Few cuckoos have been studied intensively in terms of egg mimicry, but the phenomenon is known to occur in at least some species.
A number of gastropod studies have related heavy metal exposure, in particular exposure to Cu [6]-[8] and Zn [6], [9], [10], to reduced fecundity – reproductive output usually measured in terms of egg laying.
The final outcome of the interactions between cuckoos and parrotbills in terms of egg phenotypes is obviously difficult to predict based on the results from the present 11-year study.
Toward that end, first-laid propagules would not seem to have the highest value, and, consistent with this, they incur no greater initial investment in terms of egg size than do later-laid propagules.
While fecundity, in terms of egg numbers or size, may increase through FA fish having high energy reserves, the composition of stored lipids in FA saithe and cod may differ from those of UA fish which consume a natural diet (Fernandez-Jover et al. unpubl. data).
The reproductive output in terms of egg production, egg hatching success and larvae production of females whose matings were interrupted at predetermined times showed an overall positive relationship with copulation duration, up to a certain plateau.
In terms of egg production, females laid similar numbers of eggs regardless of mating with conspecifics, heterospecifics, or one or both (Anova: F 3,116 = 0.76, P = 0.52; Figure 6).
Expression levels of vg were higher in active queens than in workers, which is consistent with studies in honey bees [ 38], and with the superiority of the B. terrestris queen over workers in terms of egg production.
Our system allows us to test for benefits of polyandry at levels of genetic similarity ranging from full siblings to heterospecifics, both in terms of egg production and hatching success.
