Content with tag evolutionary ecology .

Parasitoidism of host flies by parasitoid wasps in Spain

Parasitoid wasps may act as hyperparasites and sometimes regulate the populations of their hosts by a top-down dynamic. Nasonia vitripennis is a generalist gregarious parasitoid that parasitizes several host flies, including the blowfly Protocalliphora, which in turn parasitizes bird nestlings. Nonetheless, the ecological factors underlying N. vitripennis prevalence and parasitoidism intensity on its hosts in natural populations are poorly understood. The prevalence of N. vitripennis in...

LC-MS determination of catecholamines and related metabolites in red deer urine and hair

A novel analytical methodology for the determination and extraction of catecholamines (dopamine, epinephrine and norepinephrine) and their metabolites DL-3,4-dihydroxyphenyl glycol and DL-3,4-dihydroxymandelic acid by LC-MS is here developed and validated for application to human and animal urine and hair samples.

Size increase without genetic divergence in the Eurasian water shrew Neomys fodiens

When a population shows a marked morphological change, it is important to know whether that population is genetically distinct; if it is not, the novel trait could correspond to an adaptation that might be of great ecological interest. Here, a subspecies of water shrew, Neomys fodiens niethammeri, which is found in a narrow strip of the northern Iberian Peninsula was studied.

Juvenile pheomelanin-based plumage colouration has evolved more frequently in carnivorous species

Distinctive pheomelanin-based plumage colouration in juvenile birds has been proposed as a signal of immaturity to avoid aggression by older conspecifics, but recent findings suggest a detoxifying strategy. Pheomelanin synthesis implies the consumption of cysteine, a semi-essential amino acid that is necessary for the synthesis of the antioxidant glutathione (GSH) but that may be toxic if in excess in the diet.

“Planned obsolescence” in the plumage of larks

Larks (Alaudidae) present a heavily worn plumage for the most part of the annual cycle. Authors observed that lark feathers have unmelanized fringes and are prone to breakage. Larks may have turned need into a virtue: they possibly cannot avoid a premature damage of their fragile plumage, and instead of incurring the cost of molting repeatedly, they gain the advantage of a form of crypsis known as disruptive camouflage.