The program is easy to use.
The program is straightforward and simple to use. Deforestation is killing tropical birds, but not in the way you might think. They’re not starving to death because they can’t get an UberEats driver - they’re relying on an important service provided by ants, and that service requires large, intact forested areas. In other words, it’s a tale of dominoes falling one after the other.
When we think about deforestation, we normally think that loss of habitat is what causes animal populations to decline, after all, animals lose their homes and sources of food. But the way a forest is cleared matters as well. Forest fragmentation occurs when a large forested area is broken into small, isolated patches. It can mean that species don’t have enough space to search for sufficient food, or can’t easily travel into other forested areas.
For the various species of birds collectively called Ant Birds, fragmentation like this is especially deadly - and not because their trees or food sources gone, really, but because their ‘dining buddies’ are. Ant birds have that name not because they eat ants, but because they follow after ants to get food. In this case, army ants specifically.
Army ants are found in tropical rainforests in Africa and South and Central America such as the Amazon, and they hunt by going on raids that can be many hundreds of thousands of ants strong. Their colonies are much larger than those of other kinds of ants - I’m talking a million workers alone making up a raiding party. Instead of foraging individually for crumbs of food to bring home like a typical ant, army ants hunt together to catch live prey, including other animals way bigger than themselves. Of course, that’s usually still other insects, including their favorite - other ants. Larger individual insects, though, like grasshoppers and cockroaches, will scatter from approaching Army ant raids, and then get snapped up by the hungry ant birds who are lying in wait.
It’s a pretty smart tactic and makes for easy meals for the ant birds. A setup like this means ant birds don’t need to work much to get their food, especially when their home range is full of a reliable Army ant species that raids nearly every morning. Some species of really committed ant-following birds get upwards of 50 to 70 percent of their total diet from following these raids, and it’s those committed species that are most at risk because they have foraged and fed with ant support for so long. These ant birds can no longer hunt by themselves effectively and can’t feed themselves well any other way. After generations of adaptation, these specialist species may just not have the right behavioral skills for hunting independently anymore.
And while researchers continue to untangle ant bird ant preferences and behavior, we also keep cutting down rainforests and fragmenting their homes. Naturally, fragmentation harms the army ants first - for as small as they are, they need large, continuous space for their raids, and quantity is more important than quality of space.
And I do mean large - for a single Army colony of 10,000 to 10 million ants to meet its energy demands and survive, it requires up to 30 hectares of land - that’s 300,000 square meters, or almost a hundred football fields. A colony doesn’t stay put either - it goes through periods of low activity, active raiding, and home relocation. Raids usually spread out from home in a fan shape, and a new home is usually selected along the same Compass Direction. This helps a colony avoid re-raiding food sources that they’ve already cleared out - you know, keeps things fresh. It also means a single ant bird needs to seek out multiple Army ant colonies in their range to stay well fed.
So when we cut down trees and make smaller pockets of forest where there used to be larger, continuous forested areas, Army ant colonies start to die out first. Without enough ant colonies conducting regular raids, the poor ant birds go hungry - and not because their preferred food has died out, but because their UberEats driver is gone, and they don’t know how to find their own food.