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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

Trans-oceanic juvenile osprey migration track maps (Mercator Projection).Colors correspond with individual ospreys (pink  =  Belle; red  =  Felix; yellow  =  Moffet; light green  =  Henrietta; green  =  Bea; dark green  =  Luke; light blue  =  Caley; royal blue  =  Mittark; dark blue  =  Isabel; purple/gray  =  Chip). Symbols correspond with different constant course track segments identified by piecewise linear regression breakpoint analysis (circles  =  first track segment following departure; triangles  =  second track segment; addition symbols  =  third track segment; diamonds  =  fourth track segment). Only the trans-oceanic portion of each bird's migration is shown. Gray addition symbols correspond with Chip's movements following his first night aloft, presumably when he was resting on or in contact with one or more vessels (see text). Northing and Easting values are shown in kilometers.
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pone-0114557-g001: Trans-oceanic juvenile osprey migration track maps (Mercator Projection).Colors correspond with individual ospreys (pink  =  Belle; red  =  Felix; yellow  =  Moffet; light green  =  Henrietta; green  =  Bea; dark green  =  Luke; light blue  =  Caley; royal blue  =  Mittark; dark blue  =  Isabel; purple/gray  =  Chip). Symbols correspond with different constant course track segments identified by piecewise linear regression breakpoint analysis (circles  =  first track segment following departure; triangles  =  second track segment; addition symbols  =  third track segment; diamonds  =  fourth track segment). Only the trans-oceanic portion of each bird's migration is shown. Gray addition symbols correspond with Chip's movements following his first night aloft, presumably when he was resting on or in contact with one or more vessels (see text). Northing and Easting values are shown in kilometers.

Mentions: The GPS-enabled PTT tags we deployed are accurate to ±18 m with temporal resolutions as fine as 45 seconds. In an effort to maximize transmitter longevity, the rechargeable solar powered GPS PTT data we report were recorded at consecutive 1-hour intervals across a 12-hour period each day. This duty-cycle was chosen to conserve battery power and because it was assumed that the birds would roost during hours of darkness. The majority of tracked birds migrated largely over land or coastal environments, making it impossible to differentiate true navigational behavior from piloting behavior (i.e. Griffin's Type III navigation from Type I visual landmark-based navigation) [28], based on track data alone (Figure S1). However, ten of the twenty-four juveniles tagged in New England performed unexpected non-stop migratory movements over the western Atlantic Ocean (Figure 1), thereby presenting an opportunity to study the navigational behaviors of these birds in the absence of visual landmarks. These migrations over open ocean were surprising because Ospreys are terrestrial birds and cannot land on water. Nine of the juveniles birds we studied were tagged on Martha's Vineyard, Massachusetts, and the tenth was tagged in central New Hampshire, U.S.A. (Table 1).


Juvenile Osprey Navigation during Trans-Oceanic Migration.

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

Trans-oceanic juvenile osprey migration track maps (Mercator Projection).Colors correspond with individual ospreys (pink  =  Belle; red  =  Felix; yellow  =  Moffet; light green  =  Henrietta; green  =  Bea; dark green  =  Luke; light blue  =  Caley; royal blue  =  Mittark; dark blue  =  Isabel; purple/gray  =  Chip). Symbols correspond with different constant course track segments identified by piecewise linear regression breakpoint analysis (circles  =  first track segment following departure; triangles  =  second track segment; addition symbols  =  third track segment; diamonds  =  fourth track segment). Only the trans-oceanic portion of each bird's migration is shown. Gray addition symbols correspond with Chip's movements following his first night aloft, presumably when he was resting on or in contact with one or more vessels (see text). Northing and Easting values are shown in kilometers.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0114557-g001: Trans-oceanic juvenile osprey migration track maps (Mercator Projection).Colors correspond with individual ospreys (pink  =  Belle; red  =  Felix; yellow  =  Moffet; light green  =  Henrietta; green  =  Bea; dark green  =  Luke; light blue  =  Caley; royal blue  =  Mittark; dark blue  =  Isabel; purple/gray  =  Chip). Symbols correspond with different constant course track segments identified by piecewise linear regression breakpoint analysis (circles  =  first track segment following departure; triangles  =  second track segment; addition symbols  =  third track segment; diamonds  =  fourth track segment). Only the trans-oceanic portion of each bird's migration is shown. Gray addition symbols correspond with Chip's movements following his first night aloft, presumably when he was resting on or in contact with one or more vessels (see text). Northing and Easting values are shown in kilometers.
Mentions: The GPS-enabled PTT tags we deployed are accurate to ±18 m with temporal resolutions as fine as 45 seconds. In an effort to maximize transmitter longevity, the rechargeable solar powered GPS PTT data we report were recorded at consecutive 1-hour intervals across a 12-hour period each day. This duty-cycle was chosen to conserve battery power and because it was assumed that the birds would roost during hours of darkness. The majority of tracked birds migrated largely over land or coastal environments, making it impossible to differentiate true navigational behavior from piloting behavior (i.e. Griffin's Type III navigation from Type I visual landmark-based navigation) [28], based on track data alone (Figure S1). However, ten of the twenty-four juveniles tagged in New England performed unexpected non-stop migratory movements over the western Atlantic Ocean (Figure 1), thereby presenting an opportunity to study the navigational behaviors of these birds in the absence of visual landmarks. These migrations over open ocean were surprising because Ospreys are terrestrial birds and cannot land on water. Nine of the juveniles birds we studied were tagged on Martha's Vineyard, Massachusetts, and the tenth was tagged in central New Hampshire, U.S.A. (Table 1).

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