Geographic, seasonal, and diurnal surface behavior of harbor porpoises
Abstract During ship surveys harbor porpoises are only visible when breaking the sea surface to breathe, while during aerial surveys they may be seen down to 2 m below the surface. The fractions of time spent at these two depths can be used for correcting visual surveys to actual population estimate...
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crwiley:10.1111/j.1748-7692.2012.00597.x 2023-12-03T10:29:08+01:00 Geographic, seasonal, and diurnal surface behavior of harbor porpoises Teilmann, Jonas Christiansen, Casper T. Kjellerup, Sanne Dietz, Rune Nachman, Gösta 2012 http://dx.doi.org/10.1111/j.1748-7692.2012.00597.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2012.00597.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2012.00597.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 29, issue 2 ISSN 0824-0469 1748-7692 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2012 crwiley https://doi.org/10.1111/j.1748-7692.2012.00597.x 2023-11-09T14:11:49Z Abstract During ship surveys harbor porpoises are only visible when breaking the sea surface to breathe, while during aerial surveys they may be seen down to 2 m below the surface. The fractions of time spent at these two depths can be used for correcting visual surveys to actual population estimates, which are essential information on the status and management of the species. Thirty‐five free‐ranging harbor porpoises ( Phocoena phocoena ) were tracked in the region between the Baltic and the North Sea for 25–349 d using Argos satellite transmitters. No differences were found in surface behavior between geographical areas or the size of the animals. Slight differences were found between the two sexes and time of day. Surface time peaked in April, where 6% was spent with the transmitter above surface and 61.5% between 0 and 2 m depth, while the minimum values occurred in February (3.4% and 42.5%, respectively). The analyses reveal that individual variation among porpoises is the most important factor in explaining variation in surface rates. However, the large number of animals documented in the present study covering a wide range of age and sex groups justifies the use of the seasonal average surface times for correcting abundance surveys. Article in Journal/Newspaper Phocoena phocoena Wiley Online Library (via Crossref) Marine Mammal Science 29 2 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Teilmann, Jonas Christiansen, Casper T. Kjellerup, Sanne Dietz, Rune Nachman, Gösta Geographic, seasonal, and diurnal surface behavior of harbor porpoises |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Abstract During ship surveys harbor porpoises are only visible when breaking the sea surface to breathe, while during aerial surveys they may be seen down to 2 m below the surface. The fractions of time spent at these two depths can be used for correcting visual surveys to actual population estimates, which are essential information on the status and management of the species. Thirty‐five free‐ranging harbor porpoises ( Phocoena phocoena ) were tracked in the region between the Baltic and the North Sea for 25–349 d using Argos satellite transmitters. No differences were found in surface behavior between geographical areas or the size of the animals. Slight differences were found between the two sexes and time of day. Surface time peaked in April, where 6% was spent with the transmitter above surface and 61.5% between 0 and 2 m depth, while the minimum values occurred in February (3.4% and 42.5%, respectively). The analyses reveal that individual variation among porpoises is the most important factor in explaining variation in surface rates. However, the large number of animals documented in the present study covering a wide range of age and sex groups justifies the use of the seasonal average surface times for correcting abundance surveys. |
format |
Article in Journal/Newspaper |
author |
Teilmann, Jonas Christiansen, Casper T. Kjellerup, Sanne Dietz, Rune Nachman, Gösta |
author_facet |
Teilmann, Jonas Christiansen, Casper T. Kjellerup, Sanne Dietz, Rune Nachman, Gösta |
author_sort |
Teilmann, Jonas |
title |
Geographic, seasonal, and diurnal surface behavior of harbor porpoises |
title_short |
Geographic, seasonal, and diurnal surface behavior of harbor porpoises |
title_full |
Geographic, seasonal, and diurnal surface behavior of harbor porpoises |
title_fullStr |
Geographic, seasonal, and diurnal surface behavior of harbor porpoises |
title_full_unstemmed |
Geographic, seasonal, and diurnal surface behavior of harbor porpoises |
title_sort |
geographic, seasonal, and diurnal surface behavior of harbor porpoises |
publisher |
Wiley |
publishDate |
2012 |
url |
http://dx.doi.org/10.1111/j.1748-7692.2012.00597.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2012.00597.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2012.00597.x |
genre |
Phocoena phocoena |
genre_facet |
Phocoena phocoena |
op_source |
Marine Mammal Science volume 29, issue 2 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1748-7692.2012.00597.x |
container_title |
Marine Mammal Science |
container_volume |
29 |
container_issue |
2 |
_version_ |
1784254277181505536 |