Cost of Reproduction, Resource Quality, and Terminal Investment in a Burying Beetle

Abstract

We evaluate the cost-of-reproduction hypothesis in the burying beetle Nicrophorus orbicollis and examine how the importance of this trade-off changes as females age (i.e., the terminal-investment hypothesis). These beetles breed on small vertebrate carcasses, which serve as a food resource for them and their offspring. Consistent with the cost-of-reproduction hypothesis, females manipulated to overproduce offspring suffered a reduction in fecundity and life span when compared to controls, although all reproducing females had reduced life spans compared to nonbreeding females. Older females produced larger broods and allocated less of the carcass to their own body mass and a greater proportion to offspring than did younger females. Resource allocation to offspring increased with age. Females given larger carcasses invested more in current reproduction and less in future reproduction than did females given smaller carcasses. Our results provide unconfounded support for both the cost-of-reproduction hypothesis (i.e., current reproduction constrains future reproductive output) and the terminal-investment hypothesis (i.e., the importance of the trade-off between current and future reproduction declines with age such that allocation to current reproduction should increase as females age).

Frequent skipped spawning in the world’s largest cod population

“…2), perhaps reflecting higher migration cost for smaller individuals (38), lesser total energy reserves, and thereby decreased survival after spawning. However, evolutionary theory also predicts that older females are expected to invest more in the present reproductive opportunity, given their limited number of future reproductive opportunities (39,40) compared with younger females, which may increase their lifetime reproductive success by investing in growth (5). Accordingly, spawning omission may be caused by age-dependent differential energy allocation rather than limited energy reserves per se, and some skippers may be expected to grow more than developing fish in the year of missed migration and spawning.…”

Current versus future reproduction and longevity: a re-evaluation of predictions and mechanisms

“…This increase in resource allocation would allow females to incur a fitness benefit if they mobilized relatively more somatic tissue to support reproduction during this final bout than in prior reproductive events (Clutton-Brock, 1984). In support of this idea, several studies have observed enhanced reproductive performance during the terminal reproductive bout (Clutton-Brock, 1984;Poizat et al, 1999;Andrade and Kasumovic, 2005;Isaac and Johnson, 2005;Creighton et al, 2009;Weladji et al, 2010;Fisher and Blomberg, 2011). The physiological mechanisms that would allow females to increase somatic tissue mobilization in old age are unclear and warrant future study.…”

“…1C). Reproductive performance may increase (Andrade and Kasumovic, 2005;Isaac and Johnson, 2005;Creighton et al, 2009;Weladji et al, 2010) or it may decline (Fig. 1C) (Finn, 1963;Newton et al, 1981;Descamps et al, 2009;Hammers et al, 2015;Warner et al, 2016) during a female's final reproductive event(s).…”

Effects of Prior Contest Experience and Contest Outcome on Female Reproductive Decisions and Offspring Fitness

“…Prehatching care includes preparation of the carcass and investment of nutrients in eggs (Rozen et al 2008;Monteith et al 2012), while posthatching care includes brood defense, secretion of antimicrobials, and food provisioning (Eggert et al 1998;Smiseth et al 2003;Rozen et al 2008). Last, there is evidence for a trade-off between investment in current and future reproduction in N. vespilloides and the related Nicrophorus orbicollis: females that overproduce offspring in the first breeding attempt suffer a reduction in fecundity in future breeding attempts (Creighton et al 2009;Ward et al 2009;Billman et al 2014).…”