Tiny GPS backpacks uncover the secret life of desert bats

Date: August 16, 2019

Source: University of Helsinki

A new study from the University of Helsinki using miniaturized satellite-based tags revealed that during drier periods desert bats must fly further and longer to fulfil their nightly needs. According to researchers this signals their struggle in facing dry periods.

Wildlife tracking has revolutionized the study of animal movement and their behavior. Yet, tracking small, flying animals such as desert bats remained challenging. Now a new generation of miniaturized satellite-based tags is allowing unique insights into the life of these mysterious mammals.

Researchers used 1 g GPS devices to reconstruct the movements of yellow-winged bats, one of two false vampire bats occurring in Africa and one of the few desert bats large enough to carrying this innovative technology. "GPS tags have seen up to now a limited use with insectivorous bats due to weight constraints and low success in data collection -- we achieved great results in tracking such a light species," says Irene Conenna, a PhD candidate at the University of Helsinki and the lead author of the study.

Future under the changing climate?

"Bats are some of the most successful desert mammals. Powered flight allows them to efficiently track scarce resources and their nocturnal lifestyle buffers them from the baking sun. However, they still struggle to find enough resources during the drier periods of the year," says Ricardo Rocha, one of the co-authors of the paper.

The study was conducted in Sibiloi National Park, Northern Kenya, along the shores of Lake Turkana, the world's largest desert lake. Researchers placed GPS loggers in 29 bats, 15 in the rainy season and 14 in the dry and, for one week. Their whereabouts were recorded every 30 to 60 minutes every night. This revealed that during dry periods bats used larger home ranges and had extended activity periods, potentially to compensate for a shortage in food resources.

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Like humans, lowly cockroach uses a GPS to get around, scientists find

Date: July 7, 2016

Source: Case Western Reserve University

Rats, men and cockroaches appear to have a similar GPS in their heads that allows them to navigate new surroundings, researchers at Case Western Reserve University report.

The finding, published in journal Current Biology, is likely an example of convergent evolution--that is, distinct animals developed similar systems to manage the same problems.

Due to their simpler brain, further studies on cockroaches that would be difficult--if not impossible--on mammals may yield new insights into how humans orient themselves and navigate. Or, what goes awry in people who have extreme trouble getting their bearings.

"We've known that a mammal can come into a new area and, after a short period of being disoriented, find its way around," said Roy Ritzmann, a biology professor at Case Western Reserve and an author of the new study.

Humans and other mammals rely on head-direction, place and grid cells in their brains to process, integrate and update sensory information. The cues come from the direction they look, what they see and motion, he said.

Insects must maneuver through new environments, too.

"Orienting contributes to spatial memory, so they can return to point A or navigate to something they like or away from something they don't like," said PhD student Adrienn G. Varga, lead author of the study.

By repeating experiments that uncovered head-direction cells in rats, Ritzmann and Varga found head-direction-like activity and evidence of contextual cue processing in cockroaches.

The experiment

The researchers recorded cell activities in an area of the brain called the central complex while roaches were restrained in a tube.

Each roach was placed on a platform that rotated clockwise or counter clockwise. The platform was encircled by a black wall with a single removable landmark: a white square.

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Hedgehogs given GPS 'backpacks' to boost survival rates

Hedgehogs which have been nursed back to health are being fitted with GPS "backpacks" to find out how they go on to survive in the wild.

The 24 hedgehogs, cared for at Shepreth Wildlife Park in Cambridgeshire, will have their movements tracked.

The animals will be released in Suffolk and Cambridgeshire on Wednesday.

Rebecca Willers, chairwoman of Shepreth Wildlife Conservation Charity, hopes the study can eventually boost survival rates of rehabilitated hedgehogs.

The £150 devices weigh just over 1.8oz (50g) and have been designed for the project by Dr David Wallis of Ecometry Technologies.

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