research program in evolutionary ecology addresses the role of
interspecific interactions in structuring communities and driving
diversification. I focus on plants
pollinated by bats, and
integrate various approaches including molecular
phylogenetics, mathematical modeling, and field
experiments. The main
thrust of my current research involves using the 105 species of Burmeistera
(Campanulaceae; see Bat-Flower Images) as a case
study in angiosperm speciation. I am developing a
species-level phylogeny for
the genus to identify sister-species pairs and evaluate the importance
of pre- and post-pollination reproductive barriers in preventing gene
flow in the initial stages of speciation. Another current
involves examining the community phylogenetics of co-occuring Iochroma
(Solanaceae), and testing the hypothesis that their hummingbird
pollinators select for local overdispersion in flower color (i.e.,
floral character displacement). See below for further details and
photos of my research.
|Anoura geoffroyi pollinating
of cloud forest bat-pollinated flowers,
with photos and videos of each.
nectar bat (Anoura
geoffroyi) visiting a flower
in a flight cage experiment designed to quantify pollen transfer.
Bat-flowers typically produce nearly ten times more pollen then
flowers adapted to birds or other pollinators; results of these
experiments suggest that this is because bat fur can hold much more
pollen than feathers (Muchhala
a recently described species of nectar bat (Muchhala et al.
Note its tubular lower lip and relatively wide
honey-water from a glass tube. This bat has the longest
relative to body length, of any mammal (Muchhala
When not in
use, it stores its tongue in its rib cage (illustration).
fistulata visiting the highly specialized flower of Centropogon
8.5-cm-long floral tubes, only A.
fistulata can access
flower's nectar. The two may
have evolved together in a coevolutionary race (Muchhala and Thomson
for a flight cage experiment. Note the Anoura
hovering in front, impatient to get things started so it can feed on
This flight cage experiment was designed to examine heterospecific and
conspecific pollen transfer by bats when they are presented with
flowers from different species of Burmeistera.
the only known species in the genus that is exclusively
Note the bright red coloration and
relatively narrow corolla opening.
visiting an artificial flower in a flight cage. This
was designed to test the effects of corolla width on pollination by
bats and hummingbirds (Muchhala
visiting a straw filled with honey-water. The straw was used
to determine the length that Anoura
could project their tongues outside of their mouths.
Caiza and Juan Carlos Vizuete extracting an Anoura caudifer
from a mist net. Angelica and Juan helped with my fieldwork
in the cloudforests of Ecuador.