Can DNA traces in just two litres of water reveal how a river’s biodiversity changes over the course of a year? A study by the University of Duisburg-Essen using the River Lippe as an example shows how biodiversity in freshwater ecosystems can be monitored comprehensively, efficiently and at comparatively low cost. The results have now been published in the journal Ecological Indicators.

• White-tailed deer are less important than previously thought
• Mice matter more
• The acorn effect
• Mouse numbers don't predict the proportion of Lyme-infected ticks
• Extreme temperatures don't kill ticks in the wild

link to open access paper

https://www.cell.com/current-biology/fulltext/S0960-9822(26)00818-3

These predator-related changes in deer habitat use were associated with a 67% reduction in the probability of a deer-vehicle collision and a 76% reduction in the total expected number of collisions over a 5-year period where puma occupancy probability was high. Puma collar data corroborated these findings and further indicated a shift in deer-vehicle collision timing toward daylight hours where puma space use was high, corresponding to observed changes in deer diel activity. Thus, even where predator and prey populations are well established, pumas may substantially reduce collision risk by altering deer behavior, benefiting society through increased road safety.

Sadly, such excursions are no longer possible in many of Chernobyl’s habitats, which are now strewn with landmines placed by both Russian and Ukrainian forces. Vyshnevskiy tells me of a firefighter tackling a forest fire caused by a downed Russian drone who stepped on a mine. His remains were found 70 metres away. He knows of three wild horses killed the same way, but the size of the zone means most animal casualties will go unnoticed.

During my travels, minefields and military checkpoints became familiar. Areas that were once tourist attractions or public buildings are now highly classified sites. This militarisation has squeezed scientists out – at one point, there would have been hundreds here, but during my visit, we all fit around the same table while Vyshnevskiy cooks dinner.

In our new research published in the Journal of Applied Ecology, we amplified the natural sounds of the sea through underwater speakers. We were testing if sound cues would draw baby oysters to swim to the locations where we are trying to regrow oyster reefs. It worked better than we'd hoped. Many thousands more larvae swam to our locations than control areas and settled on the bare rocks.