The Partners in Flight databases were recently updated, and they represent an outstanding resource in understanding distribution and diversity of North American birds.
Maintained by the Rocky Mountain Bird Observatory, the databases summarize information on population estimates and the species assessments that guide the regional and global priority rankings for conservation.
For example, the Population Estimates Database provides our best information on the population size of species in the US, Canada, and globally. The database includes the source data used to make the estimates as well as descriptions of how those data were used. Here’s a sample for four Tyrannus flycatchers:
Western Kingbird, photo by Tim O’Connell
Eastern Kingbird, photo by Tim O’Connell
Gray Kingbird, photo by Dick Daniels
Scissor-tailed Flycatcher, photo by Tim O’Connell
Given the uncertainties of population estimation I use these estimates as rough guides only. For example, I don’t put too much stock in the assertion that there are 3 million more Eastern than Western kingbirds in the US, but I am comfortable with concluding that those two species are similar in abundance in this country, and that there are about 20 million of them. They also outnumber Scissor-tailed Flycatcher 2:1 and the Caribbean-distributed Gray Kingbird by at least 10:1. Based on these population assessments, it seems obvious that Gray Kingbird and Scissor-tailed Flycatcher should be higher priorities for conservation than Eastern and/or Western kingbird.
This is where the Species Assessment Database comes in. Here, additional data are folded in to derive priority rankings for different categories, e.g., population trend in addition to simple population size. Here, information is presented such as the proportion of the population within the US, Canada, and Mexico and rankings of perceived threats to the species in breeding and wintering areas. In this case, the rankings do agree pretty well with what we might expect from the Population Estimates Database:
Some of the specific information presented, however, can be quite helpful in determining conservation priorities. For example, check out the information for Purple Finch and Cassin’s Finch:
Purple Finch, photo by Cephas
Cassin’s Finch, photo by Dave Menke
In this case, Purple Finch is about twice as abundant as Cassin’s Finch, but the real difference in priority is driven by the population trend: Cassin’s Finch is not only less abundant, it is rapidly losing population.
Every day, people pore over data on bird populations, distributions, trends, etc. in an effort to achieve the three primary goals of Partners in Flight:
1) Help species at risk.
2) Keep common birds common.
3) Promote voluntary partnerships to improve conditions for birds, habitats, and people.
Worthy goals, indeed!
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