Manakins and the Plant Family Melastomataceae
Note: This online
review is updated and revised continuously, as soon as results of new
scientific research become available. It therefore presents
state-of-the-art information on the topic it covers.
Research in the tropical rainforests of the New World has revealed an
important mutualism between manakins (bird family Pipridae) and trees
and shrubs of the plant family Melastomataceae. Mutualisms are
relationships between two groups of organisms that are beneficial to both
groups.
In the case we discuss here, the plants provide the birds with food
(fruits), each of which contains many tiny seeds. The birds swallow the
fruits whole (including the seeds), and digest the fruits' pulp. However,
many of the tiny seeds pass unharmed through the birds' digestive systems.
Then, when the manakins regurgitate or defecate the seeds at long distances
from the parent plants, the plants benefit by getting their seeds dispersed
to new sites where there is often a greater chance of germination and
survival. Thus, both manakins and plants of the Melastomaceae (melastomes)
profit from the interaction.
Manakins are some of the most abundant birds in the understory of lowland
tropical rainforests in South America, Central America and Mexico. Their
abundance stems from the fact that they feed almost entirely on a very
plentiful and easily-found food: the fruits of trees and shrubs growing in
the forest, especially those of the plant family Melastomataceae (Krijger et
al. 1997; Loiselle and Blake 1999; Silva and de Melo 2011).
Thery (1990) studied the food habits of 6 species of manakins in
lowland tropical forests of French Guiana, and found that the fruits of the
Melastomaceae comprised over 50% of the diet of each of the 6 species (Tyranneutes
virescens, Manacus manacus, Corapipo gutturalis, Pipra
pipra, Pipra erythrocephala, Pipra serena).1
In the same area, Thery (1990) also studied removal by birds of the fruits
of 20 different melastome trees and shrubs during daytime. He found that
manakins removed 61 to 89% of the fruits of these plants. Thery's data
clearly demonstrate the important role that melastomes play in providing
food for manakins, and conversely, the important role manakins play in
consuming melastome fruits.
Worthington (1989) studied the passage of seeds through the guts of two
different manakin species (Pipra mentalis, manacus vitellinus).
He found that manakins usually defecated small seeds 12 to 15 minutes after
eating, but regurgitated large seeds 7 to 9 minutes after eating.
The large-scale removal of fruits by manakins that Thery (1990) found, as
well as the fact that many seeds rapidly pass through their guts unharmed,
suggests that manakins play a major role in melastome dispersal in the
lowland tropical rainforests of the New World tropics.
Seed Dispersal by
Manakins
The different sexes and age groups of manakins seem to differ in the way
they disperse seeds. Adult male manakins do not participate in nest
building or the raising of young. They spend most of their time displaying
at courtship leks in the tropical rainforest, and there regurgitate
and defecate most of the seeds they eat. In contrast, female manakins build
the nest and raise the young, and so spend much of their time at the nest
site during breeding. After breeding, however, females and sub-adult
manakins are active throughout the forest, and consequently may be more
important than males in dispersing melastomes throughout the forest (Krijger
et al. 1997).
Krijger et al. (1997) studied seed dispersal at leks of the White-throated
Manakin (Corapipo gutturalis) in French Guiana. They collected soil
samples under male display perches at the leks, and compared them to soil
samples taken in similar vegetation 50 meters away. They found that the
total density of viable seeds in the soil was over twice as great under the
display perches as in the surrounding forest.
In addition, melastome seed density was over twice as great under the
display perches as in the surrounding forest. Krijger and his coworkers
concluded that because soil seed banks and their species composition can be
important factors in the first stages of forest regeneration, the higher
density of viable seeds at leks of the White-throated Manakin, especially
melastome seeds, can be expected to influence forest regeneration at these
sites.
Another lek-breeding bird, the Guianan Cock-of-the-Rock (Rupicola
rupicola) alters the flora and vegetation of its lek sites through such
seed dispersal (for details see our review: Ecology of the Cock-of-the-Rock).
So far, this has not been found at leks of manakins, although only a few
leks have been analyzed. Perhaps the explanation for this is that manakin
leks are usually located in the deep forest, while melastomes usually
germinate best under conditions where the soil receives a lot of sunlight
(Ellison et al. 1993; Krijger & Opham 1995). Thus, by depositing the
melastome seeds in the closed forest, male manakins may actually be harming
the dispersal of these seeds by placing them at sites where they will not
germinate.
However, if one or more trees fall at a lek site, creating an
opening in the forest where direct sunlight can reach to the forest floor,
the melastome seeds will germinate, and under these conditions the leking
behavior of the manakin males can be expected to increase the number of
melastome plants at the lek site (Krijger et al. 1997).
In contrast, the
Cock-of-the-Rock is a generalist frugivore that eats fruits from a great
diversity of forest plants. Because it consumes such a wide variety of
plant seeds, including many from plant species that do not require sunlight
for germination, the male Cock-of-the-Rock is more likely than male manakins
to alter the number and diversity of plant species at lek sites with low
light conditions (Krijger et al. 1997).
The Plant Family
Melastomataceae
We conclude this review with some comments on the trees and shrubs that
provide the majority of the fruit eaten by manakins. The Melastomataceae is
the seventh largest family of flowering plants, with approximately 5000
species (Renner 1989). It occurs in the tropics of the Old World, however
three-fourths of all its species occur in the tropical forests of the New
World. There they are common from sea level up to the tops of mountains
(Gleason 1932).
A great diversity of bird species besides manakins eat the
fruits of the Melastomataceae, and it is generally recognized that these
plants are some of the most important sources of food for small frugivorous
birds in general (Stiles and Rosselli 1993). In lowland rainforests of the
Neotropics, where manakins are some of the most numerous birds, manakins
appear to be the most important dispersers of melastomes. However, the
tanagers (Thraupidae) are also important, and in mid-elevation forests of
the Neotropics they replace the manakins as the most important dispersers of
melastomes (Stiles and Rosselli 1993).
In the lowland tropical forests of
Trinidad, Snow (1965) studied 19 species of trees and shrubs of Miconia,
a genus of the Melastomataceae. Each species produced fruit during a
particular season of the year, and no species fruited the entire year.
However, the fruiting seasons of all 19 species together covered the entire
year. Snow suggested that these various species of Miconia compete
with each other for the services of animal seed-dispersers such as manakins,
and that in order to reduce competition among themselves for dispersers,
they have segmented the seed-disperser market by supplying fruit at
different times of the year.
Allied with this idea is the theory that
greater segmentation of the seed-disperser market by fruit-bearing plants
has led to the evolution of more species of plants supplying the fruit. For
example, a study by Charles-Dominique (1993) found that woody plant genera
such as Miconia, that produce fruits dispersed by specialized
fruit-eating animals like manakins, tend to be richer in species than genera
whose seeds are not dispersed by animals. For additional comments on the
fruiting seasons of Miconia, see Poulin et al. (1999).
Footnote
1. Thery (1990) also studied a seventh species Schiffornis turdina,
and found that melastome fruits made up 25-28% of its diet. However,
controversy surrounds this seventh species (popularly known as the
"Thrush-like Manakin"), because many ornithologists do not believe it is a
manakin. Modern bird classifications based on DNA fingerprinting, place it
with the New World flycatchers rather than the manakins (Sibley & Monroe
1993; Monroe & Sibley 1997).
References
Charles-Dominique P
(1993) Speciation and coevolution: an interpretation of frugivory
phenomena. Vegetatio 107/108: 75-84.
Ellison AM, Denslow JS, Loiselle BA,
Brenes MD (1993) Seed and seedling ecology of Neotropical Melastomataceae.
Ecology 74: 1733-1749
Gleason HA (1932) A
synopsis of the Melastomataceae of British Guiana. Brittonia 1:
127-184.
Krijger CL, Opdam M
(1995) Consequences of dispersal of Melastomataceae seeds towards
manakin leks. Unpublished Thesis #95-11. Department of Forestry,
Wageningen Agricultural University.
Krijger CL, Opdam M, Thery
M, Bongers F (1997) Courtship behaviour of manakins and seed bank
composition in a French Guianan rain forest. Journal of Tropical Ecology
13: 631-636
Loiselle BA, Blake JG (1999) Dispersal of melastome seeds by
fruit-eating birds of tropical forest understory. Ecology 80: 330-336
Monroe BL, Sibley CG
(1997) A World Checklist of Birds. Yale University Press, New
Haven.
Poulin B, Wright SJ, Lefebvre G, Calderón
O (1999) Interspecific synchrony and asynchrony in the fruiting
phenologies of congeneric bird-dispersed plants in Panama. Journal of
Tropical Ecology 15: 213-227
Renner SS (1989) The
current classification of the Melastomataceae. Flora Malesiana Symposium,
pp. 52-54.
Sibley CG, Monroe BL
(1993) Distribution and Taxonomy of Birds of the World. Yale
University Press, New Haven.
Silva AM, de Melo C (2011) Frugivory and seed dispersal by the
Helmeted Manakin (Antilophia galeata) in forests of the Brazilian
Cerrado. Ornitologia Neotropical 22: 69-77
Stiles FG, Rosselli L
(1993) Consumption of fruits of the Melastomataceae by birds - How diffuse
is coevolution? Vegetatio 108: 57-73
Information about
this Review
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review is also available in the following languages:
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The author is: Dr.
Paul D. Haemig, Ecology Online Sweden (PhD in Animal Ecology).
Photograph: The Blue Manakin (Chiroxiphia caudata) is found
only in the Atlantic Forest region of southeastern Brazil, Paraguay and
Argentina. This photo of a male was taken at Intervales State Park,
São Paulo, Brazil by Arthur Grosset of Scotland. © Arthur Grosset.
The
proper citation is:
Haemig PD
2012 Manakins
and the Plant Family Melastomataceae. ECOLOGY.INFO 2.
If
you are aware of any important scientific publications that were omitted
from this review about manakins, or if have other suggestions for improving
it, please contact the author at his e-mail address:
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