VARIABLE ANTSHRIKE Thamnophilus caerulescens
Variable is possibly an understatement when applied to this bird, it is extremely variable across its wide range, with at least three different forms present in Paraguay. They are shy birds, typical of their family, but ineffectually attempt to suppress a surging curiosity that instinctively makes them investigate birders! They can still be difficult to see well, but sometimes you just get lucky and the bird sits right out in the open while he tries to work out what you are up to!
As its name suggests this species is extremely variable with at least three and possibly four forms/subspecies present in Paraguay. Most distinctive is the white-bellied Chaco form paraguayensis (Gallery 2). In eastern Paraguay (Gallery 1) most of the range is occupied by the buff-vented subspecies dinelli whilst in extreme southern Paraguay a white-vented form also occurs apparently alongside it. To further complicate matters a white-bellied form similar to paraguayensis but with a streaked upper breast occurs in the Laguna Blanca area and it remains unclear to which subspecies these birds belong.
Click on the images to enlarge them.
Gallery 1 - Eastern forms
FIGURE 1 - (FPAVE1860PH) Adult male white-vented form, Hotel Tirol, Departamento Itapúa (Regis Nossent June 2005).
FIGURE 2 - (FPAVE1861PH) Same individual upperwing (Paul Smith June 2005).
FIGURE 3 - (FPAVE1862PH) Adult male buff-vented form presumably ssp dinelli, PROCOSARA, PN San Rafael (Sylvia Qu June 2008).
FIGURE 4 - (FPAVE1863PH) Adult male buff-vented form presumably ssp dinelli, PROCOSARA, PN San Rafael (Paul Smith February 2007).
FIGURE 5 - (FPAVE1864PH) Same individual upperwing (Paul Smith September 2006).
FIGURE 6 - (FPAVE1865PH) Adult female white-vented form, Hotel Tirol, Departamento Itapúa (Regis Nossent June 2005).
FIGURE 7 - (FPAVE1866PH) Adult female buff-vented form, PROCOSARA, PN San Rafael (Sylvia Qu June 2008).
FIGURE 8 - (FPAVE1867PH) Adult female buff-vented form, PROCOSARA, PN San Rafael (Paul Smith February 2007).
FIGURE 9 - (FPAVE1868PH) Same individual upperwing (Paul Smith September 2006).
FIGURE 10 - (FPAVE1869PH) Same individual as (FPAVE1860PH)  and (FPAVE1861PH)  head detail (Regis Nossent June 2005).
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Designed by Paul Smith 2006. This website is copyrighted by law.
Material contained herewith may not be used without the prior written permission of FAUNA Paraguay.
Material on this page was provided by Paul Smith, Adam Betuel, Myriam Velázquez, Alberto Madroño, Matt Denton,
Regis Nossent, Silvia Qu and Arne Lesterhuis and is used with their permission.
Thamnophilus caerulescens
1 (FPAVE1876RE) song ssp dinelli recorded PROCOSARA, PN San Rafael (Paul Smith March 2007).
2 (FPAVE1877RE) contact call ssp dinelli recorded PROCOSARA, PN San Rafael (Paul Smith March 2007).
3 (FPAVE1878RE) contact call ssp paraguayensis recorded Laguna Capitán, Cuenca Upper Yacaré Sur (Paul Smith October 2007).
4 (FPAVE1879RE) song ssp paraguayensis recorded PN Tte Enciso, Departamento Boqueròn (Paul Smith October 2007).
5 (FPAVE1880RE) contact call ssp paraguayensis recorded PN Tte Enciso, Departamento Boqueròn (Paul Smith October 2008).
6 (FPAVE1881RE) song recorded Yaguarete Forest, Departamento San Pedro (Myriam Velázquez August 2000).
Click the link to hear the call. Longer versions of this call can be downloaded from the Paraguay page of our partner website www.xeno-canto.com - the largest collection of freely downloadable Neotropical bird calls available online.
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Gallery 2 - Chaco forms
FIGURE 11 - (FPAVE2702PH) Adult male white-bellied Chaco form ssp paraguayensis, Cuenca Upper Yacaré Sur, Departamento Presidente Hayes (Matt Denton October 2010).
FIGURE 12 - (FPAVE1870PH) Adult male white-bellied Chaco form ssp paraguayensis, near Lolita, Colonia Fernheim, Departamento Boquerón (Arne Lesterhuis August 2007).
FIGURE 13 - (FPAVE1871PH) Adult male white-bellied Chaco form ssp paraguayensis, Ruta Trans-Chaco km650 (Adam Betuel June 2006).
FIGURE 14 - (FPAVE1872PH) Adult male white-bellied Chaco form ssp paraguayensis, Cerro León, Departamento Boquerón (Alberto Madroño July 1990)
FIGURE 15 - (FPAVE1873PH) Same individual dorsal view (Alberto Madroño July 1990)
FIGURE 16 - (FPAVE1874PH) Adult female white-bellied Chaco form ssp paraguayensis, PN Tte Enciso, Departamento Boquerón (Paul Smith October 2007)
VIDEO - (FPAVE1875VI) Female white-vented form, Hotel Tirol, Departamento Itapúa (Paul Smith March 2010).