Campo Troupial - Icterus jamacaii
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Mãe-da-lua
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in Itapajé, Ceará,
100 km from Fortaleza.
Presentation
Mammals

The avifauna is listed in
Birds of NE Brazil.
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Threatened species
Many species of NE Brazil are threatened by extinction. Our reserve helps to protect some of them:
Birds of NE Brazil
in Caatinga, Cerrado,
and other habitats
Bicoloured Hawk
Accipiter bicolor
Gavião-bombachinha-grande
To go to the main page for this species, click here.
Bicolored Hawk Accipiter bicolor
11/03/2012; Mãe-da-lua private reserve, Itapajé, Ceará, Brazil. 300mm f2.8 lens.
Figure 1. This bird and its mate vocalized repeatedly when I came close to the tree with their nest on 11/03/2012. The main vocalization was like sound h1682, and I was surprised by this striking vocal behavior of a bird known for its discrete life style, especially since I had not used playback.

However, I employed moderate playback later, to improve my chances to take pictures. The bird on the photo (same individual as in figure 2 of main page) is responding to this playback.

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Sound of Bicoloured Hawk (Accipiter bicolor)
19/02/2012, 09h46. Mãe-da-lua private reserve, Itapajé, Ceará, Brazil. h1682. (c) H. Redies.
Sound h1682. Song of Accipiter bicolor.

(A) Sound given by a Bicoloured Hawk that flew over me, reacting to playback, at a distance of several hundred meters from the nest mentioned before. The variing amplitude of the vocalization, first increasing and then decreasing, probably reflects the changing distance between the flying bird and the microphone, and not real changes in the loudness of the song. The two notes in the highlighted area are shown in detail in (B).

(B) Details of highlighted area of (A). The song of Accipiter bicolor has a strange, squawking-like timbre. The physical correlate of this are the many pronounced harmonics over a wide frequency range, in this example from 600-800 Hz (fundamental) to over 14 kHz.

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14/03/2012, 16h39. Mãe-da-lua private reserve, Itapajé, Ceará, Brazil. h1759. (c) H. Redies.
Sound h1759. Song of Accipiter bicolor.

Spontaneous song given by a Bicoloured Hawk (very probably the individual in figure 1), when I approached its nesting site. The bird was apparently alone at the nest, and vocalized 3-4 times during the 15 mins or so that I stayed in the vicinity. Song h1759 was given while the hawk flew from one tree to another.

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Calls of Bicoloured Hawk (Accipiter bicolor)
19/02/2012, 07h14. Mãe-da-lua private reserve, Itapajé, Ceará, Brazil. h1682. (c) H. Redies.
Sound h1698. Calls of Accipiter bicolor.

Sounds produced by a Bicoloured Hawk in response to playback. I was walking on a trail at a distance of 150-200 meters from the nesting site, which at this moment was still unknown to me. The hawk flew over me, apparantly looking for the presumed conspecific, and repeatedly gave these calls. The sonogram shows the first two (labels c1 and c2) of the four notes in recording h1698. I suppose that these vocalizations, which I also heard on several occasions, are contact calls.

In the background, Pachyramphus polychopterus, Tolmomyias flaviventris, Vireo olivaceus, and possibly Hemitriccus margaritaceiventer.

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25/02/2012, 05h33. Mãe-da-lua private reserve, Itapajé, Ceará, Brazil. h1722. (c) H. Redies.
Sound h1722. Calls of Accipiter bicolor.

Calls given spontaneously, close to nest, at dawn. The notes sound higher pitched and sharper than in h1698. Possibly, these calls have a different function (alert?).

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