Habitat loss is the…

Habitat loss is the principal driver of the decline and the disappearance of species, in Ontario and elsewhere. Accordingly, legislation intended to protect and conserve species must also protect and conserve habitat.

Notably, under this proposed change to the Endangered Species Act, the definition of “habitat” is insufficient. This new, narrower definition of habitat — “dwelling place” and its immediate surroundings — is inconsistent with ecological understanding and with the standard definition of habitat.

Caughley & Gunn (1996, Conservation Biology in Theory and Practice) were clear on this matter: that habitat constituted “the suite of resources (food, shelter) and environmental conditions (abiotic variables—temperature—and biotic variables—competitors and predators) that determine the presence, survival, and reproduction of a population” (p. 240). Habitat is thus closely tied to population limiting factors — the features that affect population rate of growth. And as Caughley & Gunn also emphasized, rate of population growth is the mark of a species in trouble. In short, their definition of habitat draws a clear link among habitat condition, population condition, and a species’ conservation status.

Woodland caribou illustrate the need for such an exact definition. It is well established that habitat modification is the main driver of the decline of forest-dwelling caribou. And, following Caughley & Gunn, a valid designation of habitat includes lichens, snowcover, wolves, white-tailed deer, and moose — because these features govern the presence, survival, and reproduction of caribou. In contrast, to protect only dwelling space (such as nursery sites and their immediate surroundings) neglects the key features that limit caribou populations. The legislation is destined to fail.

As stated in the proposal, the rationale for this change is “because the current definition of ‘habitat’ creates uncertainty, includes broad areas beyond core species protections, and results in confusion when making decisions about what actions to take when carrying out required protections. The new habitat definition ... [will] provide greater clarity to proponents when taking required protection steps.” To restrict habitat to “dwelling space” for animals or to “critical root zone” for plants, however, is to revert (in Caughley and Gunn’s words) to a “flustered concept” of habitat. Such a restricted definition conflates where a species resides with the resources that determine the species' survival.

Under this proposal, the nest of an Eastern whip-poor-will would be protected; the insects on which it depends for food would not. The den of a American badger would be protected; the open grasslands on which it depends would not. The overwintering nest of a Suckley’s Cuckoo Bumble Bee would be protected; the host species on which it depends would not. Such a narrow, unsupported definition fails to include the key limiting factors that govern the welfare of these species.

The revised definition of habitat will fail to provide clarity to proponents, as purported. The revised definition will fail to protect and conserve species, as intended. Indeed, this proposed change to the ESA is at odds with sound conservation practice.