Thursday, March 6, 2014

We Move Slowly, But Really, We Are Not Lazy!

Two toed sloth

There are 2 types of sloths on this rainforest island in the Panama Canal.  You can easily tell them apart by their coloration and how many claws they have on their front legs.  Sloths dig their long sharp claws into a branch to hold on while they are hanging upside down in the canopy layer of the rainforest.  Three-toed sloths have the slowest digestive rate of all mammals and they also have a very slow metabolism.  Sloths live in a mutualistic situation with algae and moths. Both of these live in sloth fur.  The algae supplies both green camouflage coloration and a food source for the sloth who scrapes the algae off its fur with its claws and eats it.  The algae benefits by having a constant supply of water and exposure to some sunshine for photosynthesis.   

Three toed sloth
Fur of the three-toed sloth is adapted for holding rainwater in crosswise grooves.  Moths also live in sloth fur.  These moths require that the three-toed sloth come down to the ground to poop.  Mother moths from the sloth lay their eggs on the sloth poop and the larvae hatch on the poop and eat it.  When the larvae go through metamorphosis and become adults, the adults fly back into the sloth fur.  Moths supply a necessary element (nitrogen) to sloths and sloths make it possible for moths to complete their life cycle.  This is another example of mutualism. 

If you want to read more about sloths, here are four interesting links for you:

- Fran Zakutansky

Bats Make Their Own Tents

I should have looked underneath this leaf after I took this photo.  Although it is pretty low to the ground for bats, the two sets of V-shaped notches in the leaf look a lot like how tent-making bats chew leaves to make a nice tent shelter for themselves.  I wonder if there were bats sleeping underneath this leaf.  Tent-making bats chew notches in leaves so that the leaves will form an upside-down V (much like a simple tent).  They sleep underneath the leaf in the V, which makes it difficult for predators to find them.  It also protects them from rain.  I would normally expect to find leaves used by tent-making bats to be six or more feet off the ground.

I put 2 red circles around bats in this photo who are sleeping in a leaf tent that they made by notching the leaves on this tall tree (photo taken by Selina Ruzi).  The next time that I hike on this trail, I will have to investigate further so I can determine if tent-making bats used this leaf as their tent. 

- Fran Zakutansky

They’re Bees, But They Don’t Sting

I was not too worried about getting close to these stingless bees to take the video that you see here.  I found out after I got pretty close that although they don’t sting, they can bite.  If you get too close to their nest, some species of stingless bees fly into your hair and get tangled and bite your scalp.  I was lucky this time and from now on, I will give them a little more distance.

They choose old, hollow logs and their nests are easy to spot because of the white “front entrance” that they build.  The bees that you see hovering around the “front entrance” in this video are the guards and are called angelistas.  Guards, workers, and the queen are all females.  Like other bees, stingless bees are social insects, meaning that they live in colonies and each bee in the colony has a special job to do (division of labor).  The workers leave the nest (you can see them leaving in the video) to collect pollen and nectar.  They may also collect oils and waxes from plants and hair from animal burrows to use in their nest construction.  When the workers return to the nest, they communicate with other workers about the location of the food supply.  Bees are important pollinators for plants.

Thanks to Meghan Duell, an entomologist studying stingless bees in Panama, for her helpful input for this blog entry. 

- Fran Zakutansky

Tuesday, March 4, 2014

What Foods Do Anteaters Eat?

I heard some leaves rustling outside my room on BCI (the island research field station that I’m living on for 2 weeks). I usually look outside to see an agouti when I hear rustling. If you want to learn more about agoutis and see a photo, scroll all the way back in this blog to February 19, 2013. This time, it was not an agouti; it was a tamandua (anteater).

The anteater was looking for a nice ant colony that it could rip open with its strong front claws. Then it would use its long tongue (the tongue can be one foot long) to lap up hundreds of ants. Tamandua snouts are thin and tube-like, which makes it easy for them to poke their heads into ant colonies. Anteaters also eat termites the same way by scratching open their nests with their strong front claws and using their tongue to lap out the termites. The tamandua is one of my favorite rainforest animals because it looks like it is wearing a dark vest over its tan fur.

Click here if you would like more information on tamanduas.
Here is another photo of a tamandua.

- Fran Zakutansky

Monday, March 3, 2014

Going Batty

Sometimes you don’t even have to walk into the rainforest at this incredible research field station on BCI in Panama to see wildlife.  Bats hang out (literally) on the outside walls of my room every day.  They are always gone when I come back from dinner because it’s dark out by then and they are nocturnal.  Bats are mammals like us.   They have much longer finger bones than we do, and they have a thin membrane of skin between the bones so they can fly. 

Take a look at the size of the bat’s eyes in this video.  Many nocturnal animals have very large eyes so they can see well in the dark.  This bat’s eyes are small.  Bats use echolocation to determine where they are going and to catch their food.  They send out sound waves that bounce off objects and then return to the bat. From this, bats can determine the size and shape of objects that they are approaching.

Very few species of bats are harmful to humans (for example, vampire bats may bite us).  Most bats, like the ones in the video are actually helpful to us because every night they eat hundreds of insects, like mosquitoes that are pests to us. 

There are many different species of bats on this research island and scientists come from all over the world to study these bats. I guess you realize by now that these scientists (called chiropterologists) sleep during the day and do their field work at night.  I’m glad that my roommate here is an entomologist because she works with her ants during the daytime so she and I have a similar schedule.

Click here for a lot more detailed scientific information on BCI bats:

- Fran Zakutansky

Saturday, March 1, 2014

Extreme Teamwork - Army Ants

Army ants are social insects, living in very large colonies up to half a million ants.  You definitely want to be sure that you do not step on a row of army ants marching across the trail.  They attack prey in huge numbers (as many as 100,000 simultaneously). They slice the prey with their scissor-like mandibles and they spread a dissolving acid on it, which digests the prey’s body so the ants can slurp it up.   After watching this video and seeing how large the soldier ants’ mandibles are, you can see why you would not want to have them crawling up your hiking boots and into your socks.  By the way, in this army, the soldiers are all females…And so are all of the workers….And so is the queen. 

Social insects show teamwork and division of labor and army ants are a prime example of predatory teamwork.  Army ants teach us that “there is strength in numbers”. 

- Fran Zakutansky

Friday, February 28, 2014

OUCH, What Big Spines You Have!

I was leisurely strolling thru the rainforest this afternoon, watching fireflies (lightning bugs) blink on and off and listening to the howler monkeys howl.  It’s a good thing that I was watching where I was walking because I came very close to this black palm tree trunk covered with long, black spines. 

These spines would definitely pierce through my field pants and maybe even my hiking boots.  I’m sure that I would get a nasty infection if some of these spines broke off in my skin.  It reminded me that I always need to look around when I’m hiking in the rainforest to avoid dangers.  These spines are a defense mechanism for the black palm to protect its fruit and seeds. If I were a rainforest animal who eats seeds, I would definitely think twice before scurrying up this tree trunk to get some yummy seeds. 

Notice in this other photo that Dr. Jackie Willis took that this monkey seems to be sitting very close to the spines of this black palm tree while eating its fruits.  I guess, in this case the fruits were just so enticing, that the monkey was willing to take his chances with the spines.  I know that I will stay as far away from any black palm trunks that I see on future rainforest hikes!

- Fran Zakutansky