Lights at night trick wild wallabies into breeding late
Artificial lighting knocks seasonal breeders out of sync with rains and food
WALLABY WAYS Tammar wallabies, like this one living on an Australian naval base, use day and night clues to sync the birth of their joeys with the seasons.
Kylie Robert
Artificial lighting at night delays wild tammar wallaby breeding, potentially pushing the nursing marsupial moms out of sync with their peak season for food.
Tammar wallabies (Macropus eugenii) that live on the well-lit landscape of Australia’s largest naval base muddle the timing of their natural breeding season. Births peak in February — a month later on average than normal — then dip only to surge again in April, says zoologist Kylie Robert of La Trobe University in Melbourne, Australia. By the time these late-arriving joeys have grown to their most demanding stage some 250 days in the pouch later, the best grazing greened by winter rains is fading. Nursing moms and their joeys once got through this season thanks to all the irrigated lawns on the base. New irrigation rules, however, now leave the wallabies facing food shortages.
In contrast, on the same island about six kilometers away, on land that’s still dark at night, wallaby
