DOI: 10.5061/dryad.12jm63xss
title: Individual variation in age-dependent reproduction: fast explorers live fast but senesce young?

description: 1. Adaptive integration of life history and behaviour is expected to
 result in variation in the pace-of-life. Previous work focused on whether
 “risky” phenotypes live-fast-but-die-young, but reported conflicting
 support. We posit that individuals exhibiting risky phenotypes may
 alternatively invest heavily in early-life reproduction but consequently
 suffer greater reproductive senescence. 2. We used a 7-year longitudinal
 dataset with &gt;1200 breeding records of &gt;800 female great
 tits assayed annually for exploratory behaviour to test whether
 within-individual age-dependency of reproduction varied with exploratory
 behaviour. We controlled for biasing effects of selective (dis)appearance
 and within-individual behavioural plasticity. 3. Slower and faster
 explorers produced moderate-sized clutches when young; faster explorers
 subsequently showed an increase in clutch size that diminished with age
 (with moderate support for declines when old), whereas slower explorers
 produced moderate-sized clutches throughout their lives. There was some
 evidence that the same pattern characterized annual fledgling success, if
 so, unpredictable environmental effects diluted personality-related
 differences in this down-stream reproductive trait. 4. Support for
 age-related selective appearance was apparent, but only when failing to
 appreciate within-individual plasticity in reproduction and behaviour. 5.
 Our study identifies within-individual age-dependent reproduction, and
 reproductive senescence, as key components of life history strategies that
 vary between individuals differing in risky behaviour. Future research
 should thus incorporate age-dependent reproduction in pace-of-life
 studies.
description: BirdID<br> Bird identity – individual-specific unique
 identifier Plot<br> Plot identity – nest box
 plot-specific unique identifier (12 levels)
 BroodID<br> Brood identity – brood-specific unique
 identifier associated with each nest attempt
 Year<br> Year identity (2010-2016)
 MassSummer<br> Female body mass (in .1 grams) at catching
 during focal breeding attempt ExpFieldScore<br>
 Exploration score – total number of hops among cage locations; test during
 focal breeding attempt. Detailed by Araya-Ajoy et al. (2016).
 ClutchSize<br> Clutch size – total number of eggs produced
 during focal breeding attempt NumberFledged<br>
 Number of fledglings produced during focal breeding attempt; 0 = no
 fledglings (“failed”) AvgDay14Mass<br> Average
 fledgling mass at nestling age 14 PredTreat<br>
 Predation risk treatment<br>        0 = unmanipulated (all years
 except 2013 and 2014)<br>        1 = blackbird treatment
 (“control”); 2 = sparrow-hawk treatement (“manipulated”)<br>       
 Detailed in Abbey-Lee & Dingemanse (2019)
 AgeBreeder<br> Age in calendar years. 0 = age in the year
 following birth. MinAge<br> Minimum age over all
 the records of the focal individual MaxAge<br>
 Maximum age over all the records of the focal individual
 Local<br> Local recruit<br>     1 = ringed as
 nestling in our populations<br>     0 = all other birds
 Dead<br>     1 = not recorded for two years following last
 observation in the dataset<br>     0 = all other birds
 BSManip<br> Brood size manipulation. For details see
 Nicolaus et al. (2015).<br>     0 = unmanipulated<br>     1 =
 reduced (3 nestlings removed)<br>     2 = control (nestling swaps
 applied without changing brood size)<br>     3 = enlarged (3
 nestlings added) “NA”<br> Missing values
 (applicable to multiple variables listed above).
 References<br> Abbey-Lee, R.N. & Dingemanse, N.J.
 (2019) Adaptive individual variation in phenological responses to
 perceived predation levels. Nature Communications, 10, 1601.<br>
 Araya-Ajoy, Y.G., Kuhn, S., Mathot, K.J., Mouchet, A., Mutzel, A.,
 Nicolaus, M., Wijmenga, J.J., Kempenaers, B. & Dingemanse, N.J.
 (2016) Sources of (co)variation in alternative siring routes available to
 male great tits (Parus major). Evolution, 70, 2308-2321.<br>
 Nicolaus, M., Mathot, K.J., Araya-Ajoy, Y.G., Mutzel, A., Wijmenga, J.J.,
 Kempenaers, B. & Dingemanse, N.J. (2015) Does coping style predict
 optimization: an experimental test in a wild passerine bird. Proceedings
 of the Royal Society B-Biological Sciences, 282, 20142405.