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What did giant extinct vampire bats eat?

The views expressed are those of the author and are not necessarily those of Scientific American.


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Macrauchenia having a really bad day in the Pleistocene. This scene >>is a parody and almost certainly never happened<<. Tet Zoo dollars to whomever recognises the obvious derivation. Illustration by Darren Naish.

Prior to the spread of people and domestic livestock, vampire bats (here we’re mostly talking about the Common vampire Desmodus rotundus) most likely fed on capybaras, tapirs, peccaries, deer and birds, though we know that they also sometimes feed on fruit bats and reptiles. Populations that live on islands off the Peruvian and Chilean coasts feed on seabirds and sealions. Now that the Americas are full of millions of cattle, horses, donkeys, pigs and chickens however, vampires have largely switched to these domestic prey, and it’s said that the majority of modern vampires now feed almost entirely on the blood of livestock, particularly cattle, horses and donkeys. [Image of vampire skeleton below by Mokele.]

Skull of Desmodus rotundus, showing amazing dentition. Image by Mokele, licensed under Creative Commons Attribution 3.0 Unported license.

There are three extant vampires. We know from fossils that two of them (the Common vampire and Hairy-legged vampire Diphylla ecaudata) were extant in the Pleistocene, and members of the same lineage as the third species (the White-winged vampire Diaemus youngi) must have been present too, since phylogenetic studies show that Diaemus is as old as Desmodus (Honeycutt et al. 1981, Wetterer et al. 2000, Jones et al. 2002).

But it gets better: there are numerous additional fossil vampires. They include Desmodus archaeodaptes from the Upper Pliocene of Florida (this is the oldest reported vampire species), De. stocki from the USA and Mexico, the Cuban endemic form De. puntajudensis, De. draculae from Venezuela, Belize and Brazil, and an unnamed related form from Buenos Aires, Argentina. De. stocki – sometimes known as Stock’s vampire – was 15-20% bigger than the extant Common vampire. Indeed, a specimen now included within this species was originally named De. magnus. De. draculae – sometimes referred to as a ‘giant vampire’ – was about 25% bigger than a modern Common vampire, suggesting a wingspan of perhaps 50 cm and a mass of about 60 g. This makes it on par with a large horseshoe bat or small fruit bat: keep in mind that the majority of ‘microbats’ weigh between 10 and 20 g!

What sort of animals were these fossil vampires feeding from? Of the living vampires, both the Hairy-legged vampire and White-winged vampire mostly prey on birds. However, the Common vampire mostly preys on mammals, and because the fossil species are all members of the genus Desmodus, it’s reasonable to assume that they, also, mostly fed on mammals. However, they surely exploited other prey when they were available. Here’s a wholly speculative reconstruction of a Pleistocene Desmodus feeding from the leg of a sleeping teratorn (aka teratornithid). Teratorns are giant, condor-like birds; the last time I used a version of this image I was reminded that they likely defecated down their legs as living New World vultures do today. Nevertheless, I’m sure the bat is safe in this particular instance…

Pleistocene Desmodus feeds from sleeping teratorn. Image by Darren Naish.

A few vampire bat fossils are preserved in association with large mammals. A fossil Common vampire from a Brazilian cave, radiometrically dated to about 12,000 years ago, was discovered adhering to the underside of a coprolite produced by the sloth Nothrotherium (Czaplewski & Cartelle 1998) and De. stocki fossils from Florida are preserved in the same caves as ground sloths. A skull belonging to De. draculae was preserved in association with a skull of the extinct horse Equus neogeus. None of these associations demonstrate the predatory preference of the extinct vampire species, but they are at the very least highly suggestive. The idea that some of these bats may have fed on giant sloths is likely and entirely acceptable, and one published life restoration – a drawing by Randy Babb, in Brown (1994) – depicts a De. stocki feeding on a nothrotheriid sloth.

An extinct Pleistocene vampire (probably Desmodus stocki) feeding from a giant sloth. Illustration by Randy Babb, from Brown (1994).

Intriguingly, the morphology of some of these vampires suggests that they differed in ecology and behaviour from the living vampire species. Both De. archaeodaptes and the Cuban species De. puntajudensis seems to have had far more freedom of movement in their jaw joint that the Common vampire, a feature suggesting that they somehow differed in how they bit their prey (Morgan 1991, Suarez 2005). The robust hindlimb bones of De. puntajudensis and De. stocki also suggest that their style of terrestrial locomotion differed from that of the Common vampire, though exactly how it differed remains unknown. The large size of De. stockiDe. draculae and the Argentinean giant form of course indicate that they fed on larger prey than living vampires and, as noted, these fossil bats are sometimes found associated with ground sloths.

Bats have been covered on Tet Zoo quite a bit: there’s lots in the archives on vampires and vespertilionids in particular. However, there is still tons and tons to get through!

Here are links to all parts of the enormous complete Tet Zoo series on vesper bats…

Refs – -

Brown, D. E. 1994. Vampiro: the Vampire Bat in Fact and Fantasy. High-Lonesome Books (Silver City, New Mexico).

Czaplewski, N. J. & Cartelle, C. 1998. Pleistocene bats from cave deposits in Bahia, Brazil. Journal of Mammalogy 79, 784-803.

Honeycutt, R. L., Greenbaum, I. F., Baker, R. J. & Sarich, V. M. 1981. Molecular evolution of vampire bats. Journal of Mammalogy 62, 805-811.

Jones, K. E., Purvis, A., MacLarnon, A., Bininda-Emonds, O. R. P. & Simmons, N. B. 2002. A phylogenetic supertree of the bats (Mammalia: Chiroptera). Biological Reviews 77, 223-259.

Morgan, G. S. 1991. Neotropical Chiroptera from the Pliocene and Pleistocene of Florida.Bulletin of the American Museum of Natural History 206, 176-213.

Suarez, W. 2005. Taxonomic status of the Cuban vampire bat (Chiroptera: Phyllostomidae: Desmodontinae: Desmodus). Caribbean Journal of Science 41, 761-767.

Wetterer, A. L., Rockman, M. V. & Simmons, N. B. 2000. Phylogeny of phyllostomid bats (Mammalia: Chiroptera): data from diverse morphological systems, sex chromosomes, and restriction sites. Bulletin of the American Museum of Natural History 248, 1-200.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com! Follow on Twitter @TetZoo.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. llewelly 9:11 am 07/14/2013

    Hm. Seems to parody the notion of velociraptors (do dino folk still call them that?) taking down a sauropod.

    Also, although I don’t think it’s related to the parody, the bats remind me of Dougal Dixon’s Night Stalker, even though the faces are so different, and the Night Stalker was flightless.

    Link to this
  2. 2. JoseD 10:12 am 07/14/2013

    Llewelly: “Hm. Seems to parody the notion of velociraptors (do dino folk still call them that?) taking down a sauropod.”

    Assuming you’re referring to dromaeosaurids, only 1 genus is called Velociraptor.

    Llewelly: “Also, although I don’t think it’s related to the parody, the bats remind me of Dougal Dixon’s Night Stalker, even though the faces are so different, and the Night Stalker was flightless.”

    Actually, that IS the obvious parody ( http://www.mun.ca/biology/scarr/Dixon_Night_Stalker.jpg ).

    Link to this
  3. 3. llewelly 11:31 am 07/14/2013

    Wow. I had totally forgot about the rabbuck being attacked in the background.

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  4. 4. vdinets 12:43 pm 07/14/2013

    Modern vampires spend only a small fraction of their time anywhere near the prey. Perhaps the association of fossil ones with ground sloth bones suggests that they used the sloths as permanent roosts? That would explain stronger hindlimbs and the ability to live in temperate climates.

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  5. 5. RoryD 2:04 pm 07/14/2013

    Or that they simply roosted in the same caves the sloths slept in?

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  6. 6. Laurence Clark Crossen 2:35 pm 07/14/2013

    I think it may sometimes be forgotten that on continents, unlike small islands, there would be a general tendency for animals to vary in size together. For example, during the Pleistocene we have many giant mammals including giant vampire bats and giant sloths. The existence of a giant form is evidence for it living at the time of a giant form of its prey or its predator.

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  7. 7. vdinets 3:05 pm 07/14/2013

    RoryD: could be that, too. Are all records in association from caves?

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  8. 8. Heteromeles 4:26 pm 07/14/2013

    Could also be that, since sloths defecated in caves, that the bat died before the sloth pooped, and the sloth just did paleontologists and inadvertent favor by entombing the carcass.

    As for robust hind limbs on extinct vampires, I’m reminded of the peculiar gallop of the modern vampire. So far as I know, it’s unique to vampires, which means it the movement evolved fairly recently, and it doesn’t seem to require much work from the hindlimbs (see above pictures). I’d hazard a guess that a non-galloping, terrestrial vampire would require much bigger hindlimbs, possibly more like New Zealand’s lesser short-tailed bat (Mystacina tuberculata) or a pallid bat (Antrozous pallidus).

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  9. 9. llewelly 9:10 pm 07/14/2013

    With respect to the vampire gallop, wasn’t there a thread here in which that gallop was compared to (theorized) Azhdarchid quadrupedal locomotion? Or in one of the papers referenced?

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  10. 10. Zoovolunteer 11:49 am 07/15/2013

    Given that living vampires are known rabies vectors, presumably the fossil forms would have been as well. In that case, do we know when rabies virus entered the America’s? If it entered with domestic dogs, the giant vampires would have been a potential factor in spreading rabies among the extinct megafauna.

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  11. 11. SciaticPain 2:12 pm 07/15/2013

    I would venture that vampire bats have a strong preference towards feeder species that regularly and consistently return to the same roosts or lairs during the night. I think I remember watching some documentary about vampire bats where it said they can’t go too long without a meal and members of the colony will help eachother out w/a regurgitated meal. That these bats might prefer to feed on dependable food sources is consistent with switching to a diet of domestic animals, feeding off sea mammal/sea bird rookeries, and, possibly, ground sloths that return to a home cave.

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  12. 12. Halbred 3:01 pm 07/15/2013

    Hey, here’s a stupid bat-related question.

    So, in the picture at the top, as well as all pictures of ground-walking bats, all you ever see are the thumbs. Where are they hiding those four other long, spindly fingers and the associated patagia? Are they just deftly folded up in a “fist” behind the arm?

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  13. 13. naishd 5:35 pm 07/15/2013

    Lots of good comments and questions: thanks, everyone.

    As I said in the article, the association between the fossil vampires and the ground sloths and horses may well be coincidental, and simply the result of them sharing the same resting sites. Equally, however, the association could well indicate exploitation of a reliable food source by the vampires.

    Vlad is right (comment # 4) that vampires typically spend very little time with prey species, but (1) there are also cases where vampires roost in very close proximity to a convenient and reliable prey source (e.g., tethered domestic animals, chickens in a hen house), and (2) the Pleistocene world was different from the modern one – lots more big mammals reliably using caves on a regular basis. Therefore, maybe vampire behaviour was different. Today, they fly as much as 50 km or more to food sources, but maybe they didn’t need to do that back when megafauna was more abundant.

    Darren

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  14. 14. Gigantala 6:01 pm 07/15/2013

    “With respect to the vampire gallop, wasn’t there a thread here in which that gallop was compared to (theorized) Azhdarchid quadrupedal locomotion? Or in one of the papers referenced?”

    Azhdarchid galloping was more often compared to ungulate galloping, via the similar forelimb proportions. What you’re looking for is the take off mechanism, which is omnipresent in bats – except in 100% arboreal species -, though best seen in vampires since they spend more time on the ground.

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  15. 15. vdinets 7:20 pm 07/15/2013

    Zoovolunteer: nice idea! But rabies is present in Arctic wolves, so it could have crossed the Bering Bridge without human assistance.

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  16. 16. CS Shelton 1:27 am 07/16/2013

    On a related note, I’ve hear a lot of mention of bacterial fossils, but none of viral fossils. Could they exist? Total layman here.

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  17. 17. David Marjanović 10:13 am 07/16/2013

    Viruses consist just of protein and DNA. Thus, under conditions where proteins are preserved, viruses can be preserved – such conditions are just exceedingly rare.

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  18. 18. Andreas Johansson 4:06 am 07/17/2013

    (Or protein and RNA.)

    Since viral sequences sometimes get incorporated in the host’s genome, I guess it must be possible to do another sort of “viral palaeontology” by looking at present-day genomes. If a such sequence is found in both cats and dogs say, that tells us something about viruses existing before that split.

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  19. 19. Heteromeles 10:43 am 07/17/2013

    @Andreas: I’m not sure it’s that simple. Viruses recombine in host cells, so you could get DNA mixing if two viruses of different strains infecting the same cell.

    As with bacterial fossils, the best place for finding fossil viruses is in amber or similar desiccating, long-lived environments.

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  20. 20. David Marjanović 6:48 pm 07/17/2013

    (Or protein and RNA.)

    …*headdesk* Yes, of course.

    looking at present-day genomes

    Looking at retroposon insertions is increasingly often done as a source of information for phylogenetics. That’s how it was discovered that Scrotifera and Neoaves are phylogenetic networks with incomplete lineage sorting.

    Link to this
  21. 21. philthom4s 6:07 pm 08/9/2013

    These are so cool! “The Forgotten Vampires” are awesome! I never knew they actually existed until I was sent to this site. Now I am going to be trying to look up all sorts of info on them.

    Link to this

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