Hemingway's polydactyl cats at Key West: how one writer's gift created a 100-year colony

In 1935, a ship captain named Stanley Dexter gave Ernest Hemingway a white polydactyl kitten he had brought from a Boston voyage. Hemingway named the kitten Snow White and brought her to his Key West home at 907 Whitehead Street. Nearly a century later, the Hemingway Home and Museum houses more than 60 descendants of that single cat, roughly half of them six-toed, the rest carrying the polydactyl gene without expressing it. The colony is a living biological footnote, an open-air genetic experiment, and one of the most visited tourist attractions in the Florida Keys.

The polydactyly gene

Polydactyly in cats is a dominant autosomal trait caused by a mutation in the LMBR1 gene, which regulates limb development. Cats with the gene have extra digits on one or more paws:

• Front paws: most common location for extra toes. Up to seven digits per paw documented.
• Back paws: less common; some cats have polydactyly on all four.
• "Mitten" or "thumb" polydactyly: extra digit positioned like a human thumb, giving the cat partial grasping capability.

The gene is dominant, meaning one polydactyl parent produces approximately 50 percent polydactyl offspring. Two polydactyl parents produce up to 75 percent polydactyl offspring (assuming neither is homozygous, which is lethal in some studies).

The Hemingway colony origin

Snow White was the founding cat. Hemingway, already an animal lover (he kept multiple cats and dogs throughout his life), was charmed by the extra toes and made the cat a permanent resident of the Whitehead Street house.

Over the years, the colony expanded through natural reproduction. Hemingway took an interest in the bloodline. When he died in 1961, his Key West property passed through several owners before becoming the Hemingway Home and Museum in the 1970s. The cats stayed. The museum took over their care.

In 2026, the colony numbers approximately 60-70 cats, all named for famous historical figures and writers (Marilyn Monroe, Truman Capote, Marlene Dietrich, Audrey Hepburn, Pablo Picasso, others). Roughly half have polydactyl paws.

Maritime history and "ship's cats"

Polydactyl cats are common in coastal New England and the maritime regions of the British Isles. The genetic distribution is well-documented and ties to sailing history.

The theory: sailors believed polydactyl cats were better hunters (more claws, better grip on rocking ship surfaces) and better climbers (better stability on rigging). They selectively bred and transported polydactyl cats on long voyages. Ports with significant sailing trade (Boston, Halifax, Bristol, Liverpool) ended up with high polydactyl population frequencies.

The breed name "Maine Coon" is sometimes connected to this history; Maine Coon cats were originally significantly polydactyl, though the CFA breed standard now excludes the trait. Conservation-focused registries (like the New England Coon Cat Club) still accept polydactyl Maine Coons.

Health considerations

Polydactyly itself is benign: the extra toes are functional, the cats walk normally, the lifespan is unaffected. Some specific considerations:

• Claw trimming: more digits means more claws to trim. Extra digits sometimes have claws that don't naturally wear, requiring more frequent trimming to prevent ingrown claws.
• Inbreeding within isolated populations: the Hemingway colony, like any closed-population cat colony, accumulates other genetic issues over time. The museum reports careful veterinary monitoring and occasional outcrossing.

Visiting the museum

The Hemingway Home and Museum at 907 Whitehead Street, Key West, Florida is open to the public daily. Admission includes access to the property, the house tour, and unrestricted access to wander among the cats.

The cats:

• Are fed, vaccinated, microchipped, and spayed/neutered (with the colony managed by the museum's veterinarian).
• Have outdoor freedom within the walled property.
• Are named, individually tracked, and beloved by the staff.
• Are protected by an Endangered Species Act consent decree (2005, after USDA jurisdictional action) requiring specific welfare standards.

The cats are accustomed to humans and many actively approach visitors. Touching is generally welcomed, though the staff politely asks visitors not to pick up the cats.

Polydactyly in the broader US cat population

Roughly 5-10 percent of cats in coastal New England carry the polydactyl gene. Other US regions show lower frequencies. The trait is largely absent in many parts of the Western US, where cat populations descend from different founder lines.

A few US registries have embraced polydactyl as a breed feature rather than a disqualifying trait:

• The American Polydactyl (informal registry; not CFA-recognized as a breed).
• Maine Coon polydactyl variant (accepted by some traditional Maine Coon clubs).

The CFA, the dominant US cat registry, excludes polydactyly in all recognized breeds. This has been argued by some fanciers as a missed opportunity to preserve a charming heritage trait.

What Hemingway's cats teach us

The colony is, among other things, a long-running case study in:

• Founder effects in small populations: one cat's genes amplified across a century in a confined gene pool.
• Welfare versus tradition: balancing tourist expectations, museum heritage, and modern colony management standards.
• Connection between cat history and human history: the trait Hemingway found charming is the same trait New England sailors selected for in working ships.

Hemingway died in 1961. The cats outlived him by 65 years and counting. As legacies go, it is a peculiar and durable one.

What to check before visiting

1. The Hemingway Home and Museum hours and admission policies.
2. Whether the cats are receiving food and you do not need to bring any.
3. Whether photography is permitted (generally yes).
4. The location at 907 Whitehead Street, Key West, FL.
5. That the cats are friendly, not yours; respect their space and the staff's guidance.