Study reveals impact of centuries of human activity in American tropics

Published by  Communications

On 15th Sep 2020

Subtropical Atlantic Forest, Southern Brazil
Image credit: Juliano A. Bogoni, 2016

The devastating effects of human activity on wildlife in the American tropics over the last 500 years are revealed in a new study published today.

More than half of the species in local ‘assemblages’ – sets of co-existing species – of medium and large mammals living in the Neotropics of Meso and South America have died out since the region was first colonised by Europeans in the 1500s.

Researchers at the University of East Anglia (UEA), in the UK, and University of São Paulo (USP), Brazil, found that human activity such as habitat change and overhunting is largely responsible for the overwhelming loss, or ‘defaunation’, in mammal diversity across Latin America.

The study, published in the journal Scientific Reports, compared all animal inventories at over 1000 Neotropical study sites published over the past 30 years with baseline data going back to the Colonial era.

The findings draw on a compilation of 1,029 separate mammal assemblages - typically a few kilometres apart from each other - spanning approximately 10,700 km and 85° of latitude across 23 countries, from Mexico to Argentina and Chile.

They reveal that the dominant cause of local species extinction and assemblage downsizing - the reduction in body size within each assemblage - is a direct result of habitat changes such as farming, logging and fires, and aggravated by the chronic process of overhunting.

Dr Juliano André Bogoni, a postdoctoral researcher sponsored by the São Paulo Research Foundation and working at UEA’s School of Environmental Sciences, led the study with Prof Carlos Peres, also of UEA, and Prof Katia Ferraz from USP.

Dr Bogoni said: “Our findings can be used to inform international conservation policies to prevent further erosion of, or restore, native biodiversity. Further conservation efforts should be mobilized to prevent the most faunally-intact biomes, such as Amazonia and the Pantanal wetlands, from following in the footsteps of ‘empty ecosystems’ that are now typical of historically degraded areas such as the Brazilian Atlantic Forest and the Caatinga.

“This includes effective implementation and law enforcement in existing protected areas, and curbing political pressures to either downgrade or downsize these areas. Greater investment should be allocated to more effective control of illegal hunting, particularly commercial hunting, deforestation, and anthropogenic fires, as well as ensure that fully implemented protected areas are working.”

Prof Peres said: “Sound resource management should be sensitive to the socioeconomic context, while recruiting rather than antagonizing potential local alliances who can effectively fill the institutional void in low-governance regions.

“Hominins and other mammals have co-existed since the earliest Paleolithic hunters wielding stone tools some three million years ago. Over this long timescale biodiversity losses have only recently accelerated to breakneck speeds since the industrial revolution.

“Let us make sure that this relentless wave of local extinctions is rapidly decelerated, or else the prospects for Neotropical mammals and other vertebrates will look increasingly bleak.”

The team looked at 165 species and analysed local losses in more than 1000 sets of medium to large-bodied mammal species that had been surveyed across the Neotropics.

On average more than 56 per cent of the local wildlife within mammal assemblages across the Neotropics were wiped out, with ungulates lowland tapir and white-lipped peccary comprising the most losses. The extent of defaunation was widespread, but increasingly affecting relatively intact major biomes that are rapidly succumbing to encroaching deforestation frontiers.

Over time the assemblage-wide mammal body mass distribution greatly reduced from a historical 95th-percentile of approximately 14 kg to only about 4 kg in modern assemblages.

Extent, intensity and drivers of mammal defaunation: a continental-scale analysis across the Neotropics’, Juliano A Bogoni, Carlos A Peres and Katia M P M B Ferraz, is published in Scientific Reports on September 15.

Latest News

  News
25 Feb 2021

Huge gaps in UK regulation exist following transition from EU, new academic report finds 

The UK is still not in a position to assume responsibility for regulation in several critical policy areas including trade, crime and the environment, according...

Read more >
  News
Picture of Dr Sally Howes OBE
24 Feb 2021

Space expert appointed as new UEA Chair

Dr Sally Howes OBE has been appointed as Chair of the University of East Anglia (UEA) Council, bringing with her a wealth of experience in strategic roles in the...

Read more >
  News
24 Feb 2021

How rehabilitation could help people with Covid-19 recover

Progressive exercise and early mobilisation are among the elements of rehabilitation programmes that may improve recovery for people who are hospitalised with...

Read more >
  News
18 Feb 2021

The UEA researchers Making Peace with Nature

Researchers at the University of East Anglia have been part of a UN project to urgently solve planetary emergencies and secure humanity’s future.

Read more >
Are you searching for something?
  News
18 Feb 2021

The UEA researchers Making Peace with Nature

Researchers at the University of East Anglia have been part of a UN project to urgently solve planetary emergencies and secure humanity’s future.

Read more >
  News
17 Feb 2021

Mental health disorders and alcohol misuse more common in LGB people

Lesbian, gay and bisexual (LGB) people are significantly more likely to have mental health conditions and report alcohol and drug misuse than heterosexual people...

Read more >
  News
Caring hands
16 Feb 2021

A Centenary of Caring digital exhibition to explore the impact of the pandemic on mental health

The impact of the COVID-19 pandemic on public mental health and on health and social care staff working in the community is explored in a new digital exhibition...

Read more >
  News
the elixir logo
16 Feb 2021

UEA to share life sciences resources as part of ELIXIR-UK

UEA is now part of a UK-wide infrastructure of life sciences resources, which will make it easier for scientists to find and share data in the area, exchange...

Read more >
  News
Photos of Professor Paul Hunter and Dr Kirstin Smith
15 Feb 2021

Arm in Arm: UEA academics launch global vaccine campaign

Academics from the University of East Anglia (UEA) have launched a campaign encouraging those receiving a COVID-19 vaccine to support the global response to the...

Read more >