World Anteater Day Moved in 2020, and the Highway Is Still the Danger

A giant anteater can push its tongue 35 to 40 centimeters past its lips, coat it in sticky saliva, and work it into a termite mound at a pace that lets it eat thousands of insects a day. It has no teeth at all. The front claws do the opening, ripping into mounds and nests hard enough to reach the colony inside, and the tongue does the rest.

World Anteater Day was moved six years after it began, and the old date has not gone away.

Two Institutes, Two Dates

World Anteater Day is November 19th. It started in Brazil in 2014, created by two conservation organizations, Instituto Jurumi and Instituto Tamanduá, and for its first six years it was held on November 29th.

In 2020 the day moved to November 19th, so that it would no longer share a date with the day of another emblematic Brazilian animal. November 29th is also International Jaguar Day. Anything written about the day before 2020 gives November 29th, which was correct at the time, and pages from those years still circulate under the old date.

The day covers every anteater, and there are around ten species: the giant anteater, two tamanduas, and several small, tree-living silky anteaters. In practice it is the giant anteater's day, because that is the one in trouble.

Listed Vulnerable, and Still Declining

The giant anteater is listed as Vulnerable on the IUCN Red List, with a decreasing population. Its population is estimated to have fallen by at least 30 percent over the last three generations, about 21 years, through local extinctions driven by habitat loss, wildfire, and roads.

An adult weighs 22 to 45 kilograms and lives in open grassland and cerrado, habitat that deforestation and farming have cut down and broken into fragments. The fragments are joined by highways, and highway expansion has pushed the number of anteaters hit by vehicles up.

The Road Is Where It Dies

Carlos de Freitas, Carla Justino and Eleonore Setz drove five roads in southeastern Brazil twice a month for most of a decade, from 2002 to 2012, and recorded every giant anteater killed on them. They counted 45, most of them adult males.

The team compared kill sites with control points spaced every 2 kilometers along the same roads, which let the team ask what the deadly stretches had in common. Two things stood out. Kill sites sat next to native vegetation, cerrado and grassland, and they were on straight sections of road. Together, roadside native vegetation and straight alignment raised the probability of an anteater road-kill by 40.1 percent.

The food explains part of it. Every single kill site had a termite mound or ant nest nearby, and 86 percent showed signs that the anteater had been feeding there. Roadside verges grow the insects the animal hunts, and a straight road lets traffic carry speed.

Two other results ran against expectation. Deaths were more common in the dry season, and on the two roads where traffic volume was measured, more traffic did not mean more dead anteaters. The authors proposed mowing verges and removing the insect nests along them, fencing roadsides in cerrado and grassland, and warning signs with speed radar on the worst stretches.

The Scale of It in One State

The Anteaters & Highways project, run by Arnaud Desbiez and colleagues at the Institute for the Conservation of Wild Animals, took the same question to Mato Grosso do Sul. Between 2017 and 2020 the team recorded 12,400 dead animals along 1,158 kilometers of highway, and 762 of them were giant anteaters.

The project also interviewed 229 truck drivers. Most collisions were not deliberate. The danger runs both ways, because a driver who swerves or brakes hard for an animal at night can cause a worse crash than the one avoided, and 80 to 90 percent of these accidents happen after dark. Around 40 percent of the animals killed are large enough to do serious damage to a vehicle. By the team's estimate, fencing the worst hotspots would pay for itself in avoided damage within 9 to 25 years.

The Scaly Anteater Is Something Else

The pangolin is often called the scaly anteater, and the name is the only thing they share by descent. A pangolin belongs to a separate order, Pholidota, and its armor is keratin scales over a body that, like the anteater's, has no teeth, a very long tongue and powerful digging claws. Its threat is a different one too: pangolins are trafficked at industrial scale for scales that are chemically no different from fingernails.

The resemblance comes from the diet. Eating ants and termites has evolved independently several times in mammals, in at least five placental orders: the anteaters, some armadillos, pangolins, the aardvark, and the aardwolf, which split from the hyenas within the last 10 million years. Molecular studies put more than 80 million years between these lineages. Each arrived at reduced or lost teeth, a long muzzle with an extensible tongue, thick saliva from enlarged glands, and claws for breaking into nests. A 2014 study led by Frédéric Delsuc found that the gut bacteria of anteaters, aardvarks and aardwolves had converged as well. It is a textbook case of convergent evolution: unrelated animals shaped into nearly the same tool by the same food.

The anteater's own relatives are the armadillos and the sloths, which together make up the xenarthrans.

A pangolin's danger is a buyer. The giant anteater's losses are quieter and more ordinary: a burned grassland, a cleared field, a straight road through the scrub where its food grows, and a driver at night who cannot safely stop.

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