Tag: Navigation

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Whale strike

To avoid striking
whales, great creatures of the sea,
use the app. Impact!

Blue whales can be injured or killed in collisions with ships, particularly in regions where migration routes cross shipping lanes. Yet because they travel huge distances, predicting where whales will be at any given time is difficult. However, now research by Abrahms et al (2019) suggests that statistical modelling techniques may be able to help.

The researchers used satellite tracking data from 104 blue whales across 14 years along with daily information on three-dimensional oceanic habitats to model the whales’ daily distribution. By using an ensemble modelling approach they were able to produce daily, year-round predictions of blue whale habitat suitability in the Californian Current Ecosystem.

The statistical approach allows the researchers to quantify the spatial and temporal distribution of exposure to ship strike risk within shipping lanes in the Southern California Bight. The researchers plan on converting this approach into a downloadable app which would alert ships to the risks of whale collision and could recommend alternative shipping lanes or vessel slow-downs.

It’s a truly fascinating piece of research that seems likely to have a huge impact upon a real-world problem – research at its best.

The sciku also includes a line from Mr Scruff’s truly excellent track ‘Shanty Town’ from his ‘Keep It Unreal’ album released in 1999. The full line is ‘Whales! Great creatures of the sea! Please listen to me!’ It’s well worth checking out!

Original research: http://dx.doi.org/10.1111/ddi.12940

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Their noses know

How do shearwaters

navigate across oceans?

Their noses know ¿no?

 

Many birds travel hundreds of miles across oceans with no obvious sign posts to help them find their way. So how do they navigate?

Padget et al (2017) manipulated the olfactory ability of shearwaters and then tracked them as they made free-ranging foraging trips across the Mediterranean Sea. Shearwaters that were anosmic behaved as normal whilst foraging but on their return trips they were not oriented towards their colony – they found the coastline within 40 km from their colony and travelled the rest of the way along the coast. In contrast the control birds found their colony with a significantly greater degree of accuracy. This suggests that shearwaters use an olfactory map to navigate across open water successfully.

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Orienteering

Oh little spined fish,

your habitat matters for

orienteering.

 

Animals navigating their environment may use a number of different spatial cues to find their way around, including the geometric structure of the environment or global landmarks. But some species are found in multiple habitat types where different cues might be more effective for navigation.

Three-spined sticklebacks live in rivers and ponds, environments which differ in terms of structure and rate of environmental change. When tested in an aquatic maze, sticklebacks collected from rivers used geometric and global cues to learn the maze, whereas sticklebacks collected from ponds only used geometric cues to navigate the maze. Within this one species of fish there appear to be multiple methods of navigation depending on the habitat in which the fish are found. Brydges et al, 2008.

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Lugging worker

Lugging worker ants

use a celestial compass.

Is this a moonwalk?

 

Ants often need to walk backwards when dragging heavy food items to their nests, but how do they navigate when moving in reverse? Rather than relying on visual memories of terrestrial cues, ants instead use their celestial compass – this can be disrupted by presenting ants with a mirror image of the sun’s position in the sky. Schwarz et al, 2017.

Original research: https://doi.org/10.1016/j.cub.2016.12.019