The Doñana Biological Station has explored the suitability of exotic tree plantations as breeding habitat for an island endemic raptor, the Macaronesian sparrowhawk (Accipiter nisus granti)

Biotic resistance by native communities could have a role in the spread of invasive species. Native communities with higher species richness should be less susceptible to invasion by exotic species than those with fewer component species, interspecific interactions acting as biotic barriers by creating a highly competitive environment. This seems to be the case in the invasion of the Argentine ant, Linepithema humile. The progress of Argentine ant invasion through favorable and unfavorable...

The accumulation of the amino acid cysteine in lysosomes produces toxic substances, which are avoided by a gene (CTNS) coding for a transporter that pumps cystine out of lysosomes. Melanosomes are lysosome-related organelles that synthesize melanins, the most widespread pigments in animals. The synthesis of the orange melanin, termed pheomelanin, depends on cysteine levels because the sulfhydryl group is used to form the pigment. Pheomelanin synthesis may, therefore, be affected by cysteine...

Melanins form the basis of animal pigmentation. When the sulphurated form of melanin, termed pheomelanin, is synthesized, the sulfhydryl group of cysteine is incorporated to the pigment structure. This may constrain physiological performance because it consumes the most important intracellular antioxidant (i.e., glutathione, GSH), of which cysteine is a constitutive amino acid. However, this may also help avoid excess cysteine, which is toxic. Pheomelanin synthesis is regulated by several...

Avian nests are frequently concealed or camouflaged, but a number of species builds noticeable nests or use conspicuous materials for nest decoration. In territorial species decorations may serve as extended phenotypic signaling of nest-site occupancy and social status to potential intruders. The latter may benefit both signaler and receiver by minimizing the risk of aggressive interactions. Here, it was tested whether nest decorations increased nest-site visibility to conspecifics in black...