Why habitat matters: An Ecologist’s perspective on proposed changes to Endangered Species Act enforcement
Today it’s hard to imagine any piece of US legislation with nearly unanimous, bipartisan support. But that’s exactly what happened when the Endangered Species Act (ESA) was passed by Congress and signed into law by the President over 50 years ago, reflecting a shared vision for environmental stewardship. These origins tell us that the law can work to benefit all of us.
Recently, in April 2025, the US Fish & Wildlife Service and NOAA Fisheries proposed to significantly narrow protections for endangered species (Rescinding the Definition of “Harm” Under the Endangered Species Act). This proposed change would essentially remove habitat protections, undermining the recovery of hundreds of imperiled species in diverse ecosystems. Common sense and scientific data tell us that species need a safe home (habitat protections) to survive. In addition, data shows that people from all walks of life benefit from protected habitats and healthy ecosystems. Despite the success of the ESA, regulatory enforcement often hinges on legal frameworks rather than science.
The proposed rule change opened a process for Public Comments. This process is part of democracy; it’s a way for all individuals and organizations to have a voice, and federal agencies must consider Public Comments in their rule making. More than 350,000 comments were submitted, here is mine:
As an ecologist and conservation biologist, I have first hand experience with imperiled species and their habitats. I strongly oppose rescinding the existing regulatory definition of “harm,” which includes “significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding or sheltering.”
My comment addresses (1) the regulatory definition of “take,” (2) the best available science, and (3) reliance interests that have not been adequately considered in the proposed change.
The proposed rule change argues that the currently accepted definition of “take” as harm including habitat modification and degradation exceeds the original intent of the ESA, which was passed nearly unanimously by Congress. However, the text and legislative history of the ESA actually reflect Congress’s intention for the law to adapt over time, noting that “as more is learned about the ecosystems of endangered species, further measures may be necessary.” The text therefore deliberately leaves the door open for agencies to interpret “take” as habitat modification or degradation, a definition which has been consistently upheld in Federal court. Notably, the Supreme Court upheld this interpretation in Babbitt v. Sweet Home (1995), affirming that “harm” may include significant habitat modification.
Indeed, the science on species and ecosystems has advanced considerably since Congress passed the ESA more than 50 years ago. We know that habitat loss has driven species to extinction in the United States (e.g., Moyle, 1976), and that the data shows habitat protections are crucial to the recovery of endangered species (Schwartz 2008). Protected habitat is needed to safeguard both species with limited ranges and those that are highly mobile (Roberts et al. 2021). Federal agencies are obligated to consider the best available science, and the science strongly supports retaining habitat protections in the best reading of the ESA.
Finally, landowners and regulated entities have developed land management practices in reliance on the existing regulatory definition of “harm,” and many benefit from habitat protections that promote ecosystem services, such as pest control and pollination. I have spoken with farmers who understand that wild species like birds and bats benefit their bottom line by eating agricultural pests and with ranchers who support and participate in conservation of endangered species (see another example in Knapp et al. 2015), showing that environmental and economic interests do not necessarily have to be in opposition.
In conclusion, enforcement of the existing definition of “take” as harm including habitat modification and degradation is well within the text and spirit of the ESA, is supported by the best available science, and benefits a wide swath of economic interests.
-Ann Holmes, PhD in Ecology
References:
Knapp, C. N., Chapin III, F. S., & Cochran, J. O. (2015). Ranch owner perceptions and planned actions in response to a proposed Endangered Species Act listing. Rangeland Ecology & Management, 68(6), 453-460.
Moyle, P. B. (1976). Inland fishes of California. Univ of California Press.
Roberts, K. E., Smith, B. J., Burkholder, D., & Hart, K. M. (2021). Evaluating the use of marine protected areas by endangered species: A habitat selection approach. Ecological Solutions and Evidence, 2(1), e12035.
Schwartz, M. W. (2008). The performance of the endangered species act. Annual Review of Ecology, Evolution, and Systematics, 39(1), 279-299.
Luckily, the ESA was designed to be strong. While science can be a frustratingly slow process, it is rigorous and thoughtful. Our national policy needs to move forward with the science.
For more, please see the American Fisheries Society’s statement on the proposed rule change, and the Society for Conservation Biology’s statement on the importance of scientific integrity.
Published: 16 June 2025
Ann Holmes 