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Biological diversity

Protect, repair and manage the environment

Release date and time

15/09/2025 11:30am AEST

Released 15/09/2025

Metric

Proportion of decline in Australia’s threatened and near threatened species from the Threatened Species Index

Why this matters

Biodiversity — the variety and variability of living things including animals, plants, fungi and microorganisms like bacteria — is central to the health of natural ecosystems. A loss of biodiversity threatens the capacity of our environment to sustain and provide clean air, water, medicines and is contributing to the emergence and transmission of disease.

Progress

The Australian Threatened Species Index 2024 shows that in the period from 1985 to 2021:

the relative abundance of observed threatened and near-threatened species declined by 73%
amphibian species declined in abundance by 97%
plant species declined in abundance by 68%
bird species declined in abundance by 59%
mammal species declined in abundance by 45%.

The most recent year-on-year change in the relative abundance of observed threatened and near-threatened species shows a slight overall increase. Between 2020 and 2021:

the relative abundance of observed threatened and near-threatened species increased by 2.6%
amphibian species increased in abundance by 7.9%
plant species increased in abundance by 8.5%
bird species increased in abundance by 1.2%
mammal species declined in abundance by 2.4%.

Indexes of relative abundance of Australia's threatened and near-threatened species (a)
	Amphibians	Birds	Mammals	Plants	All
1985	1.00	1.00	1.00	1.00	1.00
1986	0.91	0.98	1.28	0.96	1.04
1987	0.68	1.02	1.41	0.91	1.02
1988	0.55	1.04	1.30	0.87	0.95
1989	0.46	1.05	1.20	0.84	0.90
1990	0.39	1.01	1.24	0.82	0.87
1991	0.21	1.00	1.19	0.83	0.76
1992	0.20	0.99	1.16	0.87	0.76
1993	0.19	0.95	1.15	0.89	0.74
1994	0.13	0.94	1.13	0.94	0.71
1995	0.12	0.94	1.09	0.99	0.72
1996	0.10	0.91	0.96	0.93	0.65
1997	0.09	0.90	1.06	0.95	0.66
1998	0.07	0.90	1.11	0.99	0.67
1999	0.08	0.87	1.09	0.95	0.65
2000	0.08	0.83	0.99	0.97	0.63
2001	0.06	0.80	0.86	0.87	0.57
2002	0.05	0.73	0.82	0.81	0.52
2003	0.05	0.70	0.72	0.83	0.50
2004	0.05	0.67	0.68	0.78	0.47
2005	0.05	0.68	0.64	0.76	0.46
2006	0.04	0.62	0.66	0.67	0.43
2007	0.04	0.61	0.70	0.63	0.42
2008	0.04	0.60	0.64	0.59	0.40
2009	0.05	0.59	0.62	0.56	0.40
2010	0.05	0.57	0.64	0.54	0.39
2011	0.05	0.56	0.63	0.49	0.37
2012	0.04	0.53	0.64	0.45	0.35
2013	0.04	0.50	0.63	0.44	0.34
2014	0.03	0.46	0.59	0.40	0.31
2015	0.03	0.45	0.62	0.38	0.31
2016	0.03	0.46	0.61	0.34	0.30
2017	0.03	0.43	0.62	0.29	0.27
2018	0.03	0.43	0.60	0.30	0.27
2019	0.02	0.40	0.59	0.30	0.26
2020	0.03	0.40	0.56	0.30	0.26
2021	0.03	0.41	0.55	0.32	0.27

Indexes of relative abundance of Australia's threatened and near-threatened species (a)

["","Amphibians","Birds","Mammals","Plants","All"]

[["1985","1986","1987","1988","1989","1990","1991","1992","1993","1994","1995","1996","1997","1998","1999","2000","2001","2002","2003","2004","2005","2006","2007","2008","2009","2010","2011","2012","2013","2014","2015","2016","2017","2018","2019","2020","2021"],[[1],[0.911834],[0.675204],[0.549347],[0.456297],[0.387564],[0.209845],[0.201774],[0.186934],[0.133834],[0.1241],[0.09829],[0.088155],[0.069731],[0.077343],[0.077838],[0.062982],[0.050547],[0.047586],[0.046453],[0.049066],[0.043784],[0.041397],[0.040943],[0.049041],[0.04866],[0.046777],[0.042974],[0.03894],[0.029579],[0.032481],[0.030944],[0.028097],[0.026432],[0.023529],[0.025726],[0.027762]],[[1],[0.979144],[1.023332],[1.035345],[1.049905],[1.014288],[0.997014],[0.987048],[0.948673],[0.939679],[0.93794],[0.910608],[0.895777],[0.903508],[0.868366],[0.830848],[0.798234],[0.730444],[0.700502],[0.674982],[0.679517],[0.621427],[0.607333],[0.601172],[0.593748],[0.572969],[0.555478],[0.532688],[0.495244],[0.459948],[0.454529],[0.461331],[0.432105],[0.42711],[0.399496],[0.404726],[0.409731]],[[1],[1.278951],[1.408903],[1.299895],[1.197158],[1.238621],[1.186109],[1.162612],[1.148972],[1.125746],[1.093574],[0.96224],[1.057625],[1.112594],[1.09063],[0.986321],[0.857916],[0.818137],[0.716843],[0.682398],[0.644503],[0.664836],[0.70327],[0.64007],[0.618224],[0.63974],[0.627854],[0.644679],[0.630271],[0.594822],[0.622622],[0.610143],[0.618024],[0.604894],[0.591948],[0.560503],[0.547251]],[[1],[0.962272],[0.914152],[0.871917],[0.844838],[0.8186],[0.827376],[0.868107],[0.894095],[0.939169],[0.992812],[0.926605],[0.950333],[0.987566],[0.953491],[0.9746],[0.872059],[0.812078],[0.83115],[0.779277],[0.756617],[0.674331],[0.627892],[0.591116],[0.563806],[0.538173],[0.489013],[0.449888],[0.441709],[0.396678],[0.378108],[0.343918],[0.293564],[0.295649],[0.29708],[0.298176],[0.323409]],[[1],[1.043858],[1.018199],[0.954839],[0.901902],[0.868228],[0.758789],[0.755812],[0.742677],[0.713221],[0.715514],[0.651969],[0.66411],[0.665195],[0.650888],[0.628461],[0.567616],[0.521857],[0.49806],[0.474392],[0.464845],[0.43329],[0.422943],[0.402218],[0.395234],[0.387006],[0.367119],[0.352506],[0.338818],[0.308205],[0.307431],[0.29525],[0.272747],[0.269982],[0.261072],[0.261022],[0.267816]]]

[]

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The index does not include all threatened species, and is continually being expanded to increase the species included.

Data Source

The Australian Threatened Species Index 2024