A. fistulata (shown lapping sugar water from a tube) has the longest tongue, relative to body length, of any mammal and now scientists think they know why.
"This bat was just discovered last year, and now we've observed a very unique relationship with a local flower," said Nathan Muchhala, a University of Miami Ph.D. student whose team's findings are to be published tomorrow in the journal Nature.
Found in an Andean cloud forest in Ecuador, A. fistulata (aka the tube-lipped nectar bat) evolved mutually with an extremely long, bell-shaped flower, the team says. In fact, armed with a tongue that retracts into the bat's rib cage, A. fistulata is now the only animal that can pollinate the flower.
"This bat was just discovered last year, and now we've observed a very unique relationship with a local flower," said Nathan Muchhala, a University of Miami Ph.D. student whose team's findings are to be published tomorrow in the journal Nature.
Found in an Andean cloud forest in Ecuador, A. fistulata (aka the tube-lipped nectar bat) evolved mutually with an extremely long, bell-shaped flower, the team says. In fact, armed with a tongue that retracts into the bat's rib cage, A. fistulata is now the only animal that can pollinate the flower.
Nathan Muchhala
The extreme length of this bat's tongue might have coevolved with the long flowers it pollinates.
Abstract
Bats of the subfamily Glossophaginae (family Phyllostomidae) are arguably the most specialized of mammalian nectarivores, and hundreds of neotropical plants rely on them for pollination. But flowers pollinated by bats are not known to specialize for bat subgroups (unlike flowers that have adapted to the length and curvature of hummingbird bills, for example), possibly because the mouthparts of bats do not vary much compared with the bills of birds or the probosces of insects. Here I report a spectacular exception: a recently-described nectar bat that can extend its tongue twice as far as those of related bats and is the sole pollinator of a plant with corolla tubes of matching length.
Fieldwork was carried out in the Yanayacu, Pahuma, SierrAzul, and Bellavista cloud forest reserves of Ecuador during 16 field trips between April 2003 and June 2005. Bats were captured with mist nets opened from 1800 to 0000 hrs. For the tongue extension experiments, bats were held for two days in 3m by 3m flight cages and trained to feed from a modified drinking straw filled with honey-water. I positioned the straw at 45 degrees above the horizon with a wire, and fashioned artificial petals by cutting four 1cm longitudinal slits in the distal end and spreading out the resulting flaps of plastic (without these, bats would often miss the opening during visits). For experimental trials, I allowed the bats to visit the straw for 30 minutes, after which I measured the depth of honey-water consumed and replaced approximately half of this for the following trial. When a bat reached the same level for three consecutive trials, I considered this to be its maximum tongue extension (n = 6 A. geoffroyi, 5 A. caudifer, and 4 A. fistulata, all of which were released after the study). For pollination studies, I identified pollen carried on the fur and in the feces of all the glossophagines that I mist-netted (n = 46 A. geoffroyi, 38 A. caudifer, and 21 A. fistulata). I used clear tape to remove pollen from the fur, and placed these and the fecal samples on slides. With a light microscope, I identified pollen grains through comparison with a reference collection of pollen taken directly from flowers in the reserves. Additionally, I videotaped Centropogon nigricans flowers in Pahuma and Bellavista with Sony Nightshot Digital Camcorders to identify floral visitors, both during the day (n=7 flowers, a total of 26 hrs) and at night (n=5 flowers, a total of 29 hrs). In order to examine Anoura tongue morphology, I dissected fluid-preserved specimens (75% ethanol) from the Zoology Museum of the Pontificia Universidad Catolica del Ecuador, including two adult male A. caudifer (QCAZ 8321, 8337), one adult female A. geoffroyi (QCAZ 8324), and one adult male A. fistulata (QCAZ 8322).
May 23, 2012
DAVIS--Nathan Muchhalawho discovered and researches a tube-lipped nectar bat with a tongue longer than its body, will speak on “Bats, Birds, and Bellflowers: The Evolution of Specialized Pollination in the Neotropics” at the next UC Davis Department of Entomology seminar, set from 12:10 to 1 p.m., Wednesday, May 30 in 122 Briggs.
Host is Jessica Forrest of the Neal Williams lab.
Muchhala, a postdoctoral fellow in the Stacey D. Smith lab, Department of Biological Sciences, University of Nebraska, Lincoln, says the two-inch long bat, Anoura fistulata, found in the Equadorian Andes, can extend its tongue 3.3 inches. Proportionately, its tongue is longer than any other mammal in world. It is so long that it stores its tongue in its rib cage.
Muchhala, who discovered the new species several years ago in Ecuador, described it in a 2005 paper. He published his work in 2006 in the journalNature and was featured in a 2006 article in the New York Times.
The bat nectars Centropogon nigricans, which has a corolla the same length as the bat's tongue. The genus is found in Mexico and much of South America, including Argentina, Brazil, Chile and Peru.
Abstract: "Animal pollination is thought to have played a central role in angiosperm diversification, especially in the tropics, where more than 98 percent of plants are animal-pollinated. My research combines experiments and theory to explore the ecology and evolution of plant-pollinator interactions, with a focus on vertebrate pollination in the Neotropics. In this talk I begin by discussing research on a recently discovered species of nectar bat which can launch its tongue 1.5 times its body length, an extension more than double that of other bats and longer than any other mammal. Unique adaptations allow it to store its tongue in its rib cage.
DAVIS--Nathan Muchhalawho discovered and researches a tube-lipped nectar bat with a tongue longer than its body, will speak on “Bats, Birds, and Bellflowers: The Evolution of Specialized Pollination in the Neotropics” at the next UC Davis Department of Entomology seminar, set from 12:10 to 1 p.m., Wednesday, May 30 in 122 Briggs.
Host is Jessica Forrest of the Neal Williams lab.
Muchhala, a postdoctoral fellow in the Stacey D. Smith lab, Department of Biological Sciences, University of Nebraska, Lincoln, says the two-inch long bat, Anoura fistulata, found in the Equadorian Andes, can extend its tongue 3.3 inches. Proportionately, its tongue is longer than any other mammal in world. It is so long that it stores its tongue in its rib cage.
Muchhala, who discovered the new species several years ago in Ecuador, described it in a 2005 paper. He published his work in 2006 in the journalNature and was featured in a 2006 article in the New York Times.
The bat nectars Centropogon nigricans, which has a corolla the same length as the bat's tongue. The genus is found in Mexico and much of South America, including Argentina, Brazil, Chile and Peru.
Abstract: "Animal pollination is thought to have played a central role in angiosperm diversification, especially in the tropics, where more than 98 percent of plants are animal-pollinated. My research combines experiments and theory to explore the ecology and evolution of plant-pollinator interactions, with a focus on vertebrate pollination in the Neotropics. In this talk I begin by discussing research on a recently discovered species of nectar bat which can launch its tongue 1.5 times its body length, an extension more than double that of other bats and longer than any other mammal. Unique adaptations allow it to store its tongue in its rib cage.
"Experiments suggest that this bat is involved in a coevolutionary race with the long-tubed flowers; tongue elongation allows bats to reach more nectar, while flower elongation maximizes pollen transfer. In the second part of the talk, I present evidence for character displacement among Burmeistera flowers. In response to competition for pollination, co-occuring Burmeistera place their pollen in different regions of bats heads’, thus maximizing conspecific pollen transfer despite sharing bats as pollinators. In the final part of the talk, I discuss why bat-flowers produce so much pollen, a little-understood aspect of chiropterophily that was previously ascribed to poor pollination by bats. Experiments instead demonstrate that bats’ fur can successfully transfer larger amounts of pollen than birds’ feathers. This leads to a more linear male-fitness gain curve for bat-flowers, and selection for increased pollen production."
Biosketch: Muchhala first traveled to the Neotropics with a Fulbright Fellowship in 1999, and has been returning for fieldwork on bat and bird pollination ever since. He received his doctorate in biology in 2007 from the University of Miami, was a postdoctoral fellow with the University of Toronto from 2007 to 2010, and is currently a postdoctoral fellow with the University of Nebraska. He has authored 24 scientific papers.
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