Vast lands & variable data:systematic analyses to understand the patterns and processes of mammal decline

Small-mammal declines in northern Australia

Alex Kutt, CSIROChris Johnson, JCU/UTasDiana Fisher, UQMichael Lawes, CDUSusanne Fritz, BiK-F GermanyHamish McCallum, UQJeremy VanDerWal, JCU

Colette Thomas, CSIROAlaric Fisher, NT DLRMIain Gordon, CSIROBrett Abbott, CSIROAnke Frank, JCU/UTasSarah Legge, AWCMichael Letnic, UNSW

Small mammals in Kakadu NP, Woinarski et al. (2011) Cons Lett

Problems in diagnosing cause

Lots of contenders: fire, grazing, cats, climate/weather, disease, toads…Patchy survey, observational & historical data, spread unevenly over a vast areaAlmost no in-depth study of declining populationsDeclines happening fast

Our aims:

Collate and analyse existing data & evidence

Evaluate hypotheses/formulate new hypotheses

Guide new policies for land management

Some results and impacts

1. Review of hypothesis set, through a formal deliberative process

Interaction of factors crucial:predation by feral cats, interacting with fire and grazing

2. Comparative analysis of traits associated with mammal decline, north and south [size, life history, ecology, climate etc]

Small body size and open habitat predict declineSimilar to past declines in the southBut smaller species affected in the north

The main results:

3. Improved distribution/abundance database for Australian mammals

Data from fauna surveys, added to museum (etc) data; > 600,000 records

Better models of distribution & change due to climate/weather – work continuingsee mammal distribution visualisation portal

Thanks ACEAS

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