Tag Archives: parasitoid

Is the Enemy of My Enemy My Friend?

Natural enemies have inconsistent impacts on the coexistence of competing species (2021) Terry et al., Journal of Animal Ecology. http://doi.org/10.1111/1365-2656.135434

Image Credit: Alandmanson, CC BY 4.0

The Crux

In nature, organisms are often competing with other organisms for food, mates, or even just for a place to call home. This competition comes in two forms: interspecific competition (meaning competition between two different species) and intraspecific competion (meaning competition within the same species). These two forms of competition play into the phenomenon known as mutual invasibility (see Did You Know), which is a necessary component of coexistence. If two organisms coexist, one species will not outcompete the other and drive it extinct, and thus the two species will coexist over time.

Because competition plays such a strong role in species coexistence, any factor that affects competition between two species has the potential to also affect coexistence. Today’s authors wanted to ask how an antagonistic species interaction (specifically, interactions with a parasitoid) affected coexistence in rainforest flies.

Read more

It Pays to Break from the Crowd

Image Credit: Pete, CC BY-NC 2.0

Increased reproductive success through parasitoid release at a range margin: Implications for range shifts induced by climate change (2020) MacKay, Gross, & Ryder, Journal of Biogeography, https://doi.org/10.1111/jbi.13795

The Crux

Predicting the response of organisms to climate change is a challenge for ecologists and wildlife managers alike. Fortunately, some responses are common enough that it is still possible to make fairly accurate predictions about them without too much information. One common response is that of the range shift, whereby a population of organisms facing some alteration (eg. climate change) in their current habitat, making it unfavorable, begin to move to another location. This allows them to track favorable environmental conditions and possibly mitigate any negative effects of climate change.

Sounds easy, right? Just pack it all up and move when things get hard? Well, for some organisms it may be that simple (looking at you, birds), but for others (like trees) it is significantly harder to do so. Trees (and other plants) are limited in that they depend on other organisms or things like wind to help disperse their seeds. Making things even more difficult are plant species that depend on specific pollinators, and in order for a successful range shift to happen trees AND their pollinators have to make the move. Today’s authors wanted to study how relationships between trees and their pollinators changed at the leading edge of a range shift, allowing them to understand how and why trees succeed during a range shift.

Read more