Wildlife energy: Survival of the fittest

Using a wildlife version of fitness trackers, biologists can finally measure how much energy animals need to stay alive.

Andrew Curry

10 September 2014

After attacking more than a dozen young Hawaiian monk seals, the aggressive male known as KE18 had to be banished from his island home. He now lives in a seawater pool in California, a few hundred yards from the Pacific Ocean.

Instead of assaulting more members of his species — one of the most endangered marine mammals on the planet — KE18 is now providing information that could help to keep the seals from going extinct. On a breezy June day at the University of California, Santa Cruz, an animal trainer is working to teach him to wear a metal tube containing a trio of accelerometers, tiny devices that track and log changes in velocity. It is the seal version of the fitness trackers that joggers and other endorphin addicts wear on their wrists to capture their every move.

Heaving his 200 kilograms up on the side of the pool, KE18 opens his mouth to show off his teeth and gets a fish as a reward. “We use a lot of fish and hot dogs in our lab,” says biologist Terrie Williams, who heads the mammalian physiology lab.

The hope is that data collected on KE18 will help to explain a mystery about the threatened Hawaiian monk seal (Monachus schauinslandi). Most of the population lives in the remote northwestern end of Hawaii's island chain, where four in every five pups die before reaching adulthood and the population is falling by more than 3% a year. “They end up starving to death,” says Charles Littnan, who runs the Hawaiian Monk Seal Research Program at the National Oceanic and Atmospheric Administration in Honolulu. But a much smaller population living close to the crowded beaches of the main Hawaiian islands is actually growing, despite all the human activity nearby.

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Personality Differences: In Lean Times Red Deer With Dominant Personalities Pay A High Price

Saving energy is important for humans and animals alike when resources are limited. Scientists at the Research Institute of Wildlife Ecology of the University of Veterinary Medicine, Vienna, found out that although higher-ranked red deer gain privileged access to patches of food, they also have higher metabolic rates and thus use more energy. This can be a serious disadvantage in winter when red deer rely largely on their limited stored body fat to survive.

Energy budget adjustments

Energy is the currency of life, and a central topic of wildlife ecological research is to understand how animals regulate their energy budgets with respect to its limited supply in the environment. Chris Turbill and colleagues set out to test the hypothesis that high rank, i.e. social dominance might be associated with higher metabolic rate. They measured heart rate and body temperature (proxy indicators for metabolic rate) using minimally invasive rumen transmitters in a herd of female red deer (Cervus elaphus) during winter. Red deer have a highly hierarchical herd structure. Before the experiment, behavioral observations were used to determine the social status of individuals in the group. The animals were allowed to move freely in the approx. 45 hectare large natural enclosure of the Research Institute. Owing to the poor natural forage available over winter, the deer were also fed pellets at an automated feeding station, which enabled the researchers to periodically restrict food rations and test the physiological impact of dominance in situations of food scarcity.

Dominance is costly

Red deer must withstand a negative energy balance over the winter season and maintenance of their body mass is critical to survival and reproduction. In lean times red deer, and other northern ungulates, save energy by drastically reducing their metabolism over cold winter nights – an energy-saving mechanism scientists refer to as “hypometabolism“. Socially dominant animals, however, are less good at this. The experimental results found that dominant individuals do have faster heart rates and higher body temperatures during winter compared to subordinates. Consequently, dominant individuals suffered higher rates of body mass loss during periods of low food availability than subordinates. Because the normally disadvantaged lower-ranked individuals do better in keeping their head low, slowing down, and chilling out, they seem to withstand severe winter conditions better.

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Light-Trapping Bug Acts Like Plant

A tiny insect called the pea aphid might be one of the only animals to turn sunlight into energy like a plant.

Scientists say they've found evidence suggesting that the insect (Acyrthosiphon pisum) traps light to produce adenosine triphosphate, or ATP, the cellular energy currency that powers biochemical reactions. (For animals, cells typically convert energy from food into ATP, while plants make ATP via photosynthesis.)

Aphids are already remarkable in the animal world, because they produce their own carotenoids, pigments usually produced by plants, fungi and microorganisms that can act as antioxidants when consumed by humans. Previous research found that aphids got this pigment-producing power after swapping genes with fungi, and now the new study suggests these carotenoids might be behind the aphid's apparent photosynthesis-like abilities.

Read on:  http://www.livescience.com/22558-aphid-light-energy-plant.html

Shetland Islands to host 'world's most productive' windfarm

Windfarm given go ahead despite local opposition, and should produce enough energy to power 175,000 homes.

A major windfarm on Shetland, which could be the most productive in the world, has been approved by ministers despite a bitterly fought campaign against the scheme by local residents.

The Viking windfarm will straddle the hills and moors of Shetland's main island, where the onshore wind speeds are frequently the highest in Europe, and lead to earnings of £30m a year for islanders and Shetland's wealthy charitable trust.

The project has been cut in size by Fergus Ewing, the Scottish energy minister, from 127 turbines to 103, to protect safety for Scatsta airport near Sullom Voe oil terminal.

The joint venture between energy giant SSE and Viking Energy Ltd, owned by the trust, will have 370MW capacity and is expected to generate enough energy for 175,000 homes – sixteen times the number of homes on Shetland.

One small turbine on a hill north of Lerwick, called Betsy, already holds a world record for its efficiency, reaching 59% of its potential output, thanks to the consistently powerful winds which sweep Shetland.

The developers said that meant the Viking scheme had the potential to be the most productive in the world. Councillor Bill Manson, chairman of Viking Energy Partnership, said: "This is good news for Shetland, good news for Scotland and good news for the fight against climate change."

The Viking scheme has been vigorously opposed by many Shetland residents, who have complained about its dominant position through the centre of the main island, and its impact on the scenery and recreation value of the moors and hills.

Read on:  http://www.guardian.co.uk/environment/2012/apr/04/shetland-islands-windfarm-scotland-energy?newsfeed=true