Green Group discussion

A photo of a large bat was posted online recently in the Philippines. Wow, that's a bat and a half.

https://www.taiwannews.com.tw/en/news...

"The bat can be found in the Philippines and has a wingspan of up to 1.7 meters (5.58 feet). Despite their hulking size, these bats are vegetarian and consume primarily fruit.

The giant golden-crowned flying fox typically dwells deep in forest caves, however, which makes this sighting so spectacular."

I would wonder if the caves are getting flooded or there is no food left in the area.

The bat-katydid interaction studied.

"In Neotropical forests, there are many species of bats. Some of these bats eat fruit and others catch flying insects. Most of these bat species are no risk to a perched, singing katydid. However, all of these bats produce echolocation, so while the forest is full of echolocation calls, less than 4% of those calls come from bats that might eavesdrop on katydid calls. For a katydid, this means that calling is very risky, but because there are so many bats producing echolocation calls, if katydids stop singing when they hear echolocation, they would have few opportunities to attract a mate."

https://phys.org/news/2020-08-katydid...

More information: Laurel B. Symes et al, Sheep in wolves' clothing: prey rely on proactive defences when predator and non-predator cues are similar, Proceedings of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rspb.2020.1212
Journal information: Proceedings of the Royal Society B

My husband and I enjoy watching bats any time we are camping. Ideally, near a lake or open grass near trees, bats will appear once it's properly dark and start catching insects. They could come out earlier, but they wait for the crows to go to bed.

Bats have a winter roost where they tuck up together for warmth, often inside a building space like an attic where it's dry.
Bats also have summer roosts, for a smaller number of bats, near the food sites and often in a tree or a crack in stonework like a bridge.
The common point will be height. This keeps the defenceless bats safe from many predators.
Under EU and Irish law it is illegal to disturb bats or their summer or winter roosts.

Studies in Irish Limnology

Good chapter on bats around lakes, and protecting their roosts when bridges are being repaired. A bat detector can be used to amplify any noises they are making, which can indicate their presence.

Here is an excellent site by Bat Conservation Ireland. This explains and illustrates bat boxes, the law around bats, the species found in Ireland and more.

https://www.batconservationireland.or...

Thriller, so the bats have to be scary:
Nightwing


Suspenseful story, so the vampire bat has to be rabid:
The Black Stallion and Flame


First in an excellent series told from the bat's (black and white) point of view:
Silverwing

Sorry I'm a bit slow to post this but apparently it's Bat Fest

I only noticed it just as the opening zoom chat was live last night, but apparently there are things happening for the next few weeks, with a virtual BatWalk happening this evening.

Excellent, thank you! I knew this was a good time of year to watch bats - I did not know about a Bat Fest.

By studying bat genes, scientists realised that what they thought were two species, were actually four species.

https://phys.org/news/2020-08-penis-b...

"In addition to examining the bats' bodies, the researchers analyzed the bats' calls that they recorded back in the "wedding dress." Different species call at different frequencies to communicate with each other, explains Patterson: "Bats divide up call frequencies for the same reason that radio stations divide up the airwaves, to avoid interfering with one another."

The researchers found that the bats' calls, all higher than the highest-pitched squeak a human can hear, distinguished them from other bats in the area. The final verdict was that there were three species new to science, and two new genera among the vesper bats they studied."

This claim that people can't hear bats is not the case. Most children are able to hear bats. People damage their hearing with loud noises as they go through life. I learned this as a child, so I decided I was going to keep my hearing protected, and I have always been able to hear bats any time I see them.
They say bzzzt. I can often feel the vibration inside my head before I hear the noise.
Scientists who tell you nobody can hear bats, have just listened to too much loud music.
Eventually age-related hearing changes will probably catch up with me, but I have enjoyed hearing bats.

Love sitting on on our deck at dusk and watching the bats flit and dart along the tree line, hunting for insects. The way they change direction on a dime in mid-flight just amazes me!

Brian wrote: "Love sitting on on our deck at dusk and watching the bats flit and dart along the tree line, hunting for insects. The way they change direction on a dime in mid-flight just amazes me!"

They are magnificent to watch aren't they!
I watched a Virtual Bat Walk across the UK as part of the #BatFest sat in the dark, watching the bats flying around our garden too.

We've not long bought our house & now the inside is pretty much sorted, we're now in the planning stages of sorting out our garden & drive, hoping to get some bat boxes up, but until then we plan on making the most of our local Nature Reserves & going for evening walks to see some more bats

Don’t Blame Bats

A new campaign called #DontBlameBats has been launched to dispel widespread unfounded fears and myths about bats which are threatening conservation during the pandemic.

I love watching bats off of my back porch. I am very lucky to be able to do that.

Jimmy wrote: "I love watching bats off of my back porch. I am very lucky to be able to do that."
It's like watching birds that have ears.

Jimmy wrote: "I love watching bats off of my back porch. I am very lucky to be able to do that."

I was sat outside reading yesterday evening & then stopped to watch a bat swoop & dive around the garden for 20 mins amazing to watch them.

We're thinking of going to a nature reserve Friday evening to see some more on our way home from visiting friends

An ecologist works in bat caves...

"Occasionally, a bat is startled from sleep, wings brushing by as it takes flight.

People in this part of Zimbabwe call bats "winged dragons", "flying rats" or simply the "evil ones".

Like elsewhere in the world, the flying mammals are much misunderstood. For this wildlife ecologist, they're beautiful and incredible creatures. "They are fascinating," he says. "People are frightened of something they don't know.""

https://www.bbc.com/news/science-envi...

As bats are protected, felling a woodland to build a high speed rail that nobody seems to want, and in the process disturbing a bat colony, is a bad move.

https://www.theguardian.com/uk-news/2...

It's great to see bats gaining popularity after all these years

"The bat uses the time delay between each echolocation call and the resulting echoes to determine how far away prey is. They tilt their heads to catch the changing intensity of echoes to figure out where the prey is in the horizontal plane. Bats must put together echo information about object distance and direction to successfully track an erratic moving insect.

But because bats are such good hunters, the research team thought that in addition, the bats must also be somehow using this information to predict where they prey is headed. To test this in the lab, they designed an experiment that closely mirrored the situation of a bat hunting in the wild.

They trained bats to stay on a perch and track insects. The team recorded the bat's echolocation calls and head movements as they changed where the insects moved and how quickly. They also added obstacles that interrupted the echoes."

A couple of short clips (a few seconds) are included. To me the most startling point is "They trained bats to stay on a perch and track insects."

https://phys.org/news/2020-11-future....

More information: Angeles Salles el al., "Echolocating bats accumulate information from acoustic snapshots to predict auditory object motion," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.201...
Journal information: Proceedings of the National Academy of Sciences
Provided by Johns Hopkins University

https://www.theguardian.com/environme...

"Every year, between October and December, 8–10 million straw-coloured fruit bats descend on the park to feast on an abundance of fruit. From west Africa, over the forests of the Congo basin and on to Zambia, the bats migrate thousands of kilometres over savanna and open land, dispersing seeds into deforested areas, and reforesting and regenerating landscapes on their journey. Scientists are still trying to fathom why these fruit bats, or “flying foxes”, gather at Kasanka in numbers not seen anywhere else. Each night they leave their evergreen swamp fig roosts to fly up to 55 miles (90km) in search of wild berries and fruit.
...
"While sightings have revealed where the bats have been spotted, the precise route they take is unknown. Dechmann’s teams is about to deploy satellite trackers to follow the migration. “I think this bat is crucial for Africa – more than most other species in that [they] cover long distances,” says Dechmann. “If you think about seed dispersal, antelopes, monkeys, birds, you name it – even most other bats – they will not leave the protection of the forest canopy, so they are not as effective as seed dispersers. If you have a colony like in Kasanka with several million bats, if each disperses one seed every night – that’s huge.”"

A new and striking species has been discovered in the Nimba mountains of West Africa.

https://www.ecowatch.com/new-bat-spec...

"Frick was part of a team of scientists from Bat Conservation International and the University of Maroua in Cameroon who were investigating natural caves and mining shafts in Guinea's Nimba Mountains. The mountains, which rise about one mile above sea level, are known as sky islands and are important biodiversity hotspots for species including bats.

One especially important bat species is the Lamotte's roundleaf bat, or Hipposideros lamottei, which lives only in the Nimba Mountains, and especially in abandoned mineshafts known as adits. But while trapping for the existing species, the scientists found something they did not expect.

"I looked in a net and there was just something interesting in there," Jon Flanders, director of endangered species intervention at Bat Conservation International, told The Washington Post.

Flanders said he first saw the bat with his colleague Eric Moïse Bakwo Fils from the University of Maroua.

"Eric and I got back to camp and we independently started trying to figure out what the hell was going on. Finding a new species of specially colored bats is very rare. I was like, 'I'm pretty sure this is a new species'. We walked in the room in the morning and simultaneously said 'I think we've got a new species.' "

So the pair called up bat expert and American Museum of Natural History Curator Nancy Simmons for help.

"As soon as I looked at it, I agreed that it was something new," Simmons, who is also the paper's lead author, said in the museum press release.

Simmons confirmed her initial opinion with help from the Smithsonian and the British Museum of Natural History, she told The Washington Post."

More about how bats fly.
New word: "orographic uplift that happens when air is pushed up over rising terrain to help them fly high,"

https://phys.org/news/2021-02-fast-fl...

""These free-tailed bats seem to find ways to minimize how much energy they have to spend to find food each night," O'Mara said. "It's a pretty incredible challenge for an animal that can only really perceive the 30 to 50 meters ahead of it in detail. It takes a lot of energy to fly up to 1,600 meters above the ground, and these bats have found a way to ride the wind currents up."

Although the researchers already had a pretty good idea based on past work that the bats also could fly amazingly fast, they say this fast-flying ability remains "a bit of an unsolved problem."

"Their small body sizes and large, flexible wings covered in a thin membrane were assumed to prevent these really fast speeds," O'Mara said. "But it's now clear that bats can fly incredibly fast when they choose. It's up to us to figure out how they do that and if it can be applied to other scenarios," such as engineering bio-inspired high-speed and low-energy flight."

More information: Current Biology, O'Mara et al.: "Bats use topography and nocturnal updrafts to fly high and fast" www.cell.com/current-biology/f … 0960-9822(20)31894-7 , DOI: 10.1016/j.cub.2020.12.042
Journal information: Current Biology
Provided by Cell Press

From 2017:
https://phys.org/news/2017-11-farms-m...

"The Mammal Review findings suggest that mountain ridges are key habitat features that help with foraging and navigation for some bats. Therefore, development of wind farms along mountain ridges might be in conflict with the conservation of some open-space foraging bats.

"Mountain ridges seem to be sensitive places for bats because some open-space bats use these sites for foraging and for launching into the nightly skies. The recorded flight paths suggest that some bats may be attracted to wind turbines when these are placed along mountain ridges—a fatal attraction for bats," said senior author Dr. Christian Voigt, of the Leibniz Institute for Zoo and Wildlife Research, in Germany."

More information: Manuel Roeleke et al, Bats probe the aerosphere during landscape-guided altitudinal flights, Mammal Review (2017). DOI: 10.1111/mam.12109
Provided by Wiley

"Some migratory bats are attracted to artificial green light which may interfere with their flight paths, according to a study published May 31, 2017 in the open-access journal PLOS ONE by Christian Voigt from the Leibniz Institute for Zoo and Wildlife Research and the Free University of Berlin, Germany, and colleagues.


Artificial light at night is increasing worldwide, and is thought to affect bats. Some migrating birds are also known to become disorientated, particularly by red and white light, "

https://phys.org/news/2017-05-nathusi...

More information: Voigt CC, Roeleke M, Marggraf L, Pētersons G, Voigt-Heucke SL (2017) Migratory bats respond to artificial green light with positive phototaxis. PLoS ONE 12(5): e0177748. doi.org/10.1371/journal.pone.0177748
Journal information: PLoS ONE
Provided by Public Library of Science

More on echolocation and tiny computers stuck to tiny bats.

""When the bats are hunting, they stay at least a prey detection distance away from the vegetation. We think they do this to avoid masking of the weak prey echoes by the loud echoes from vegetation. By continually adjusting both their flight patterns and their sensory volumes during the hunt, the bats simplify the information they need to process," said senior author Professor Peter Teglberg Madsen of Aarhus University."

https://phys.org/news/2021-03-tiny-re...

More information: L. Stidsholt el al., "Hunting bats adjust their echolocation to receive weak prey echoes for clutter reduction," Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abf1367
Journal information: Science Advances

https://www.rte.ie/news/ireland/2022/...

"Back in 1998, the Vincent Wildlife Trust discovered 25 lesser horseshoe bats had started to use Walsh’s old stone farm building as a summer roost.
...

"Estimates suggest Ireland has no more than 13,000 of them. Those that are here are confined to small sites in six western counties where habitat destruction and roost deterioration are constant threats.
...

"The echolocation sounds they use for navigation only travel a few metres. It is like as if they cannot see things far away in good detail.

As a result, they stick close to linear markers when they fly – the likes of a stone wall, or a line of trees, or a hedgerow – to ensure they don’t lose their bearings or fall prey to predators.
...

" also concerned about the genetic diversity of the species in Ireland. Because they don’t fly very far from their roosts or safe areas, the main population groups don’t get to mix.

Studies have found that, even though they are only present in clusters in small areas in the western counties from south Mayo down to west Cork, Ireland has in fact got four distinct genetic populations of lesser horseshoe bats.

The bats prefer to feed in broadleaf woodlands. But these woodlands make up less than 2% of Ireland's tree cover.

Planting more native tree corridors and other suitable landscape and environmental improvements could make it easier for the different population groups to find one another.

Habitat improvements, such as that, are a key part of the Government’s new lesser horseshoe bat Species Action Plan just published.

The five-year action plan sets out a series of practical conservation measures to improve roosts, habitat, connectivity, and outreach in relation to this species."

We love to sit on the back deck and watch the little brown bats cruise along the tree line behind us, darting and flitting in acrobatic ways as they hunt insects at dusk. They seem to defy the laws of physics, changing direction on a dime. Amazing creatures!

They are truly amazing to watch!

https://phys.org/news/2023-08-feast-i...

"University of Exeter scientists identified seven bat species and 66 insect species (90% of which were moths) in the Pass of Bujaruelo, near Spain's border with France. The paper, published in the journal Royal Society Open Science, is entitled, "Bat activity correlated with migratory insect bioflows in the Pyrenees."

The study shows that migrating insects are a vital food source for both migrating bats and those that live in the mountains.

It also provides the first ever evidence of migratory bats feeding on migratory insects while both are migrating.

"Mountain passes are hotspots for a wide variety of insect species that fly south in the autumn," said Dr. Will Hawkes, of the Center for Ecology and Conservation on Exeter's Penryn Campus in Cornwall.

"This migration of nocturnal insects happens over about two months each autumn, but varying weather conditions mean there are just three or four key nights each year when large numbers of insects fly through the Pass of Bujaruelo.

"On these nights, activity of both migratory and residential bat species increased significantly, suggesting these are important moments for the bats to build and maintain their energy reserves."...

"The species preyed on by the bats included the cotton bollworm, a moth whose caterpillars are a major crop pest. By eating species such as this, bats may provide an important pest-control service that helps humans."

More information: Kelsey Davies et al, Bat activity correlated with migratory insect bioflows in the Pyrenees, Royal Society Open Science (2023). DOI: 10.1098/rsos.230151. royalsocietypublishing.org/doi/10.109...

Journal information: Royal Society Open Science

Provided by University of Exeter

https://www.linkedin.com/posts/aoife-...

David H. Davis , MS, CWB®
Wildlife Biologist at United States Department of Defense

"One in the heart of the University of Coimbra, one of the oldest educational institutions in Europe, is the Joanina Library, a veritable treasure trove of knowledge and baroque architecture. This unique library is not only an impressive place with its sumptuous design, but also with an unusual method of protecting the books: a colony of bats has been living inside the library for over two centuries!

At night, the bats emerge from the massive carved wooden shelves and begin to fly among the old books, feeding on insects that might damage the fragile pages of the historic volumes. These little book guardians play an essential role in preserving valuable collections by naturally eliminating pests without the use of chemicals that could harm sensitive materials.

To protect the library's wooden furniture and surfaces from bat droppings, staff cover the reading tables with special leather at the end of each day. In the morning, the library is carefully cleaned and life goes on in this sanctuary of learning.

The Joanina Library houses approximately 60,000 volumes, including rare manuscripts, books from the 17th-18th centuries and works of inestimable value. Thanks to bats, these literary treasures are preserved in excellent condition, and this unusual collaboration between man and nature continues to fascinate visitors from around the world.

So...if you ever get to Coimbra, don't miss the chance to see this unique library with your own eyes, where history, architecture and nature work together !"

New bat species found in Mexico. The species was already recorded, just not in this location.

https://phys.org/news/2025-07-large-f...

"Along the banks of the Lacantún River, a hollow tree hid two creatures never before reported in Mexico.

Just a stone's throw from an "extensive, well‑preserved tract of tropical rain forest," two Phyllostomus hastatus, also known as the greater spear-nosed bat, were roosting in the trunk of the large Ceiba pentandra, or Kapok tree, according to a study published in the journal Check List.

The sighting extends the species' known range by about 75 miles northwest from its closest occurrence in Alta Verapaz, Guatemala, the study said. This is also the first time the species has been documented using Kapok trees to roost, according to the study."

More information: J. Manuel Aranda-Coello et al, First records of Phyllostomus hastatus (Pallas, 1767) (Chiroptera, Phyllostomidae), Greater Spear-nosed Bat, in Mexico, Check List (2025).
https://checklist.pensoft.net/article...

The Ig Nobels. These are a comedy version of the Nobel Prize Awards.

https://phys.org/news/2025-09-cows-st...

""It's a great honor for us," said Francisco Sanchez, one of the researchers from Colombia who studied the drunken bats. "It's really good. You can see that scientists are not really square and super serious and can have some fun while showing interesting science."

Sanchez said their research found that the bats weren't fans of rotten fruit, which often has higher concentrations of alcohol. Maybe for good reason. When they were forced to eat it, their flying and echolocation suffered, he said.

"They actually got drunk similar to what happens to us," Sanchez said. "When you take some ethanol, you move slower and your speech is impaired.""

Never place a bat box or a bird box in full sun.

https://phys.org/news/2025-10-overhea...

"Bat boxes are often designed to retain heat to keep bats cozy, which could place the animals at even greater risk during heat waves, depending on the box's position in the sun. Researchers de Mel, Dylan Baloun and Zenon Czenze, also from the University of New England, wondered how much of a risk poorly positioned bat boxes pose to roosting big brown bats (Eptesicus fuscus) during a heat wave.

Published in the Journal of Experimental Biology, the team's research shows that bat boxes situated in full sun on a hot day could warm to temperatures exceeding 50° C while the bats are asleep and unable to move, causing them to die from extreme dehydration."

More information: Using physiology to unravel the implications of heatwaves for big brown bats (Eptesicus fuscus)., Journal of Experimental Biology (2025).
https://journals.biologists.com/jeb/a...
Journal information: Journal of Experimental Biology

Provided by The Company of Biologists