18.9 Dating the Last Great Migration
323
Working from this secure chronological marker enables us to establish a date for
the Heke. The land attack on Tawheta’s pa led to the capture of Tawheta’s daughter,
brought back as a slave wife for Uenuku. She gave birth to a son, Ruatapu, whose
war with his father provides the next episode in the history of Uenuku. Ruatapu was
the first, possibly the only man to successfully challenge Uenuku’s power. It is likely
that the events involved in Ruatapu’s challenge to his father took place after, rather
than before, the Heke, because the Heke migrants fleeing from Uenuku’s decision
to exterminate them still regarded Uenuku as invincible. Having drawn his enmity,
they believed they would be defeated if they stayed to fight.
In dating the Heke, it is important to realize that there is a good reason why it
was the last migration fleet to reach New Zealand. The migration occurred at the
cusp between the end of the Medieval Climatic Optimum and the beginning of the
Little Ice Age, which brought an end to long-distance voyaging to New Zealand.
There is some controversy concerning the dating for the Little Ice Age in New
Zealand. Lamb suggests that the peak of the Medieval Climatic Optimum in New
Zealand may have been as late as AD 1200–1400 [23]. Though the Sporer Minimum
(which records a significant reduction in solar activity) is dated in the northern hemisphere 1400–1510, Grant suggests that in New Zealand “the Sporer Minimum is
contained within the longer cool interval of 1350 to 1510 AD”. He describes this
period graphically:
Temperatures fell to 11.9 ◦ C, at least 0.6 ◦ C cooler than at present. Winds prevailed from the
west and southwest. A paucity of auroral counts, an absence of naked-eye sunspot reports
and descriptions of the eclipsed sun with no corona mark this period. There were again
probably almost no sunspots, and we may presume a similar dearth of other features of solar
activity. In the tropics the Sporer Minimum was the coolest spell for the last 1,800 years
(Eddy 1977). Generally, the country became drier, and in Hawke’s Bay, the Wairarapa and
Marlborough southward to Southland, drought became more severe [24].
Drought in the North Island of New Zealand, caused by an El Niño, is usually
matched by drought in Eastern Polynesia, although the South Island is not subject
to it. The drought Grant describes, associated with low sunspot activity worldwide,
appears to have affected both islands of New Zealand and to be associated with
falling temperatures. It is possible that a severe El Niño-driven drought triggered
the conflict over land and resources between Uenuku and Hoturoa, the captain of
the Tainui, that is recorded in tradition as a reason for the migration of his people. In
Eastern Polynesia, as we have seen, after about AD 900 El Niño-driven drought and
consequent starvation and conflict over land and resources typically led to enforced
migration for the starving and defeated. Tradition establishes conflict and fear of
defeat as the triggers for the last migration to New Zealand. Additional dating evidence for the timing of the Heke can perhaps reasonably be sought from El Niño
proxy data.
Searching the El Niño proxy data for likely timings for possible El Niño events
that may have caused drought and conflict in Eastern Polynesia, we find that in 1403
there was a level 4 El Niño. This was the strongest El Niño in the 200 years from
1245 to 1449. This seems to be the best candidate for dating the Heke. The next best
option is a level 3 El Niño in 1408. In 1403, given the time of his conception, the
323
Working from this secure chronological marker enables us to establish a date for
the Heke. The land attack on Tawheta’s pa led to the capture of Tawheta’s daughter,
brought back as a slave wife for Uenuku. She gave birth to a son, Ruatapu, whose
war with his father provides the next episode in the history of Uenuku. Ruatapu was
the first, possibly the only man to successfully challenge Uenuku’s power. It is likely
that the events involved in Ruatapu’s challenge to his father took place after, rather
than before, the Heke, because the Heke migrants fleeing from Uenuku’s decision
to exterminate them still regarded Uenuku as invincible. Having drawn his enmity,
they believed they would be defeated if they stayed to fight.
In dating the Heke, it is important to realize that there is a good reason why it
was the last migration fleet to reach New Zealand. The migration occurred at the
cusp between the end of the Medieval Climatic Optimum and the beginning of the
Little Ice Age, which brought an end to long-distance voyaging to New Zealand.
There is some controversy concerning the dating for the Little Ice Age in New
Zealand. Lamb suggests that the peak of the Medieval Climatic Optimum in New
Zealand may have been as late as AD 1200–1400 [23]. Though the Sporer Minimum
(which records a significant reduction in solar activity) is dated in the northern hemisphere 1400–1510, Grant suggests that in New Zealand “the Sporer Minimum is
contained within the longer cool interval of 1350 to 1510 AD”. He describes this
period graphically:
Temperatures fell to 11.9 ◦ C, at least 0.6 ◦ C cooler than at present. Winds prevailed from the
west and southwest. A paucity of auroral counts, an absence of naked-eye sunspot reports
and descriptions of the eclipsed sun with no corona mark this period. There were again
probably almost no sunspots, and we may presume a similar dearth of other features of solar
activity. In the tropics the Sporer Minimum was the coolest spell for the last 1,800 years
(Eddy 1977). Generally, the country became drier, and in Hawke’s Bay, the Wairarapa and
Marlborough southward to Southland, drought became more severe [24].
Drought in the North Island of New Zealand, caused by an El Niño, is usually
matched by drought in Eastern Polynesia, although the South Island is not subject
to it. The drought Grant describes, associated with low sunspot activity worldwide,
appears to have affected both islands of New Zealand and to be associated with
falling temperatures. It is possible that a severe El Niño-driven drought triggered
the conflict over land and resources between Uenuku and Hoturoa, the captain of
the Tainui, that is recorded in tradition as a reason for the migration of his people. In
Eastern Polynesia, as we have seen, after about AD 900 El Niño-driven drought and
consequent starvation and conflict over land and resources typically led to enforced
migration for the starving and defeated. Tradition establishes conflict and fear of
defeat as the triggers for the last migration to New Zealand. Additional dating evidence for the timing of the Heke can perhaps reasonably be sought from El Niño
proxy data.
Searching the El Niño proxy data for likely timings for possible El Niño events
that may have caused drought and conflict in Eastern Polynesia, we find that in 1403
there was a level 4 El Niño. This was the strongest El Niño in the 200 years from
1245 to 1449. This seems to be the best candidate for dating the Heke. The next best
option is a level 3 El Niño in 1408. In 1403, given the time of his conception, the