Mothers adjust egg size to helper number in a cooperatively breeding cichlid
By B. Taborsky, Eva Skubic, R. Bruintjes. 2007
106 citations recorded by the source corpus.
Mothers should adjust the size of propagules to the selective forces to which these offspring will be exposed. Usually, a larger propagule size is favored when young are exposed to high mortality risk or conspecific competition. Here we test 2 predictions on how egg size should vary with these selective agents. When offspring are cared for by parents and/or alloparents, protection may reduce the predation risk to young, which may allow mothers to invest less per single offspring. In the cooperatively breeding cichlid Neolamprologus pulcher, brood care helpers protect group offspring and reduce the latters' mortality rate. Therefore, females are expected to reduce their investment per egg when more helpers are present. In a first experiment, we tested this prediction by manipulating the helper number. In N. pulcher, helpers compete for dispersal opportunities with similar-sized individuals of neighboring groups. If the expected future competition pressure on young is high, females should increase their investment per offspring to give them a head start. In a second experiment, we tested whether females produce larger eggs when perceived neighbor density is high. Females indeed reduced egg size with increasing helper number. However, we did not detect an effect of local density on egg size, although females took longer to produce the next clutch when local density was high. We argue that females can use the energy saved by adjusting egg size to reduced predation risk to enhance future reproductive output. Adaptive adjustment of offspring size to helper number may be an important, as yet unrecognized, strategy of cooperative breeders. Copyright 2007, Oxford University Press.
Subfields: Ecology, Ecology, Evolution, Behavior and Systematics
View Paper: https://www.semanticscholar.org/paper/1b39bbd8c386074125b3ff63a6dbf9571fa57a11
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In Ecology
In Ecology, Evolution, Behavior and Systematics
Citations in the corpus
- Size-dependent task specialization in a cooperative cichlid in response to experimental variation of demand (2011, background): “2005), which increases fecundity (Taborsky 1984) and affects egg size (Taborsky et al. 2007).”
- How to balance the offspring quality–quantity tradeoff when environmental cues are unreliable (2011, unknown): “Several empirical studies have given support for this theoretical prediction (Jonsson et al. 1996, Fox et al. 1997, Hendrickx et al. 2003, Bashey 2006, Taborsky et al. 2007, Allen et al. 2008, Leips et al. 2009) and have identified the environmental factors linked with offspring size plasticity.”
- The Evolution of Social Behaviour (2021, background): “Safety of subordinates is traded against energetic load- lightning of breeders (Taborsky et al., 2007; Zöttl et al., 2013a) and offspring survival (Brouwer et al., 2005), and this is stabilized by a latent threat of punishment and eviction (Fischer et al., 2014).”