Image Credit: Kevin Pluck, CC BY 2.0, Image Cropped
Brain expansion in early hominins predicts carnivore extinctions in East Africa (2020) Faurby et al, Ecology Letters, https://doi.org/10.1111/ele.13451
We’ve covered humans and their harmful effects many times here on Ecology for the Masses (see my recent breakdown from last month). Despite all of the colorful examples of our current effects on the wildlife of our planet, a significant amount of research has implicated Homo sapiens as the driver of the extinction of some of the megafauna of the prehistoric world, events that happens millions of years ago. Another possibility is that we as organisms (hominins, not Homo sapiens specifically) have been impacting other species for a very, very long time.
Today, East Africa is home to the most diverse group of large carnivores on the planet (though it is still less diverse than what was once seen in North America and Eurasia). Millions of years ago East Africa had an even more diverse assemblage of large carnivores, including bears, dogs, giant otters, and saber-toothed cats. The change in climate since that time may have caused the decline in large carnivore diversity, but another explanation is the rise of early hominins (our ancestors). Using fossil data, the authors of today’s paper wanted to figure out if it was indeed early hominins that drove many large carnivores extinct.
Image Credit: Manfred Antranias Zimmer, Pixabay licence, Image Cropped
Invasion of freshwater ecosystems is promoted by network connectivity to hotspots of human activity (2019) Chapman et al., Global Ecology and Biogeography, https://doi.org/10.1111/geb.13051
The spread of invasive species throughout freshwater ecosystems is a topic we’ve looked at before on Ecology for the Masses. In a previous paper breakdown we talked about how recreational is heavily responsible for the presence of non-native fish at a European scale.
Our paper this week takes a more local approach. Can we predict the presence of non-native birds, invertebrates and fish by looking at the presence of human activity, and where that human activity is present?
Increased urbanisation may have a negative effect on the richness of moth species like this Vine’s Rustic, but it depends on what scale we consider richness (Image Credit: Patrick Clement, CC BY 2.0, Image Cropped)
Urbanization drives cross-taxon declines in abundance and diversity at multiple spatial scales (2019) Piano et al., Global Change Biology, https://doi.org/10.1111/gcb.14934
You would think that the effect of building a whole lot of stuff on something’s habitat would have a negative effect on just about anything. But building a whole lot of human stuff (maybe let’s retain a modicum of science-ness and call it urbanisation) hasn’t always been shown to be necessarily bad for species. There are a lot of studies out there which show that urbanisation is can be a negative for biodiversity (which makes sense, since for starters it generally breaks up habitat patches and introduces a whole lot more pollutants). But there are also studies showing that urbanisation can increase biodiversity.
The Cataract Gorge in Launceston, Tasmania, where the 2019 Ecological Society of Australia Annual Meeting was held (Image Credit: Marina Schmoeller, CC BY 2.0)
I just got back from 10 days in Tasmania, Australia. As a temporary visitor in the country, I extended my trip to attend the Ecological Society of Australia’s annual conference (ESAus) as much as I could, so I could explore the surroundings and get to know a little of the place, its people and its unique biodiversity.
The conference was held in Launceston, the second largest city in Tasmania. With about ninety thousand inhabitants, a rich history with deep roots in its eye-catching landscapes, the Tamar River Valley and the Cataract Gorge, Launceston is a charming place with a lot to offer all visitors. But let’s talk about the conference.
Image Credit: James Wheeler, Pixabay licence, Image Cropped
Last week, my colleague Stefan Vriend had published an article explaining the concept of the Anthropocene – the proposed name for the epoch that started when humans had a noticable impact on the earth’s geology. Two days beforehand, an article appeared in the Atlantic proclaiming that the Anthropocene was a joke. The basic tenet of the article was that because our impact on the planet has taken place over such a short period of time, the fact that we’ve seen fit to name a new geological epoch (the Anthropocene) after the short timespan that we’ve been wreaking havoc on the planet is incredibly self-centred and arrogant.
Mostly limited to ocean animals, transparency is thought to help escape predators by blending the animal in with its environment, but is this what actually happens? (Image Credit: birdphotos.com, CC BY 3.0, Image Cropped)
Transparency reduces predator detection in mimetic clearwing butterflies (2019) Arias et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13315
Predators are one of the strongest forces of selection in the natural world, and as a result it can be quite costly to stand out and be more easily noticed. This means that in order to survive, animals must adapt to avoid predators. Besides running away from what is trying to eat you, your best bet is to evolve body coloration that helps you avoid being seen by a predator.
Animals that rely on blending in will match the color or even the texture of their backgrounds, but when prey species live in areas where they cannot easily blend in (like plankton in the water column) they often evolve to be transparent. Unlike their marine counterparts, transparency is normally rare in terrestrial animals. The clearwing butterfly is one notable exception to this rule, and the authors of today’s paper wanted to test whether or not these clear wings actually reduce predation.