Some people would argue that bats are anything but cute. But that is simply because they have never met a bat. Some bats are very adorable. A study in 2016 analyzed a strange and cute mannerism observed in many bats: head waggling. A waggle is when the bat turns its head side to side while looking at something.
“It’s an adorable behavior, and I was curious about the purpose,” said Melville J. Wohlgemuth, a postdoctoral fellow in the Krieger School of Arts and Sciences’ Department of Psychological and Brain Sciences. “I wanted to know when bats were doing this and why. It seemed to occur as bats were targeting prey, and that turns out to be the case.”
Earlier this year White Nose was discovered for the first time in the Pacific North-west. This is disheartening news.
The question begs: what can we do more to prevent this spread? Obviously we can stop visiting caves. But are there steps we can take before we reach that conclusion? What do you think?
From the article:
On 11 March 2016, a moribund little brown bat (Myotis lucifugus) was found in King County, WA (United States), and submitted to a local wildlife rehabilitation center. The animal presented with dried and contracted areas of crusted skin on the wings and died 2 days later. Swab samples of the wings were positive for P. destructans by real-time PCR (8), and the bat was confirmed to have WNS in accordance with defined histopathologic criteria (9). An isolate of P. destructanswas obtained by culturing a portion of wing skin on Sabouraud dextrose agar containing chloramphenicol and gentamicin at 13°C.
In eastern North America, P. destructans appears to be spreading clonally, with all isolates exhibiting no genetic diversity at the markers examined (10). However, isolates of the fungus from Europe display significant genetic variation (11). To determine whether the isolate of P. destructans from Washington matched the clonal lineage from eastern North America, we conducted whole-genome sequencing using the Ion Torrent Personal Genome Machine (PGM) on the Washington isolate (NWHC#27099-001), as well as on three additional isolates of P. destructans from eastern North America. These isolates originated from M. lucifugus bats collected in Albany County, NY, in 2008 (NWHC#20631-008) and in Iowa County, WI, in 2016 (NWHC#26994-002) and a tri-colored bat (Perimyotis subflavus) in Jackson County, AL, in 2015 (NWHC#44797-145).
Please read the full report at msphere.org, the online journal for the American Society of microbiology.
Climate change and spreading bat populations; what a topic! Europe is experiencing a impressive spread of the Kuhl’s pipistrelle and they think changing climate is increasing it’s habitable territory. Springer has the report:
The team collected 25,132 high-resolution records of where the bat occurred in Europe between 1980 and 2013. These were used in conjunction with various models to predict whether the colonisation of new areas over the years has been prompted by increased urbanisation or by changes in the climate.
When first recorded, Kuhl’s pipistrelle was typically found over large areas of North Africa, southern Europe and Western Asia. In southern Europe its distribution was originally confined to the Mediterranean basin. It extended east to the Balkans, west to the Iberian Peninsula and north to the Alps and western France. By the 1980s, the bat was also reported in northern France and Bulgaria. Slowly but surely it has spread to other countries, including the United Kingdom to the north and eastern regions such as the Czech Republic, Slovakia, Ukraine, Hungary, Romania, Bulgaria, Serbia and Poland.
Research into how bats’ brains filter noise show that they are super good at sifting through a sea of sound, and focusing on their own chirp echoes.
“With so many stimuli in the world, the brain needs a filter to determine what’s important,” said Melville J. Wohlgemuth, the lead author and a postdoctoral fellow in the Krieger School of Arts and Sciences’ Department of Psychological and Brain Sciences. “The bat brain has developed special sensitivities that allow it to pick out sounds from the environment that are pertinent to the animal. We were able to uncover these sensitivities because we used the perfect stimulus — the bat’s own vocalizations.”
The researchers experimented with five big brown bats, playing them a variety of sounds while monitoring their midbrain activity. They played recordings of natural chirps, the actual sounds bats made as they hunted. They also played artificial white noise and sounds between the two extremes. All of the sounds were identical in amplitude, duration and bandwidth.
Although sensorimotor neurons in the bat midbrain reacted to all of the sounds, the neurons involved in stimulus selection, those that guide orienting behaviors, responded selectively to a subset of the natural chirps.
This release has made waves in the news: bat wings influencing the creation of new drones:
A team of researchers led by Professor Bharathram Ganapathisubramani at the University of Southampton, in England, have been experimenting with adjustable bat-inspired membrane wings that also vibrate as air passes over them. They’ve mounted these wings onto a micro air vehicle that uses them (along with ground effect) to zip across water fast and efficiently.
These membrane wings aren’t just flexible, they’re also controllable. They incorporate electroactive polymers that respond to voltage by changing the wing’s stiffness, allowing you to dynamically adjust the wing shape and “dramatically” altering their performance.
Read the full article at Creative Planet Network. Be warned, I am using Safari and had a lot of trouble getting the article to scroll correctly.
Bats use sonar to navigate. Just like humans they have unique ‘voices.’ But just like humans, they can only distinguish a certain amount of sounds at once. Think about it, you recognize your voice and the voice of family members and close friends. But have you ever tried to pick out someone’s voice in a crowded auditorium full of excited people talking?
How do bats recognize their own echoing voice clicks when they are surrounded by hundreds of fellow clicking bats?
Tel Aviv University has an interesting article on this and the ramifications of the findings:
A new Tel Aviv University study published in Proceedings of the Royal Society B: Biological Sciencesidentifies the mechanism that allows individual bats to stand out from the crowd. The research, by Dr. Yossi Yovel of TAU’s Department of Zoology, finds that individual bats manage to avoid noise overlap by increasing the volume, duration and repetition rate of their signals.
According to Dr. Yovel, unlocking the mystery of bat echo recognition may offer a valuable insight into military and civilian radar systems, which are vulnerable to electronic interference.
Reports of bat deaths worldwide due to human causes largely unique to the 21st century are markedly rising, according to a new USGS-led analysis published in Mammal Review.
Collisions with wind turbines worldwide and the disease white-nose syndrome in North America lead the reported causes of mass death in bats since the onset of the 21st century. These new threats now surpass all prior known causes of bat mortality, natural or attributed to humans.
A comprehensive studyreveals trends in the occurrence and causes of multiple mortality events in bats as reported globally for the past 200 years, shedding new light on the possible factors underlying population declines.
Many of the 1,300 species of bat are considered to be threatened and declining. A new analysis reveals trends and causes of death in bats around the world, shedding new light on the possible factors underlying population declines.
In the analysis, 1180 mortality events, each involving more than 10 bats, were represented in a detailed canvassing of the literature dating from 1790 to 2015, and could be divided into 9 categories.