Category Archives: New Research

Opportunity to help save a bat species

It isn’t often that an opportunity comes along where one person could make a real difference in the survival of a species. But the new PHd opportunity offered by the Hawkesbury Institute for the Environment to work on the critically endangered Christmas Island Flying-fox (Pteropus melanomas natalis) does just that.

Christmas Island Flying-fox
Christmas Island Flying-fox

Christmas Island is one of Australia’s most remote and impressive natural wonders. It is home to the unique annual red crab migration, rare and unusual birds and, until recently, two bat species.

christmas Island MAP

The Christmas Island Flying-fox is now the last remaining bat species on the island and it is in real trouble.  The last individual of it’s only other neighboring bat species, the Christmas Island Pipistrelle (Pipistrellus murrayi) was recorded in late August 2009. Two decades earlier the island’s population of pipistrelles had been healthy. However a mix of human impacts and unknown factors on the island lead to the species’ sharp decline and to many scientists dismay, its extinction.

Christmas Island Pipistrelle (Photo: Lindy Lumsden)
Christmas Island Pipistrelle (Photo: Lindy Lumsden)
A Monograph of the Chirstmas Island Flying-fox - Andrews, C.W. (1900), British Museum of Natural History, London
A Monograph of the Chirstmas Island Flying-fox – Andrews, C.W. (1900), British Museum of Natural History, London

The Christmas Island Flying-fox is now facing a similar uncertain future. The species has declined dramatically in numbers over the last three generations, leading to its listed as Critically Endangered by the Commonwealth Scientific Committee in January 2014. Before we can take actions to help save this species from extinction, we first need to understand which threatening processes, such as habitat alteration, predation and competition from invasive species, are making the greatest impact on the species.

This PHd offers a unique opportunity to someone to make a real impact to a species’ survival and I encourage bat passionate candidates from around the world to apply!

 

 

 

 

What is it like to find a new bat species?

One of the greatest privileges of working at the Smithsonian is that you get to be on hand when exciting discoveries happen, like finding a new bat species!

My friend and fellow bat specialist Ricardo Moratelli has been working on finding new bat species for over 10 years! His focus is on the Myotis genus, one of the most difficult Neotropical genera of bats to understand. So far he as found 6 new species to science, including the recent golden bat species, Myotis midastactus.  

In an article for Smithsonian Science, I ask Ricardo what it is like to be a bat detective finding new species!! 

Bolivia’s golden bat: one of six new species found by the Smithsonian’s bat detective

Ricardo Moratelli, a scientist at the Oswaldo Cruz Foundation (Brazil) and post-doctoral fellow at Smithsonian’s National Museum of Natural History.
Ricardo Moratelli, a scientist at the Oswaldo Cruz Foundation (Brazil) and post-doctoral fellow at Smithsonian’s National Museum of Natural History.

 

Squeak to me baby! Female bats prefer mates with high-pitched voices.

Every female has a certain something they are looking for in a mate. In humans, women often prefer males with low voices, but in bats it may be the opposite.

New research published by Emma Teeling, an associate professor at University College Dublin’s school of biology and environmental science, has discovered male bats with higher-pitched sonar calls find more mates and father a higher number of babies.

Mehely's horseshoe bat -Rhinolophus mehelyi Photo: F. C. Robiller
Mehely’s horseshoe bat -Rhinolophus mehelyi Photo: F. C. Robiller

Bats use echolocation, a series of radar-like squeaks, to help navigate and find food while on the prowl at night. The sound waves that bounce back then help them to hone in on a good meal or find the best route home.

By following Mehely’s horseshoe bats in Tunisia and Bulgaria, Teeling and her team found a third use for their high-pitched calls – sizing up potential mates.

“High frequency calls indicate really good body condition, where the male is strong and healthy. The smaller bats did not have such a high frequency” Teeling told the Irish Mirror.

The benefits of males with high-frequency calls certainly did not go unnoticed by the ladies, with females preferentially selecting them to sire their young. This not only sheds new light on the mammals’ mating rituals but also provides evidence for the first time that sexual selection may have played a role in the evolution of echolocation.

It is commonly assumed that echolocation has been shaped solely by ecology via natural selection – primarily for abilities in orientation and food detection. However Teeling’s study demonstrated for the first time, using a novel behavioral, ecological and genetic approach, that echolocation calls play a role in female mate choice.

So, if high-pitched Casanovas can find more sexual partners, why don’t all bats have high-frequency calls?

“Having a higher echolocation call might mean more mates and babies, but its high frequency also makes it more difficult to find food. Essentially it is an attractive handicap, a little like a peacock’s tail” Teeling said.

Echolocation calls are not the only mode of communication that bats use. All species also have a rich repertoire of social calls not used in finding food or their way home. The next step in understanding the role of sexual selection in the evolution of bat calls would be to test these social calls and to expand the research to include a wider range of bat species.

This study was published in PLOS ONE

Feature image courtesy of Johannes Lundberg

 

New Mormopterus species honors a true bat lady.

One of the biggest honors you can ever receive, as a biologist, is to have a species named after you. Just that happened last week to a dear friend and mentor of mine Dr. Lindy Lumsden, who had a species of free-tailed bat named after her.

New species, Mormopterus lumsdenae, named after Dr. Lindy Lumsden.
New species, Mormopterus lumsdenae, named after Dr. Lindy Lumsden.

The Northern Free-tailed Bat, now known as Mormopterus lumsdenae, is found in the northern regions of Australia across the states of Queensland, the Northern Territory and Western Australia. It is one of three new species for this genus having been recently described in a paper published in the Australian Journal of Zoology. This new research published by Reardon et al. is important not only because it honors my dear friend, but also because it finally sheds light on a taxonomic group whose uncertainty has been a longstanding impediment to research and conservation efforts.

Members of this genus have been notoriously hard to identify for a long time mainly because they all look incredibly similar in the field. Indeed for a long time several species of this genus could be distinguished only by the structure of the glans penis, which requires some very intimate examinations and large magnifying glasses. It was Lindy who showed me how to do this when she took me on my first ever field trip catching bats, something I am not likely to ever forget!

Species of the genus Mormopterus are some of my personal favorites, as these bats are not only some of the first I ever had the privilege to catch but they also have interesting little behaviors as well. For example, instead of desperately trying to get away like most microbats do when you trap them, often Mormopterus species like to play dead. It comes in very handy when you are trying to take measurements, as they are not always struggling to get away!

Dr. Lindy Lumsden, Wildlife Ecology team leader for the Arthur Rylah Institute for Environmental Research

I think it is very fitting that Lindy have a Mormopterus species named after her as Lindy is well known for having two little bats of this genus help her with the hundreds if not thousands of public talks she has done over the years. If you were to ask any of the participants what their favorite memory was from one of Lindy’s talks, no doubt they would mention George or Grump. These two little Mormopterus bats came to Lindy a long time ago and could not be released back into the wild. So instead, Lindy looked after them, believing that they may only live six months to a year as no one had ever kept these bats in captivity. Twenty plus years later Lindy was still taking them to public talks, showing children to pensioners how beautiful these little creatures truly are. George sadly passed away in 2012 but Grump, although retired from public life, is still going strong.

Lindy has always had a passion for bats, something that she has not only passed on to me but also the thousands of people she has come across in her many years of teaching students, giving public talks and advocating for the conservation of bats. I commend Terry Reardon and his colleagues for not only a truly important piece of taxonomic work that will help the conservation of these species, but also the wisdom for celebrating a dedicated scientist with the highest honor her colleagues could bestow.

Penis spines help scientists identify bat species

Sometimes you need to look in unusual places to tell species apart. Some mammal species are easily distinguished by differences in their fur or skeletons, while other more cryptic groups require further scrutiny in their more delicate areas.

Ph.D. student Ligiane Moras is doing just that in her attempt to find characteristics that can separate species in a group of dog-faced bats, Cynomops, native to Central and South America. Using the extensive bat collection at the Smithsonian’s National Museum of Natural History and a very powerful electron microscope, Moras has found potential species differences in the tissues, glans and spines that cover the skin of their tiny penises.

“Epithelial spines can be found on the penis of many bat species. The spines on these bats are microscopic, about 20 micrometers long, so you can only see them with the electron microscope” Moras says. “All the bats in this group have these spines, but I have been able to find differences between potential species in spine length.”

 

Genitals come in many different shapes and sizes

DSC01655

Extreme variation in male genital morphology is a common trend across animals that reproduce through internal fertilization, including bats. Even closely related species with similar general morphology often have strikingly different genitalia. “When I couldn’t find differing characteristics in the skeleton or skins of this bat group, I started looking at the structures of the penis,” Moras explains. “Often changes can be found in the genitals between species due to sexual selection.”

 

Sexual selection is a mode of natural selection in which some individuals out-reproduce others of a population, which eventually can lead to the formation of a new species. Successful individuals may have behavioral or morphological traits that better ensure their genes are passed on to the next generation. These may include traits that attract the opposite sex, enable the successful delivery of sperm or ensure the survival of their young.

 

Penis spines wage war in the sperm competition

bat_penis_spikes

While the purpose of the spines has not been fully uncovered, scientists believe they might assist in this sexual competition. In mammal species where females frequently mate with multiple males, competition between males extends beyond attraction of mates to include sperm competition. These spines might have several roles, such as acting like a microscopic brush to remove competing sperm from the female reproductive tract or, in some bat species, aiding in the removal of a sperm plug.

 

In some bat species the male deposits a gelatinous secretion into the female’s genital tract after his sperm is delivered. This secretion later hardens to create a barrier to the sperm of competing males. Breaking down this barrier and removing the rival sperm before they reach the egg is crucial if a newcomer is going to have a fighting chance at fatherhood.

 

Looking in other unusual places to organize the bat family tree

 

While Moras has had some success in finding several characteristics of the penis that differ between potential species of the Cynomops genus, it is not the only place she is looking.

 

“I have also used the electron microscope to look at the tongue structure of these specimens,” Moras says. “I have found that the number of fungiform papillae on the side of the tongue–the little bump-like structures we also have on our own tongues–vary in frequency between potential species of this genus”.

 

Moras, who is studying zoology at Universidade Federal de Minas Gerais inBelo Horizonte, Brazil, aims to publish her taxonomic work in the near future, when she will present a complete family tree for this bat genus based on the different morphological characteristics she has found in some unusual places.