Koalas prosper despite, or because of, the latest bushfires

Back in May, NSW's Natural Resources Commission and Department of Primary Industries as well as three universities quietly published a report about forest monitoring. It states that north coast koala populations have been stable for the last five years, despite 30% of koala habitat being burnt by the disastrous Black Summer megafires.

Readers may have noticed some advertising by registered charities involved in the multimillion-dollar multinational Koala Industry, which seems to have convinced most Australians that the fires pushed koalas to the brink of extinction. They've probably also heard of NSW's $200 million plan to 'save' koalas. Some readers would also have seen a webinar, where the Chair of the Threatened Species Scientific Committee explained how expert advice after the fires led to an Endangered listing for NSW and QLD koalas.

NSW bureaucrats obviously know that the koala population wasn't adversely affected by Black Summer. So, one wonders why they're not shouting the good news from the rooftops. I only found out about this report from an NRC notification of a forest monitoring 'forum' to be held next month. The notice contains a link to the report on forest monitoring. But the information about koala monitoring isn't highlighted, it's just a "For example:". Here's the relevant extract:

Koala detectability in the 1990s was low using the listening, call playback and spotlighting methods available at the time. This resulted in an imprecise median occupancy estimate (27% ± 17%) across all public forest lands. An analysis of recent trends in Koala occupancy in north-eastern NSW, where surveys [recorded] Koala calls, provided greater precision and higher estimates of occupancy (averaging 68% ± 7%). This recent trend shows a stable meta-population over the last 5 years, including after fires burnt 30% of Koala habitat in 2019.

This 'information' is not quite right and doesn't tell the full story. In view of well-publicized campaigns for a Great Koala National Park to 'save' the iconic species from logging, you'd think that the bureaucrats and academics would clearly set out the facts. I've done this in previous articles for ARRN. Most importantly, koalas feed on soft young shoots and irrupt when new growth is plentiful.

At Coffs Harbour in the 1960s, koalas had been increasing in dense young regrowth forests created by intensive post-war logging using chainsaws and bulldozers. Then they invaded former grazing paddocks acquired for residential development. A similar process occurred in southeast Queensland from the 1980s when the Moreton Bay District became the Koala Coast. Now it is happening in new residential areas such as Waterview Heights near Grafton.

By 1991, koalas had increased dramatically in regrowth forests and plantations around Coffs Harbour. There were three times as many koalas in heavily logged forests (22% detection rate) compared to unlogged oldgrowth forests (6%). The regional detection rate in listening/spotlighting surveys was 16%.

In 1995 regrowth forests and plantations near Coffs Harbour were reserved as Bongil Bongil National Park to 'protect' koalas. By that time, koalas were irrupting in both young and old forests suffering decline and constantly turning over soft young shoots as a result of reduced maintenance by mild burning. They were detected at 46% of survey sites in the Upper Clarence and Richmond Valleys. They had become the most common arboreal mammal in the Urbenville District.

From 2015, DPI found that there are a lot more koalas on the north coast than previously thought. They are common right through the forests, irrespective of tenure or logging history: "Neither occupancy nor bellow rate are influenced by timber harvesting intensity, time since harvesting or local landscape extent of harvesting or old growth".

After Black Summer, DPI reported that koalas were lost where high fire severity dominated, but they were returning within a year. Where moderate severity fire dominated, koala density was reduced by about 50% in the first year. In areas dominated by low severity fire, there was no impact on koala numbers. Ten percent of the landscape was burnt by very severe fire and six percent by moderately severe fire, so there was about 13% loss of koalas in the fires.

Given that koalas on the north coast increased by about 29% in two years before the fires (~75% occupancy in 2017 to 97% in 2019), the logical conclusion is that there was a net increase of more than 15% in koalas despite the fires. DPI presented these data, which, considered together, allow us to assess changes in koala densities as a result of the fires, in three separate scientific papers. I believe that public interest would be better served by transparency. Koalas are now increasing faster than ever, because of increased recruitment of young in all the soft young growth from the fires.

At the other end of the State near Eden, National Parks and Wildlife Service says that koalas are extinct except for a handful in a 'climate refuge' which they've 'protected' from logging in apparent contravention of the Regional Forest Agreement with the Commonwealth. But a DPI survey in 2017 detected them there at even higher rates than on the north coast. Nevertheless, DPI agreed with NPWS that it's a "low density population".