Tag Archives: over

Finished Before You Even Started

Predators are known to affect prey while they are adults and juveniles, but what about when they haven’t even hatched yet?  (Image Credit: Bernt Rostad, CC BY 2.0)

Predation risk affects egg mortality and carry over effects in the larval stages in damselflies (2018) Sniegula et al., Freshwater Biology, p. 1-9

The Crux

In the natural world, one of the most dangerous things that a prey animal has to worry about is a predator. These organisms depend on the prey for their sustenance, and as such have become very good at finding ways to eat them. These are known as direct effects, as a predator eating prey is a direct interaction.

Another aspect of the predator-prey relationship is that of indirect effects, or effects that a predator has on prey that don’t involve it eating the prey animal. These can include predator-induced changes in the prey’s behavior, immune function, or even survival. These indirect effects are usually studied in prey species that are adults or juveniles, but the authors of today’s paper were interested in what indirect effects predators had on the eggs of prey species.

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If You Can’t Stand the Heat, Get Out of the Pond

Dragonflies like this Western Pondhawk female are particularly vulnerable to warming due to climate change. (Image Credit: Eugene Zelenko, CC BY-SA 4.0)
Simulated climate change increases larval mortality, alters phenology, and affects flight morphology of a dragonfly (2018) McCauley et al., Ecosphere, doi:10.1002/ecs2.2151

The Crux

Climate change is something that we hear about on a daily basis. The dire warnings tend to concern sea levels rising and temperatures varying so much that we have more intense and deadly storms than before, but these are all direct effects of the climate. Another thing that climate change can do is have indirect effects on organisms.

Organisms with complex life cycles spend the juvenile part of their lives in one environment before moving on to the adult stage in another environment. The researchers in this study wanted to know how simulated climate change during the juvenile stage of the organisms lifetime could affect the adult stage.

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