Rare rodent prefers invasive noxious weed over native vegetation, study finds.
A new study shows that a threatened rodent, the greater stick-nest rat, which only survives on offshore islands, prefers to eat one of Australia’s most invasive weeds, African boxthorn, instead of native vegetation. The research was published in Wildlife Research and found that African boxthorn makes up over half of the rat’s diet, despite making up only a small proportion of available vegetation.
The study’s lead author, Annie Kraehe, spent weeks analyzing the droppings of stick-nest rats to identify what they had been eating. She compared this with the availability of potential food plants in the area and found that African boxthorn was a top dining destination for the rats.
The researchers also observed that stick-nest rats are more present in areas with higher boxthorn abundance, using it for nesting and shelter. They noted that African boxthorn offers excellent cover from predators, making it a preferred location for the rats to nest.
While this finding may seem surprising, it highlights the importance of considering how native animals may adapt to changes in their ecosystems. The researchers stress that invasive weeds like African boxthorn are incredibly damaging to Australia’s biodiversity and can have devastating effects on native ecosystems.
The study also notes that there are cases where individual native animals benefit from invasive weeds around the globe, such as blackberry invasions helping the southern brown bandicoot survive in some areas.
However, the researchers caution against any perceptions that invasive weeds aren’t as bad as they seem. They emphasize that African boxthorn is by no means a good thing and can have destructive effects on ecosystems if it continues to spread.
Overall, the study suggests that further research is needed to understand how the greater stick-nest rat benefits from African boxthorn and how this compares to the destructive effects of the weed on the rest of the ecosystem.
Source: https://phys.org/news/2024-07-rare-rodent-invasive-noxious-weed.html