DOI: 10.5061/dryad.6t9p3
title: Data from: Birth date predicts alternative life-history pathways in a fish with sequential reproductive tactics

description: In species with plastic expression of alternative reproductive tactics
 (ARTs), individuals of the same sex, usually males, can adopt different
 reproductive tactics depending on factors such as body size. The ‘birth
 date hypothesis’ proposes that condition-dependent expression of ARTs may
 ultimately depend on birth date, because individuals born at different
 times of the year may achieve different sizes and express different
 reproductive tactics accordingly. However, this has rarely been tested.
 Here, we tested this hypothesis in a fish with ARTs, the peacock blenny
 (Salaria pavo). A long-term (6 years) mark–recapture study demonstrated
 that ARTs in the peacock blenny were sequential and that males may follow
 at least two alternative life-history pathways: a nest-holder pathway, in
 which males express the nest-holder tactic from their first breeding
 season onwards, and a parasitic pathway, where males reproduce on their
 first breeding season as sneaker males and subsequently as nest-holders.
 We have found evidence of a birth date effect on the expression of ARTs in
 the peacock blenny. Males following the nest-holder pathway are born
 earlier and are larger at the first breeding season than males following
 the parasitic pathway, but they have similar growth curves. The mechanisms
 underlying a birth date effect are far from clear and might be diverse. We
 have not found support for a mechanism of body size threshold triggering
 sexual maturation and subsequent ARTs. A mechanism of tactic determination
 that is strictly based on timing of first maturation is also unlikely. A
 proxy of lifetime reproductive success shows crossing (body size
 associated) fitness curves for the two main life-history pathways.
description: Data for Birth date
 predicts alternative life history pathways in a fish with sequential
 reproductive tacticsThe data refer only to
 males whose pathways were possible to identify in the cohorts 2000-2004.
 Comments to the excel table: On sheet "TL pathways": Pathway -
 life-history pathway followed by the male; TL switch - total length at the
 moment of switch from Sneaker to Nest-holder morphotype (the average TL
 value estimated for the last time the male was seen as Sneaker and the
 first time that it was seem as Nest-holder ); switch month - mid point
 between the month in which the male was last seen as sneaker and the first
 month in which it was seen as a Nest -holder as long as these 2 dates were
 not more than 2 months apart; For each male the value of TL in presented
 for each of the census in which that male was captured and measured.
 Values are presented in cm. On sheet "reproductive success
 pathways": Pathway - life-history pathway followed by the male; TL
 1st breeding season - average of total length during the first breeding
 season, age 0+/1; Lifetime eggs - sum of all eggs present inside the nest
 of the male for the whole time in which it was a Nest-holder (not
 corrected for the eggs that are ind^side the nest but are actually
 fertilized by other males, sneakers; also not taken into account
 ).Data
 birthdate ART Spavo.xlsx