Like rainforests? Thank bats! Zac Albert gives us the mega and micro on bats.
Bats could be described as the ‘bohemians’ of flying animals – they love the night life, are wanderers and the pollinators are definitely flower children.
Because they are nocturnal, we notice them less than birds and bugs, but there is a lot to love and the varied bat species are absolutely integral to our biodiversity and environmental systems.
PlantingSeeds is supporting the less understood and observed microbat through the construction and implementation of microbat roosting boxes. Even though microbats aren’t pollinators, they eat a lot of insects, which translates to less predation on plants. The microbat roosting boxes initiative has been funded by Responsible Wood and supported by the Community Timber Partnerships program, a partnership between Forestry Corporation NSW, Pentarch Forestry and Planet Ark’s Make it Wood Campaign.
Here are some mega and micro reasons bats are important for the environment:
- Megabats are important pollinators because of the odd fact that some flowers are nocturnal. Yes, even without having a sleep schedule, your common daisy probably has a better sleep-schedule than the average person. While most flowers bloom in the morning and close at night, a select few bloom at night and close during the day. In the bloody, millennia-old war between flowers vying for pollinators’ attention, these flowers noticed some animals would rather work during a night shift. Many nocturnal plants have adapted to bat pollination through strategies ranging from where their flowers are located to how the flowers are shaped. Quite simply, without pollinator bats, these plants would not be pollinated.
- Chiropterophilous flowers are flowers that use bats to pollinate, and are typically bigger, contain more nectar, and have a different colour palette and smell to other non-chiropterophilous flowers. Chiropteran flowers generally come in one of two forms. The first is with a firm, large mouth, which forms the shape of a bell or a dish. The second is a ‘brush type,’ that is either formed by a large flower carrying many stamens or an inflorescence of many clustered flowers without corollas (a fancy word for petals).
- Bats are among the fastest flying animals and so they can transfer pollen very long distances. Rainforest systems are reliant on bat pollen transfer.
- Microbats have their own special characteristics and behaviours and offer assistance with pest control. University of Sydney microbat expert, Dr Caragh Threlfall, explains that researchers are investigating microbats’ insect dietary habits to establish how they could be used to reduce our pesticide use. Pesticides have been known to cause detrimental damage to the environment, and sometimes the strategy of introducing other species to control pests (aka cane toads) can create more problems. The strategy of co-opting bats to assist – a local pest-controlling species – is a solution right under our noses. They protect important flora species and can lead to a decline in pesticide use that will benefit many pollinators too.
- There are numerous differences between microbats and megabats. Their most obvious difference is their size. Microbats tend to have a 25cm wingspan, while megabats can have a wingspan of up to a metre. Another major difference is that only microbats use echolocation. Contrary to popular belief, most people are blinder than a bat, as megabats rely on sight (and smell) when flying at night and do not possess echolocation. While both species live in colonies, microbats tend to live in caves, under tree bark, and in tree hollows, while megabats hang (literally and metaphorically) in trees. Lastly, a big difference is that megabats eat fruit, blossoms and nectar (meaning they are pollinators) while microbats eat insects.
- As a result of these differences, it may be more accurate to distinguish bats not for their size but for their other attributes. Scientists are starting to split bats between ‘echolocating bats’ and ‘fruit and nectar-eating bats’.
- Urban environments are threatening microbat species for a number of reasons. A cause for real concern is that urban areas are home to many cats – notorious killers. Humans in urban environments often destroy the flora that microbats rely on as well. If you do own a cat, make sure it is inside at night.
- Researchers are learning how to preserve microbat populations by understanding their roosts. With research currently investigating microbats’ flora habits, it is known that larger trees are vital. Large trees can support multiple insects (which are part of a microbats’ diet) and large tree hollows provide reliable roosts. Unfortunately, urban areas typically remove trees when they are ‘in the way’ of construction, and merely planting a replacement tree would still render colonies with one less roost. According to Dr Threlfall, microbat boxes can potentially provide a level of permanent sanctuary in urban environments.
- Dr Threlfall’s research indicates that microbats like living in groupings and it is better to offer numerous bat nesting boxes at each location. Our bat installations at schools are implementing five per location, a number that Dr Threlfall explains is arbitrary but a good place to start. She also explains that microbats like to switch around. With studies into microbats and their colony’s choices still underway, recommendations will continue to develop.
- Studying microbats is particularly difficult, since they are nocturnal and small. Dr Threlfall herself explained that she started her PhD on microbats in 2008 after working in ecological consultancy and realising that we know very little about these species. Communal citizen science groups have helped study these animals by counting the number of microbats per colony. One of the best ways to help these species is to set up some microbat boxes in your neighbourhood. And of course, keep cats home at night! Even if a colony frequents your nesting box, they will be in that specific box less than 20 per cent of the time, as colonies could have over five different roosting locations.
Plantingseeds’ microbat nesting box project
PlantingSeeds’ latest nesting box project is due to a grant awarded from the 2021 Responsible Wood program. This program is a feature of Community Timber Partnerships which provided the timber and its transportation to Sydney to allow construction. The program brings together the Forestry Corporation NSW, Pentarch Forestry and Planet Ark’s Make it Wood Campaign.
Timber provided by the Responsible Wood project has created scores of possum and parrot nesting boxes, as well as microbat boxes based on two designs, and platforms for native stingless beehives. The research that supports the microbat box designs is based on the latest academic field research with the University of Sydney’s Dr Caragh Threlfall advising on structure, dimensions and optimum numbers for installation. Research indicates that microbats prefer ‘safety in numbers’ and will be more likely to roost in a nesting box if others are nearby. Consequently, PlantingSeeds is installing at least five microbat boxes in each of the schools that can support these important and threatened pollinators.
Additionally, the Responsible Wood project supports the creation of B&B hubs in a number of new locations. As a result of the grant, PlantingSeeds has completed the implementation of plantings, habitats and educational sessions at four Sydney schools near the Cumberland State Forest – at Asquith Public School, West Pennant Hills Public School, Castle Hill Public School and Muirfield High School. We are also intending to place nesting boxes produced by this project into schools in other B&B locations. 2023, for example, will see them installed in at least four schools in the Parramatta local government area.
Special thanks to Tim Liston from Forestry Corporation NSW and the Cumberland State Forest, the Waverley, Hornsby Berowra and Ku-ring-gai and Men’s Sheds, and Dr Caragh Threlfall from the University of Sydney who advised on the microbat box designs.