In this paper the authors used a relatively common North American bird from a study site located in a very large urban park in a large city where there are likely 100s – 1000s of the birds living. Given that the authors state “Variation among individuals in late learning may reflect variation in their developmental histories upon entering the lab.” do you think that the study would have benefited from using more birds?
Related, what are the benefits vs. the costs of using more or using fewer animals in research studies like this one that involve manipulating hormone levels?
The text says that: “this population of fish live in a spring-fed stream with constant year-round temperatures and therefore inhabit a relatively stable environment where the need to rapidly respond to unpredictable and dynamic changes is reduced”. What do you think about this? How much did it actually affect the results of the experiment? Would you choose this population for your research?
Since females invest more into the brood than males, do you think that if we tested females who have a decreased fitness they would still choose to invest more into offspring care rather than self-care (meaning spending more time with feeding and drinking rather than parental care)? And if so, would that influence the male’s parental care through the lack of parental care social cues?
How do you think a T mediating gene on the Y chromosome would affect the fitness of both parents?
Please comment with a 2-3 sentence response to each pf the questions below:
Question 1: It seems from the article that S. ocellatus males don’t transform into a different morph once they’ve “reached” the nesting morph. Do you think that if we manipulated a nesting male’s hormone levels (for example increase the cortisol and decrease the 11-kt), they would transform into a satelite/sneaker, which are better suited for these hormone levels, or still remain in the seemingly solid nesting morph?
Question 2: In this paper, they described the hormonal pattern of different alternative reproduction tactics from transcriptomic level to behaviour in Symphodus oscellatus. There are still no information about what causes the transitions between the reproductive morphs. Based on this study, how would you start to investigate the hormonal background of the transition to nesting male? (What would be your general methods and/or which hormone and/or which receptor etc. would you start your investigation with?)
Adkins-Regan et al., 2013 Reading Discussion Leader Question 1:
In the conclusions the authors of the paper state that (when referring to parental effects on offspring) “Some are hormonally mediated or have hormonal consequences. Some are behaviorally mediated or have behavioral consequences. Some are influenced by social factors or learning.” Do you think that some parental effects could be mediated by an interaction between hormones and behavior? If so, why? If not, why not? Please explain using just 2-3 sentences.