How do fires in river habitats affect wildlife?

Monash University scientists described the findings of a 10 year study on the effect of fires (both high and low intensity) in river habitats, in a new Journal of Applied Ecology paper.

A male purple-crowned fairy-wren amongst his offspring in a riparian zone impacted by fires
A Western male purple-crowned fairy-wren and his three young offspring. The use of low-intensity fires reduces breeding success of birds. Credit: Niki Teunissen/AWC

New research from Monash University discovers that fires in riparian zones – the area between land and a river/stream – in Australia’s tropical savannas affect the breeding success and survival of endangered Western purple-crowned fairy-wrens, which live exclusively along rivers and creeks.

Large, destructive fires can be mitigated with the practice of prescribed burns. This involves deliberately creating fires during the early dry season, when they typically burn at a low intensity. Australian land managers often employ this strategy for conservation and carbon farming purposes. However, despite their importance, fire management approaches to best protect riparian zones in particular aren’t widely understood.

A purple-crowned fairy-wren in a riparian zone, prone to fires
A male Western purple-crowned fairy-wren singing to defend his territory along the creek. Credit: Niki Teunissen/AWC

In a new study of fires in riparian zones, researchers have found that the fairy-wren population was impacted by fire – regardless of intensity – for over 2.5 years, in two ways. With low intensity fires, reproductive success dropped during and immediately after the fire. However with high intensity fires, birds were found to die 2-8 months after the fire, but not during the fire itself.

Lead author Dr Niki Teunissen said “Our study highlights the need for future research to improve our understanding of the impact of riparian fire in savannas”. Riparian zones are home to lots of wildlife, including the Western purple-crowned fairy-wrens, but they are vulnerable to fire. They also serve as a passageway to roam the landscape and seek cooler climates.

From 2011 to 2021, the researchers studied the wren’s breeding, density, dispersal and breeding along 15km of creek and river. Using this data, they compared the effects of both low and high intensity fire in the dry season on riparian vegetation and wildlife.

A riparian habitat with fires consuming the plants around it
Riparian habitat is threatened by intensifying fire frequency and severity due to climate change. Credit: Brett Murphy

“Our findings can be used to improve fire management strategies in tropical savannas,” continued Dr Teunissen. “As Western purple-crowned wrens represent a biological indicator for riparian health, we urge fire managers and scientists alike to give greater consideration to the effects of fire on riparian habitat.”

Article based off a Monash University press release.

Read more:

Teunissen, N.McAlpine, H.Cameron, S. F.Murphy, B. P., & Peters, A. (2023). Low- and high-intensity fire in the riparian savanna: Demographic impacts in an avian model species and implications for ecological fire managementJournal of Applied Ecology001– 10