Browsing All Posts filed under »feeding«

Herbivory is important in freshwater systems

March 27, 2017

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Until the 1990s it was believed that, in the main, freshwater and marine plants were connected to aquatic food webs only indirectly, through the breakdown of decaying vegetation by decomposers. However, over the last two decades there’s been a growing realisation that the activities of aquatic herbivores in consuming plants and channeling the derived nutrients […]

Water birds bring up the subject of plant dispersal

December 13, 2016

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Waterfowl play an important role in the dispersal of plants by consuming and then defaecating their seeds. However, although birds such as ducks ingest a wide range of seeds, the digestive activity in their guts generally means that soft-bodied seeds become non-viable. Regurgitation of still-intact seeds is a possible alternative method of dispersal that allows […]

Dietary data can be misleading

December 18, 2015

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Information on the structure and function of food webs is commonly collected by using gut content analysis to reconstruct the diets of a wide range of animal species. However, this approach can be very time consuming and expensive, and gives no information on how much ingested food is actually assimilated into the body. A supplementary […]

Cutting reed beds while protecting bird diversity

December 18, 2015

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The common reed (Phragmites australis) occurs throughout the world and provides habitat for a wide range of animal species, including a number of reedbed specialists. Although reeds are commonly cut for commercial reasons and to prevent plant succession to wet woodland, it’s been shown that large-scale cutting can reduce the feeding and breeding success of […]

Creating fast flow refuges in streams

October 15, 2015

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Hydroelectric power plants create frequent, intense pulses in downstream river flow (hydropeaking) that are typically accompanied by increased sediment movement, high turbidity and habitat scouring. These changes can affect several aspects of the biology of fishes, including migration, spawning, early development and growth. In Switzerland, a 60% decline in catches of brown trout since 1980 […]

Food predictability changes the structure of animal populations

October 15, 2015

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Although it’s known that animal behaviour is affected by the predictability of food resources, the population-level implications of food predictability haven’t received much attention. Researchers at Oregon State University recorded the behaviour of 3-cm long juvenile steelhead trout (Oncorhynchus mykiss) in artificial streams fitted with programmable feeders. Each stream contained three feeding patches made of […]

Rivers of plastic are hazardous to fish

October 15, 2015

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The annual global production of plastics is close to 30 million tonnes and plastic items are one of the most ubiquitous types of pollutant. Although much plastic debris is transported to the oceans by way of freshwater streams, there are very few estimates of plastic loads in rivers. A recent study carried out on the […]