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14 New Zealand Palaeodemography
(i) First, the survival outcomes for all tribal areas, whether occupying richer or
poorer lands, would have depended on the local ceiling of sustainability in
relation to tribal population levels.
(ii) Second, conquest or defeat in tribal conflict both between and within each division would also have determined relative survival outcomes for different tribes.
The building of nearly 7,000 pa shows the importance for the horticulturalist
of not suffering defeat either at the hands of other tribes from pa areas or at the
hands of outside tribes attempting to gain a horticultural foothold.
(iii) Third, decade by decade, improvement or worsening in the impact of climatic
stress on the biota and on horticultural harvests would have affected survival
outcomes. Although, working with limited data, we can only consider average
rates of decline, it seems likely that there were constantly fluctuating population decline rates over the 600-year period represented by the skeletons
studied.
14.6 Establishing Estimates for the Total Non-pa Population
of the North Island in AD 1445
Given the extreme demographic implications of the population decline rates derived
from skeletal evidence and recorded in Table 14.2, we can reasonably argue that
the most plausible overall decline rate for the non-pa areas of the North Island will
be one that minimizes estimates for population levels in 1445 and is correspondingly based on a conservative rate for infant mortality. Option 8, the last estimate in
Table 14.2, with the highest infant mortality rate at 29.7% and the extreme population decline rate of 2.035% p.a., for example, implies impossibly high population
levels for the non-pa areas of the North Island in 1445: a population estimate of
500 times the population in 1801. Even Option 5 implies a population for the nonpa areas alone 194 times the population in 1801. Option 1, at the other end of the
spectrum, which implies the lowest population estimates, has to be discounted at the
outset because its estimate for infant mortality at only 3.5% is unrealistically low in
the light of Weiss’s claim that prehistoric populations in the best of circumstances
had an infant mortality rate of 10%. Option 2 has a feasible infant mortality rate of
12.2% and implies less extreme population levels: the population in 1801 would be
1.13% of that in 1445. As the most conservative of the remaining options, it is a
plausible first choice.
To use the population decline rate of Option 2 to obtain an estimate for the
non-pa population of the North Island in 1445 requires us to make one assumption, an assumption as to the number of survivors in 1801. If, with a decline rate
of 1.251% p.a. from Option 2, maintained over the 356-year span from 1445 to
1801, we assume the survivors in the non-pa areas numbered 10,000 in 1801, we
can derive an estimate for the total non-pa population in the North Island in 1445
of 884,000. Estimating there to have been 6,000 survivors in 1801 would give a
total non-pa population for the North Island in 1445 of 530,000. In either case the
14 New Zealand Palaeodemography
(i) First, the survival outcomes for all tribal areas, whether occupying richer or
poorer lands, would have depended on the local ceiling of sustainability in
relation to tribal population levels.
(ii) Second, conquest or defeat in tribal conflict both between and within each division would also have determined relative survival outcomes for different tribes.
The building of nearly 7,000 pa shows the importance for the horticulturalist
of not suffering defeat either at the hands of other tribes from pa areas or at the
hands of outside tribes attempting to gain a horticultural foothold.
(iii) Third, decade by decade, improvement or worsening in the impact of climatic
stress on the biota and on horticultural harvests would have affected survival
outcomes. Although, working with limited data, we can only consider average
rates of decline, it seems likely that there were constantly fluctuating population decline rates over the 600-year period represented by the skeletons
studied.
14.6 Establishing Estimates for the Total Non-pa Population
of the North Island in AD 1445
Given the extreme demographic implications of the population decline rates derived
from skeletal evidence and recorded in Table 14.2, we can reasonably argue that
the most plausible overall decline rate for the non-pa areas of the North Island will
be one that minimizes estimates for population levels in 1445 and is correspondingly based on a conservative rate for infant mortality. Option 8, the last estimate in
Table 14.2, with the highest infant mortality rate at 29.7% and the extreme population decline rate of 2.035% p.a., for example, implies impossibly high population
levels for the non-pa areas of the North Island in 1445: a population estimate of
500 times the population in 1801. Even Option 5 implies a population for the nonpa areas alone 194 times the population in 1801. Option 1, at the other end of the
spectrum, which implies the lowest population estimates, has to be discounted at the
outset because its estimate for infant mortality at only 3.5% is unrealistically low in
the light of Weiss’s claim that prehistoric populations in the best of circumstances
had an infant mortality rate of 10%. Option 2 has a feasible infant mortality rate of
12.2% and implies less extreme population levels: the population in 1801 would be
1.13% of that in 1445. As the most conservative of the remaining options, it is a
plausible first choice.
To use the population decline rate of Option 2 to obtain an estimate for the
non-pa population of the North Island in 1445 requires us to make one assumption, an assumption as to the number of survivors in 1801. If, with a decline rate
of 1.251% p.a. from Option 2, maintained over the 356-year span from 1445 to
1801, we assume the survivors in the non-pa areas numbered 10,000 in 1801, we
can derive an estimate for the total non-pa population in the North Island in 1445
of 884,000. Estimating there to have been 6,000 survivors in 1801 would give a
total non-pa population for the North Island in 1445 of 530,000. In either case the