Sahara desert ants: A study in adaptability

The Sahara desert is about as unforgiving an environment as exists on Earth.

The African desert is characterized by intense heat and a scorching sun, especially during the hot season, when surface temperatures can reach more than 150 degrees during midday.

Most living organisms wait out the broiling heat in the shade, but not the Sahara desert ant, which seizes on the opportunities presented by the high temperatures.

Once the heat becomes unbearable for other species, the Sahara desert ant (Cataglyphis bicolor) emerges from the shade of its burrow to feast on the corpses of insects that have succumbed to conditions.

This species is reported to be able to forage in surface temperatures of up to 158 degrees for short periods despite the fact that it lives in an environment which has almost no identifiable features, according to the BBC.

Several abilities enable the Sahara desert ant to accomplish this feat:

• While venturing out it periodically takes measurements of its angle in respect to the Sun, which allow it to plot a straight line back to its nest;
• It relies on a unique odor signature that can guide it back to its home; and
• It appears to use an internal pedometer to count its steps in a harsh setting where odors quickly vanish, enabling it to “count back” to its nest.

Being able to withstand such extreme heat reduces competition for food from less thermo-tolerant scavengers and likely reduces its chances of running into a predator.

“Three main characteristics and behaviors allow the Sahara desert ant and other thermophilic ants to be active in temperatures that would quickly kill most other animals,” according to the BBC. “They are quick; Cataglyphis fortis and Cataglyphis bombycina, its close relatives, have been clocked moving at one meter (3.3 feet) per second. Their relatively long legs mean temperatures at the height of their bodies are 6-7 degrees cooler than on the ground.

“They also pause on dry stalks of grass onto which they off-load excess body heat,” the news service added.

These abilities allow the Sahara desert ant to venture out at midday for 3-5 minutes at a time. Given the speed at which it can travel, Cataglyphis bicolor has the ability to travel farther from its nest than any other creature that lives in the Sahara with respect to size.

How ants work together to survive floods

Fire ants are a major hazard in the Southern US. Whether you stumble onto a colony of these tiny stinging demons or simply stand too near a nest, you’ll likely end up with painful reminders of how appropriately these insects are named.

The mounds – which can approach a density of 1,000 per acre – are usually 1 to 3 inches tall and made of soft dirt, but can sometimes approach a full 12 inches in height. It’s not unusual for a medium-sized nest to hold tens of thousands of ants.

Among environments fire ants like to construct nests is along riverbanks and around ponds. As someone who likes to fish, I’ve discovered many a fire ant nest the hard way.

So, while I have a soft spot for most living things, it is with a child-like glee that, after a day of fishing, I will take occasion to carefully kick ant nests into the water when the opportunity presents itself.

The way I see it, anything that can harm me or my kids – along with any other living creature unfortunate enough to blunder along – is fair game. And if I can help cut down on these invasive pests, even better.

One thing that always caught my attention was how the ants, after being punted into the drink, would cling together. This is no accident, according to a recent study released by scientists from the University of Lausanne in Switzerland.

When faced with a flood, ants use their own bodies to form a raft and rely on the buoyancy of the brood and the recovery ability of workers to minimize injury or death, according to the study, released earlier this week. In addition, the queen ant is placed in the middle and protected on all sides by the rafting ants.