A reintroduced ecosystem engineer species may exacerbate ongoing biological invasion: selective foraging of the Eurasian beaver in floodplains (2020) Juhasz et al., Global Ecology and Conservation, https://doi.org/10.1016/j.gecco.2020.e01383
The reintroduction of species to an area from which they have been wiped out can have benefits which extend beyond that one species. Often they can restore ecological functions that have since been lost, which can result in everything from an increase in biodiversity to restructuring of an entire landscape.
That last example might seem a bit far-fetched, but beavers (Castor fiber) are capable of just that. Their damming activities can change river flows and restore healthy floodplains, and as such beavers are the target of a large reintroduction campaign now occurring throughout much of Europe.
But what happens when a species like the beaver is reintroduced to an ecosystem that has seen significant changes since it has been gone, like the introduction of invasive species? Today’s authors wanted to find out whether or not the presence of the beaver benefited native plants, or whether it made things easier for the invasive species.
Tasmanian Devil at the Zoo Duisburg, in 2017. The only zoo in Germany that keeps them. (Credit: Mathias Appel / CC0)
With the seemingly endless stream of bad news relating to the environment we’re often faced with these days, hearing ecosystem restoration or conservation success stories are always a welcome relief. With the number of species that have been displaced from their native habitats, the news of an endangered species being successfully introduced to a new area should be shouted out. So you cannot blame a conservation geneticist like me for jumping happily when I heard news of the release of the European bison and Tasmanian devil back to their native habitat.
Image Credit: Mike Baird, CC BY 2.0; Chuck Szmurlo, CC BY 3.0; Ryan Hagerty, USFWS, Public Domain)
Nowadays we know to avoid mating with close relatives so that your children are healthy. As close relatives accumulate similar genetic diversity, mating between relatives of most species can lead to genetic diseases in their offspring. Humans have a lot of options; there are 7 billion of us worldwide. But how about an endangered species with less than 10 individuals in the wild?
The Burmese python, which has spread throughout the Everglades in Florida as a result of accidental or intentional releases by pet owners (Image Credit: US NInvaders, Aliens, and tational Park Service, Public Domain Mark 1.0, Image Cropped)
Language is important. It’s a lesson many biological scientists would have learned a long time ago if we hadn’t kept social sciences at such a wary arm’s length. Ecologists have a tendency to label and relabel ecological concepts (anyone up for a debate about the word ‘niche’?), species and even global phenomena (think global warming vs. climate change) based on anything from shifts in public perception to new findings that challenge our earlier labels.
Image Credit: USFWS Endangered Species, CC BY 2.0, Image Cropped
Rewilding is a tricky business. Bringing back species that once roamed a country as their native land may seem like a worthy cause, but it is often fraught with conflict. People don’t want predators threatening their safety, or herbivores destroying their crops. Rural vs. urban tensions come into play. Local and federal politics get thrown into the mix.
With that in mind, I sat down with Associate Professor Fredrik Widemo, currently a Senior lecturer with the Swedish University of Agricultural Sciences. Fredrik has previously worked at both the Swedish Association for Hunting and Wildlife Management (where he was the Director of Science) and the Swedish Biodiversity Centre. We explored some of the complexities behind the rewilding of wolves and its effects on the hunting and forestry industries in Sweden.
African forest elephants populations are declining rapidly due to local human pressures. But is it fair to expect other humans to live among potential threats to their livelihood? (Image Credit: US Fish and Wildlife Service Headquarters, Public Domain Mark 1.0, Image Cropped)
Some species of animal do a better job of capturing our attention than others. For many of us, the exotic nature of these animals is often the kicker. Think of the majesty of an elephant strolling across the savannah, or the romanticised stalk of the tiger through the jungle. Yet while the public ogles these creatures in the wild or at the local zoo and mourns the decline of their wild populations or the reported deaths of iconic individuals, we often ignore the harsh reality: that there are people who live in close proximity to these animals, to whom they represent a day-to-day threat. So how does our attitudes to charismatic species in places like Africa and Asia here need to shift, and where can we start?
Rasmus Hansson, former leader of the Norwegian Green Party and the Norwegian WWF (Image Credit: Miljøpartiet de Grønne, CC BY-SA 2.0, Image Cropped)
Environmental politics is a tricky business. We live in a world where environmental crises are at the forefront of the news cycle, and in which science is simultaneously becoming the subject of distrust. So it makes sense that at this point, politics should be adapting and evolving as science does.
So when Rasmus Hansson stopped by NTNU last month, Sam Perrin and I took the chance to sit down with him and see whether this was the case. Rasmus studied polar bears at NTNU in the 70s, before later becoming the leader of the World Wildlife Fund in Norway and then of the Norwegian Green party. We spoke with Rasmus about the transition from conservation to politics, the clash of ideologies and the future of environmental politics.
When species like this toucanet are lost, the interactions that they are a part of are lost too. So how can we restore them? (Image Credit: Jairmoreirafotografia, CC BY-SA 4.0, Image Cropped)
Estimating interaction credit for trophic rewilding in tropical forests (2018) Marjakangas, E.-L. et al., Philosophical Transactions of the Royal Society of Biology, 373, https://dx.doi/10.1098/rstb.2017.0435
We have reviewed more than enough papers on biodiversity loss to entitle us to skip the whole “losing species is bad” spiel (see here, here and here). But what we haven’t talked about is that when some species are lost, specific interactions that those species participate in disappear from an ecosystem. Those interactions range from the minute to the crucial. One such crucial example is that of seed dispersal, whereby specific plants rely on specific animals to disperse their seeds, thus maximising biodiversity in other parts of the forest and creating a positive feedback loop.
Naturally, conservationists will want to reintroduce animals to propagate some of these reactions. But as is always the case in conservation, maximising return is absolutely essential when you’re faced with limited resources and a lot of ground to cover. Today’s authors wanted to develop a system for maximising the effect of species reintroduction.