On March 22, 2011, the U.S. Fish and Wildlife Service proposed to more than double the total acres of critical habitat for the Pacific Coast population of the Western Snowy Plover (Charadrius alexandrines nivosus). This proposal is important because it marks one of the few situations where the Service is seeking to expand an existing critical habitat designation to help a species adapt to climate change.
The plover forages and nests along coastal and inland beaches. Its coastal habitat will be degraded and lost to sea-level rise resulting from climate change. To partially compensate for these losses, the proposed critical habitat rule extends the current critical habitat boundaries further inland where appropriate. The plover is expected to use these inland areas and adjust its use of nesting habitat. Some of these inland areas are not currently occupied by the plover, but protecting them helps ensure they can be occupied the future.
I applaud the Service for taking this concrete step to help a species adapt to climate change. In fact, the new release for the proposed rule states that although the Service’s “policy direction in 2005 emphasized the designation of occupied habitat for critical habitat designations,” the “current policy direction encourages more consideration of the role that unoccupied habitat can provide for the conservation of the species to better support recovery.” And the proposed rule explicitly acknowledges that “limiting the designation of critical habitat to those areas that were considered occupied at the time of listing is no longer sufficient to conserve the species because…[w]e anticipate a further loss of habitat in the future due to sea-level rise resulting from climate change.”
In December of 2010, the Service responded in a similar manner in its final revised critical habitat rule for the Preble’s meadow jumping mouse (Zapus hudsonius preblei). There, the revised critical habitat designation was intended to adequately address “likely climate change scenarios by designating critical habitat areas throughout the north-south range of the [mouse] in Colorado that vary in elevation and in stream size.” Some of these redesignated areas actually exceeded the amount of critical habitat called for in the 2003 preliminary draft recovery plan for the species.
While these recent critical habitat decisions are encouraging, there are several related issues that the Service will need to grapple with in the near future. First is how to help less mobile species, such as amphibians and certain insects, adapt to climate change. While birds and large mammals can easily move further inland in response to rising sea levels, less mobile species will likely require more help. Second is whether the Service should designate critical habitat outside of a species’ historic range, where doing so would help the species adapt to climate change. Climate change will continue to reshuffle ecosystems dramatically, which means that our notions of where species “belong” may need to shift as well. Third is whether the Service will find that critical habitat designation is “not prudent” for species for which the prospects of survival and recovery grow increasingly dim. This is an unfortunate challenge given the magnitude of anticipated climate change impacts.
Finally, it is worth noting the connection between range shifts and the current House bill that California Representative Joe Baca has introduced to delisting certain endangered species. As discussed in a prior blog post:
- A second implication [of the bill] is that a species could become a “limited listed species” simply by shifting its range since the time of listing. Shifts can happen for several reasons, including climate change, stochastic events, and habitat alteration. For these shifting species, it may not be “reasonably possible” to determine whether they have been extirpated from their range at the time of listing. As a result, the bill could consign the species to “extinction”—even if they clearly occupy areas outside of their range at the time of listing.
This bill clearly ignores the best available science on climate change in favor of political expediency.