Scarlet Secrets: Scientists Uncover Ancient Breeding of Scarlet Macaws

Evidence from the Old Town archeological site suggests scarlet macaws were bred in today’s New Mexico in the 1100s, predating known breeding sites in Northwestern Mexico.

According to an analysis of eggshell fragments found at the Old Town archaeological site, scarlet macaws (Ara macao) were being bred in what is now New Mexico during the 1100s. Cyler Conrad and his team studied six of these eggshell fragments, which were discovered alongside the articulated remains of a macaw. The eggshells are indirectly dated to the early 1100s by previous bone radiocarbon dating of the macaw.

Using a non-destructive scanning electron microscope, the authors looked for evidence of fetal development inside the eggs, which can be inferred from the reabsorption of a layer of eggshell known as the mammillary cone. Five specimens showed clear evidence of reabsorption, and the samples included at least two separate eggs, based on the developmental ages identified.

The presence of fertilized scarlet macaw eggs at this site strongly suggests macaw breeding was occurring at Old Town in the 1100s. This is the first evidence of macaw breeding north of Paquimé, in Northwestern Mexico, where macaw breeding was known to occur after 1275.

According to the authors, the findings may help shed light on the practice of breeding and keeping macaws in the Americas.

The birds are native to the rainforests of Mexico and Central America but were transported and kept by people as far north as the desert Southwest in what is now the United States as early as the 600s. Contemporary experts are not sure precisely why scarlet macaws were bred and translocated.

Reference: “Scarlet macaw (Ara macao) breeding at the Mimbres archaeological site of Old Town (early AD 1100s) in Southwestern New Mexico” by Cyler Conrad, Kimberly Wurth, Travis Tenner, Benjamin Naes, Steven A LeBlanc, Darrell Creel, Katharine Williams and E Bradley Beacham, 13 June 2023, PNAS Nexus.
DOI: 10.1093/pnasnexus/pgad138