Monday, 11 July 2016

The bats are back in town

Black flying-foxes, Herston.

During a bird survey at Rasey Park on the weekend, I found a colony of black-flying foxes (Pteropus alecto) in the mangroves lining Breakfast Creek.

The sight was a relief: earlier last month, the Brisbane Times reported on the mysterious disappearance of South-east Queensland’s flying-foxes, as observed by Gold Coast bat expert, Trish Wimberley. 

The news had triggered alarm in me—suddenly I couldn’t recall having seen any bats for at least a few weeks, an unusual occurrence for anyone living within the Norman Creek catchment area.

A walk with the spotlight through Dawn Road Reserve in mid-June didn’t allay my worries either, as not a single flying-fox was seen or heard.

Where were they?

It seems this year that the flying-foxes are having to chase food supplies a little harder than usual, and the nomadic grey-headed (P. poliocephalus) and little red flying-foxes (P. scapulatus) have sought nourishment further south where the eucalypt blooming season has already commenced.

The black flying-fox is considered more of a sedentary species however, travelling distances each night of around 15 to 30km away from its roosting camp; that there also seems to be very few of these presently in South-east Queensland is therefore notable.

Flying-foxes are very susceptible to heat stress thanks to their lean bodies, large surface area and exposed roosting sites; with the twelve months between July 2015 and June 2016 being the warmest on record for Australia, it is possible that our bats have had a very poor breeding season.

Now that the forest red gums (Eucalyptus tereticornis), tallowwoods (E. microcorys) and various ironbarks are coming into flower, it will be interesting to see if flying-fox numbers perk up in the local area.

4 comments:

  1. I do hope the BAt numbered will increase and be back in force.

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    1. Thanks Margaret, they are important pollinators of our forests, so I hope so too!

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  2. Black flying foxes are awesome bats, one of my favourite! I have found that they are common up here in Caloundra, but their numbers can be quite variable. shame to see them in such low numbers in Brisbane!

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    1. I think I am more partial to the grey-headeds, probably just because my encounters with them have been fewer and therefore more memorable! Hopefully the low numbers at present mostly reflects seasonal variability, so will keep an eye out on the fly outs :)

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