The crested caracara (Caracara cheriway) is a large raptor found in Central and South America, Mexico, and the southern United States. This distinctive bird has a fascinating history and origins that provide insight into its current range and ecology.
Taxonomy and Classification
The crested caracara belongs to the family Falconidae, which includes falcons, falconets, and caracaras. It is placed in the genus Caracara and is generally considered to be monotypic, meaning there are no recognized subspecies. Its closest relatives are the southern caracara and mountain caracara.
The scientific name Caracara cheriway was given to the crested caracara by the French naturalist Jacques Barraband in 1783. The genus name Caracara is derived from the Portuguese name “caracarĂ¡” for this group of raptors, while the species name “cheriway” also has Tupi-Guarani origins.
Evolutionary Origins
The evolutionary history of the crested caracara can be traced back around 6 million years to the Miocene epoch when the ancestral caracaras diverged from other falconids. During the Pleistocene Ice Age, populations became isolated in southern refuges leading to the differentiation of the crested caracara and its closest relatives.
Recent genetic studies have helped shed light on the phylogeny of the crested caracara. Analyses of mitochondrial DNA sequences found that the crested caracara lineage diverged from that of the mountain caracara around 1.6–4.6 million years ago. The divergence between the crested caracara and southern caracara likely occurred more recently, around 440,000 years ago.
So while the crested caracara shares a common ancestry with other caracaras, it has followed its own distinct evolutionary path for hundreds of thousands to millions of years. Isolation and adaptation to different environments drove the divergence that led to the unique traits seen in the crested caracara today.
Origins of the Current Range
The range of the crested caracara has shifted over time in response to glacial cycles, habitat changes, and other factors. During the Last Glacial Maximum around 18,000 years ago, populations contracted into refugia in Central America, Cuba, and potentially Florida.
As the ice sheets retreated, the crested caracara expanded its range northward, reaching the southern United States by around 10,000 years ago. Fossil evidence indicates crested caracaras occurred as far north as Kansas during the Pleistocene. After the last glaciation, its range contracted again to the south.
The modern range extends from central Mexico south through Central America and much of South America. In the United States, the core range includes southern Texas, Louisiana, and Florida. Breeding populations also occur in Arizona and small numbers reach southern California and New Mexico.
Habitat availability has played a key role in shaping the distribution of the crested caracara. It prefers open or semi-open country including pastures, agricultural areas, savanna, and desert scrub. Deforestation and the clearing of land for ranching likely enabled the crested caracara’s expansion northward from its tropical origins.
Evolution of Ecological Niche
The ecology and behavior of the crested caracara also sheds light on its origins and adaptations. This unique raptor fills an unusual niche as a scavenger and opportunistic forager. It often feeds on carrion and even excrement, helping clean up the environment.
The crested caracara’s resourcefulness and generalist diet may have evolved due to high levels of competition from other raptors in its tropical range. Vultures dominate scavenging and predation niches in Central and South America, likely limiting the role of the caracara as a predator.
Morphological traits also point to the crested caracara’s scavenging lifestyle. Its robust, vulture-like build allows it to efficiently search for and consume carrion. Strong legs and feet help drive off competitors from meals. The large bill enables tearing and processing of meat.
Interestingly, populations in Florida and Mexico are more predatory, actively hunting snakes, lizards, squirrels, and other prey. This variation in diet and foraging strategies underlines how the crested caracara has adapted to local conditions across its range.
Ancient History and Early Descriptions
The crested caracara has a long history of interaction with humans, as evidenced by its presence in Mayan iconography dating back to the first millennium AD. Caracaras were symbolically important birds among the Mayans, representing vision and power. This reverence perhaps stemmed from the caracara’s keen eyesight and audacity.
Early naturalists made note of the remarkable caracara. The species was first scientifically described by the French ornithologist Louis Pierre Vieillot in 1816 based on a specimen from Paraguay. He gave it the name Polyborus plancus, placing it in the same genus as the southern caracara.
In 1844, the German naturalist Johann Jakob Kaup moved the crested caracara to its current genus Caracara, noting significant differences from the southern caracara warranting separation into a new genus. Kaup gave it the specific epithet cheriway but retained the name Caracara plancus.
Other notable early descriptions came from John James Audubon, who called it the “Mexican eagle” and “guadalupe caracara,” and Alexander Wilson, who referred to it as the “Brazilian eagle” and “carrion crow”. These early accounts captured the crested caracara’s distinctive appearance and varied diet.
Conservation Status
The crested caracara has a wide distribution across Central and South America and sizable populations in Florida, Texas, and Mexico. The total population is estimated at around 650,000 individuals. Numbers increased significantly in Florida during the 20th century as the caracara expanded into anthropogenic habitats.
Due to its large and stable population, the crested caracara is classified as Least Concern on the IUCN Red List. However, localized threats include poisoning from feeding on carcasses killed with pesticides, vehicle collisions, and habitat loss. The population in the southwestern United States is small but appears to be increasing.
While not globally threatened at this time, the crested caracara warrants continued monitoring given its niche as a scavenger and the ongoing conversion of its native grasslands. Sustainable agricultural practices and protection of natural habitats will benefit this unique raptor across its range.
Conclusion
In summary, the crested caracara has a long independent evolutionary history dating back millions of years. Isolation of populations and adaptation to open environments of its tropical range shaped the niche we see today. It has a fascinating natural history intertwined with ancient Mayan culture and early scientific study.
While the survival of the crested caracara is not currently at risk, maintenance of healthy ecosystems across Central and South America will ensure the persistence of this remarkable bird into the future. The crested caracara’s flexibility and resourcefulness may allow it to withstand some habitat changes, but conservation of grasslands and sustainable practices will be critical over the long term. Looking back at where the crested caracara has come from provides insights that can guide conservation efforts going forward.