Unlocking the Secret Lives of Sika Stags

Over the past 3 years, Poronui has participated with Cam Speedy, wildlife biologist, in a radio tracking study of sika stags in the Taharua Valley of the central North Island. Using a helicopter and a net-gun, a sample of sub-adult and fully mature stags were caught and fitted with radio collars. Twice a month fixes were being taken and plotted on GIS.

Study Objectives

1. To determine the seasonal movements (when and where) of mature stags, particularly between summer velvet/fattening areas and rutting grounds
2. To quantify dispersal patterns/distances (when and where) of young stags once they mature and leave their family group / birth place.

Key Findings

We have observed the following behaviour during the study:

Young Stags (<3 years old)

• Same home range (~2.5 km) for a full year
• Often live in large groups through spring and summer
• Groups disperse during the rut
• Groups re-form in June after rut

Mature Stags (>3 years old)

• Limited movements during summer (1-2km)
• Live alone or in small groups
• During the rut most moved from Poronui to scrub beech habitat (between 4-12.5km)
• Travels started early March and were complete by late March
• Small ranges during the rut (<1km)
• Returned to their summer ranges by late May for winter, living alone or in small groups

Conclusion - Key Findings

Upon conclusion of the study, during which 15 satgs were tracked over the three year period, we have found the following:

• 8 of 14 stags that carried working collars were shot over the 3 years of the study.
• 7 of 12 stags tracked for more than 2 years moved significant distances (4km to 14km) to rut.
• 5 of 12 stags tracked for more than 2 years did not move to rut.
• 1 of 4 spikers tracked for more than 2 years dispersed (13km) as a sub adult
• and never returned.
• 3 of 4 spikers tracked for more than 2 years did not leave the property.

Conclusion - Key Management Implications

• Many stags occupy ‘fattening’ or ‘finishing’ country for 10 months of the year.
• Stags are traditional in where they rut – and it’s probably not where they were born to avoid ‘in-breeding’.
• Stags move to ‘breeding’ country to be with hinds for 8 - 10 weeks during rut.
• Some stags move big distances (14km), some move smaller distances (3 - 4km), and some don’t move (variation protects herd from catastrophe?).
• At least half the stags you see in rut are not ‘local’ – they fatten and grow out somewhere else. Many will have come from miles away.
• If one marks a 5km radius around the best velvet (finishing country) in the Central North Island, big stags can appear almost anywhere during the rut.
• Careful management on strategically important properties like Poronui & Ngamatea has
• a huge influence on public sika hunting areas.
• The 2km exclusion buffers around pesticide use are ineffective in the Feb to June period due to these rut movements.

Home Range Maps

Here are images of the home range maps of some of our young stags, the borders of which are typically 2-3 km.

Caught as a 2 year old spiker - turned 5 pointer:






Caught as a 2 year old spiker - turned 5 pointer:






Here are images of the home range maps of some of our mature stags, the borders of which varied from 5-14 km.

Caught as fully mature stag – age unknown:






Caught as a small 6 pointer (3 yrs) – now large 6 pointer:

Thanks to all our Sponsors & Supporters!

Wildlife Management Associates
The Sika Show
NZ Outdoor Hunting Magazine
Hunters & Habitats
AJ Productions
Paradise Pure Pictures
KiwiTrack Ltd
Heli Hunt’n’Fish, Taupo
Serpentine Maps
Bob Berg