The Pukerua Bay Scientific Reserve extends west 35km north of Wellington, adjacent the old SH1, and managed by DOC and classified as a Designated Ecological Site. Together with the Raroa Bush and the Wairaka Gorge there is 35 ha which has extensive predator control, especially to manage the Threatened and At-Risk plant, bird and lizard species.
Walking the Pukerua Bay Scientific reserve along the narrow coastal path on a windless, sunny, midwinter morning in July, (14 degrees Celsius) , I savoured the last weekend of the school holidays along with other scattered family groups. I observed and photographed 42 Common copper butterflies Lycaena salustius, sunning themselves on vegetation refreshed from the previous two days of rain. Other butterflies were observed higher up the slope but were not counted or photographed.
Both male and female butterflies were present in about equal numbers and two pairs were seen making mating overtures. Only two butterflies showed signs of wear and tear, the rest were in pristine condition which suggests they may have been newly hatched.
Pukerua Bay has its own microclimate tucked away from the southerly winds: perhaps these warmer mid-winter conditions were conducive to hatching a new batch of common coppers. I was pleased to see so many adult butterflies about in mid-winter. On the same walk and same duration three months previously, I photographed 52 common copper butterflies.
This morning, I witnessed an opportunist piwakawaka taking advantage of natures’ bounty. I was stunned as the butterfly I had just admired and photographed, jerkily flew off and was snatched in mid-air by this piwakawaka.
I observed this bird using its acrobatic manoeuvres to successfully catch another two common coppers. The common copper’s jerky flying strategy didn’t foil this clever insect specialist. Was this a random action or a common occurrence, as piwakawaka are here in numbers in this habitat and would have ample opportunity to perfect catching this food source.
Native and non-native flora
It is pleasing to see both native and non-native flowering plants providing food sources for the common copper in the reserve. The non-native or so-called weeds, are useful sources of nectar when the natives aren’t flowering.
Pohuehue Muehlenbeckia australis thrives on this sloping hillside and is the host plant on which common coppers lay their eggs. It shelters the pupae underneath the plant until they are ready to eclose. Other natives providing nectar and a sunny place to rest were kaihua or NZ jasmine Parsonsia heterophylla; beach spinach Tetragonia trigyna; shore bindweed Calystegia soldanella  and taupata Coprosma repens.
Non-natives included the pink scrambling fumitory Fumaria muralis; Velvety nightshade Solanum chenopodioies, white clover Trifolium repens, and Bermuda buttercup Oxalis pes caprae.
Common coppers were not the only insects enjoying the sun. Four rusty dotted triangle moths Mnestictena flavidalis flitted from bush to bush, a grasshopper Trigonidium maoricum, a yellow-shouldered stout hoverfly Simosyrphus grandicornis, and a large hoverfly Melanguna novaezelandiae along with bumblebees and flies were also seen.
