I’ve never been a super fan of Halloween…I don’t have any problem with it, it just never caught my fancy BUT now that I am living in Ireland, I have recently discovered that Halloween originated as Samhain* in Ireland’s Celtic past. Here is an interesting article on it.** And because I am doing my best to learn as much as possible about Ireland while it is generously hosting me, here’s a post dedicated to Samhain/Halloween (and vampires in nature)!
A lot of cultures celebrate the blurring of the boundary between the dead and the undead, and vampires have always been considered to be a form of the undead. However, there are a lot of vampires in nature that are very much alive. Here are some examples of natural vampires…
We all know about vampire bats, but did you know that there are also vampire moths?
I always believed the oxpecker/ungulate relationship to be mutualistic***, where the oxpecker removes parasites from large grazing mammals, and gets fed in return. BUT it’s been known for a while that oxpeckers are actually VAMPIRES! They open wounds and only eat ticks that are already engorged with blood. They are parasites not mutualists (Weeks 2000).
There are also vampire fish, which actually do look like something out of a nightmare. Many lamprey species eat blood…and they’re being welcomed back into British rivers with open arms****.
Source: The Cosmos News
Of course, we know there are a lot of blood-sucking insects, including mosquitoes, bedbugs, kissing bugs, biting midges, and bat flies (also this), plus non-insect arthropods including ticks and leeches. I should add here that there is a spider that is an indirect vampire…it feeds on engorged mosquitoes (weird, right?).
But a useful question is why aren’t there MORE vampires out there? Blood is readily available (especially human blood), but blood feeding habits are incredibly rare compared to other feeding strategies (e.g. carnivory, frugivory, insectivory, omnivory etc.). As far as I know, in the vertebrates, it’s only a couple of bird species (in addition to the oxpecker, the vampire finch), a few bat species, and some fish…no reptilian or amphibian blood suckers at all.
Well, it turns out that blood isn’t such a great thing to live on by itself! It’s fat-free, which though it may sound good to dieters, is not useful in general in the animal kingdom. It also is very high in iron and amino acids that can be dangerous in high concentrations. Animals that consume only blood, such as the lamprey mentioned above, have special adaptations to process these things, but you might expect that there is a processing cost involved and any animal not adapted for consuming blood would not last long on a diet of blood alone.
*Pronounced “sow – en”
**this article also taught me that fairies live in hawthorne trees, so maybe that explains my ethereal goldcrest!
***You know how I feel about mutualisms