11.2 Factors Determining Population Growth Rate for Prehistoric New Zealand
183
of Hawaiian demography [4] suggests a low average population growth rate over
1,400 years of only 0.25%, though Hawaii is the largest and most fertile archipelago
in Eastern Polynesia and had an extensive horticultural system.
11.2 Factors Determining an Appropriate Population Growth
Rate for Prehistoric New Zealand
Colonists from Eastern Polynesia reaching New Zealand after AD 1200 brought
with them the kumara, tropical taro, yam and gourd. But even with a limited
horticulture based on these vegetables, the late colonists would still have been fundamentally dependent on hunting, fishing and the gathering of forest foods. None
of the Polynesian tropical tree staples – coconut, breadfruit, banana and tree nuts –
which are easily grown and readily harvested in tropical Polynesia, could be translocated to New Zealand. And the kumara could yield only one harvest a year in New
Zealand. In Polynesia it had repeated harvests because it grew there as a perennial
rather than an annual.
Douglas Sutton [5] demonstrates the limited nutritional value both of forest foods
and of the Polynesian cultivars introduced into New Zealand after about AD 1200.
He claims, for example, that an adult would need to eat 2 kg daily of any of these
cultivars to meet energy needs and he questions Houghton’s opinion [6] that the
prehistoric diet was “generally adequate”. He relates recognized poor fertility rates
for prehistoric Maori women to inadequate nutrition:
It appears that there was a significant reduction in the availability of terrestrial and shoreline sources of protein through time. Although there were many edible indigenous plant
foods, probably about 40 in total, most were small and dispersed while more important
ones required lengthy detoxification processing and cooking over 12–24 hours, and offered
only relatively poor food value per unit weight. Only small parts of most wild plants were
edible and these were limited in their spacial distributions, concentrations and season of
availability (p. 303).
Though poor nutrition and even chronic malnutrition may not have had a direct
impact on female fertility, they are likely to be associated with a restrained population growth rate. Allowing for the importance of marine and estuarine resources in
New Zealand and the initial abundance of seals, the giant moa and many other birds,
an initial 0.5% per annum rate of population increase might have been possible. But
it is unlikely that this rate could have been sustained for long for a society that till
AD 1200 lacked horticulture.
Certainly the prehistoric growth rate of settled hunter/gatherers in New
Zealand would be higher than that of the nomadic hunter/gatherers of prehistoric
Australia, largely because Maori had a calorie-saving settled existence. Nomadic
hunter/gatherers can only afford to sustain a static population growth. Because they
cannot store food against the risk of scarcity, they need to maintain a population
level far below the level of physical sustainability. They have to do so to protect
183
of Hawaiian demography [4] suggests a low average population growth rate over
1,400 years of only 0.25%, though Hawaii is the largest and most fertile archipelago
in Eastern Polynesia and had an extensive horticultural system.
11.2 Factors Determining an Appropriate Population Growth
Rate for Prehistoric New Zealand
Colonists from Eastern Polynesia reaching New Zealand after AD 1200 brought
with them the kumara, tropical taro, yam and gourd. But even with a limited
horticulture based on these vegetables, the late colonists would still have been fundamentally dependent on hunting, fishing and the gathering of forest foods. None
of the Polynesian tropical tree staples – coconut, breadfruit, banana and tree nuts –
which are easily grown and readily harvested in tropical Polynesia, could be translocated to New Zealand. And the kumara could yield only one harvest a year in New
Zealand. In Polynesia it had repeated harvests because it grew there as a perennial
rather than an annual.
Douglas Sutton [5] demonstrates the limited nutritional value both of forest foods
and of the Polynesian cultivars introduced into New Zealand after about AD 1200.
He claims, for example, that an adult would need to eat 2 kg daily of any of these
cultivars to meet energy needs and he questions Houghton’s opinion [6] that the
prehistoric diet was “generally adequate”. He relates recognized poor fertility rates
for prehistoric Maori women to inadequate nutrition:
It appears that there was a significant reduction in the availability of terrestrial and shoreline sources of protein through time. Although there were many edible indigenous plant
foods, probably about 40 in total, most were small and dispersed while more important
ones required lengthy detoxification processing and cooking over 12–24 hours, and offered
only relatively poor food value per unit weight. Only small parts of most wild plants were
edible and these were limited in their spacial distributions, concentrations and season of
availability (p. 303).
Though poor nutrition and even chronic malnutrition may not have had a direct
impact on female fertility, they are likely to be associated with a restrained population growth rate. Allowing for the importance of marine and estuarine resources in
New Zealand and the initial abundance of seals, the giant moa and many other birds,
an initial 0.5% per annum rate of population increase might have been possible. But
it is unlikely that this rate could have been sustained for long for a society that till
AD 1200 lacked horticulture.
Certainly the prehistoric growth rate of settled hunter/gatherers in New
Zealand would be higher than that of the nomadic hunter/gatherers of prehistoric
Australia, largely because Maori had a calorie-saving settled existence. Nomadic
hunter/gatherers can only afford to sustain a static population growth. Because they
cannot store food against the risk of scarcity, they need to maintain a population
level far below the level of physical sustainability. They have to do so to protect