Tiny ants are changing the diet of Kenya's lions

March 16, 2024 11:32 PM

Tiny ants are changing the diet of Kenya's lions. Invasive ants are affecting how lions hunt. The insect invasion has led to the loss of cover for lions to ambush zebra from and forcing them to target buffalo instead. An army of big-headed ants is changing the food chains of the savannah. Though they’re little, these ants are fierce. Their arrival in parts of Kenya has decimated populations of local ants which usually live in and protect the whistling-thorn tree. Without the insects’ protection, these trees are increasingly being eaten by elephants, providing less shelter for a range of species. One animal this has had a particular impact on is the African lion. These big cats usually use the shelter of trees to sneak up on zebras. But with fewer trees, this strategy becomes increasingly risky.
posted by chariot pulled by cassowaries (7 comments total)

So, this is a depressing story, but I did learn about the superb starling, who’s is pretty superb, so that’s nice.
posted by GenjiandProust at 4:55 AM on March 17 [2 favorites]

Are we gearing up for a million-year battle between big-headed ants, fire ants, and Argentinian ants?
posted by clawsoon at 5:59 AM on March 17

I think I missed a step in here somewhere. Local ants formerly protected the whistling-thorn tree from elephants?

Wikipedia:

Like other acacias, whistling thorns have leaves that contain tannins, which are thought to serve as deterrents to herbivory. Like all African acacias, they are defended by spines.[11] In addition, whistling thorn acacias are myrmecophytes that have formed a mutualistic relationship with some species of ants. In exchange for shelter in the bulbous spines (domatia) and nectar secretions, these ants appear to defend the tree against herbivores, such as elephants and giraffes,[12][13] as well as herbivorous insects.

At a site in Kenya, three Crematogaster and one Tetraponera ant species compete for exclusive possession of individual whistling thorn trees: Crematogaster mimosae, C. sjostedti, C. nigriceps, and Tetraponera penzigi.[4][5] Ant species vary in their level of mutualism with whistling thorn trees. The most common ant symbiote (~ 50% of trees), C. mimosae, has the strongest mutualistic relationship, aggressively defending trees from herbivores while relying on swollen-spines for shelter and feeding from nectar produced by glands near the base of leaves. (See also: Crematogaster peringueyi.)

So the local ants bite the elephants? Must be pretty nasty bites to scare off a hungry elephant. But not nasty enough to scare off invasive ant species.
posted by pracowity at 6:06 AM on March 17

So the local ants bite the elephants?

That's what the original article said too, which seems bizarre. However, the linked paper suggests that the acacia ant secrete chemicals that makes the trees taste bad, which makes a little more sense.
posted by CheeseDigestsAll at 6:26 AM on March 17 [1 favorite]

However, the linked paper suggests that the acacia ant secrete chemicals that makes the trees taste bad, which makes a little more sense.

Don't elephants push over trees just for the fun of it (and/or to clear the landscape), not because they want to eat them? I feel like I've heard that somewhere.
posted by clawsoon at 6:32 AM on March 17

When an elephant tries to eat the tree, “ants swarm up inside its nostrils and bite from the inside out,”

Idk how big you are, that's gotta hurt.
posted by SaltySalticid at 7:57 AM on March 17 [6 favorites]

ants swarm up inside its nostrils and bite from the inside out

See, that's the difference between okay-ish science writing and good science writing. Don't leave us wondering how ants protect trees from elephants when you can say it in one line.

All it needs now is a chart to show the dependencies, because everyone in the neighborhood is affected: lion, giraffe, elephant, buffalo, zebra, whistling thorn, local ant, and invading ant.
posted by pracowity at 10:53 AM on March 17 [3 favorites]