Tag Archives: web

Whom to Blame – Cats or Rats?

Feral cats are responsible for the decline of many endemic species worldwide. But will removing them boost rat populations, causing more potential harm?

Feral cats are responsible for the decline of many endemic species worldwide. But will removing them boost rat populations, causing more potential harm? (Image Credit: Brisbane City Council, CC BY 2.0, Image Cropped)

Trophic roles of black rats and seabird impacts on tropical islands: Mesopredator release or hyperpredation? (2015) Ringler et al., Biological Conservation, https://doi.org/10.1016/j.biocon.2014.12.014

Guest post by Bart Peeters

The Crux

For centuries, rats have been portrayed as carriers of diseases and death; whereas our feline friends, worshipped by the ancient Egyptians, will definitely make your YouTube video go viral (a quick Google search of “cat video” shows 1 310 000 000 results). Both have been introduced, either accidentally or deliberately, to islands where endemic species have evolved and adapted to an environment without these generalist predators. So how do you know if eradicating one of them will make things better for the native wildlife?

Before taking radical conservation actions, it may be a good idea to understand how feral cats (the apex predator), rats (the mesopredator) and their common prey are affecting each other. Namely, if you kill all the cats, will there be more rats to prey on seabirds? On the other hand, will killing all the rats really reduce the predation by cats on seabirds?

Read more

The Pacific Oyster

The Pacific oyster could make its way further north as the Arctic and sub-Arctic regions warm

Image Credit: Hans, Pixabay licence, Image Cropped

Last Monday, I wrote about how climate change can facilitate the spread of non-native and invasive species. Today, we look at a species that whilst problematic now, could spread further throughout Norwegian waters as temperatures rise.

The last time we looked at an ocean-dweller in this series, we saw that while some species may not be great for ecosystems, they can provide an obvious benefit to other aspects of the region, in this case the fishing industry. The Pacific oyster (Crassostrea gigas) was also introduced intentionally for cultivation and is now on the verge of becoming a major problem in Norwegian waters.

Read more