A reprodução do cancão na caatinga
Autor: Nilton de Brito Cavalcanti | Publicado: 2017-04-24T10:51:00-07:00

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As fotos


Nestas fotografias podemos observar alguns aspectos da reprodução do cancão na
caatinga. As fotografias foram obtidas no município de Petrolina, PE.




























































Os fatos


O cancão com suas cores pretas e brancas é uma das mais belas aves da caatinga.
Seu canto é forte e marcante. É um pássaro muito curioso e quando percebe
qualquer coisa estranha começa a cantar, para chamar a atenção dos outros
animais. Normalmente o cancão anda em bando de 3 pássaros. Parece que o grupo é
o que nasce em cada ninhada. Para fazer o ninho, o cancão recolhe pequenos
gravetos no chão da caatinga e levar para uma árvore onde faz o ninho, de
preferência, jurema, umburana e imbuzeiro. O ninho frequentemente é abandonado.
Normalmente são encontrados 3 a 4 ninhos onde eles não realizaram a postura
porque alguma coisa assustou os pássaros. O período de postura ocorre
geralmente de janeiro a março, contudo em anos de seca, a reprodução pode estende-se
até o mês de abril e maio Normalmente, põe três ovos que geram filhotes
aproximadamente aos 20 a 28 dias. Quando os filhotes nascem, há uma intensa
disputa por alimento e muitas vezes sobrevivem apenas dois, embora os filhotes
sejam alimentados por todos os membros do grupo. O filhote nasce com uma
membrana sobre os olhos que cai nos primeiros 5 a 7 dias. Como o ninho é muito
pequeno e raso, muitas vezes não acolhe devidamente os filhotes quando crescem.
Um fato muito curioso é que o cancão retira ou consome todos os excrementos dos
filhotes. Não são encontrados restos de fezes ou de alimentos na proximidade do
ninho do cancão. Talvez essa prática seja para não despertar os predadores. O
cancão alimenta-se de quase tudo que encontra na caatinga, más da preferência a
ovos de outros pássaros e larvas de insetos encontradas em ocos e em baixo das
folhas que caem ao chão. Na caatinga, este pássaro é o principal consumidor dos
frutos das cactáceas, tais como, mandacaru, xiquexique, facheiro e do imbuzeiro
e da umburana. No imbuzeiro o cancão consome muitas sementes.