Links between personality, reproductive success and re-pairing patterns in a long-lived seabird

In long-lived monogamous species, the trigger of costly re-pairing is not
always clear. Limited research suggests that within-pair behavioural
compatibility may be an important driver of partnership success, as
cooperation should be enhanced when pair members’ decisions complement one
another. Animals’ decision-making processes are influenced by personality
traits – defined as individual differences in behaviour that are stable in
time. Despite the potential for the personality trait ‘boldness’ to a)
directly impact individual willingness to re-pair and b) indirectly impact
re-pairing choices via reproductive success, there is currently little
work exploring how re-pairing decisions might be impacted by the pair
members’ personalities. Using a 13-year dataset, we investigated whether
within-pair boldness and its relationship with breeding success explained
re-pairing patterns of black-legged kittiwakes (Rissa tridactyla),
breeding in two Arctic colonies. We found that pairs with dissimilar
boldness levels were more likely to experience breeding failure and that
failed pairs were more likely to re-pair the following year. Despite this,
only one colony displayed evidence of assortative mating by boldness, and
there was no indication that re-pairing impacted reproductive success the
following season. Neither individual nor pair boldness directly influenced
re-pairing probability, however, in both colonies, re-pairing birds chose
partners that were slightly more similar to themselves in boldness than
their previous mates. These results imply an indirect pathway by which
poorer behavioural compatibility within pairs may lead to breeding failure
and ultimately re-pairing. Our findings highlight the importance of
behavioural compatibility, and possibly personality, in mitigating sexual
conflict and its population-specific drivers.