Fear as an ecosystem engineer

This post contributed by Cristina Eisenberg, conservation biologist at Oregon State University Over the past three years I have conducted thirteen hundred focal animal observations on elk in the northern and southern Rocky Mountains. This involves patiently watching one animal at a time for up to twenty minutes and recording its wariness–that is, the amount of time it spends with its head down feeding versus head up, scanning...

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When it comes to economics, diversity is key

A study published this week in Nature compared the U.S. economic downturn with a current ecological issue: a decline in biodiversity. In the study, economist Andrew Haldane of the Bank of England and zoologist Robert May of Oxford University basically described the financial system as having similar weaknesses as a monoculture. That is, if all banks are run equally, they are more susceptible to a uniform crisis; much in the way that a...

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Can birds affect tree growth?

Growing conditions, such as water and nutrient supply, are the major determinates of tree growth, but insectivorous birds can also play an important role, say scientists in a study published in the January issue of Ecology. Under the right conditions, birds contribute to whole tree growth by preying on herbaceous arthropods, such as leafhoppers, caterpillars and grasshoppers…

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Reduced predator populations lead to algal blooms

Algal blooms are a phenomenon in which algal populations in a marine area proliferate rapidly, creating a water-column shield that blocks sunlight and oxygen. These blooms are usually attributed to rises in nitrogen levels from human agriculture and industrial runoff, which fertilize the algae. But a study in the current issue of Ecological Applications shows that overfishing of top fish predators can also lead to algal blooms....

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