Inside Biodiversity

In this episode, podcast host Volker Hahn talks to Louise McRae about the new Living Planet Index (LPI) featured in WWF’s new Living Planet Report, published on 8 October 2026.

In this episode, host Volker Hahn speaks with macroecologist Shai Meiri about the state of reptiles worldwide. Which reptile groups are most threatened? Why do we know so little about lizards and snakes? And how do public perceptions influence research and conservation? The episode explores global reptile trends, the major threats they face, and why these often-overlooked animals deserve far more attention.

Thorny devil (Moloch horridus) – Australian desert lizard known for its spiny appearance and specialized ant diet: https://en.wikipedia.org/wiki/Thorny_devil

Leaf-tailed geckos – Masters of camouflage from Madagascar and Australia: https://en.wikipedia.org/wiki/Uroplatus
https://australian.museum/learn/animals/reptiles/southern-leaf-tailed-gecko/

Tropiocolotes yomtovi – Tiny gecko inhabiting the Sahara–Arabian Desert: https://reptile-database.reptarium.cz/species?genus=Tropiocolotes&species=yomtovi

Skinks: https://en.wikipedia.org/wiki/Skink

Caribbean iguanas: The Grand Cayman Blue Iguana is a rare conservation success story: https://www.iguanafoundation.org/what-we-support/rock-iguanas/grand-cayman-blue-iguana/?utm_source=chatgpt.com However, not all Caribbean iguanas are increasing: https://www.iucn-isg.org/

Marine turtles – Among the world's best-known and most intensively conserved reptiles: https://www.worldwildlife.org/species/sea-turtle

Is biodiversity always declining? Or is the story more complicated? In this special review episode, host Volker Hahn revisits highlights from previous episodes to explore biodiversity change and the biodiversity conservation paradox. Featuring insights from leading researchers, the episode explains why biodiversity trends depend on scale, the metrics we use, and the species we study. It revisits scientific debates, challenges common assumptions, and shows why understanding biodiversity change requires nuance rather than simple narratives.

Episode 1: Is Biodiversity Declining Everywhere? Guest: Maria Dornelas

Episode 4: Is Biodiversity Change Always Bad? Guest: Henrique Pereira

Episode 3: Is More Biodiversity Always Good? Guest: Jonathan Chase

Episode 2: How Much Are Humans Changing Biodiversity? Guest: Andrew Gonzalez

Episode 10: How Is Climate Change Changing Biodiversity? Guest: Miguel Bastos Araújo

Episode 13: How Are the Insects Doing? Guest: Roel van Klink

Episode 15: How Are the Mammals Doing? Guest: Carlo Rondinini

Episode 16: How Are the Plants Doing? Guests: Helge Bruelheide & Ute Jandt

Episode 11: Is the Planetary Boundaries Concept Useful for Communication? Guest: Katrin Böhning-Gaese

In this episode, plant ecologists Ute Jandt and Helge Bruelheide explain why a greener planet isn’t necessarily a more diverse one. They discuss global greening, the rise of generalist species, the homogenisation of ecosystems, and how rewilding, forestry, and agriculture can help conserve plant biodiversity in a changing world with podcast host Volker Hahn.

Plants mentioned in this episode:

Laurophyllous subtropical forest: https://en.wikipedia.org/wiki/Laurel_forest

Bryophytes: https://en.wikipedia.org/wiki/Bryophyte

Carpobrotus: https://lifegate.idiv.de/#genus-14-187.95-1542.99,zoom=auto

Limonium auriculifolium: https://www.botanicalrealm.com/plant-identification/limonium-auriculifolium/

Related links:

Ute Jandt at the Martin Luther University Halle-Wittenberg: https://www.botanik.uni-halle.de/geobotanik/ute_jandt/?lang=en

Helge Bruelheide at the Martin Luther University Halle-Wittenberg: https://www.botanik.uni-halle.de/geobotanik/helge_bruelheide/

Flora Incognita (app for identifying plant species): https://floraincognita.com/

In this episode, Volker Hahn talks to Carlo Rondinini, Professor of Zoology at Sapienza University of Rome, about wolves, beavers, otters, hedgehogs, jackals, and the global fate of mammals. They explore why some species are making remarkable comebacks in Europe, while one quarter of mammals worldwide are at risk of extinction. And although the threats are complex — from habitat loss and overexploitation to climate change — Rondinini says one solution matters more than almost anything else.

Related links:

Carlo Rondinini at the Gobal Mammal Assessment: https://globalmammal.org/staff/carlo-rondinini-2/

Wild mammals are making a comeback in Europe thanks to conservation efforts: https://ourworldindata.org/europe-mammal-comeback

Almost all of the world’s mammal biomass is humans and livestock: https://ourworldindata.org/wild-mammals-birds-biomass

Global trends and scenarios for terrestrial biodiversity and ecosystem services from 1900 to 2050: https://www.science.org/doi/10.1126/science.adn3441#tab-contributors

How many bird and mammal extinctions has recent conservation action prevented?: https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12762

Global protected areas seem insufficient to safeguard half of the world's mammals from human-induced extinction: https://www.pnas.org/doi/10.1073/pnas.2200118119

Why are insects declining — and what can social media teach us about biodiversity? Entomologist Dr Shawan Chowdhury talks with host Volker Hahn about his research on insect conservation and protected areas, the striking lack of data from tropical regions, and how Facebook, iNaturalist and other platforms can help fill these gaps. Shawan also shares how he uses social media not only as a scientific tool, but as a bridge between research and the public — and why communicating science across cultures matters as much as doing it.

Shawan Chowdhury’s lab website: https://shawanchowdhurylab.com/

“Protected areas and the future of insect conservation” (discussed in this episode):

“Three-quarters of insect species are insufficiently represented by protected areas” (discussed in this episode):

Shawan on Facebook:

Shawan on X:

Shawan on LinkedIn:

Shawan on Bluesky:

Are insect numbers really declining — and if so, why? In this episode, entomologist Roel van Klink explains what long-term data reveal about global and local insect trends and why the causes behind these changes remain surprisingly uncertain. We also discuss why it is difficult to distinguish between natural fluctuations and human-driven impacts, such as land-use change or climate change. We explore what scientists currently know, what they still don’t know, and why understanding these drivers is crucial for biodiversity conservation.

Dr. Roel van Klink is an entomologist at iDiv and the Martin Luther University Halle-Wittenberg. He is the lead author of one of the largest meta-studies on global insect trends.

Related links:

Roel van Klink at iDiv:

Roel van Klink on LinkedIn:

Roel van Klink’s major study on global insect trends, published in the journal Science in 2020 and discussed in this episode:

Study of insect declines in the Krefeld area, published in 2017 and mentioned in this episode. This study drew massive public attention to the issue of insect declines:

How can conservation succeed in a polarised society? This episode features Taylor Dotson, a Science and Technology Studies scholar and an associate professor at New Mexico Tech. Together with podcast host Volker Hahn, Dotson discusses his new book, “Conservation by the people – The Future of Biodiversity in a Divided World”. In it, Dotson describes “fanatical confrontations over nature”, and he explores ways of resolving environmental disputes productively and democratically. How can we better understand those who oppose conservation policies? How do we prevent biodiversity policy from becoming as polarising as climate change? How can incremental change through trial and error help us achieve what Dotson calls “biodiversity democracy”?

Related links:

Taylor Dotson at New Mexico Tech: https://www.nmt.edu/academics/class/faculty/tdotson.php

Taylor Dotson on Substack: https://tamingcomplexity.substack.com/

Taylor Dotson’s latest book “Conservation by the people – The Future of Biodiversity in a Divided World”: https://mitpress.mit.edu/9780262052092/conservation-by-the-people/

Taylor Dotson’s second book “The Divide – How Fanatical Certitude is Destroying Democracy”: https://www.taylorcdotson.com/the-divide.html

In this episode, Professor Katrin Böhning-Gaese, scientific director of the Helmholtz Centre for Environmental Research – UFZ, and podcast host Dr. Volker Hahn discuss the Planetary Boundaries framework, focusing not only on the science but also considering the value of this framework for communication. Other questions at the heart of this episode are: Where has communication on climate and biodiversity gone wrong? Is there a tendency to exaggerate risks and understate progress? What are the consequences of catastrophizing rhetoric for mental health and people’s readiness to act? What can biodiversity communication learn from climate communication, and vice versa? Most importantly, how can researchers and the media do better?

Related links:

Katrin Böhning-Gaese on the UFZ website: https://www.ufz.de/index.php?en=51666

The Planetary Boundaries Framework and its control variables discussed in this podcast (HANPP, industrial nitrogen fixation, among others): https://www.science.org/doi/10.1126/sciadv.adh2458

“Global Catastrophic Risks 2026”, “Ecological Collapse” section, cited in this episode: https://globalchallenges.org//app/uploads/2025/12/GCF-Risk-report-2026-Risk-2-.pdf

In this episode of Inside Biodiversity, Volker Hahn speaks with iDiv's sabbatical guest Miguel Bastos Araújo (Spanish Research Council at the National Museum of Natural Sciences, Madrid), one of the leading experts on species distributions and climate change. Araújo explains how species are shifting their ranges due to climate change, why some traditional protected areas are reaching their limits, and how conservation policy should adapt to a changing climate. The conversation explores how scientific evidence can inform policy and why effective conservation requires navigating multiple, often competing, rationalities. A thought-provoking episode on climate change, biodiversity, and the science-policy interface.

Related links:

Miguel Bastos Araújo’s website:

Towards a climate-resilient conservation network in Portugal. Araújo’s Biological Conservation paper mentioned in this episode: https://www.sciencedirect.com/science/article/pii/S0006320725002861

Conflicting rationalities limit the uptake of spatial conservation prioritizations. Araújo’s comment in Nature Reviews Biodiversity, mentioned in this episode: https://www.nature.com/articles/s44358-025-00042-z

Host: Dr. Volker Hahn, Head of iDiv’s Impact Department