Environmental Scientist: Dr. Leroy Gonsalves, Bachelor of Environmental Science (Hons); PhD

Leroy now works as a Biodiversity Research Officer, NSW Department of Primary Industries and Sessional Lecturer at ACU.

Leroy talks with Alisse Grafitti (InSIGHT Magazine) about his research into Microbats.

Microbats go largely unnoticed due to their tiny size and quiet, nocturnal habits.

Description of the Research:

“People don’t give a lot of thought to bats. I guess they’re not all that popular seeing as they only come out at night and have creepy connotations.

The bats I’m working with for my research though are tiny. Most of them weigh about four grams and can fit in a matchbox, so they’re pretty cute.
I’m studying the diet of microbats that live on the Central Coast for a project funded by the NSW Environmental Trust.

My study area in Empire Bay has large areas of saltmarsh, which can support huge numbers of mosquitoes at different times of the year. Apart from nuisance biting, these particular mosquitoes have the potential to spread diseases such as Ross River and Barmah Forest viruses – which can cause rashes, fever and rheumatic pains.

Map of Empire Bay on Central Coast of NSW

A local residents group has been lobbying the local government to control mosquito numbers by spraying the larvicide Bti, which kills the mosquito larvae. The larvicide doesn’t eliminate mosquitoes completely, it just reduces their numbers.

Empire Bay Moorings	Mosquito Larva (Culex species - just an example of mosquito larva, the species here in Empire Bay will be different in some aspects)
Mosquitoes are a problem at Empire Bay	Empire Bay Wharf - because of the environment here, mosquitoes are in abundance!
Empire Bay Wharf	On the Job - getting ready!

However these mosquitoes may also be food for up to 14 rare insectivorous bat species. Before the government can give the go-ahead for spraying they need to know if it’s going to be problematic for bats in the area, some of which are threatened species and protected by legislation.

So my research is closely examining the movements of these bats in association with the mosquito fauna of the area, and investigating bat diets to determine just how important mosquitoes are to their survival.

There are several ways I’m going about this.

One is radio-tracking the bats. We put little tags on their backs and release them, then track their movements, both when mosquito numbers are high, and when they are much lower.

Bats are pretty smart and a lot of them avoid traps, so we also record their echolocation call – which is a type of sonar that bats use to navigate and find prey.

Another method is light-tagging, where we stick a little glow-stick on their stomach and observe where and how they fly in different habitats.

One of the Microbats that Leroy is studying

Bat Poo or Guano

I’ve also been studying guano, or bat poo, to see what they’ve been eating. I’m using DNA techniques to give species-level identification of their prey, which hasn’t been done before for bats in Australia.

So far I’ve confirmed that certain bat species do feed on saltmarsh mosquitoes. I am continuing to look at what the other bat species in the area are eating.

Next I’ll be doing a feeding trial, giving bats different quantities of mosquitoes and other insects in order to get an insight into the relative importance of mosquitoes to bat diet.

I’m also looking to see if bats turn to eating different insects, or move to different areas, when mosquito numbers are reduced.

It’s been an interesting research project, and pretty eventful.

What it is like researching:

I’ve been bitten by bats twice, and had to quickly get the rabies vaccine because they can carry Australian bat lyssavirus (ABL). The only two known people who’ve been infected with ABL in Australia both died, so I guess you could say it has a 100 per cent mortality rate.

The lack of sleep is definitely the worst part. When I’m radio tracking, it’s two weeks straight of being out in the saltmarsh from sunset to 2am, and then back at it again from 4am till daylight.

The mozzies are also a killer. I’ll be covered up completely, usually with two layers of clothing and a whole can of Aeroguard, and they still get me. They have a nasty bite too.

When I first started my research project, bats did freak me out a little – it must have been the whole lyssavirus thing.

But after having one of them in the palm of my hand, that all changed. They are fascinating little creatures, each with their own personality, and now I just love them."

Leroy Gonsalves | Bachelor of Environmental Science (Honours) & PhD
https://youtu.be/Rqd07K6v3wk

Microbats get tiny houses in last ditch attempt to save the species | ABC Australia
https://youtu.be/ozZdOi3ZZvk

Attract bats to your garden with DIY bat boxes | Gardening for wildlife | Gardening Australia
https://youtu.be/4_pTNzw2DOo

Bat Conservation & Rescue Qld Inc	All about Bats of Southern Queensland - Microbats
Enquiring Minds - Bridges to Higher Education Project Leroy Gonsalves - the expert. Lots of activities, Lesson Plans - Years 3 - 6. Melbourne Museum - Little Forest Bat	WIRES - Microbats Meet Sydney's Microbats
Australian Museum: Australian Bats Another page	Australasian Bat Society
Full Scientific Paper at PlosOne (Complex reading) Mozzies motivate microbats While the humble mosquito is not welcome buzzing around and sharing viruses with humans, it has a valuable ecological role to play as a prey item for insectivorous bats, an ACU-led study has revealed. Balancing the competing needs of environmental conservation and human health is critical, as urbanisation threatens wildlife, and their habitats and the very wildlife we are trying to protect may sometimes pose risks to our own health. The multi-disciplinary team including Dr Leroy Gonsalves and Dr Vaughan Monamy (ACU), Dr Bradley Law (NSW Department of Primary Industries) and Dr Cameron Webb (University of Sydney and Westmead Hospital) has examined the role of mosquitoes as prey for bats as part of a broader project investigating potential indirect effects of mosquito control on the diet of small forest bats. Findings of this study, Foraging Ranges of Insectivorous Bats Shift Relative to Changes in Mosquito Abundance, have just been published in the international journal, PLOS ONE. The article presents the results of a radio tracking study in which the research team tracked the movements of a small (4 g) bat species (Vespadelus vulturnus, little forest bat) during two periods of contrasting extremes of mosquito abundance. Vespadelus vulturnus, a predator of mosquitoes, shifted from foraging in endangered coastal saltmarsh to endangered coastal swamp forest communities. “The shift in foraging range of V. Vulturnus was relative to changes in abundance of mosquitoes (and no other prey) in these two habitats, highlighting the importance of mosquitoes as prey for this bat species,” lead researcher Dr Gonsalves said. This study was the first in Australia to provide quantitative data about the importance of mosquitoes to the insectivorous bat diet by assessing whether foraging ranges of predators shift in relation to mosquito abundance and distribution. Important recommendations that may be applied to the management of pest and vector mosquito species while protecting local wildlife that use these as prey are also presented in the article.

Online: Create a VoiceThread around the relationship between Mosquitoes and Bats

Primary & Middle

Online: Debate the issue: Topic: Should we get rid of "pesty"Mosquitoes?

Secondary

Topic Stimulus:

"While the humble mosquito is not welcome buzzing around and sharing viruses with humans, it has a valuable ecological role to play as a prey item for insectivorous bats, an ACU-led study has revealed."

1. Using Popplet, collate your teams views, ideas, and research and divide up the issues to your three team members.

2. After reading the information from Leroy and his research, in your group, investigate the following websites:

University of Sydney: 10 Tips to keep you mosquito free this summer	ABC News 15 February 2015
The Conversation 20 September 2016	ABC Late Night Live
ABC Late Night Live 30 October 2019

3. From your research: What are the pros and cons of keeping or getting rid of mosquitoes? You are to weigh up your findings!

What are the ethics of wiping out a whole species of animals that other animals depend on because we, humans, think of them as "pesty"?

4. In the class, in teams of three, debate the issue:

Should we get rid of "pesty" Mosquitoes?