Spotlight on a Unique Bird: the Guira Cuckoo

Guria Cuckoos are often seen huddled together on branches

I was researching the birds that we might come across in the Pantanal when I discovered an article on the Guira Cuckoo. It is unique among its relative species for many reasons, among which are its communal breeding and its gregariousness. Most cuckoos are obligate parasites, meaning they lay their eggs in other birds' nests and rely on the other birds to rear their chicks. The Guira Cuckoo, however, forms groups of 6 to 8 birds that will lay their eggs within a single nest. Competition between parents is rife within nests, which is often detrimental to the survival of their chicks. Approximately one in four of the chicks survive to fledgling, with the other three quarters of chicks dying from being destroyed, buried or killed during stand-offs between parents.

The Guira Cuckoo has a broad range across most of South America, including eastern Brazil, Bolivia, Paraguay, Uruguay, and northern Argentina. Although it is found most commonly in drier habitats, it is one of the most common cuckoos throughout its range. Birders commonly spot Guira Cuckoos in the Amazon River Basin and the Pantanal.

Sources:
http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=204056
Macedo, Regina HF, Mariana Cariello, and Laura Muniz. "Context and frequency of infanticide in communally breeding Guira Cuckoos." The Condor103.1 (2001): 170-175.
Macedo, Regina H. "COMMUNAL GUIRA CUCKOO (GUIRA GUIRA) IN." The Auk 109.4 (1992): 786-799.