3. Between June and August, I recorded
24 hummingbird species along a
4,000ft transect.
This is equal to the total
species ever observed in th
United States.
4. What are the mechanisms that promote
species co-occurrence?
How do patterns of regional distribution
relate to local processes?
8. Niche Conservatism and Abiotic Filtering
Due to phylogenetic constraints,
niches (through adaptive traits)
evolve slowly, such that closely
related species tend to have similar
niche requirements.
Darwin, The Origin of Species.
and
Species with similar niche requirements should
occur in similar environments.
Joseph Grinnell
9. If this were universally true, species richness
would be a product of time since colonization
of closely related species.
Wiens, J. J., et al. (2011). Ecology letters 14(7)
11. Species with overlapping niches compete for
resources, leading to competitive exclusion or
character divergence.
12. Therefore we expect a non-linear relationship
among relatedness and niche overlap
Predicted based on environment
Closely Related
Observed
Distantly Related
13.
14.
15. As species become more
related, they are more likely
to overlap in environmental
tolerances
Very closely related
species have a
decreased probability
of co-occurrence
Increasing phylogenetic relatedness leads to
increased probability of co-occurrence
17. Aglaiocercus kingi
Eriocnemis luciani
Phaethornis yaruqui
Damophila julie
Body mass is associated with thermal regulation in cold
environments and competitive dominance
Wing size influences flight performance and behavior
Bill length and shape is important in resource use and
resource partitioning
18. Weaker results for traits, which is likely explained by
behavioral diversity and a loose connection between
traits and environments.
19. Can we measure local scale processes
that might explain regional patterns?
21. H1 Closely related species should choose
similar resources.
H2 Resource selection will be a function of
floral and bill morphology
H3 Niche partitioning should minimize niche
overlap of competing species, either through
behavior, temporal shifts, or micro-scale
distribution
44. Hypotheses
• Closely related species
will choose similar
resources.
• Hummingbirds will
choose resources that
match their bill
morphology.
• Hummingbirds should
be most specialized when
there are fewest available
resources.
Considerable morphological var – traits are related to foraging, competition and flightSpecialized nectarivores – western hemisphereLots of species co-occur (up to 30)We have been studying them in the Andes Mountains and associated lowlands of SAApplying the phylogenetics framework I just described and given what we know about hummingbirds we might predict…
