America Hernandez

Autonomous University of Tlaxcala · Departamento de Biología

Colorful traits play an important role in animal communication. Melanin‐based colorations are the most extended color traits in animals and are produced by two types of endogenous melanic pigments: eumelanins and pheomelanins, the last ones being the least studied in the context of communication. The production of pheomelanin requires a semi‐essent...

Insulin-like growth factor 1 (IGF-1) is positively linked with growth and reproduction but negatively linked with survival, so a potential role of IGF-1 in modulating life history trade-offs has been proposed. However, the underlying mechanisms of the negative link between IGF-1 and survival are not yet clear, and oxidative stress has been proposed...

The environmental stressors that females face before egg laying, such as competition for resources, can impact the fitness prospects of the female as well as her offspring through hormone‐mediated maternal effects. In obligate secondary cavity‐nesting species, suitable nest‐holes are a limited resource, so gaining access to nest‐sites may require c...

Colourful traits in females are suggested to have evolved and be maintained by sexual selection. Although several studies have evaluated this idea, support is still equivocal. Evidence has been compiled in reviews, and a handful of quantitative syntheses has explored cumulative support for the link between condition and specific colour traits in ma...

Female of obligate secondary cavity-nesting species compete aggresively over nest cavities. Aggresive events can promote change in steroid hormone deposition in yolk, and influence offspring development. In the Western bluebird (Sialia mexicana), we experimentally evaluated whether aggressive intrusions during nest building affect testosterone and...

An effective immune response is essential for surving the attack of parasites and pathogens during early life but its activation can be energetically costly. Is still largely unknown, however, whether activating the immune response trade-offs against growth or survival during early development, and if so what are the physiological mechanisms that c...