Tag Archives: species

Does Invading Change You?

The red lionfish, an aggressive, fecund, and competitive species invasive to the Atlantic Ocean (Image Credit: Alexander Vasenin, CC BY-SA 3.0).

The genomics of invasion: characterization of red lionfish (Pterois volitans) populations from the native and introduced ranges (2019) Burford Reiskind et al., Biological Invasions, https://doi.org/10.1007/s10530-019-01992-0(0123456789

The Crux

Invasive species are one of the most destructive forces and largest threats to native ecosystems, second only to habitat loss. The “how” and “when” of a species invading new habitats is obviously important, and as such many studies focus on if invasive species are present and if they are spreading. Yet these studies often disregard the mechanisms behind why a species is spreading or succeeding in these new environments. The mechanisms are important here, because by and large most invasive organisms will have very small populations sizes, leaving them vulnerable to stochastic events like environmental flux, disease, and inbreeding depression.

Two key paradoxes of invasive species are that these small groups of invasive organisms tend to not only have more genetic diversity than the native species (making them more adaptable to environmental change), but they are also able to outcompete the native organisms, despite having evolved in and adapted to what may be a completely different environment. The authors of this study used genomic approaches to address and try to understand these paradoxes.  Read more

Re-Analysing Forest Biodiversity

The Gribskov Forest in Denmarkj, where this study took place (Image Credit: Malene Thyssen, CC BY-SA 3.0)

Biodiversity response to forest structure and management: Comparing species richness, conservation relevant species and functional diversity as metrics in forest conservation (2019) Lelli et al., Forest Ecology and Management, https://doi.org/10.1016/j.foreco.2018.09.057

The Crux

The classification of biodiversity is something that has become more and more relevant as the term ‘biodiversity’ has worked its way into the public’s vernacular. How we measure biodiversity can vastly influence our perception of it, and whilst we’ve previously looked at spatial interpretations of biodiversity on EcoMass, today I’m examining a paper that looks at interpretations of biodiversity by species groups.

Species richness (how many species are present in a given place) is often the go-to measurement for biodiversity. But it doesn’t always help when trying to conserve an ecosystem. For instance, we may wish to focus on certain types of species which are rare, or that preserve certain ecosystem functions. This paper looks at the differences in the effect of management on biodiversity, depending on which approach to biodiversity you take.

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Ecology in Media: Thoughts, Questions and the Insect Apocalypse

Recent reports of collapses in insect populations were eagerly devoured online. But were the reports exaggerations, and if so, how did they make it into the headlines? (Image Credit: Barta IV, CC BY 2.0)

Two weeks ago, an article on the Insect Apocalypse hit my Facebook feed. It popped up everywhere. People seemed genuinely concerned about the plight of the world’s insects, which was a first for me.

An hour later I was sitting at a conference seminar in which the speaker bemoaned the poor data that had contributed to the key statistic in the article: that biomass of flying insects had decreased by 75% over the last 27 years. The methods used in the report apparently show huge bias towards large bodied species, which may have exaggerated the findings significantly. So here lies our quandary. Read more

How to Ecology Your Dragon

In our second week on the dragons of Dreamworks’ How to Train Your Dragon trilogy, we have a flamin’ good time discovering why those dragons are WAY too wacky, exactly how much intraspecies predation goes on in Berk and why you should really make up your mind about domestication.

03:49 – Vikings in Cinema
10:57 – Ecology of the Dragons
29:17 – Toothless vs. the Furious Five

You can also find us on iTunes and Google Play.

The Motivation Behind Migration

Species like this red-crowned crane perform yearly migrations, but how do they weigh up the costs and benefits? (Image Credit: Alistair Rae, CC BY-SA 2.0)

Where the wild birds go: explaining the differences in migratory destinations across terrestrial bird species (2018) Somveille, Manica & Rodrigues. Ecography, 42, p. 225-236.

The Crux

Migratory birds make up a huge chunk of the world’s bird life, yet there are still a lot of gaps in our knowledge concerning why they migrate to the areas they do. There’s a variety of potential benefits to migration, from remaining within a comfortable temperature range or a preferred habitat, to gaining access to areas that have a surplus in resources, to escaping competition with resident species. However, migration also results in increased mortality due to the amount of energy it takes. This week’s study tried to analyse the drivers of migration, and what trade-offs were made between migration’s potential benefits and costs.

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Johanna Schmitt: Climate Change and Plant Life

We sometimes ignore the effects of climate change on plant life, but the potential severity of these effects isn’t something that should be ignored for long (Image Credit: Pisauakan, CC0)

From the California wildfires to the recent strikes across Australian primary schools, climate change is a topic that only seems to grow in its ubiquity. Yet whilst humans are increasingly focused on more obvious repercussions, such as extreme weather events, animal extinctions and shifting coastlines, we sometimes forget that climate change will have severe repercussions for plant life as well.

I spoke to Professor Johanna Schmitt of the University of California earlier this year to discuss some of those repercussions. Johanna’s team is working to determine how well certain plant species will be able to adapt in the face of rapid climate change.

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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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