Advanced

When and where does mortality occur in migratory birds? Direct evidence from long-term satellite tracking of raptors.

Klaassen, Raymond LU ; Hake, Mikael; Strandberg, Roine LU ; Koks, Ben J; Trierweiler, Christiane; Exo, Klaus-Michael; Bairlein, Franz and Alerstam, Thomas LU (2014) In Journal of Animal Ecology 83(1). p.176-184
Abstract
Information about when and where animals die is important to understand population regulation. In migratory animals, mortality might occur not only during the stationary periods (e.g. breeding and wintering) but also during the migration seasons. However, the relative importance of population limiting factors during different periods of the year remains poorly understood, and previous studies mainly relied on indirect evidence. Here, we provide direct evidence about when and where migrants die by identifying cases of confirmed and probable deaths in three species of long-distance migratory raptors tracked by satellite telemetry. We show that mortality rate was about six times higher during migration seasons than during stationary periods.... (More)
Information about when and where animals die is important to understand population regulation. In migratory animals, mortality might occur not only during the stationary periods (e.g. breeding and wintering) but also during the migration seasons. However, the relative importance of population limiting factors during different periods of the year remains poorly understood, and previous studies mainly relied on indirect evidence. Here, we provide direct evidence about when and where migrants die by identifying cases of confirmed and probable deaths in three species of long-distance migratory raptors tracked by satellite telemetry. We show that mortality rate was about six times higher during migration seasons than during stationary periods. However, total mortality was surprisingly similar between periods, which can be explained by the fact that risky migration periods are shorter than safer stationary periods. Nevertheless, more than half of the annual mortality occurred during migration. We also found spatiotemporal patterns in mortality: spring mortality occurred mainly in Africa in association with the crossing of the Sahara desert, while most mortality during autumn took place in Europe. Our results strongly suggest that events during the migration seasons have an important impact on the population dynamics of long-distance migrants. We speculate that mortality during spring migration may account for short-term annual variation in survival and population sizes, while mortality during autumn migration may be more important for long-term population regulation (through density-dependent effects). (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
animal migration, annual survival, ecology of death, long-distance migration, satellite radio-telemetry
in
Journal of Animal Ecology
volume
83
issue
1
pages
176 - 184
publisher
Federation of European Neuroscience Societies and Blackwell Publishing Ltd
external identifiers
  • wos:000328615300019
  • pmid:24102110
  • scopus:84890634342
ISSN
1365-2656
DOI
10.1111/1365-2656.12135
language
English
LU publication?
yes
id
b32c1f6d-fbc8-4a25-9ebd-50db5604c6d4 (old id 4143568)
date added to LUP
2013-11-20 16:28:15
date last changed
2017-11-12 03:07:06
@article{b32c1f6d-fbc8-4a25-9ebd-50db5604c6d4,
  abstract     = {Information about when and where animals die is important to understand population regulation. In migratory animals, mortality might occur not only during the stationary periods (e.g. breeding and wintering) but also during the migration seasons. However, the relative importance of population limiting factors during different periods of the year remains poorly understood, and previous studies mainly relied on indirect evidence. Here, we provide direct evidence about when and where migrants die by identifying cases of confirmed and probable deaths in three species of long-distance migratory raptors tracked by satellite telemetry. We show that mortality rate was about six times higher during migration seasons than during stationary periods. However, total mortality was surprisingly similar between periods, which can be explained by the fact that risky migration periods are shorter than safer stationary periods. Nevertheless, more than half of the annual mortality occurred during migration. We also found spatiotemporal patterns in mortality: spring mortality occurred mainly in Africa in association with the crossing of the Sahara desert, while most mortality during autumn took place in Europe. Our results strongly suggest that events during the migration seasons have an important impact on the population dynamics of long-distance migrants. We speculate that mortality during spring migration may account for short-term annual variation in survival and population sizes, while mortality during autumn migration may be more important for long-term population regulation (through density-dependent effects).},
  author       = {Klaassen, Raymond and Hake, Mikael and Strandberg, Roine and Koks, Ben J and Trierweiler, Christiane and Exo, Klaus-Michael and Bairlein, Franz and Alerstam, Thomas},
  issn         = {1365-2656},
  keyword      = {animal migration,annual survival,ecology of death,long-distance migration,satellite radio-telemetry},
  language     = {eng},
  number       = {1},
  pages        = {176--184},
  publisher    = {Federation of European Neuroscience Societies and Blackwell Publishing Ltd},
  series       = {Journal of Animal Ecology},
  title        = {When and where does mortality occur in migratory birds? Direct evidence from long-term satellite tracking of raptors.},
  url          = {http://dx.doi.org/10.1111/1365-2656.12135},
  volume       = {83},
  year         = {2014},
}