Our Response - Page 5

 

Objective

This cooperative plan is primarily designed to detect declines in territory occupancy, nest success, and productivity in six regions across the United States. Regional data for all population measures will be combined to examine trends nationwide. Territory occupancy, nest success, and productivity all are indices of population health. Estimates of all three indices were very low between 1950 and 1980 when Peregrine populations declined severely, but rebounded during population recovery (Cade et al. 1988, Enderson et al. 1995, Mesta 1999, White et al. 2002).

Data will be collected from a randomly selected subset of Peregrine territories for five sampling periods, at three-year intervals, with full implementation to begin in 2003 and end in 2015. The plan is designed to achieve an 80% probability ($= 0.20) of detecting a decline of 12.5 percentage points in territory occupancy and nest success after the first sampling occasion with a Type I error rate of 10% ("= 0.10; i.e., there is a 10% chance that the data will indicate a declining trend in nest success or territory occupancy greater than 12.5 percentage points when, in fact, there is no such decline occurring). Smaller declines will be detectable over subsequent sampling occasions. Productivity will be measured from the same subset of territories. Rates of productivity typical of expanding or stable populations average between 1.0 and 2.0 young per occupied territory (refs. in White et al. 2002), and most historical and recent productivity estimates fall within that range (Hickey 1942, Mesta 1999). (emphasis added) Thus, data from the first two sampling seasons will be compared to this range; trends will be measurable thereafter. The FWS will also request and synthesize population and territory location data collected by States and other partners and report this information with a regional perspective for years that fall in between the monitoring years suggested by this plan. Finally, we will collect addled eggs and feather samples and archive these for later analysis of contaminant levels in Peregrines nationwide if information indicates that contaminants may be causing a significant population decline.

The Peregrine Club of Philadelphia requests that PGC Biologists use the same metrics for establishing a healthy and expanding population. We recognize USFWS measurement metrics as scientific, repeatable and reliable methods for assessing peregrine populations without prejudice towards those birds that nest on nontraditional sites and the even larger number of peregrines that appear in Pennsylvania each year.

Anatum Peregrines - Eastern Population

It is highly probable that the demise of the Eastern anatum population was due to egg-collectors (oologists), exterminators (such as game managers, pigeon racers, farmers, etc.) plus recreational activity after WWII on and at the eyrie sites (McDonald, 2010), loss of habitat (large scale deforestation of mature trees), and loss of a primary prey species (for the prey species hypothesis see Beebe below and in Hickey, 1969, pp. 399-402), all of which was having catastrophic consequences for the Eastern anatum prior to any possible influence of DDT.

 

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