Results: Site List
The following tables gives prominent statistical community measures for each Site.
Currently displaying data for
2011. Change to
Migration (through May 31)
Breeding (after May 31)
Because species with few sightings may simply be passing through, and not actually
setting up breeding territories, species with a relative abundance of less than
.5% at each site have been dropped from these calculations.
Explanations of the statistics:
- Species Density (not shown above) is a measure of the number of birds of
a particular species per unit area (birds/hectare), based on species counts that
have been adjusted for sampling effort. In this point count methodology, density
is calculated using the log ratio of counts within and outside of 50 m to adjust
for detection probability.
- Species Richness is
essentially a count of distinct species observed at a given location; here, the
count is based on species for which density could be calculated.
- The Shannon Index is a
measure of the diversity of species present: the higher the number, the more diverse
the population of species at the site. The calculation here is based on the densities
of each species.
- Evenness is calculated
from the actual diversity and species richness. This measure ranges between 0 and
1. The higher the number, the more evenly distributed are the counts for
each species. So, the diversity index might be high because there are many species,
but if only a handful of species dominate the landscape, then the evenness is said
to be low.