Function of the plumage. First that the whole plumage is a system of attraction for its couple, mainly she/he is carried out an exhibition of the plumage in reproduction times. The plumage of the oldest males is more sementado due to the continuous ones silent annual. These copies use the plumage to carry out games and disputes with other males, having manifestations of territorial behavior mainly. The plumage, as much in the female as in the male, prevents attacks of possible predators, since they are camouflaged very well in the hábitat in which you/they live. The male with their yellow head and black body achieves an almost perfect camouflage among the Bidens, while the female achieves it in such plants as the Rumex crispus and the rushes (Scirpus californicus ) due to her plumage of color green olive.

The Agelaius icterocephalus bogotensis makes two changes a year, mainly in winter season, where simultaneously the reproductive phase begins. In our study we will describe the pursuit carried out several chicks and adults that contributed to the exhibition of the topic it has more than enough plumage.

Native plumage. The pursuit made a recently left chick of the they cracked it put us in evidence that there are small down dark brown color in the superior part of the body. This down extends until the second or third day of having been born.

Postnatal plumage. Inside the process of development of the chick we find the postnatal plumage, which understands from the third day until the tenth third day, where the chicks are volantones reason for which you/they possess a developed plumage and they prepare to pass to the juvenile phase. The down you darker tornan until ending up being black and in the small males the first features of the yellow hood are evidenced in the occipital part and storm of the head, while the females in their immature state conserve the green tonality a little. Our observations gave us rules to affirm that the follicles expand much more to open the way to the first down and feathers. The last part in being populated is the neck and the initial part of the tarsos.

Juvenile plumage. In the juvenile one a very similar plumage is observed that of the adult, although with some exceptions. In the juvenile males the plumage has acquired most of the characteristics of the mature plumage, although it has been observed that the yellow color of the head doesn't still possess the adult's intense tonality and as for the plumage of the body, you black restitution as that of the adult, but contrary to the adult it has not been developed smaller density of the same one totally since it is observed. In the female something happens very similar; this has not still acquired the brilliant coloration in their chest and the general plumage is more opaque than that of the mature female, giving the appearance of clear brown color.

Maturity of the plumage. The maturity of the plumage is acquired with the arrival of several winter stations; in the area we observe that most of the flock possesses a consolidated plumage and of adult.