<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The annual survival rate of adult raptors is an important parameter in population dynamics and is needed to derive measures for population stability and conservation management. Here we studied adult European honey buzzards (<italic>Pernis apivorus</italic>), a migratory land bird, using satellite telemetry throughout the year for up to three years. We used the Kaplan-Meier method of survival estimation in combination with the distribution density function for survival. This function describes the number of survivors N as a function of time t, based on the survival rate SR. This probabilistic extension of the Kaplan-Meier estimator results in a simple method that does not require a commercial statistical program to extract survival rates from event time analysis. It can be applied to analysing any event-time data, not only telemetry results but also ring recoveries, as demonstrated using European honey buzzards as an example. The average adult survival rate in our study, based on permanent satellite telemetry monitoring, was 0.44/year (linear correlation factor f = 0.99). This implies an adult mortality rate of 0.56 per year. It seems that particularly unfavourable weather conditions during the crossing of the Sahara and the Mediterranean led to this high mortality rate of our birds during migration from 2001 to 2011, but is likely to vary greatly from year to year. However, the loss rate in the wintering area was also high, at one third of the birds. More honey buzzards need to be tracked throughout the year to assess factors affecting survival and threats to populations adequately.</p>
</abstract>

The annual survival rate of adult raptors is an important parameter in population dynamics and is needed to derive measures for population stability and conservation management. Here we studied adult European honey buzzards (Pernis apivorus), a migratory land bird, using satellite telemetry throughout the year for up to three years. We used the Kaplan-Meier method of survival estimation in combination with the distribution density function for survival. This function describes the number of survivors N as a function of time t, based on the survival rate SR. This probabilistic extension of the Kaplan-Meier estimator results in a simple method that does not require a commercial statistical program to extract survival rates from event time analysis. It can be applied to analysing any event-time data, not only telemetry results but also ring recoveries, as demonstrated using European honey buzzards as an example. The average adult survival rate in our study, based on permanent satellite telemetry monitoring, was 0.44/year (linear correlation factor f = 0.99). This implies an adult mortality rate of 0.56 per year. It seems that particularly unfavourable weather conditions during the crossing of the Sahara and the Mediterranean led to this high mortality rate of our birds during migration from 2001 to 2011, but is likely to vary greatly from year to year. However, the loss rate in the wintering area was also high, at one third of the birds. More honey buzzards need to be tracked throughout the year to assess factors affecting survival and threats to populations adequately.

Annual survival rates of satellite-tracked adult European honey buzzards (<italic>Pernis apivorus</italic>) based on the Kaplan-Meier estimator and its probabilistic extension

Raptor Journal

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Annual survival rates of satellite-tracked adult European honey buzzards () based on the Kaplan-Meier estimator and its probabilistic extension

The annual survival rate of adult raptors is an important parameter in population dynamics and is needed to derive measures for population stability and...

Annual survival rates of satellite-tracked adult European honey buzzards (Pernis apivorus) based on the Kaplan-Meier estimator and its probabilistic extension

Published Online: Jun 26, 2024

Page range: 15 - 24

Received: Apr 03, 2024

Accepted: May 04, 2024

DOI: https://doi.org/10.2478/srj-2024-0003

Keywords
year-round monitoring, satellite telemetry, mortality, tagging, biologging, raptors, birds of prey

© 2024 Bernd-Ulrich Meyburg et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Annual survival rates of satellite-tracked adult European honey buzzards (Pernis apivorus) based on the Kaplan-Meier estimator and its probabilistic extension

Published Online: Jun 26, 2024

Page range: 15 - 24

Received: Apr 03, 2024

Accepted: May 04, 2024

DOI: https://doi.org/10.2478/srj-2024-0003

Keywordsyear-round monitoring, satellite telemetry, mortality, tagging, biologging, raptors, birds of prey

© 2024 Bernd-Ulrich Meyburg et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
year-round monitoring, satellite telemetry, mortality, tagging, biologging, raptors, birds of prey