Connecticut
scientists have published the results of a 13-year monitoring study of what
happens to tick numbers and the incidence of Lyme disease when deer populations
are reduced in number: tinyurl.com/oaqf65s.
They
found that when an area’s deer population was reduced in number by 87%+, as in
their case by hunting, the numbers of ticks found on people and cases of Lyme
disease dropped 76 and 80%, respectively.
Computer
modeling studies indicate that populations of some species can be eliminated
over time by reducing the number of fertile individuals below some threshold.
In the case of feral cat colonies that are not artificially augmented (e.g., immigration, abandonment), TNR
must sterilize ≥ 82% for colony die-out over 11 years. I suspect that similar
rates might be appropriate for some other mammals. However, 87% is evidently not
too high for deer in Connecticut (and likely not for feral hogs, either).
Nonetheless,
these two sets of observations lead to two notions, that (1) we might be able
to reduce the incidence of Lyme disease by reducing deer populations through
intense hunting pressure and predator restoration, and (2) large predators
and the pre-Columbian, contiguous Eastern forest together may have limited deer
numbers and consequently kept Lyme disease case numbers down.
Eat
mo’ venison!
