Every Bat Tells a Story...

Monitoring wildlife opens up windows of understanding. In some cases, it allows us to peek inside the mysterious life of rather cryptic species. One such species is the White-striped Fee-tailed Bat (Austronomus australis). These little creatures, only weighing an average of 37 grams (equivalent to two and half teaspoons of sugar), have big stories to tell.

The Park is fortunate to have a maternity roost of this species in the wall cavity of a heritage building in Newington Armory. Maternity roosts are where female bats gather together to have their babies; babies that weigh almost 30% of their mother’s body weight! This maternity roost at Sydney Olympic Park has been monitored since its discovery in 2005 in partnership with Marg Turton, a bat specialist, through an annual microchipping (tagging) program to allow all-year-round recording of tagged individuals entering and leaving the roost.

Over seventeen years, there are many stories to tell, and some special characters include:

• Bat#13: A male first tagged in March 2008, was found to be a regular visitor of the roost until 2019, an unusual activity for males who don’t usually intrude in maternity roosts. His last recapture exposed is grand old age of (minimum) 11 years. Prior to this study, it was not known how long this species could live!
• Bat #9: Also first tagged in 2008, this female was selected along with five others for radio tracking. The resulting data saw this individual moving between the main building roost and three separate tree roosts over an 18-day period. This information indicates that an individual could regularly utilise multiple roosts, and that tree hollows in close proximity to the maternity roost are very important too. 
• Bat #23: A female first trapped in 2008 and later trapped in April 2018.  At the old age of at least 10, she was showing signs of post lactation, indicating a long reproductive life. For this species, single young are born between mid-December and late January, with most young weaned by May and females being sexually mature by August. That means that this bat could have had at least 10 babies so far!
  
  • Bat #103: A newly tagged bat from this season! She is a post lactating female, so has recently reared young using this maternity roost.  Like the individuals in her maternity roost, she will migrate north during the colder months. We can’t wait to welcome her back and learn more from her unfolding story.

Bat # 13 is a male that was first tagged in 2008 and  has reached a grand age of at least 11 years old. © Marg Turton	Bat #23 is a female that is at least 10 years old and still showing signs of post lactation, indicating a long reproductive life. © Marg Turton	Bat #103 is a female recently tagged in 2022… and the start of a new story. © Lachlan Hall