Some Birds Smell To Navigate, Experiment Shows
Mohammad Ali (@ChaudhryMAli88) Published August 29, 2017 | 10:05 PM
At least one species of sea-faring bird uses its sense of smell to navigate over ocean waters, according to a novel experiment described in a study released
PARIS, , (APP - UrduPoint / Pakistan Point News - 29th Aug, 2017 ) - At least one species of sea-faring bird uses its sense of smell to navigate over ocean waters, according to a novel experiment described in a study released Tuesday.
Temporarily deprived of the ability to smell, Scopoli's shearwaters had trouble finding their way home after embarking from the Spanish island of Menorca to forage, researchers reported in the journal Scientific Reports.
The olfactory-challenged birds easily flew nearly 200 kilometres (125 miles) to the Catalan coast to gather food, but set off at the wrong angle on the return trip. "They embarked on curiously straight but poorly oriented flights across the ocean, as if following a compass bearing ...
without being able to update their position," lead author Oliver Padget, a doctoral candidate at the University of Oxford, said in a statement. Earlier experiments had produced similar results, but with a shortcoming in methodology: birds stripped of the capacity to smell were displaced long distances and then released.
That left open the possibility that any disorientation might come from the displacement itself, or the inability to gather information on the outbound journey, rather than the lost sense of smell.
"To the best of our knowledge, this is the first study that follows free-ranging foraging trips in sensorily manipulated birds," said senior author Tim Guilford, a professor in the University of Oxford's Department of Zoology.
In the new experiments, researchers split 32 birds into three groups. One was made anosmic -- the technical term for "unable to smell" -- by inserting zinc sulphate into the nasal passage, while another was fitted with small but powerful magnets.
- Odour signature - =================== It is also thought that migrating birds -- some of which cross the globe in a single go -- use Earth's magnetic field to find their way. Nothing was done to the third "control" group that might change the birds' behaviour.
All three groups wore miniature GPS trackers. "Precision, on-board tracking technology and new analytical methods -- too computationally heavy to have been possible in the past -- have made this feasible," said Guilford.
The birds bearing magnets were unperturbed in their journeys, but the ones dosed with zinc had to reach land before fully recovering their bearings and rectifying their trajectories. If the study removes any doubt that olfactory faculties play a role in navigation, the question still remains: what are the birds smelling? "The short answer is that we do not know what odours shearwaters" -- which fly close to the water -- "might be using to navigate," Padget told AFP.
Other research has suggested that albatrosses, petrels and shearwaters are sensitive to an organic chemical given off by marine algae and phytoplankton, single-cell organisms at the bottom of the ocean food chain.
But rather than following a scent to its source, birds may use them like landmarks, biologists have suggested. "It is more likely that different places in the environment have characteristic odour signatures, and that these signatures may become associated with particular directions back toward the home colony," Padget said.
Related Topics
Recent Stories
Tennis: ATP Barcelona Open results - 1st update
Swiatek's perfect 10 in Stuttgart as Vondrousova stuns Sabalenka
Arandu's roads closed due to flooding
Oil tanker catches fire in Islamabad’s Blue Area
Pakistan committed to ensure safety of foreign nationals: FO
Tennis: WTA Stuttgart results - 1st update
Four passengers injured as train hit an empty vehicle
Over- speeding bus crushed to death two bike riders
Turkey's Freedom Flotilla ready to set sail for Gaza
French teen dies from heart failure after knife attack near school
Iranians appear unfazed by Isfahan blasts
UAF celebrates Int'l Chinese Language Day
More Stories From World
-
Togo lawmakers approve contested political reform
16 minutes ago -
NATO must choose 'whether we indeed are allies': Zelensky
16 minutes ago -
US House to vote on Ukraine, Israel, Taiwan aid package
16 minutes ago -
Calls for calm after reported Israeli strike on Iran
46 minutes ago -
IMF calls on EU to deepen single market integration to boost growth
46 minutes ago -
Second Ecuadoran mayor killed ahead of anti-crime referendum: police
46 minutes ago
-
Oil, gas drilling blocked in Alaska wilds as Biden seeks green cred
2 hours ago -
Man sets self on fire outside Trump trial
2 hours ago -
Turkey's Freedom Flotilla ready to set sail for Gaza
3 hours ago -
French teen dies from heart failure after knife attack near school
3 hours ago -
Iranians appear unfazed by Isfahan blasts
3 hours ago -
Ecuador mayor killed ahead of anti-crime referendum: police
3 hours ago