That's what my first post meant.
I'm sure it was, I just feel that you articulated it much better the second time around, and that you eliminated the major weaknesses of the argument (particularly the wording).
Even though there are only 250 of these squirrels left, I can't see cars making a significant enough dent in their population if they only kill about 5 per year. You have to think more than 5 of these squirrels are born each year.
When you study population dynamics, you find that there are lower-limit thresholds for populations and their recovery. When a population drops below a certain number and/or density (this varies on a species-to-species basis, and you've already hit upon two important factors involved in that variation: fecundity (reproductive potential) and predation), it becomes virtually impossible for them to recover unless you adjust or relieve even seemingly minor pressures on that population.
Limiting the number of predators is, at times, a valid approach to such situations. However, none of these organisms live in a vacuum. The repercussions can at times not only affect the population you act directly upon, but can affect others with almost unpredictable consequences. As a result, such an approach can be dangerous and create a situation that was more harmful than the original one.
Being personally ignorant of the life history of this particular species and the ecosystem in which it resides, I can't say with any level of confidence what approach would be best. I do know, however, that even small contributions to the relief of the pressures of mortality on a heavily threatened or endangered species can be very (at least relatively) helpful.
I'm not necessarily justifying the plan as it stands. I'm just trying to show that there are many, many factors to be considered, and these situations tend to be fairly complex. I'm still not sure whether this is the correct approach, or if the situation even justifies the cost.
