Deathgleaner

Deathgleaner; Temporal range: 5 million AD;
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Chiroptera
Gallery

“

Deathgleaners can be seen hanging in the air, resting on updrafts of wind blown off the sandy ridges below. They circle like vultures, seeking an easy meal on the ground. Now and again, one wheels and banks, signaling to the others that it has found something. Soon, a large group will gather and prepare to feast.

— The Future Is Wild: A Natural History of the Future.

”

The deathgleaner is a species of giant, social, diurnal bat native to the North American Desert and Rocky Mountains of 5 million AD. With a wingspan of about 4¼ feet (1.3 meters) and a body mass of roughly 21 ounces (595 grams), it is the largest known carnivorous bat in history—and of all bats, only some frugivorous Human era megabats were larger. Its mouth alone is about 1⅛ inches (28.6 millimeters) long, and its teeth are ⅛ inch (3.2 millimeters) long.

Evolution[]

As the cold desert spread across North America, the deathgleaner's forest-dwelling ancestor evolved to become larger and more social in order to cover more ground in its search for prey. As the bitterly cold conditions of the 5 million AD ice age spread across North America, bats were able to occupy the niches left over by numerous species of hawks and vultures, which had experienced huge declines in biodiversity. The deathgleaner has become diurnal in order to avoid the freezing temperatures of the desert night.

Biology[]

The deathgleaner hasn't changed much from its forest dwelling ancestors, however it is much larger than most extant bats. Deathgleaners avoid excess heat loss through a countercurrent exchange system in the wings, this enables blood flowing at different temperatures in opposite directions to exchange their heat content without mixing. Efficient strategies for regulating body temperature such as these alone, have enabled bats to survive and and thrive in such desolate conditions, whilst numerous species of mammals and birds have gone extinct.

Behaviour[]

The deathgleaner has become diurnal (active exclusively during the day) in order to avoid the freezing temperatures of the desert night. At nightfall deathgleaners will return to their roosts, huddling together in large groups to conserve heat. Any leftover scraps from attacks are returned and shared with uneaten members of the bat colony. Sharing food not only aids the survival of certain individuals but of the entire species.

Ecology[]

An important prey item for the deathgleaner is the spink, a subterranean flightless bird which lives in underground colonies. As spinks are usually inaccessible to deathgleaners in their burrows, the bats have two main hunting strategies. The first is to follow a North American rattleback or look out for one digging, as rattlebacks frequently dig up desert turnips from spink burrows, scattering the birds on the surface and exposing them to deathgleaners. Alternatively, recently-matured spinks gather on the desert surface during the night to mate, so deathgleaners which hunt in the early hours of dawn may find some stragglers still exposed.

Deathgleaners will also hunt baby rattlebacks that wander away from their parents, but they will not attack a large adult, whose armor is tough and unpalatable. Rattlebacks can make themselves seem larger and more frightening by shaking their scales, the sharp edges of which could easily tear a deathgleaner's delicate wings.

Extinction[]

With the end of the ice age, the world warms up and many of the animals that had adapted to the bitterly cold conditions of the ice age are unable to keep up with these rapid changes to their habitat and climate. The fauna of the deserts - North American rattlebacks, spinks, and deathgleaners - go extinct. [1]

Appearances[]

In the documentary[]

Deathgleaners appear in "Cold Kansas Desert". A colony are attracted by a digging rattleback to a spink burrow, where they catch and eat several of the flightless birds, before returning to their cave at dusk to roost for the night. At dawn, they return to the desert to catch some slow spinks which are still on the surface after their nighttime mating ceremony. When the mother and infant rattlebacks who are the focus of the episode become separated, the deathgleaners surround and attempt to attack the infant, but are frightened off by the charging mother rattling her scales.

Behind the scenes[]

Criticism[]

Certain viewers have pointed out competition from birds of prey (such as vultures) would be too great, therefore it would be doubtful evolution could give rise to the deathgleaner.

List of appearances[]

Notes[]

It is unclear what group of bats the deathgleaner belongs to. In "Cold Kansas Desert," footage of the predatory Tropical American spectral bat (Vampyrum spectrum) is shown as the narrator states that "bats like these could respond to the spreading cold desert by growing much larger," but the spectral bat is a leaf-nosed bat, while the deathgleaner has no visible nasal adornments. Its French name, "noctule géant," alternatively suggests that it is a giant noctule bat, but noctules are insectivorous and are only found in the Old World.
- On the other hand, the name "noctule géant" could possibly be a reference to the Azores noctule (Nyctalus azoreum), which is the only known bat which principally hunts in the daytime, like the deathgleaner.
Deathgleaners are the first animals to appear in The Future Is Wild's opening, and by extension in the series as a whole.

In other languages[]

Language	Name	Translation
French	Ange de la mort or noctule géante	"Angel of death" or "giant noctule [bat]"
Italian	Cacciamorte	"Death hunter"
Japanese	Desugurīnā (デスグリーナー)	Transcription of English name
Czech	smrtonoš	Means "grim" or "the one who brings death"