Our MECMR models further provide strong support for the proposition not only that current breeding state affects subsequent breeding states, but also that the amount of current reproduction negatively affects subsequent breeding states: a COE reflecting the trade-off between current and future reproduction as predicted by life-history theory [ 23].
From this perspective, perenniality is closely associated with greater resource allocation to growth and somatic maintenance at the expense of current reproduction.
The trade-off between current reproduction and survival is one of the most prominent topics in ecology and life history theory (Williams 1966; Stearns 1992; Ricklefs and Wikelski 2002).
As we have shown, subordinates may be prepared to increase their payments in return for opportunities for current reproduction (the 'pay-to-reproduce' hypothesis).
The trade-off between current reproduction and survival is likely to be more marked in long-lived animals, which are expected to favour the maintenance of their own body condition over that of their young (Drent and Daan, 1980).
One of the costs associated with investment into current reproduction is decelerated somatic growth, which reduces future reproductive output (Roff 1983; Lester et al. 2004).
Furthermore, our previous experimental work shows that burying beetles practice reproductive restraint, holding back resources from current reproduction so as to prolong the lifespan, presumably to increase the chance of breeding again (Cotter et al., 2011).
The findings suggest that adults favour maintenance of cellular homeostasis, and physiological equilibrium over current reproduction, and that the costs induced by both stressors, flea infestation and increased brood size, are carried by the offspring.
Current reproduction may reduce future survival for the parent and hence reduce the reproductive chances in the future (Bell 1980; Lessells 1991; Forbes 1993; Carey and Gruenfelder 1997).
Both genders of uninfected snails fit into the patterns observed for the parasitic castrator species, allocating as much to growth and to current reproduction as expected given their probability of reproductive death (castration by trematode parasites).
