A typical black bat and an albino bat at the Tolga Bat Hospital. PHOTO CREDIT: COURTESY TOLGA BAT HOSPITAL
Leucism is a partial hypopigmentary congenital disorder previously recorded in Mexico in seven bat specimens of six species. In August 2009, in the state of Hidalgo, we caught one Sturnira ludovici and one Artibeus lituratus (both females) exhibiting leucism. In addition, one leucistic Macrotus waterhousii was caught in April 2010, in Guerrero. Leucism has not been frequently reported and it may be more common than suggested by published results. In order to evaluate this supposition, we checked the mammal collection of the Escuela Nacional de Ciencias Biológicas (Instituto Politécnico Nacional) to look for other evidences of leucism in bats. We found six more specimens, three Artibeus jamaicensis and three Tadarida brasiliensis with this condition. These specimens raise to 16 the records of bats of nine species with leucism in Mexico.
pipistrelle Pipistrellus pygmaeus
Abstract: Albinism and leucism are commonly confused in the literature. Despite the fact that these congenial disorders affect only a small proportion of bat populations, they seem to be widely spread since reports of affected bats are found from over the world. In this communication we report for the first time a leucistic Pipistrellus pygmaeus (Leach 1825). It was captured in the Ebro Delta Natural Park (Iberian Peninsula) in a biological field station near a wetland with rice paddies, where over 100 bat boxes are deployed to monitor bat populations. The individual had whitish fur over the whole of its body (dorsal and ventral parts); nevertheless its eyes and wing membranes had normal pigmentation. Although an albino P. pygmeaus has been reported from Spain, this represents the first report of leucism in this species.
This doesn't mean, however, that all white or fair animals or people are albino. Polar bears, Kermode bears (spirit bears) and Scandinavians, for example, carry fair genes, but not gene mutations that inhibit colour. Some animals also suffer from different disorders that affect their pigmentation to a different extent.
Even within albinism, there are varying degrees of colouration, ranging from coppery through to very white. And so it's a common misnomer that all albinos have pink eyes; indeed some do, but some have blue and even hazel and brown eyes. Some plants are also only partially albino, producing either regular or random stripes or colour patchers. Other people and animals are only white at the warmest points on their bodies.
Oculocutaneous Albinism (OCA) for example is classified along a scale. "So classically OCA1a is super-duper, duper white; white as snow," explains Dr Shari Parker, a medical doctor with The Albinism Fellowship of Australia. "OCA1b has a temperature-sensitive variant and so the cooler the parts of the body the greater the pigmentation. So in people that means they might be a little bit darker towards the ends of their arms and legs. The eyelashes one of our members are white where they grow out and at their tips they're black."
This, in fact, is the mutation is that creates the highly valued colouration in Siamese cats, which are all albino. Breeders call it "point colouration". At birth Siamese kittens come out of their mother's warm womb all white. With exposure to air, the kitten's markings slowly darken in the body's coolest areas. This causes the tail, face, and paws to darken over time to the colour that would have expressed had it not been for the mutation.
The longer a cat with temperature-sensitive albinism is exposed to cold, the darker his markings will get. For this reason, many end up a solid blackish-brown. Although some Siamese cats have impaired vision, they are otherwise mostly functionally fine.
Albino animals vulnerable in the wild
In the wild albino animals are much less likely to survive for a number of reasons. Being fair or white makes them vulnerable to predators, sunburn and cancer; they have a reduced ability to mate, so are likely to die before they get to pass on their genes.
Some amazing examples have survived these challenges, including Migaloo, an albino humpback whale frequently spotted off the Australian east coast during the yearly humpback whale migrations. Migaloo - an Aboriginal word meaning 'white fella' - is the world's only confirmed albino whale and is thought to be 25 years old. Two or three other white whales are known of, but spots on their skin suggest they may have a different disorder called leucism. Track sightings of Migaloo
Bruny Island off Tasmania's south-eastern coast has also nurtured a population of albino wallabies, where their sheltered island life and remote population has meant they've managed to carve out a niche for themselves. Across the country sightings of naturally occurring albinos are also periodically reported to newspapers. Everything from kookaburras to echidnas pop up regularly, but it's rare to see them survive to maturity in the wild.
One of the rarest bats in the world, a completely white (albino) micro bat, nestles on the thumb of carer Pam Tully while recovering from a cat attack at the Batreach Bat Rescue and Rehabilitation Centre at Kuranda, near Cairns in northern Australia. PHOTO CREDIT: AAP PHOTO/BRIAN CASSEY