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< Picture 1. Granivorous birds: a Rufous-collared
Sparrow (Zonotrichia capensis) 'scratching' the litter
with its legs to find seeds underneath an algarrobo tree
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Picture 2. Granivorous birds: a Many-colored
Chaco-Finch (Saltatricula multicolor) discovered 'in
fraganti' while eating grass seeds from the soil surface.
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< Picture 3. Granivorous birds: a Common Diuca-Finch
(Diuca diuca) on an algarrobo.
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Picture 4. Granivorous birds: a Carbonated
Sierra-Finch (Phrygilus carbonarius) captured with
a mist net, changing its plumage (during the breeding season
the male turns black). >
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< Picture 5. Granivorous birds: a Cinnamon Warbling-Finch
(Poospiza ornata) on an algarrobo; it is present in
Ñacuñán only during spring-summer.
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Picture 6. Granivorous birds: a Ringed Warbling-Finch
(Poospiza torquata) looking for insects on an algarrobo
during the summer (it changes its diet to seeds extracted
directly from the stalks during autumn and winter). >
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< Picture 7. A Ringed Warbling-Finch
(Poospiza torquata) trapped in a mist net. The capture
of birds by means of nets and traps constitutes the first
stage of several of our studies.
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Picture 8. Javier and Víctor measuring some
of the captured birds close to the nets. >
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< Picture 9. Javier obtaining the stomach content
of a Carbonated Sierra-Finch (Phrygilus carbonarius)
by passing warm water through an esophageal cannula. By employing
this technique he was able to perform diet studies of many
bird species without hurting them.
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Picture 10. Eduardo examining the content
of a nest of a White-crested Tyrannulet (Serpophaga griseiceps)
on a Geoffroea decorticans' trunk, with the help of
a round mirror. >
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< Picture 11. A nest (containing three eggs) of
a Many-colored Chaco-Finch (Saltatricula multicolor),
located on the lower branches of an algarrobo.
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Picture 12. Acrylic
cage (a.k.a. "fish tank") used for seed-preference
experiences. Inside it, a Cinnamon Warbling-Finch (Poospiza
ornata) eating seeds. >
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< Picture 13. A Many-colored Chaco-Finch (Saltatricula
multicolor) eating dark Setaria italica seeds (moha)
on a contrasting floor within the acrylic "fish tank".
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Picture 14. Device used for measuring birds'
efficiency in finding and extracting seeds from different
types of substrates. The three portions of the "pizza pan"
with algarrobo-type litter are shown (on natural litter underneath
an algarrobo). >
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< Picture 15. Common Diuca-Finch (Diuca diuca)
searching for seeds in the algarrobo-kind litter in one of
the "pizza pan" portions within the acrylic "fish tank".
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Picture 16. Fernando
measuring the structure and composition of the vegetation
in order to characterize the sites where he detected granivorous
birds feeding and compare them with randomly located sites
in the same area. >
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< Picture 17. One of the 300 devices ('glasses')
where seeds were offered to granivorous birds to evaluate
if they select for a certain type of foraging microsite.
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Picture 18. Characterization of one of the
microsites. Most measurements involved recording the vegetation
touches on a graduated aluminum stick placed at different
distances along 4 radial transects. >
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< Picture 19. Field aviary used to study granivorous
birds' preferences for foraging microsites. Inside the aviary
there's a box from which the bird was set free and outside
it there's the piece of cloth from which the experiences were
recorded (there was an equal one at the opposite side of the
aviary).
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Picture 20. Rufous-collared sparrow (Zonotrichia
capensis) on a perch inside the aviary, just about to
descend and feed in one of the two contrasting microsites.
>
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