Data from: Research design considerations to ensure detection of all species in an avian community

1.Recent advances in the estimation of species richness from count data
have allowed avian ecologists to incorporate incomplete detectability of
species when comparing richness across space or time. Raw counts from
single or repeated visits to sample point(s) are nonetheless still used
for assessing community composition, and the failure to account for
detectability when making these evaluations may lead to incorrect
inferences about the community. 2.We estimated detection probabilities (p)
for a suite of bird species and used these detection probabilities to
determine the minimum number of visits at a single point and the minimum
number of points in a grid required to confidently (≥ 90%) detect the full
community of birds for rare, moderately rare, and common species. We used
occupancy modeling to estimate the detection probabilities for species
from two study sites in Nebraska and Saskatchewan. 3.Some common or highly
detectable species were confidently detected in a single visit to a point,
whereas others with low detection probabilities (p < 0.20) required
more than ten visits to be confidently detected at a point. The grid size
required to detect a species in an area varied from a single point for a
common highly detectable species to over 30 points for a rare species with
low detectability. 4.Detection probabilities of the least detectable
species in a study area can be used to determine the number of visits to a
single point or the number of points in a grid to be confident that the
full community is detected. Biologists can conclude that a species is most
likely absent from the community if it remains undetected using the
appropriate sampling effort.