fruit bats (Eidolon helvum) beginning their evening departure from a city park in Ivory Coast, Africa. Cities often provide the only homes safe from commercial hunters who sell them for people to eat. Despite such large numbers having lived in close association with humans throughout recorded history, they have not caused disease outbreaks. Their remarkable safety record casts grave doubt on recent speculation of their being dangerous carriers of disease.

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Updated Wind Energy Resources

Updated Wind Energy Resources

By Merlin Tuttle
4/3/17
Next to irrational fear, wind power production now poses the greatest threat to bats, especially in industrialized countries. The full impact of this exponentially growing industry remains largely unmeasured and unreported, but available evidence is alarming. Wind production companies, widely viewed as “green,” have not lived up to their reputation, and too many conservationists have remained silent for far too long. Bat researchers have worked diligently to help wind energy producers become truly green. However, only a small proportion of companies have implemented even the most cost-effective measures. 
As Merlin reports in his updated resource documents, it’s difficult to explain how we can know so much about cost-effective solutions, yet do so little. He suggests it’s time for cooperation among responsible energy producers and leading conservation organizations to simply rank companies on a true green scale and share these rankings with energy investment advisers, providing incentives for progress before it’s too late.
Read the updated resource pages here:
 

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Field Guide to Amazonian Bats

The Field Guide to Amazonian Bats by Adria López-Baucells, Ricardo Rocha, Paulo Bobrowiec, Enrico Bernard, Jorge Palmeirim and Christoph Meyer is a giant step forward for the world’s most diverse bat assemblage. As one who has spent years identifying and photographing Amazonian bats, I’m exceedingly well impressed with all aspects of this publication, not just its clear and well-illustrated keys, but also with the quality and completeness of photos and the strong conservation orientation. I’m proud to have contributed in a small way.
-Merlin Tuttle

Please download and enjoy The Field Guide to Amazonian Bats!

Pictured is a spectral bat (Vampyrum spectrum), one of the many unique Amazonian bats. This is the largest New World bat, with a wingspan of nearly three feet. It is a carnivore that feeds on a wide variety of small vertebrates, including rats, birds and small oppossums. Mates appear to take turns hunting for food versus baby-sitting. They live in large, hollow trees.

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Ebola: Bats Prematurely Blamed

Ebola: Bats Prematurely Blamed
By Merlin Tuttle
1/14/16

If public health concerns were based on actual threats to human mortality, diseases speculated to be spread by bats would take a distant back seat. Even our beloved dogs are many times more dangerous than bats (1). Real killers, like consumption of over processed and contaminated foods dwarf any risks associated with animals (2).

Yet we squander millions of scarce public health dollars on witch hunts for rare diseases in bats, when those funds could save far more human lives if spent on reducing already proven killers such as obesity and environmental toxicants linked to escalating rates of cancer, heart disease, dementia and diabetes.

An adult male straw-colored fruit bat (Eidolon helvum), the species most often blamed for Ebola.

In recent years speculation linking scary diseases to bats has gained unprecedented media headlines and grants.

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