Sumatran tigers very sensitive to human disturbance

Tigers live at surprisingly low densities in Sumatra

July 2013. Sumatran tigers, found exclusively on the Indonesian island of Sumatra, are on the brink of extinction. By optimistic estimates, perhaps 400 individuals survive. But the exact the number and locations of the island's dwindling tiger population has been up for debate.

Very low density of tigers

Virginia Tech and World Wildlife Fund researchers have found that tigers in central Sumatra live at very low densities, lower than previously believed. 

The study suggests that high levels of human activity limit the tiger population. Researchers studied areas and habitat types not previously surveyed, which could inform interventions needed to save the tiger.

Sensitive to human disturbance

"Tigers are not only threatened by habitat loss from deforestation and poaching; they are also very sensitive to human disturbance," said one of the researchers, called Sunarto, (a native of Indonesia, where people typically have one name). "They cannot survive in areas without adequate understory, but they are also threatened in seemingly suitable forests when there is too much human activity."

Continued

Human Disturbances Keep Elk On High Alert

ScienceDaily (Nov. 28, 2012) — University of Alberta researchers discovered that elk are more frequently and more easily disturbed by humans such as ATV drivers than by their natural predators like bears and wolves.

The U of A researchers, led by biologist Simone Ciuti, spent 12 months in southwestern Alberta. The study involved elk herds made up of females and their offspring. The researchers observed the animals' reactions to different rates of human disturbances in the form of traffic on nearby roads and off-road, all-terrain vehicles.

The elk in the study were found on a variety of land types -- public, private and inside Waterton National Park.

The research data showed that starting with a rate of just one vehicle passing by an elk herd every two hours, the animals became disturbed and more vigilant. In this state the elk consume less food, which can affect their health and possibly their calving success.

The researchers found that the highest level of disturbance happened on public lands where the effect of hunting and ATV use was cumulative.

Read more:  http://www.sciencedaily.com/releases/2012/11/121128183051.htm