Browsing All Posts filed under »behaviour«

Worms, midges and the greenhouse effect

July 5, 2018

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Severely impacted aquatic environments such as urban wetlands and wastewater treatment ponds are designed to treat large amounts of carbon and nitrogen, which raises concerns about their potential greenhouse gas emissions.  Because pollution-tolerant worms (oligochaetes) and insects (midges) can reach very high densities in such systems, it’s possible that their activities influence  the flux of […]

Embryos learn about future predators

July 5, 2018

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Because anti-predator strategies are highly adaptive, many prey species have evolved the ability to assess future predation risk and respond accordingly.  It’s been discovered that this capacity extends to embryos, which can use environmental cues, such as odours from predators and injured fellow prey, to learn about predators that will pose a threat for them […]

Guppies know their way around

March 25, 2018

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Rats, mice and other rodents can quickly learn to solve complex spatial problems such as mazes consisting of sequences of left-right turns. Although the spatial abilities of rodents may be the result of their burrow-dwelling existence, it’s also possible that such abilities are widely shared by other vertebrates. Fish are known to have well-developed spatial […]

How sedimentation affects the food web

March 25, 2018

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In rivers and streams, high predator densities are predicted to boost algal biomass by reducing the number of grazing animals. However, in disturbed systems the smothering of stream bed surfaces by sediment is expected to have an opposite, negative effect on algal biomass.  Studies that investigate interactions between sedimentation (an abiotic stress factor) and predation […]

Benefits and costs of habitat complexity

December 21, 2017

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The fact that biodiversity tends to be higher in structurally complex habitats suggests that, on balance, the fitness-related advantages of habitat complexity outweigh the disadvantages.  Possible advantages include a greater supply of locations where animals can hide from predators and conserve their energy, and higher abundances of potential prey.  Also, in complex habitats less energy […]

Size and survival in tadpoles  

December 21, 2017

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  Because interactions between predator and prey species are usually size-dependent, their ecological impacts are affected by variations in body size within predator and /or prey populations.  However, there’s been little research on the ways that such variation affects animal communities.   Using tadpoles of the brown frog (Rana pirica) as model prey and larvae of […]

Why are cold water fish bigger?

December 21, 2017

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In a wide range of animal groups, maximum body sizes tend to be higher in temperate and polar species than in those living closer to the equator, and there’s been a lively debate about the underlying reasons for this trend.  French and Bolivian scientists  investigated possible explanations by using a family of freshwater fish (the […]