Polynesian Influence on Hawaiian Natural History

Thomas S. Dye (tdye@hawaii.edu)

19 February 2025

Public Availability

The slides for this lecture are publicly available: http://tsdye.online/natural-history/hawaii-natural-history.html

Chronological Framework

My talk today summarizes archaeological evidence for Polynesian influence on Hawaiian Natural history. One of archaeology's strengths is its ability to establish age estimates for activities that took place in the distant past. I've structured the talk to reflect this strength. We'll start with an estimate of when Polynesians discovered these isolated islands and then move on to discuss three periods that overlap one another in time.

The long Colonization period is a time when there is little direct evidence for human activities. I'll argue that this is due, in part, to the long ocean voyages required to colonize Hawaiʻi from a homeland in the South Pacific. Nevertheless, this is a time of widespread change in Hawaiian natural history, due primarily to introduction of the Polynesian rat.

The Settlement period yields abundant direct evidence for human activities. It is during this period that we have evidence for establishment of taro plantations, and for establishment of a Polynesian forest populated with plants transported to the islands in voyaging canoes. The Hokuleʻa is a modern example of a voyaging canoe.

Finally, the long Innovation period sees the clearing of large areas to establish sweet potato gardens, which at the time of Captain Cook's visit in 1778–1779, fed the largest pig herds in the Pacific. The nearshore environment was altered during this period, as well. We'll discuss the archaeological evidence for fishpond construction on the south shore of Molokaʻi Island.

The period of Polynesian influence on Hawaiian natural history ended in the middle of the nineteenth century, when the land distribution known as the Māhele introduced a Western form of land tenure.

Discovery (ᴀᴅ 900–1100)

Remote Oceania

I like this map projection because it illustrates how isolated Hawaii is. North pole is at the center. The map is oriented so that north from Hawaii is vertical.

The broken red line at the left divides Near Oceania, whose large islands are easy to get to from Asia, and Remote Oceania, where the islands are smaller and difficult to get to. As one voyages into Remote Oceania, the islands get smaller and are located farther from one another.

The earliest voyaging into Remote Oceania around 1600 BC settled the Western Micronesian islands of Palau, Yap, and the Marianas. Over the next 400 years, voyagers established settlements throughout the islands of Melanesia as far east as Samoa and Tonga in Polynesia.

The Micronesian atoll islands between these two early developments were settled about 200 BC, when isostatic rebound helped create coral islands and atolls. A once empty ocean was now populated by hundreds of islands. Sailing distances were reduced and the entire area was explored and settled.

The last expansion, labeled AD 1000 on the map, represents modern humans' last great migration, during which nearly every island in the Eastern Pacific was discovered and settled. This accomplishment of Polynesians was so rapid that archaeologists find it difficult to distinguish discovery dates among the island groups.

Estimates of Polynesian Discovery

Attempts to estimate when Polynesians discovered Hawaii have been pretty wild.

The dashed line represents invention of radiocarbon dating by Libby after World War II. The shaded horizontal band at AD 900–1100 represents a Bayesian estimate that is the consensus estimate among archaeologists today.

Fornander and Emory based on tradition.

Well into the 1990's, archaeologists pretty consistently moved away from the discovery date as we see it today, and it wasn't until Matthew Spriggs and Atholl Anderson pointed out the problem of in-built age from dating pieces of wood that were already old when they were used that the estimate started to move in the right direction. As late as 2000, there were still arguments for an early discovery.

The dam burst in 2011, when three papers all proposed late estimates.

My colleagues and I contributed a Bayesian solution that models two periods, a pre-discovery period and a post-discovery period, then finds dated materials from each of the periods. The two groups of dates book-end the discovery date.

The model is well-behaved. Initially, with one date from the pre-discovery period and five or six dates from the post-discovery period, the estimate was imprecise. When we added about 2 dozen more dates, precision increased considerably. The new estimate was within the range of the old estimate, suggesting that the old estimate was accurate.

Colonization Period (ᴀᴅ 1000–1300)

Early introductions

ʻiole, Rattus exulans
kukui, Aleurites moluccana
ʻōhiʻa ʻai, Syzygium malaccense

After Polynesian discovery around 1000 AD, actual settlement of the islands appears to have been a multi-generational affair. Current evidence indicates the settlement process played out over the course of a few centuries. Here are the earliest documented introductions.

The Polynesian rat is small, in between the size of a mouse and a house rat. It is fully capable of stowing away on a long ocean voyage, such as the approximately 3 week sails between Hawaiʻi and the homeland. Scholars have argued that rats were inadvertently introduced, but we'll never know for certain whether the introduction was inadvertent or purposeful.

The kukui and the mountain apple are both propagated by seeds, and so would have been easier to transport successfully from the homeland than plants dependent on vegetative reproduction that would be easily killed by saltwater inundation during a long ocean voyage.

Timing of Polynesian Introductions

Long Voyage Hinders Colonization Effort

Canoe plants

Early Site Locations

Early settlement locations

Dates of Early Sites

Effects of Colonization on Natural History

The environmental effects of discovery and what looks to be intermittent visits by Polynesians were breathtaking.

Several species of flightless birds, the so-called moa-nalo, went extinct. There is no evidence that these birds were hunted and eaten, as were the moa of New Zealand.

The lowland forest, which pollen records indicate was dominated by loulu palms, were radically altered. The loulu pollen declines precipitously during the Settlement period. In 1851, when Dr. Hillebrand planted this loulu on the grounds of what is now Foster Botanical Garden, native loulu palms were rare. This one is protected by City ordinance as an exceptional tree, which indicates how far we've come from a lowland forest dominated by trees such as these.

The situation with Kanaloa kahoolawensis was more dire. Pollen from this legume is very common in the paleoenvironmental records, where it was identified as UNKNOWN for many years. It wasn't until botanists discovered the last survivors on a sea stack off Kahoʻolawe Island, and Jerome Ward was able to get some pollen from them, that it was possible to identify this once common plant.

The culprit here appears to be the Polynesian rat, which occupies the same niche as the moa-nalo once did and likely drove the moa-nalo to extinction, and is fully capable of breaking the reproductive cycle of loulu by eating all of the fruit it drops, transforming the lowland forest.

Settlement Period (ᴀᴅ 1250–1500)

Jerry Konanui

Abandoned Loʻi at Mānoa, Kauaʻi

Hydraulic Engineering of Loʻi

Chronology of Loʻi Construction

Irrigated Agriculture

Irrigated agriculture

Transporting the Polynesian Forest

Transported landscapes

Fire-pits at Waimānalo and Lānaʻi

Fire-pits

At the top left is archaeologist, Windy McElroy, excavating a traditional Hawaiian cultural deposit that she discovered. This is Bellows Air Force Station today. You can see one of the World War II era runways in the background. Inland Waimanalo is still prime agricultural land today, and as we saw earlier its sandy coastal plain appears to be one of the areas first settled by Polynesians.

At the bottom left is a stratigraphic section of the excavation. You can see all the oven stones imported to the plain from inland, and the bases of a few large fire-pits in the section. We collected charcoal from the bases of individual pits, identified the firewood species, and dated material that was young when it was burned.

At the top right you see a portion of the Miki Basin on Lanai. Lanai is in the rain shadow of Haleakala and is an environment less hospitable to Polynesian settlement than Waimanalo. This area was cultivated with pineapple by Dole Corporation for many years. The construction project shown here built a greenhouse complex that is functional today.

The fire-pit base in the bottom photo was discovered by Kaleo Ropa while he was monitoring the huge earth-moving machinery that prepared the foundation for the greenhouses.

Importance of canoe plants as firewood

Innovation Period (ᴀᴅ 1400–1850)

Mullet and sweet potatoes

This brings us to the final 250 year period, which is a time of innovation and remarkable achievement that brought large parts of the islands under intensive sweet potato cultivation and pig husbandry, and invented aquaculture technology that was deployed around the coast of most islands.

The close of this period in the middle of the nineteenth century marks the end of traditional Hawaiian land tenure. The introduction of private property in land during the Mahele dissolved the corporations, known as 'ili, established by the "people of the land", maka'ainana, to develop and steward the agricultural lands of the islands.

Most of the canoe plants established in the islands originated in SE Asia and had been cultivated by Polynesians and their ancestors for many centuries. The sweet potato isn't one of those. It originated in South America and came into the Pacific with Polynesians returning to the islands after visiting the continent.

As we saw earlier, it was introduced to Hawaii nei during the landscape transport period. With no history of cultivation, it was up to the farmers to work out the best way to raise it.

Coastal Fishponds around Hawaiʻi

Coastal fishponds

Coastal Fishponds on Oʻahu

$O\okina{}ahu fishponds$

Fishpond Development at Kawela, Molokaʻi

$O\okina{}ahu fishponds$

Leeward Kohala Field System

Pig Herds Raised on Sweet Potato

Roasting pigs on Niuatoputapu

Leeward Kohala Field System on Google Earth

Google Earth image of leeward Kohala field system

Leeward Kohala Field System on LiDAR Image

LiDAR image of leeward Kohala field system

Chronology of Agricultural Wall Construction

Agricultural Sequence at Punaluʻu, Oʻahu

$O\okina{}ahu fishponds$

Rain-Fed Agriculture

Rain-fed agriculture

Polynesian Influence on Hawaiian Natural History

Discovery (ᴀᴅ 900–1100)

Hawaiʻi one of the last places discovered on earth
Short 700–900 years of influence on natural history

Colonization Period (ᴀᴅ 1000–1300)

Scant archaeological evidence implies small population
Introduction of Rattus exulans
Flightless birds driven to extinction
Lowland loulu forest replaced by shrubs and grasses
Kukui groves established

Settlement Period (ᴀᴅ 1250–1500)

Development of irrigated agriculture in valleys
Canoe plants established in favorable lowland environments
Abundant evidence for a growing population

Innovation Period (ᴀᴅ 1400–1850)

Invention and development of fishpond aquaculture
Large-scale clearing for sweet potato fields
Development of largest pig herds in the Pacific
Māhele land division ends traditional land tenure

Bibliography

Athens, J. S., Rieth, T. M., & Dye, T. S. (2014). A paleoenvironmental and archaeological model-based age estimate for the colonization of Hawaiʻi. American Antiquity, 79(1), 144–155.

Athens, J. S., Tuggle, H. D., Ward, J. V., & Welch, D. J. (2002). Avifaunal extinctions, vegetation change, and Polynesian impacts in prehistoric Hawaiʻi. Archaeology in Oceania, 37, 57–78.

Bibliography

Bayman, J. M., & Dye, T. S. (2013). Hawaii’s past in a world of Pacific Islands, Washington, DC: SAA Press.

Carson, M. T., & Athens, J. S. (2007). Integration of coastal geomorphology, mythology, and archaeological evidence at Kualoa beach, windward Oʻahu, Hawaiian Islands. Journal of Island & Coastal Archaeology, 2, 24–43.

Bibliography

Dye, T. S. (2011a). A model-based age estimate for Polynesian colonization of Hawaiʻi. Archaeology in Oceania, 46, 130–138.

Dye, T. S. (2011b). The tempo of change in the leeward Kohala field system, Hawaiʻi Island. Rapa Nui Journal, 25(2), 21–30.

Bibliography

Dye, T. S. (2014). Wealth in old Hawaiʻi: Good year economics and the rise of pristine states. Archaeology in Oceania, 49(2), 59–85.

Dye, T. S. (2015). Dating human dispersal in Remote Oceania: A Bayesian view from Hawaiʻi. World Archaeology, 47(4), 661–676.

Bibliography

Dye, T. S. (2016). Long-term rhythms in the development of Hawaiian social stratification. Journal of Archaeological Science, 71, 1–9.

Dye, T. S. (2021). A case for Handy and Pukuʻi’s ethnographic reconstruction of the Polynesian family system in Hawaiʻi. Journal of the Polynesian Society, 130(1), 45–68.

Bibliography

Dye, T. S., & Pantaleo, J. (2010). Age of the O18 site, Hawaiʻi. Archaeology in Oceania, 45, 113–119.

Dye, T. S., & Sholin, C. E. (2013). Changing patterns of firewood use on the Waimānalo Plain. Hawaiian Archaeology, 13, 30–68.

Bibliography

Earle, T. K. (1978). Economic and social organization of a complex chiefdom: The Halelea District, Kauaʻi, Hawaii, Ann Arbor, MI: Museum of Anthropology, University of Michigan.

Field, J. S., & Graves, M. W. (2008). A new chronology for Pololu Valley, Hawaiʻi Island: Occupational history and agricultural development. Radiocarbon, 50(2), 205–222.

Bibliography

Ladefoged, T. N., Kirch, P. V., Gon III, S. M., Chadwick, O. A., Hartshorn, A. S., & Vitousek, P. M. (2009). Opportunities and constraints for intensive agriculture in the Hawaiian archipelago prior to European contact. Journal of Archaeological Science, 36, 2374–2383.

Lincoln, N., Zhang, Q., & Chen, Q. (2020). State of the state tree: Historical and modern ecology of kukui (Candlenut, Aleurites moluccanus) in Hawaiʻi. Pacific Science, 74(4), 419–434.

Bibliography

Quintus, S. J., Rieth, T. M., Dye, T. S., … Duarte, T. (2023). Ideal distribution models and the tempo of agricultural development in a windward valley of Hawaiʻi. Antiquity. Retrieved from https://doi.org/10.15184/aqy.2023.121

Rieth, T. M., & Cochrane, E. E. (2018). The chronology of colonization in Remote Oceania. In E. E. Cochrane & T. L. Hunt, eds., The Oxford handbook of prehistoric Oceania, New York, NY: Oxford University Press.

Bibliography

Rogers, A. J., & Weisler, M. I. (2024). Terrestrial cultural landscapes changed inshore marine ecosystems: Eight centuries of shellfish harvesting from the Kawela Mound site, Hawaiian Islands. The Holocene. doi:doi.org/10.1177/095968362312194

Bibliography

Weisler, M. I., Hua, Q., Collins, S. L., Rogers, A. J., & Mendes, W. P. (2023). Dry, leeward regions support Colonization Period sites: Stratigraphy, dating, and geomorphological setting of one of the earliest habitations in the Hawaiian Islands. Journal of Island and Coastal Archaeology. doi:https://doi.org/10.1080/15564894.2023.2165200

Bibliography

Whistler, W. A. (1991). Polynesian plant introductions. In P. A. Cox & S. A. Banack, eds., Islands, plants, and Polynesians: An introduction to Polynesian ethnobotany, Portland, OR: Dioscorides Press, pp. 41–66.

Credits

Photograph of kukui:

Forest & Kim Starr, CC BY 3.0, via Wikimedia Commons

Photograph of ʻōhiʻa ʻai:

Forest & Kim Starr, CC BY 3.0 US, via Wikimedia Commons

Drawing of moa nalo:

H. Glyn Young, Simon J. Tonge, Julian P. Hume, CC BY-SA 3.0, via Wikimedia Commons

Herbarium sheet for Kanaloa kahoolawensis: National Tropical Botanical Garden

Photograph of Jerry Konanui in a taro patch: Scot Nelson's Flickr Photostream

Photograph of sweet potatoes:

miya, CC BY-SA 3.0, via Wikimedia Commons

The map of coastal fishponds was produced by Eric Komori.