Although it would be inaccurate to call them bandicutes, just look at that adorable little pointy nose and those darling little ears. But this site is not about the surface, it's about the service. So what do bandicoots do for humans? In particular what does the Southern Brown Bandicoot bring to the party?
Bandicoots are small marsupials found in a variety habitats in Australia. There are various types but the one discussed in detail here is specifically and scientifically known as Isoodon obesulus. The adult Southern Brown female is about 1kg in weight and about 40 cm long. The male is about 20% bigger all round. They have short tails and their fur is brownish on their backs, and creamy coloured across the underside. Their toes are adapted for digging. They have a life span of approx. 3 - 4 years. They communicate via a variety of vocal calls.
Southern brown bandicoots are nighttime feeders, and are omnivorous with a diet consisting of insects, spiders, worms, plant roots, ferns, and fungi. Bandicoots are eaten by some native predators such as barn owls, snakes, and quolls.
Their preferred habitat is scrub which provides them with suitable food and and safe spaces to avoid predators.
They lead solitary lives, each foraging for food in their own territories, and only come together for mating. As they are marsupials, the young are born in a very immature state after 12 days of gestation (weight at birth just 0.35g), so they reside in the mother's pouch until they are mature enough to move around by themselves at about 50 days. The pouch has eight teats but the maximum litter sizes tend to be about 5.
Mammals that move or manipulate soil for food or to create shelter are often called ecosystem engineers. Natural soil turnover services are carried out in Australia by several groups of small mammals - bettongs, potoroos, bilbies and bandicoots. Wombats are also diggers but, due to their greater physical size, they are not subjected to some of the threats that the others are.
In the course of foraging for food, bandicoots poke their noses into soil to sniff for favoured foods. This leaves small conical holes called snout pokes which are often the first visual sign of the presence of bandicoots in an area. If something tasty is detected, a forage pit is then dug to extract the food items from the soil. An individual southern brown bandicoot could create ~ 45 foraging pits per day, displacing ~ 10.74 kg of soil which scales up to ~3.9 tonnes per year. They also dig resting holes and line them with litter, leaves, and debris to sleep in during the day.
The moving around and transformation of soils by animals is now well recognised as a biotic influence on soil processes and functions, and is considered an important ecosystem service. A study of environmental characteristics of the bandicoot’s foraging pits found they typically contained a higher moisture content due to increased penetration of rainfall. Also the disturbed soil (often known as the spoil) was less hydrophobic than undisturbed soil. And the % of fine litter compared to coarse litter was higher in the disturbed soil.
Foraging pits are likely to provide a conducive microhabitat for litter decomposition, potentially reducing litter loads and enhancing the process of nutrient decomposition and recycling. Seedling recruitment for native plant species was also higher in areas with artificial diggings.1
Bandicoots also support the diversity and integrity of an ecosystem as they assist in the dispersal of plant seeds and spread soil fungi spores which encourage plant growth.
Losing bandicoots from ecosystems has cascading effects on plant diversity, species composition and structure of forests and woodlands.
Summary of services provided for us
- Soil enhancement
- Distribution of seeds and root fungi.
- Services for ecosystem stability
Threats to the services?
Although the IUCN listed the status of Southern Brown Bandicoots as of Least Concern in 2004, the species is listed as nationally endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
Despite once being described as common, digging mammal species have been lost from the Australian landscape over the last 200 years during white settlement. Around half of Australia digging mammal species are now extinct or under conservation threat, and the majority of remaining species have undergone marked loss of range.
Introduced predator animals have taken a heavy toll on bandicoot numbers. Indeed all the Australian diggers except the wombat (too big) and echidna (too well protected) have been diminished by the introduction of non-native animals that eat small mammals, primarily foxes, dogs and cats (both feral and domestic).
Habitat disruption patchwork and clearing
Habitats suitable for bandicoots especially the Southern Brown have been cleared for habitations and for crops. Not only does this reduce the range size, it also fragments what ever habitats are still available, primarily by building roads that represent dangerous barriers.
Changes in rainfall patterns due to climate change have interfered with breeding cycles in the Southern Brown Bandicoot.
What can we do to retain these services?
- Control dogs' and cats' activities in situations where they might encounter bandicoots.
- Fence areas of remnant vegetation to exclude dogs and livestock from predating and destroying bandicoot habitat respectively.
- Object to and preventing further land clearing.
- Restore and replant native vegetation, especially corridors linking habitat.
- Slow down on roads, especially in the evening, night-time, and early morning when bandicoots may be out and about
- Urge relevant Road Authorities to install fauna underpasses to allow safe passage under roads and reduce habitat fragmentation and isolation owing to roads separating populations.
- Protecting the Southern Brown Bandicoot
- Foraging activity by the southern brown bandicoot (Isoodon obesulus) as a mechanism for soil turnover
- Southern Brown Bandicoot Video
- Is the loss of Australian digging mammals contributing to a deterioration in ecosystem function?
- Ecosystem services of digging mammals