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Chiropterophily: Bat Pollination

I see you! Geoffroy's tailless bat (Anoura Geoffroyi) - photo by Nathan Muchhala
Ever since coming across this word, I can't stop saying it: chiropterophily. Chiropterophily, or pollination of plants by bats, is very common in the tropics. Hundreds of tropical plant species are exclusively or at least partly pollinated by nectar-feeding bats.

Many tropical flowers are night-blooming, specializing in attracting bats. Bat-flowers are typically white, cream, or pale green in color, making them easier to see in the dark. They usually have a musky, fermented odor - like that of the bat - or sometimes a fruity odor. They have a large, sturdy, open shape with long, bushy anthers so that the bat's head and chest get coated in pollen when it visits. In return for the bat pollinating the flower, the flower provides the nectar that these high-energy flying mammals need.*

Tube-lipped nectar bat (Anoura fistulata) - photo by Nathan Muchhala
Nectivorous bats have both good eyesight and a kee…

Eyeshine in Nocturnal Animals

Peters' Epauletted Fruit Bat (Epomophorus crypturus), Kruger National Park - photo by Peet van Schalkwyk

Have you ever noticed how under certain lighting conditions some animal's eyes seem to glow? Animals that are nocturnal hunters - and a few of them that are not - have something called eyeshine. Eyeshine is the light that we see reflected back from the animal's tapetum lucidum (a membrane behind the animal's retina). Light enters the eye, passes through the retina, strikes the reflective membrane, and is reflected back through the eye toward the light source. This phenomenon makes the most of what little light there is at night for these nocturnal creatures.

a moth with pink eyeshine
Humans can display the red-eye effect in flash photography, but we do not have a tapetum lucidum, and thus, do not have eyeshine.

Eyeshine is best observed by wearing a head lamp or holding a flashlight at eye level against your temple because the light is reflected right back into your li…

Animal Pollination in the Tropics: Hummingbirds to Hawkmoths

Inside a tropical rainforest, there's not a lot of wind, apart from high up in the canopy, and plant species tend to be very rare and quite far away from each other. Therefore wind pollination is not an effective means of plant reproduction. The preferred method is animal pollination, and many fascinating processes have evolved both in the pollinizer (the plant) and pollinator (the animal).

It's a coevolutionary process - both plants and pollinators become specialized to attract each other. Tropical plants have evolved flowers that entice their preferred pollinator - be it hummingbird, insect, or bat - so that the pollinator will hopefully carry the plant's genes, via the pollen, to another plant of the same species. Sometimes it entices by rewards like nectar - making it a mutualistic relationship - sometimes by trickery,* but it will match its characteristics to the characteristics of a specific pollinator and discourage all other pollinators. At the same time, the pollin…