From September 17 through November 3, the G2 Gallery in Venice, California will feature an exhibit called Night Fliers, which will display photographs of bats, including some of my own taken during fieldwork in southern Costa Rica. I am excited to have my photographs included in this display for a variety of reasons, not the least of which is that I have long admired Christian Ziegler’s nature photography, which will also be featured in the exhibit.
More importantly, bats are often not as easy to appreciate as some other kinds of organisms, like birds or butterflies. Without specialized equipment and training, bats in the wild can just seem small and dark, prompting awkward questions like Are they birds or insects? and They’re all blood-sucking vampires, right? Photography is one way that the interesting and diverse natural histories of bats can be captured and revealed widely.
In that spirit, here are a few tropical bat photos from my 2012 field season.
Spix’s disc-winged bat (Thyroptera tricolor) at Piro Biological Station on the Osa Peninsula in southern Costa Rica. Disc-winged bats are so-called because they have suction cups on their wrists and ankles that they use to hang onto the inside of young, rolled-up leaves of tropical plants like Heliconias. As the leaves get older, they unfurl, stripping the bats of their hiding place. Navigating life between these ephemeral refuges, disc-winged bats maintain group cohesion using a Marco Polo-esque call-and-response system between bats that have found a new leaf to hang out in and bats that are flying around seeking their companions.
Many people in Latin America think that all bats are vampire bats that suck blood. This is not true. There are more than 110 bat species in Costa Rica and they have a diversity of life histories. Costa Rican bats may feed, for instance, on insects, fruit, nectar, fish, frogs, birds, other bats, or the blood of birds and mammals. If everyone could feed a piece of watermelon to a Heller’s broad-nosed bat (Platyrrhinus helleri), such misconceptions would quickly fade away.
This is a Jamaican fruit-eating bat (Artibeus jamaicensis), one of the biggest bat species that we caught in Costa Rica. An interesting fact about this species is that it exhibits lunar phobia – timing its feeding bouts to correspond to the darkest nights or hours when the moon isn’t very bright. It might more apt to call this condition owl phobia.
This Myotis is one of the smallest bats that we caught. The genus Myotis is made up of insect-eating bats that catch their prey in mid-air. Unlike the leaf-nosed bats, bats in this family (Vespertilionidae) are more diverse in northern latitudes than in the tropics. The adaptation that allowed this family to diversify in the cold north is hiburnation – a good strategy that has recently become a bit of a liability for some species.
Nectar bats prefer juice boxes to watermelon. This orange nectar bat (Lonchophylla robusta) one was particularly fond of the pera. One species of nectar bat (Anoura fistulata) has a tongue so long that it has to be stored inside of its rib cage.
The common vampire (Desmodus rotundus) gives other bats a bad name by feeding on mammalian blood, occasionally including the blood of Hominids. Vampire bats have modified front teeth that are very sharp which they use to create small lacerations on larger animals (often cows). Their saliva contains an anticoagulant that maintains blood flow. A farmer in Costa Rica told me that the pioneers used to tie a cat at the foot of their baby cribs to keep away vampire bats.