Bat flight: No gliding ancestor...

aidoh

I saw this today: http://blogs.nature.com/news/2011/11/new_theory_on_bat_flight_has_e_1.html#more
Hopefully it's not old news. I couldn't find a link anywhere to the primary source but thought it was an interesting idea.
From nature news blog (the link above):

"When the researchers looked at which modern bats are most like those ancient progenitors, they realized that they are climbing, cave-dwelling, insect feeders rather than tree-dwelling, pollen, blood or fruit eaters. But this presents a mystery, because most insect-feeding bats today are fast and powerful flying animals that rely on echolocation to zero in on their prey. Palaeontological analyses of bat skulls conducted in recent years indicate that early bats lacked the bony structures that would be required for echolocation.

On the basis of this, Padian and Dial theorized that bats started out eating crawling insects that would not have required echolocation to be caught. Yet if such insects were the preferred diet of early bats, they wondered why these bats had evolved to become capable climbers that could hang upside down from cave walls.

An answer came to the two researchers while they were looking at video footage of a baby bat being dropped off a ledge in a lab (onto a pillow). The bat, they noticed, rapidly fluttered its wings to help it control itself as it fell. In the same way, they propose, proto-bats, when dropping down from the ceilings of caves, could use flapping to control their descent and land in the right place to gobble up prey."

Do you think this is true or is it just extrapolating a slightly whacky (and really cool) possible ecological scenario from a little bit of evidence?

Mickeroo

It's possible! Are you familiar with the Lesser Short Tailed Bat (Mystacina tuberculata)? The only mammal native to New Zealand (apart from sea mammals).

They're they only bat in the world(that I'm aware of) that hunt their prey on the ground. They don't sound a world apart from what you're describing and they're still alive today.

The lesser short-tailed bat is the only member of its family, Mystacinidae, known to still survive. It is listed by the Department of Conservation as a `species of highest conservation priority'.

• Short-tailed bats weigh 12-15 grams, have large pointed ears, a free tail and are a mousy-grey colour.

• Unlike most bats, which catch their prey in the air, the short-tailed bat has adapted to ground hunting and is one of the few bats in the world which spends large amounts of time on the forest floor, using its folded wings as `front limbs' for scrambling around.

• Short-tailed bats are found in indigenous forests where they roost, singly or communally, in hollow trees. The bats go into a 'torpor' in cold weather and stay in their roosts. They wake up as soon as the weather becomes warmer.

• Thought to be a lek breeder, i.e. males compete for traditional `singing' posts and `sing' for a female.

• Its diet consists of insects, fruit, nectar and pollen and it is thought to be an important pollinator of the Dactylanthus or woodrose, a threatened parasitic plant which grows on the roots of trees on the forest floor.

https://www.youtube.com/watch?v=P2wjXRTd1vU

Adam Khor

Since the earliest bats known are so similar to those today, I would suposse that their ancestors, gliding or not, would probably have coexisted with dinosaurs at the end of the Cretaceous!

recedite

Mickeroo wrote: »

It's possible! Are you familiar with the Lesser Short Tailed Bat (Mystacina tuberculata)? The only mammal native to New Zealand (apart from sea mammals).

https://www.youtube.com/watch?v=P2wjXRTd1vU

I would guess its the other way round for these bats; ie their flying ancestors got blown off course, ended up on an island with no competition from rodents, and gave up flying. Like the dodo.

Adam Khor

recedite wrote: »

I would guess its the other way round for these bats; ie their flying ancestors got blown off course, ended up on an island with no competition from rodents, and gave up flying. Like the dodo.

I agree.

Mickeroo

recedite wrote: »

I would guess its the other way round for these bats; ie their flying ancestors got blown off course, ended up on an island with no competition from rodents, and gave up flying. Like the dodo.

They still fly, but yea they are not as threatened on the ground as they would be elsewhere, at least they used to not be as threatened.