Cackling Goose

Cackling Geese are monogamous and typically pair for life, re-pairing only after the death of a mate. Most birds do not breed until they are two or three years old. The female selects the nest site — usually a dry, elevated patch of tundra such as a hummock, or a small island in a tundra lake, almost always close to water. The hutchinsii subspecies also nests on cliffs and steep rocky slopes, sometimes in colonies of several hundred pairs. The leucopareia subspecies forms dense nesting colonies on the Aleutian Islands, where suitable habitat is limited.

The female builds the nest alone: a shallow scrape filled with grasses, sedges, twigs, leaves, lichens, and mosses, with the inner bowl — typically around 15 cm across — lined with down feathers plucked from her own breast as laying progresses. Clutch size is 2–8 eggs, typically 3–6, which are creamy white and quickly become stained by the nest material. Incubation is performed solely by the female for 25–28 days, while the male stands guard nearby. During incubation breaks, the female covers the eggs with her own down to retain heat and conceal them from predators.

Goslings hatch covered in down with eyes open and leave the nest within 24 hours, immediately able to swim and feed themselves. Both parents protect the goslings vigorously. First flight occurs at approximately 6–7 weeks of age. Young birds remain with their parents for the following 12 months or longer, migrating south with the family in autumn and staying together through the winter. This prolonged parental investment is characteristic of geese. Breeding season timing varies by latitude; high-arctic nesters typically begin incubation in late May or early June.

A male banded in Alaska in 1987 and shot in Oregon in 2010 — at least 22 years and 8 months old — holds the longevity record for the species, having completed at least 22 round-trip migrations in his lifetime. Typical lifespans in the wild fall in the range of 10–20 years, but that record hints at what is possible for a bird that survives its early years.

Survival rates are highest once birds reach adulthood. The main causes of mortality are hunting, predation — particularly of eggs and goslings by Arctic foxes, large gulls, skuas, and raptors — and starvation during severe winters or failed migrations. Goslings face the highest mortality in their first weeks of life, before they can fly and escape predators.

Compared to related species, the Cackling Goose's lifespan is broadly similar to that of the Canada Goose, which has a comparable maximum recorded age of around 24 years in the wild. The lifelong pair bond and extended parental care of goslings — which remain with their parents for up to 12 months — likely contribute to higher juvenile survival rates than would be achieved by less attentive parents.

The Cackling Goose is listed as Least Concern on the IUCN Red List, with a global population estimated at approximately 4.5 million mature individuals (BirdLife International / Partners in Flight, 2020–2021). The overall population trend is increasing, though the picture varies by subspecies. The hutchinsii subspecies is the most numerous at around 2,499,000 birds; the leucopareia subspecies numbers approximately 215,000 (2022 survey); the minima subspecies approximately 205,000 (2022 Alaska survey), slightly below its management goal of 250,000; and the taverneri subspecies approximately 59,000.

Primary threats include wetland and tundra habitat loss and degradation, pollution and pesticides, and hunting pressure — an estimated 157,863 birds were harvested in the US during the 2021–2022 seasons, with approximately 85,000 per year taken in Canada. Climate change poses a growing long-term threat by altering tundra breeding habitats and disrupting the timing of spring migration and breeding.

The species was long confused with the Canada Goose in survey data, meaning population trends are not fully known for the period before the 2004 taxonomic split. The now-extinct Bering subspecies (B. h. asiatica) disappeared around 1929, likely through a combination of hunting and habitat loss. A formerly established non-breeding winter population in Japan is now considered extirpated by the IUCN, though reintroduction efforts have been undertaken in Japan and Siberia.

Four subspecies of Cackling Goose are currently recognised, each with a distinct breeding range, wintering area, and set of identification features. Getting to grips with the subspecies is essential for anyone hoping to identify Cackling Geese reliably, since the largest subspecies overlaps in size with the smallest Canada Goose.

Richardson's Cackling Goose (B. h. hutchinsii) is the subspecies most likely to be encountered in the UK. Small and pale, sometimes with a silvery cast to the upperparts, it breeds in the high Arctic from the Mackenzie River Delta east to Baffin Island and winters on the Southern Great Plains. It typically shows a narrow or diffuse white neck collar, a short stubby bill, and a steep forehead.

Aleutian Cackling Goose (B. h. leucopareia) is perhaps the most striking of the four, with a bold, usually complete white neck collar and a somewhat square head profile. Its recovery from a low of 790 birds in 1975 to over 215,000 by 2022 — following the systematic removal of introduced foxes from the Aleutian Islands — is one of North American conservation's great success stories. It breeds on the western and central Aleutian Islands and winters in California's Central Valley.

Cackling Goose (B. h. minima) is the identification challenge at the other end of the size scale. At 1.1–1.5 kg — barely larger than a Mallard — it is the smallest and darkest subspecies, often with a purplish cast to the breast and usually lacking a white neck collar entirely. It breeds on the Yukon-Kuskokwim Delta and winters in the Pacific Northwest.

Taverner's Cackling Goose (B. h. taverneri) is the largest subspecies and the one most likely to cause confusion with the Lesser Canada Goose, sharing its pale plumage and rounder head. Even experienced observers can find the separation genuinely difficult. It breeds across northern and western Alaska and winters in the Pacific Northwest and Southern Great Plains.

From 790 birds in 1975 to approximately 215,000 by 2022, the Aleutian Cackling Goose's recovery stands as one of the most documented successes of the US Endangered Species Act. From around 1750 onwards, Arctic foxes were introduced to approximately 190 Aleutian Islands by Russian and later American fur traders. The foxes proved catastrophic for ground-nesting birds: by 1975, the entire Aleutian Cackling Goose population had been reduced to just 790 individuals, confined to a handful of fox-free islands. The subspecies was listed under the US Endangered Species Act as endangered in 1967.

Recovery required a multi-decade effort. Foxes were systematically removed from island after island — a logistically demanding programme that ultimately cleared introduced predators from all 190 Aleutian Islands where they had been introduced. Hunting was banned. Translocation programmes moved birds to newly fox-free islands to accelerate recolonisation. By 2001, the population had recovered sufficiently for the subspecies to be delisted from the Endangered Species Act. By 2022, the population stood at approximately 215,000 birds — nearly four times the Pacific Flyway management goal of 60,000.

The story carries a cautionary footnote. The Bering subspecies (B. h. asiatica), which bred on Bering Island and Copper Island in the Commander Islands, was not so fortunate. It disappeared around 1929, almost certainly through a combination of hunting and the same fox introductions that devastated leucopareia. It is now extinct. The contrast between the two subspecies — one saved by timely intervention, one lost before action was taken — underlines how quickly island-breeding birds can be driven to extinction, and how much difference targeted conservation can make.