The new proposal would set guidelines for when the regulators can use alternate factors, like habitat, environmental conditions or the prevalence of another species, to calculate the impact on a species. Those other data points are known as “surrogates.”
“This amendment to the regulations would clarify the Services’ discretion to use surrogates to express and monitor the amount or extent of anticipated take when they determine it is the most practical means to do so,” the agencies said in the proposal.
Using surrogates might "be especially useful in cases where the biology of the listed species or the nature of the proposed action makes it impractical to detect or monitor take-related impacts to individual animals," they added.
The agencies already use the alternate calculations, but the draft regulation would clarify that they can be used when there is a “causal link” between the species and the other factor.
Wildlife advocates said that the rule wasn’t specific enough.
“This causal link is described in such vague terms that basically there’s almost always a causal link,” said Jake Li, an endangered species policy advisor at Defenders of Wildlife. “Really, in a case like this, the devils are in the details oftentimes. We would recommend that the service provide more clarity on what type of causal link they believe is going to suffice.”
In addition to the alternate calculation, the agencies also proposed a new system that would grant preliminary estimates about the effects of major projects expected to impact endangered species in the future. Those initial statements would then be supplemented with more detailed site-specific calculations once they are initiated.
Li said that his organization would be asking for more details there, too.
“There’s a lot of gaps, I think, and open questions that at least I have about how they will administer” the early reviews, he said, which could lead to confusion.