News
Evolution of Manatees in Florida

FOR IMMEDIATE RELEASE—January 13, 2025
Contact: media@savethemanatee.org, 407-539-0990
Recent news articles and broadcasts have claimed that manatees are not native to Florida or only arrived on Florida’s west coast in the 1950s. These claims, based on limited anthropological records, point to where manatees were historically exploited by humans and assume that a lack of evidence means manatees were absent from certain areas. However, absence of evidence is not evidence of absence—it’s like looking for stars in the daytime; just because you can’t see them doesn’t mean they’re not there. Moreover, genetic and fossil evidence indicate manatees have been present in Florida for the last 12,000 years.
The Florida Fish and Wildlife Conservation Commission (FWC), which manages Florida manatee populations, has created a manatee timeline highlighting key dates and notable information about manatee presence in Florida (https://myfwc.com/education/wildlife/manatee/timeline/). Historical records suggest that manatees have been observed in Florida as far back as the 1500s, with some details presented by the Florida Fish and Wildlife timeline aligning with evidence presented in the publication.
Manatee species, such as the African manatee and the Antillean manatee, continue to be poached by humans (Marsh et al., 2022). As a result, these species are difficult to observe in the wild and may adapt by foraging at night to avoid human encounters (Rycyk et al., 2021). This behavior could help explain why historical Florida manatee populations that were hunted by humans are absent from middens and rarely mentioned in historical accounts.
Further, the publication only briefly touches on the paleontological record and genetic evidence, which indicate that manatees have existed in Florida for a much longer period. Fossil and genetic evidence reveal a rich history of manatees in Florida. Manatees belong to the order Sirenia, which includes the Amazonian, African, and West Indian manatee species. While Sirenian fossils have been found globally, only Florida and the Caribbean contain specimens from every epoch over the past 50 million years (Reep and Bonde, 2006). The modern manatee, as we know it, emerged in the Caribbean about 2 million years ago (Domning, 1982).
The evolution of manatees during the Pleistocene epoch provides valuable insights into how environmental changes shaped their distribution and genetic diversity. During the Pleistocene epoch (2.59 million to 11,700 years ago), there were roughly 20 cycles of long glacial periods (40,000–100,000 years) followed by shorter interglacial periods lasting around 20,000 years. At the start of these warmer periods, Caribbean manatees migrated northward with the warming waters (Reep and Bonde, 2006). Water currents and thermal barriers isolated these manatees from populations in Mexico and the Caribbean, leading to genetic divergence. Fossil evidence indicates that Trichechus manatus bakerorum lived in Florida and North Carolina about 125,000 years ago but did not survive the last glacial period, which began 100,000 to 85,000 years ago (Domning, 2005). This subspecies was eventually replaced by modern Florida manatees.
This evolutionary theory is further supported by genetic evidence. Research indicates that Florida manatees trace their evolutionary origins to Caribbean ancestors that migrated northward over the past 12,000 years (Garcia-Rodriguez et al., 1998). A 2012 study by Tucker et al. reinforces this theory, showing higher genetic diversity in manatees on Florida’s west coast compared to those on the east. Over time, core populations migrated northward, with some groups moving south and east along the Florida coastline before heading north along the Atlantic. This migration pattern left the west coast population with greater genetic diversity, while the east coast population retained only a smaller subset. These findings suggest that the founding population of Florida manatees—arriving approximately 12,000 years ago—originated along Florida’s southwestern coast, which became the center of the state’s manatee population (Reep and Bonde, 2006). The process of vicariance further supports this hypothesis; as geographic and ecological barriers emerged, they likely isolated the Florida manatee populations from their Caribbean ancestors. This isolation likely limited migration back and forth between regions, fostering the establishment of local populations in southwestern Florida.
Manatees are not only a cherished symbol of Florida’s natural heritage but also a species with deep evolutionary and historical ties to the region. In sum, despite recent claims questioning their nativity, extensive fossil and genetic evidence confirms that manatees have been present in Florida’s waters for thousands of years, with ancestors dating back over 12,000 years. We agree with the authors of the published article that protecting these iconic creatures and their habitats is essential to preserving Florida’s unique ecological identity for future generations.
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Beth Brady is the Senior Science and Conservation Associate at Save the Manatee Club whose work focuses on manatee biology and conservation. She has her PhD from Florida Atlantic University and her Master’s in Marine Science from Nova Southeastern University.
References
Domning, D. P. (1982). Evolution of manatees: a speculative history. Journal of Paleontology, 599-619.
Domning, D. P. (2005). Fossil Sirenia of the West Atlantic and Caribbean region. VII. Pleistocene Trichechus manatus Linnaeus, 1758. Journal of Vertebrate Paleontology, 25(3), 685-701.
Garcia‐Rodriguez, A. I., Bowen, B. W., Domning, D., MIGNUCCI‐GIANNONI, A. A., Marmontel, M., Montoya‐Ospina, R. A., … & McGuire, P. M. (1998). Phylogeography of the West Indian manatee (Trichechus manatus): how many populations and how many taxa?. Molecular Ecology, 7(9), 1137-1149.
Marsh, H. (Ed.). (2022). Ethology and behavioral ecology of Sirenia. Cham: Springer.
Reep, R. L., & Bonde, R. K. (2021). The Florida manatee: biology and conservation. University Press of Florida.
Rycyk, A. M., Factheu, C., Ramos, E. A., Brady, B. A., Kikuchi, M., Nations, H. F., … & Takoukam Kamla, A. (2021). First characterization of vocalizations and passive acoustic monitoring of the vulnerable African manatee (Trichechus senegalensis). The Journal of the Acoustical Society of America, 150(4), 3028-3037.
Tucker, K. P., Hunter, M. E., Bonde, R. K., Austin, J. D., Clark, A. M., Beck, C. A., … & Oli, M. K. (2012). Low genetic diversity and minimal population substructure in the endangered Florida manatee: implications for conservation. Journal of Mammalogy, 93(6), 1504-1511.
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