Theory 61/Population/Allee effects
Allee Threshold Is Encounter Against Death
The claim
The Allee threshold is set by the ratio of mate encounter rate to mortality, so sparse populations decline when encounter cannot keep pace with death.
01Mechanism
Below a density, individuals fail to find mates before dying; the ratio sets the density at which growth turns negative.
02Prediction
Threshold should track the ratio.
03Refutation
Threshold tracking density alone would remove mortality.