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Showing posts from February, 2010

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…

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…

The Disk-Winged Bats of Lapa Rios

Spix's Disk-Winged Bats (Thyroptera tricolor) roost upright in rolled Heliconia and banana leaves.


You can see the little suction discs on the thumbs and ankles. These lightweight little insectivores use these to cling to the leaves.




The other bat species found at Lapa Rios are the Greater Fishing Bat (Noctilio leporinus), Thomas' Fruit Eating Bat (Artibeus watsoni), and the Greater White-Lined Bat (Saccopteryx bilineata), which is seen but uncommon.

These pictures were taken on 6/29/08 along the Osa Trail at Lapa Rios. Link to "Costa Rica: Day 11 - Lapa Rios Osa Trail."


Read about the Sucker-Footed Bat (Myzopoda aurita) that also roosts head up in "Sucker-Footed Bats Don't Use Suction After All" (Science Daily).

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…

Be Kind to the Googlebots!

As I posted last week, I am currently working on optimizing this blog. In doing so, I came across something that I am now completely fascinated with (and mostly because of its name and how I imagine it to look in my head): the Googlebot.

(I think I imagine it to be something like the little obsessive-compulsive robot M-O that cleans things in WALL-E.)

So there's not actually a Googlebot - it's Google's search bot - or spider - software that searches the web and indexes the information it finds in the Google search engine. Here are some of the things the Googlebot likes:
Relevant and descriptive titles (blog title bar, blog post titles, titles in the permalinks)*Relevant and descriptive labels (categories, tags) Relevant and descriptive anchor textYou updating your blog often!Anyway, these are some of the things I'm implementing in an effort to be kind to the Googlebots, so, again, please bear with me while I'm changing some things around (like titles, labels, and perm…

Bat Anatomy and Behavior

Bats are the only true flying mammals. They belong to the order Chiroptera (coming from the Greek words for "hand" and "wing"). They are further divided into 2 suborders: Megachiroptera (megabats) and Microchiroptera (microbats).

Bats account for 20% of all of the world's mammals. They are present on every continent except Antarctica. They are integral in seed dispersal and the pollination of certain flowers, and they help keep the insect/pest populations down.

Being a mammal, the skeletal structure of a bat's wing is more like a human arm than a bird's wing. In fact, a bat's wing very closely resembles a human arm - the difference is in the proportions. (Imagine your arm with extremely elongated fingers - link to bat wing anatomy).

Monteverde Bat Jungle
Also, the difference between bat and bird flight is that bats do not flap their entire forelimbs like birds, but rather flap only their spread-out "fingers".

bat skeleton, Monteverde Bat Jungle

Shuffling and Optimization

Please note that I will be shuffling some things around because I am currently doing some site optimization. This will involve reworking some of the posts already up and hopefully adding more posts regularly, especially those bat- and Costa Rica-related. (My husband and I visited Costa Rica a second time over the holidays!)

One reader commented about the blog's colors and fonts, saying it was kinda hard to read. I don't have a problem with it (but different monitors display things so differently) and no one else has commented on this; but if it is a problem, I don't want to turn people away with my color and font selections. So let me know.