Selective disappearance based on navigational efficiency in a long-lived seabird

Whilst efficient movement through space is thought to increase the fitness of long-distance migrants, evidence that selection acts upon such traits remains elusive. Here, using 228 migratory tracks collected from 102 adult breeding common terns (Sterna hirundo) aged 3 – 22 years, we find evidence that older terns navigate more efficiently than younger terns, and that efficient navigation leads to a reduced migration duration and earlier arrival at the breeding and wintering grounds. 
We additionally find that the age-specificity of navigational efficiency in adult breeding birds cannot be explained by within-individual change with age (i.e. learning), suggesting the selective disappearance of less navigationally efficient individuals. 
This suggests that, at least in common terns, learning of navigational skills may be largely absent in adulthood, and limited to the pre-breeding phase of life where tracking is more difficult.
We propose that selection might explain parts of the age-spec..., Study population
 
The common tern is a long-lived, migratory seabird (Becker and Ludwigs 2004). The data we present here come from a long-term study population of common terns located at the Banter See in Wilhelmshaven on the German North Sea coast (53°30’40” N, 08°06’20” E). Here, chicks have been ringed since 1980, while the presence and reproductive performance of individually marked adults has been monitored following a standard protocol since 1992. Hereto, 101 adult birds were caught and marked with individually numbered subcutaneously injected transponders, and, since 1992, all locally hatched birds have been ringed as well as marked with such a transponder shortly prior to fledging.
 
As part of the standard protocol, arrival date is monitored using antennae affixed to the walls of the colony (Moiron et al. 2024) and the colony site is checked three times a week to find nests and record laying dates, clutch sizes and egg sizes. During incubation, which is shared between partners..., , # Selective disappearance based on navigational efficiency in a long-lived seabird

[https://doi.org/10.5061/dryad.m63xsj4cj](https://doi.org/10.5061/dryad.m63xsj4cj)

## Description of the data and file structure

The common tern is a long-lived, migratory seabird (Becker and Ludwigs 2004). The data we present here come from a long-term study population of common terns located at the Banter See in Wilhelmshaven on the German North Sea coast (53°30’40” N, 08°06’20” E). Here, chicks have been ringed since 1980, while the presence and reproductive performance of individually marked adults has been monitored following a standard protocol since 1992. Hereto, 101 adult birds were caught and marked with individually numbered subcutaneously injected transponders, and, since 1992, all locally hatched birds have been ringed as well as marked with such a transponder shortly prior to fledging.

As part of the standard protocol, arrival date is monitored using antennae affixed to the walls of the c...