Kangaroos as ecosystem engineers
Kangaroos are ecosystem engineers, meaning that that contribute to the health of landscapes. They consume plant biomass contributing to regeneration, reduce vegetation that are important for bushfire hazard reduction, spread the seeds of native grasses when foraging and fertilise nutrient deficient soils.
Kangaroos play a central role in the health and persistence of grassland ecosystems across Australia. Kangaroo fur traps spores and seeds which can then be distributed throughout the landscapes they move around, leaving them in ready-made holes created by their large toes. Their toes also aerate compacted and depleted soils. In this way, they play an important role in maintaining levels of vegetation diversity (Dawson 2012).
Kangaroos drive ecosystem processes through soil turnover and catchment of litter in their diggings (hip-holes),cycle nutrients, disperse seeds and maintain open pastures with greater diversity and less fuel for fires (Eldridge & Rath 2002).
Kangaroos contribute to ecosystem health. A long term study in Mulga dry forests in Queensland that had been chronically degraded by livestock grazing found that where kangaroos were present had the highest species richness and that the presence of kangaroos had led to an increased range and abundance of native plants including perennial grasses as well as regeneration of Mulga forest (Fensham 2011). Similarly, a CSIRO study in2014 which examined kangaroo impacts on the ACT's urban reserves, areas where kangaroos were present were found to have healthier ground level vegetation with higher levels of vegetation (Vivian, Godfree 2014).
These findings and the importance of the role of kangaroos in ecosystem health and species richness was also acknowledged in a conservation research technical report published by the ACT government (Snape, Caley et al2018) which described the key role of the kangaroo as follows:
“As the overwhelmingly dominant herbivore in lowland grassy ecosystems, kangaroos occupy a central place in the ecology of such ecosystems (Fletcher, 2006) due to a strong preference for feeding on grass and other monocotyledonous species (Billing, 2007; Davis et al., 2008; Jarman and Phillips, 1989).
In some situations they are ‘ecosystem engineers’ as defined by Jones et al.(1997) and Wilby et al. (2001) due to their ability to modify both their own habitat and that of other species.”