  Estimating the mortality of birds and bats at wind turbines based on periodic
carcass counts is challenging because carcasses may be removed by scavengers or
may be missed in investigators' searches, leading to undercounting. Existing
mortality estimators intended to correct for this offer wildly different
estimates when search intervals are short.
  We introduce a new estimator that includes many existing ones as special
cases but extends and improves them in three ways to reflect phenomena
discovered in the field:
  * Decreasing removal rate by scavengers as carcasses age;
  * Diminishing proficiency of Field Technicians in discovering carcasses
  as they age;
  * Possibility that some (but not all) carcasses arriving in earlier search
  periods may be discovered in the current period. It is this feature
  that makes the new estimator "partially periodic".
  Both point estimates and 50% and 90% Objective Bayes interval estimates are
provided for mortality. The new ACME mortality estimator will significantly
improve the accuracy and credibility of mortality estimates for birds and bats
near wind turbines.
