Tag Archives: fragmentation

Shannon McCauley: The Rise of Community Ecology

"...there’s been huge growth in what we can do, but I think there’s been some loss in understanding the behavioural base of biology." (Image Credit: Shannon McCauley)

Community ecology is one of the more recent ecological disciplines, and has enjoyed a rise in popularity in the last decade. Yet it’s often been criticised as a little obscure, and has had difficulties integrating with other branches of ecology like evolution and population dynamics.

With this in mind, I sat down with Doctor Shannon McCauley of the University of Toronto during her recent visit to the University of Arkansas. Shannon is a community ecologist at the University of Toronto-Mississauga who uses dragonflies and other aquatic insects to answer questions about dispersal, community connectivity, and the effects of climate change. We attempted to put a little more context behind community ecology, and highlighted its relevance in the coming years.

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Populations Can’t Grow without Homes

Sea otters are one of many charismatic species found along the California coast, yet recovery doesn’t seem to be helping them. Is it something about their habitat that is preventing population growth? (Image Credit: “Mike” Michael L. Baird, CC BY 2.0)

Gaps in kelp cover may threaten the recovery of California sea otters  (2018) Nicholson et al., Ecography, DOI:10.1111/ecog.03561

The Crux

In the 18th and 19th centuries, the fur trade was a massive industry in North America. As a result, many species were hunted and trapped to near extinction. The California sea otter (Enhydra lutris) was reduced in population to less than 50 total individuals. The enactment of the Internation Fur Treaty allowed the species (and others) to come back from the brink of extinction, and they now number over 3200 individuals and are spread across 525km of the California coast. Interestingly, although the population is recovering, it has not bounced back as quickly as other protected mammals living in the same habitat. The California sea lion, for example, has a maximum population growth rate more than twice that of the sea otter (11.7% compared to 5%).

Despite the remarkable recovery of the species, the sea otters occupy less than a quarter of their historic range and have not expanded along the coast in 20 years. The authors of this paper wanted to investigate what it is about the sea otters and their habitat that is slowing this population’s growth rate and spread along the coast.

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Kath Handasyde: Charisma, Culling and Conservation

Koalas are gorgeous, no doubt. But does their overwhelming charisma mean that we forget about other species?

Koalas are gorgeous, no doubt. But does their overwhelming charisma mean that we forget about other species? (Image Credit: Erik Veland, CC BY-SA 3.0)

Australia plays host to a wonderful range of very endearing species. Tourists come from the world over to get up close with kangaroos or koalas. But the charisma of these animals can often lead to issues, whether it’s prioritisation of resources for them over other more endangered species, or even to the detriment of the species themselves.

Doctor Kath Handasyde of Melbourne University has been working with Australian field wildlife for almost 40 years, and is perhaps the most charismatic teacher I had during my Bachelor’s at the same institute. During my time in Melbourne, I had the chance to talk to Kath about the sometimes problematic role of charismatic species in Australian wildlife conservation.

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Marie-Agnès Coutellec: The Problem with Pesticides

Europe's freshwater ecosystems are increasingly exposed to pesticides, and the trend is only getting worse. So is there hope for our aquatic life?

When I’ve talked about anthropogenic effects, I’ve been guilty of focussing far too much on climate change and land use. But our dependence on toxicants like pesticides also has a profound impact on ecosystems, freshwater ecosystems in particular. On her recent visit to NTN in Trondheim, I spoke to ecotoxicologist Dr. Marie-Agnes Coutellec about her research group’s work with pesticides, and the likely future for much of Europe’s aquatic life.

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Between a Dam and a Hard Place

Dams like this change the flow regimes of rivers, and prevent some species from accessing their spawning grounds, lowering population viability. But is removing them completely danger-free? (

Dams like this change the flow regimes of rivers, and prevent some species from accessing their spawning grounds, lowering population viability. But is removing them completely danger-free? (Image Credit: pxhere, CC0)

Anybody who has ever studied freshwater ecosystems will end up having to study dams at some point. And they’ll no doubt learn that dams are the enemy. They fragment ecosystems. They cut fish off from their spawning grounds. They change flow regimes. So it makes sense that the recent trend of dam removal across Europe and the world in general would please ecologists. But there’s a problem with dam removal, and it comes in the form of invasive species.

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