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Juvenile Osprey Navigation during Trans-Oceanic Migration.

Horton TW, Bierregaard RO, Zawar-Reza P, Holdaway RN, Sagar P - PLoS ONE (2014)

Bottom Line: Although some species of bird, fish, insect, mammal, and reptile are capable of drift compensation, our understanding of the spatial reference frame, and associated coordinate space, in which these navigational behaviors occur remains limited.These results are best explained by extreme navigational precision in an exogenous spatio-temporal reference frame, such as positional orientation relative to Earth's magnetic field and pacing relative to an exogenous mechanism of keeping time.Through integration of movement and meteorological data, we propose a new theoretical framework, chord and clock navigation, capable of explaining the precise spatial orientation and temporal pacing performed by juvenile ospreys during their long-distance migrations over open ocean.

View Article: PubMed Central - PubMed

Affiliation: Department of Geological Science, University of Canterbury, Christchurch, New Zealand.

ABSTRACT
To compensate for drift, an animal migrating through air or sea must be able to navigate. Although some species of bird, fish, insect, mammal, and reptile are capable of drift compensation, our understanding of the spatial reference frame, and associated coordinate space, in which these navigational behaviors occur remains limited. Using high resolution satellite-monitored GPS track data, we show that juvenile ospreys (Pandion haliaetus) are capable of non-stop constant course movements over open ocean spanning distances in excess of 1500 km despite the perturbing effects of winds and the lack of obvious landmarks. These results are best explained by extreme navigational precision in an exogenous spatio-temporal reference frame, such as positional orientation relative to Earth's magnetic field and pacing relative to an exogenous mechanism of keeping time. Given the age (<1 year-old) of these birds and knowledge of their hatching site locations, we were able to transform Enhanced Magnetic Model coordinate locations such that the origin of the magnetic coordinate space corresponded with each bird's nest. Our analyses show that trans-oceanic juvenile osprey movements are consistent with bicoordinate positional orientation in transformed magnetic coordinate or geographic space. Through integration of movement and meteorological data, we propose a new theoretical framework, chord and clock navigation, capable of explaining the precise spatial orientation and temporal pacing performed by juvenile ospreys during their long-distance migrations over open ocean.

No MeSH data available.


Related in: MedlinePlus

Transformed magnetic coordinate osprey locations.Colours and symbols as in Figure 1. Gray shaded area corresponds with the area encompassed between 20° and 42° north latitude and −67° and −78° west longitude. The origin of the transformed magnetic coordinate space shown here corresponds with each bird's hatching site (see text).
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pone-0114557-g008: Transformed magnetic coordinate osprey locations.Colours and symbols as in Figure 1. Gray shaded area corresponds with the area encompassed between 20° and 42° north latitude and −67° and −78° west longitude. The origin of the transformed magnetic coordinate space shown here corresponds with each bird's hatching site (see text).

Mentions: Transformed magnetic coordinate maps (yT-zT plane) of the juvenile osprey movements show several notable results. Most importantly to the topic of navigation, the different tracks follow different trajectories in yT-zT space (Figure 8). This is distinctly different than what was shown above for the same track data expressed in F-I bicoordinate space. Multiple ANOVA (t-test) performed on 300 different pairs of the 25 track segments we identified show that >81% of these pairs are significantly different in transformed magnetic coordinate space (Table S2). Thus, unlike the F-I coordinate space, there is considerable resolution (ca. ∼6,000 nT × ∼17,000 nT) in the yT-zT plane across the trans-oceanic migratory spatial domain spanned by these birds. The observation that most of the track segments follow different transformed magnetic trajectories is also consistent with the fact that we know these birds followed different wind-drift compensated constant course track segments in geographic space. The results of a similar multiple ANOVA performed on the same track segment pairs, shows that >77% of the track segment pairs are significantly different in Mercator coordinate space (Table S3).


Juvenile Osprey Navigation during Trans-Oceanic Migration.

Horton TW, Bierregaard RO, Zawar-Reza P, Holdaway RN, Sagar P - PLoS ONE (2014)

Transformed magnetic coordinate osprey locations.Colours and symbols as in Figure 1. Gray shaded area corresponds with the area encompassed between 20° and 42° north latitude and −67° and −78° west longitude. The origin of the transformed magnetic coordinate space shown here corresponds with each bird's hatching site (see text).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262435&req=5

pone-0114557-g008: Transformed magnetic coordinate osprey locations.Colours and symbols as in Figure 1. Gray shaded area corresponds with the area encompassed between 20° and 42° north latitude and −67° and −78° west longitude. The origin of the transformed magnetic coordinate space shown here corresponds with each bird's hatching site (see text).
Mentions: Transformed magnetic coordinate maps (yT-zT plane) of the juvenile osprey movements show several notable results. Most importantly to the topic of navigation, the different tracks follow different trajectories in yT-zT space (Figure 8). This is distinctly different than what was shown above for the same track data expressed in F-I bicoordinate space. Multiple ANOVA (t-test) performed on 300 different pairs of the 25 track segments we identified show that >81% of these pairs are significantly different in transformed magnetic coordinate space (Table S2). Thus, unlike the F-I coordinate space, there is considerable resolution (ca. ∼6,000 nT × ∼17,000 nT) in the yT-zT plane across the trans-oceanic migratory spatial domain spanned by these birds. The observation that most of the track segments follow different transformed magnetic trajectories is also consistent with the fact that we know these birds followed different wind-drift compensated constant course track segments in geographic space. The results of a similar multiple ANOVA performed on the same track segment pairs, shows that >77% of the track segment pairs are significantly different in Mercator coordinate space (Table S3).

Bottom Line: Although some species of bird, fish, insect, mammal, and reptile are capable of drift compensation, our understanding of the spatial reference frame, and associated coordinate space, in which these navigational behaviors occur remains limited.These results are best explained by extreme navigational precision in an exogenous spatio-temporal reference frame, such as positional orientation relative to Earth's magnetic field and pacing relative to an exogenous mechanism of keeping time.Through integration of movement and meteorological data, we propose a new theoretical framework, chord and clock navigation, capable of explaining the precise spatial orientation and temporal pacing performed by juvenile ospreys during their long-distance migrations over open ocean.

View Article: PubMed Central - PubMed

Affiliation: Department of Geological Science, University of Canterbury, Christchurch, New Zealand.

ABSTRACT
To compensate for drift, an animal migrating through air or sea must be able to navigate. Although some species of bird, fish, insect, mammal, and reptile are capable of drift compensation, our understanding of the spatial reference frame, and associated coordinate space, in which these navigational behaviors occur remains limited. Using high resolution satellite-monitored GPS track data, we show that juvenile ospreys (Pandion haliaetus) are capable of non-stop constant course movements over open ocean spanning distances in excess of 1500 km despite the perturbing effects of winds and the lack of obvious landmarks. These results are best explained by extreme navigational precision in an exogenous spatio-temporal reference frame, such as positional orientation relative to Earth's magnetic field and pacing relative to an exogenous mechanism of keeping time. Given the age (<1 year-old) of these birds and knowledge of their hatching site locations, we were able to transform Enhanced Magnetic Model coordinate locations such that the origin of the magnetic coordinate space corresponded with each bird's nest. Our analyses show that trans-oceanic juvenile osprey movements are consistent with bicoordinate positional orientation in transformed magnetic coordinate or geographic space. Through integration of movement and meteorological data, we propose a new theoretical framework, chord and clock navigation, capable of explaining the precise spatial orientation and temporal pacing performed by juvenile ospreys during their long-distance migrations over open ocean.

No MeSH data available.


Related in: MedlinePlus