Next microbat survey 21 Feb -10pm to midnight

Here’s the report on our 17 January survey. Conditions : temp 26C, Wind slight SE 20km/ph 44% R humidity, Clear skies. Moon phase: full (not applicable).

Welcome to newbies: Robert Schiller, Tegan Gross Lovely Bat regulars : Rhonnie, Baida, Ricki, Esther, Bruce, and nice to see Caroline again. Sorely missed ☹ Jen & Pete.

Summer is such a difficult time for us to monitor the bat boxes in daylight and then wait until sunset and beyond until the bats are feeding by night in order for us to record their calls on the echo meters. We decided to just monitor the boxes this time and have a discussion afterwards about next steps in the programme.

It was a beautiful clear warm summer afternoon and the swans are nesting on the lake again, the pelicans have also returned. We found single bats in boxes 16 & 14 both double chambered, box 1 (3 chambered) box 8 and 10 (double chambered) The bat in box 1 looked a bit different to the usual Goulds Wattled bats we usually see- more fur – bigger ears?? Hard to tell!

Plenty of marbled geckos co habiting in many boxes – it’s great to have full-time cleaners keeping the spiders (and webs away 19/13/3/) although we did need the housekeeping duster on a few occasions!

It was so warm that we felt very thirsty so stopped off at The North Port for a long cool drink and something to eat!

Discussions were what do we know (summary)

1. Bat numbers in boxes are increasing with more bats in boxes seen in 2025 than 2024. (will drill down on this as we have more access to more boxes since removing covers.
2. Multiple bats seen roosting together for the first time– mostly during cold month ( May 2025 had 5 bats in no 13 – North facing)
3. Bats move around a lot – they don’t stay long in 1 place (maybe due to temp/parasites/predators/disturbance?)
4. So far we have seen Goulds Wattled bats or poss Chocolate Wattled bats use our boxes.

(both design types)

5. Goulds wattled bats are not that fussy!

What we don’t know (lots)

1. Are other bat species feeding in Westgate Park – (have 1 faint recording of a Lt forest bat and poss Myotis/long eared picked up by Marie when she visited us)
2. Why are some nights busy with bats and others not? Too early/too bright/ too many gulls/other?
3. Why are only Goulds Wattled bats using boxes? Is the design too big for smaller bat species?

Something else?

4. Bats are sharing boxes in colder months – temp check? Add more south facing boxes?
5. Do we just need to monitor for longer and just be patient?

What do we need to do next… Box 7 needs to be taken down and repaired and box 17 needs to be put back up the tree where it fell. Box 15 now has a wasp nest in it – leave until winter and remove it!/?

There are still bottom chambers that require removing for monitoring so that we can check if bats are using them (4 , 5 & 2 on the hill and 1 isolated box near the Melbourne water works.)

I attended a microbat echo monitoring event in January hosted by Friends of Nature Watch in Beaumaris and many Little Forest bats appeared after 9:15 (along with a few Goulds Wattled) I learnt that some microbats such as Free-tailed bats do not appear until much later in the night.

We decided we need to monitor for echolocation later in the park next time to see if there are more bats or different bat species visiting. We also need a static echo meter that we can leave overnight and check for different bats at different times throughout the night. Looking into borrowing or renting one first over summer.

Other talk about putting up additional bat boxes away from where the new DATA CENTRE location will be; so that when construction starts with noise and lights the bats will have other spaces to go.

We should also check that minimum lumen lights with sensors are considered in the design stage if we possibly can. P Owl could also lose the park habitat if this is not considered.

Minimise lights for construction stage as well.

Can we utilise Data Centre walls for microbat box habitat? (they like warm places !)

We’ll also be researching or prototyping other types of “boxes’ that may be more desirable to other bat species… little forest bats, long eared bats etc once all-night echo location results are in.

 If anyone has experience in this area please reach out.

Linda