Summary: How do colonies of ants live in trees? Find out in this episode about arboreal ants.

For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean

Show Notes:

“Adventures Among Ants” by Mark W. Moffett

Music written and performed by Katherine Camp

Transcript

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Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

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Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating.

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

We are rounding the bend with the ants series and there is no better way to do that than to take to the sky. The title of this episode is Arboreal Ants. There are ants that live in trees and never touch terrestrial earth their entire lives. You thought the Leafcutter ants were amazing, well hold on to your hat because the seventh thing I like about ants is the colonies that live in the trees.

Arboreal ants, which are ants that live in trees, are found on many different continents and there is more than one species, but we are going to focus on one species in particular so we can really see their amazing qualities in detail. We’re spending some time with the Weaver ants of Africa, Oecophylla longinoda. Now living in a tree for an ant is no small feat, so how do they do it? Terrestrial ants dig into the dirt and create many chambered nests. It’s kind of difficult to dig into a tree, so where are arboreal ants living?

Weaver ant nests are most common in the outer, uppermost branches of trees where the sun light is bright. Here, the ants will bind adjacent healthy leaves together to create a treetop tent. The size of each nest will vary but is often between the size of baseball or a volleyball. They are as light as an inflated ballon and can withstand wind, rain, and enemy invasions. To begin building a nest, a worker ant will pull the edge of a leaf toward the edge of another leaf. If her bending is successful other workers will come to her aide.

Now weaver ants get their name from the next step. To keep the leaves together they employ their larvae. If you’re think, “What?” I hear ya! The larvae are picked up by workers and taken to the edge of the leaf connection. The workers tap the larvae on the leaf to encourage the larvae to release silk. Yes, the larvae of many species of ants create silk. The Weaver ants use this silk to secure the leaves together. The motion of shuttling the larvae back and forth to connect the leaves with the silk is where the weaving comes in. The nests may last for years because when one leaf dies the ants will just weave in another living one.

The nests are larger enough to house thousands of ants, but the weaver ants don’t have just one nest in the tree. They travel all over the tree that they call home, so they often build other trees op tents so they can maximize their resources. They don’t stick to one central nest, they have the ability to move around when they need to. One territory can have multiple nests. The queen is often in a nest that is the most centralized to the territory, but her eggs are distributed throughout all the nests.

With all of these spread out workers, Weaver ants have to have an excellent communication strategy. And boy, do they! Earlier we learned that pheromones are integral to ant communication. It’s the same with weaver ants, but they have a specialized gland that helps the pheromones that they use to create their paths last longer than terrestrial ants. They have an anal gland that helps them make their poop a bit more than just poop. To keep their pathways from wearing away too quickly, weaver ants use their feces to create longterm smell paths. The droplets of worker excrement hardens into a shellac like substance that can last for months.

This form of communication also allows these ants to do something most other ants do not, defend a specific territory. Weaver ants are known to defend their treetop territories from other ants they encounter. With the pheromone lines drawn already it gives them an advantage in skirmishes. Their scent is already laid down. If a weaver ant encounters an enemy worker, she will race back to more familiar territory to recruit help. She does this by mimicking fighting motions and other workers will follow her prepared for battle.

So what do weaver ants eat? This species of ant is omnivorous. They eat both meat and veggies. One of the coolest things they target is nectaries created by trees. These are spots on the leaves of trees that seep nectar. This isn’t like the sap that leaks from the tree’s bark, this is like the nectar that a flower produces. When they find a nectary, the weaver ants will built a tent around it to hide it from other animals that might be interested in this pot of gold as well.

Weaver ants do eat meat in the form of other insects, Mark Moffett retells an experience he had in Cambodia as he watched some local Oecophylla drag a 5 cm long scorpion up a tree to pull it apart, as well as other meat items such as birds, bats, and other ants. The protein is eaten mainly by the larvae while adults typically consume sap and nectar.

Does the tree benefit from the ants in residence or are they detrimental? This is a question that ecologists try to answer through cost/benefit analysis. Some benefits to the tree are weaver ants culling leaf eating insects before they can defoliate the tree. Foliage lasts longer in areas where the weaver ants live. The ants also provide a bit of fertilizer to the tree as well by pooping on the leaves. Trees can absorb some nutrients through their leaves. On the cost side, some of the leaves the weaver ants use to create their nests are permanently lost, but considering the small percentage of leave the ants use, I think the benefits outweigh the costs.

I hope this quick foray into the treetops with these arboreal ants was worth it, because treetop living ants is my seventh favorite thing about ants.

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change.

Join me next week for another exciting episode about ants.

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This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, my very own piano playing hero.