A very rare Cabit chick (a Cahow / Rabbit hybrid) has been photographed on Nonsuch Island!
When animals come close to extinction, as in the case of the Cahow, there is always the possibility of cross species heterozygous offspring.
Rabbits from nearby Hen Island must have swum over to Nonsuch Island at some point in the past, prior to the Cahows' rediscovery in 1951 when they were down to the last few pairs and were forced to resort to hybridization to ensure their survival. The gene for the ears seems to be recessive, only appearing every few generations (with the offspring named a "Cabit"), however all chicks in the colony still hatch with soft grey rabbit type fur instead of feathers, which they then molt prior to fledging. The Cahows have also retained the habit of nesting in deep underground burrows which they spend several seasons excavating with their mate.
As explained by Wikipedia:
In general usage, hybrid is synonymous with heterozygous: any offspring resulting from the breeding of two genetically distinct individuals.
Jean-Pierre Rouja, Nonsuch Expeditions Team Leader:
Back in the 1970's when I was a cub-scout we used to go camping on Hen Island in St. Georges which was still overrun with rabbits. Prior to the Airport being built in the 1940's it would have been a relatively easy swim for them to reach Nonsuch. We spent today trying to catch one so that we could take a DNA sample, however they are just too fast. Fortunatley the CahowCam photographed one early this morning so we have further proof of their existence.