Researchers find that traded species have distinctive life histories with extended reproductive lifecycles

A new study by researchers from Durham University, UK, Queen’s University Belfast, UK, University of Extremadura, Spain and Swansea University, UK have revealed that vertebrate species involved in the live wildlife trade have distinctive life history traits, biological characteristics that determine the frequency and timing of reproduction.

Researchers discovered that traded species produce large numbers of offspring across long reproductive lifespans, an unusual profile that is likely financially advantageous for trades involving captive breeding such as the pet, food and fur/skin trades.

Traded species that have also been introduced into non-native areas have a more extreme version of this same life history profile, suggesting that species most likely to become problematic invaders are at a heightened risk of trade and release.

The study suggests that humans favour species with high reproductive output for trade and release, which are the very species likely to become problematic invaders in future.

Researchers point out that life history traits are therefore potentially useful for predicting future invasions.

Full study results have been published in the journal Nature Communications.

Reflecting on the study results, first author Dr Sally Street of Durham University, said: “Invasive species can cause huge environmental problems but are challenging to manage once established. This means it is really important to try to identify characteristics that increase the risk of species passing through the earliest stages of the invasion pathway, transportation and introduction, which have been relatively understudied.

“We show that not only are life history traits useful for identifying species at risk of trade, introduction and ultimately invasion, human activities unfortunately seem to favour trade in species that are most likely to succeed if released. We hope our study will contribute to the management and mitigation of future invasions and the damage they can cause to biodiversity.”

Co-author of the study, Dr Isabella Capellini of Queen’s University Belfast, said: “The rate of traded species is rapidly increasing worldwide; some of these species are accidentally or deliberately introduced and may become problematic invaders damaging native ecosystems. Given the high costs of managing alien invasive species, preventing the release of potentially invasive species may help protect native biodiversity.

“To help achieve this, in our study we have also identified some vertebrate species at risk of becoming future invaders should they be traded and recommend such species to be monitored and banned from trade.”

The researchers studied trade data from the United States Fish and Wildlife Service (USFWS), Law Enforcement Management Information System (LEMIS) and the International Union for Conservation of Nature (IUCN).

They analysed the role of life history traits in the probability that mammals, reptiles and amphibians are involved in the wildlife trade and that these species have been released outside of their native ranges.

Invasive species can cause huge environmental problems and monetary costs. Once established, invasive populations can be difficult or impossible to manage.

Therefore, understanding the early stages of invasion and predicting future invasions is crucial to minimising this harm.

The researchers call for increased regulation of the live wildlife trade that is likely crucial for preventing future invasions.





“Human activities favour prolific life histories in both traded and introduced vertebrates”, (2023), S. Street, J. Gutierrez, W. Allen and I. Capellini, Nature Communications.

Full paper is available online:


Associated images are available via the following link:

Useful Web Links 

Dr Sally Street staff profile:

Dr Isabella Capellini staff profile:

Department of Anthropology:

Durham Cultural Evolution Research Centre:

About Queen’s University Belfast

Queen’s University Belfast is one of the top 200 universities in the world. A member of the Russell Group UK’s 24 leading research-intensive universities, Queen’s is an international centre of research and education, with a student-centred ethos.

Queen’s is ranked 17th in the world for international outlook (Times Higher Education World University Rankings 2022), 1st in the UK for entrepreneurial impact (Octopus Ventures, 2020) and 24th in the UK for Research Power (REF 2021/ Times Higher Education). Our research shapes worlds and continues to make a difference to lives and livelihoods, with 88% assessed at world leading or internationally excellent.

The university is a lead partner in the Belfast Region City Deal which will unlock £1 billion of transformative co-investment, bringing forward projects in advanced manufacturing, clinical research and secure, connected digital technologies.

About Durham University

Durham University is a globally outstanding centre of teaching and research based in historic Durham City in the UK.

We are a collegiate university committed to inspiring our people to do outstanding things at Durham and in the world.

We conduct boundary-breaking research that improves lives globally and we are ranked as a world top 100 university with an international reputation in research and education (QS World University Rankings 2023).

We are a member of the Russell Group of leading research-intensive UK universities and we are consistently ranked as a top 10 university in national league tables (Times and Sunday Times Good University Guide, Guardian University Guide and The Complete University Guide).

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