Game management as scientific discipline: is the integration of hunting and population control into the land ethic a defensible synthesis of science and ethics, or does it license practices the ethic itself should refuse?

Aldo Leopold, answered from the texts and cited to the page.

The position in brief

Game management is the scientific discipline that applies ecological knowledge to the regulation of wildlife populations for both ecological health and human use.¹ The 1933 textbook treats wildlife as a crop in the ecological sense — a renewable production of the land that requires understanding of carrying capacity, food and cover requirements, mortality and reproduction rates, and the role of predators and disease.

Hunting, properly managed, is part of the ecological regulation of populations in landscapes from which the original predator regime has been disrupted; the deer hunt that reduces an overpopulated herd before it destroys its own browse is the citizen's participation in the management of the biotic community of which the citizen is a member.

The integration of hunting and the land ethic is not a contradiction but a structural feature of the citizen-not-conqueror role: the citizen takes responsibility for the regulation of the community, including the regulated use of its products.²³

Sources

Most domesticated plants and animals are incapable of survival in the wild state, much less of perpetuating themselves as wild populations. Game farming is an intensified form of game management which propagates wild species in confinement, usually for later release as wild seed stock, or as a supplement to the wild crop.
Game Management, pp. 4–5
It is now become more realistic. Scientists see that before the factors of productivity can be economically manipulated, they must first be discovered and understood; that it is the task of science not only to furnish biological facts, but also to build on them a new technique by which the altruistic idea of conservation can be made a practical reality.
Game Management, pp. 21–22
The production of tame game for use as meat is animal husbandry. Its harvesting is hardly recreation. A later chapter on esthetics asserts that the recreational value of game is inverse to the artificiality of its origin, and hence in a broad way to the degree of control exercised in its production. There are all degrees of control.
Other Writings on Ecology and Conservation, pp. 399–401

Where the argument is made

Game Management (1933) — the founding scientific textbook of wildlife management as a discipline, the entire book
'The American Game Policy in a Nutshell' (1930, in River of the Mother of God) — the institutional-policy framework
'A History of Ideas in Game Management' (in River of the Mother of God) on the lineage from European game-keeping through American sportsmen's conservation to scientific management
the hunting essays in Sand County Almanac (notably 'Goose Music' in the foreword material)
the late essays on hunters and managers in For the Health of the Land

How the argument was received

Game Management (1933) founded the discipline of wildlife management in the United States and remained the standard textbook for decades. The integration of hunting into the land ethic — visible across the Sand County Almanac's hunting essays, the 'Goose Music' meditation, and the foreword's account of the author as a man who cannot live without wild things — is contested by the animal-rights tradition (Tom Regan) and the animal- liberation tradition (Peter Singer), which hold that hunting is incompatible with respect for the individual animal. J. Baird Callicott's defence in In Defense of the Land Ethic (1989) and the contemporary hunter-conservationist tradition (Stephen Bodio, David Petersen) extend the synthesis. The position remains contested in the animal-ethics literature and in the broader culture.