Spotlight

Small Beach Patrollers
At Large

Lloyd Esler

Why would any kid willingly leave the comfort of television, put on wet weather gear and get dumped on a bleak beach to walk six kilometres in the wind and rain picking up dead things?

Every week a group of Invercargill youngsters, members of the Southland Explorers Club, take part in a beach patrol along Southland's Oreti Beach. The beach stretches 26 kilometres from Riverton in the north to Sandy Point at the mouth of the New River estuary. The beach is special to Southlanders. It has the only toheroa beds of harvestable size, it was the site in 1910 of New Zealand's first successful aeroplane flight and has long been a favourite place for picnics, surfing and sandcastles on the finest sand in New Zealand.

Facing west, Oreti Beach is fully exposed to the prevailing wind, and the tideline is often littered with the debris of the sea, pushed ashore by the wind and the two currents that merge offshore -- the west wind drift that sweeps eastwards around the temperate latitudes, and the east Australia current that comes from the tropics, down the Australian coast and across the bottom of the Tasman Sea.

Amongst the kelp and driftwood, we collect, count and identify birds that have died and been washed ashore -- several hundred each year. We have found more than 50 species, the commonest being sooty shearwaters, diving petrels, short-tailed shearwaters, fairy prions and broad-billed prions.

Many people assume that any dead birds on the beach have been killed by humans -- either tangled in plastic, oiled or starved because of overfishing. In fact almost all birds have died naturally -- drowned when they have been too weak to take off after landing in the sea. Occasionally we find gulls that have been shot and birds with wings or feet probably injured after being entangled in fishing line, but that's about all.

Why collect dead birds at all? Well there are a number of good reasons:

• it tells us what species live off our coast
• we find out about the seasonal movements of birds
• we get an early warning of disasters such as disease epidemics and oil spills
• from banded birds we find out about how long they live and what distances they travel
• it is good exercise

There are often bonuses such as fishing floats, ambergris, unusual shells, seals and a flounder from a friendly fisherman. We also do our share of digging out bogged cars.

Other beaches such as Ninety Mile Beach and Muriwai are excellent for beach patrols, but can they match our view? Stewart Island, a distant glimpse of Codfish Island, Omaui Island with its new royal spoonbill colony, Centre Island, Bluff Hill, the Longwood Range and the snowy Fiordland mountains.

The long summer evenings make Friday night the best time for the patrol. When it doesn't get dark until well after 10pm you have a lot of time for a long walk followed by a swim. Contrary to popular opinion, the pack ice stops well short of the Southland coast.

What happens to the birds? Most of them are identified on the spot and tossed into the dunes to avoid counting them again the following week. The collected data is collated by the Ornithological Society. Any particularly unusual or fresh specimens are kept by museums for eventual skeletonising or mounting. At various times researchers want seabirds for analysis, and we can help out here too by providing birds for metal and pesticide analysis, gut contents, skeletal and plumage difference between races and DNA testing.

As well as the common birds listed above, we also find lots of uncommon species: yellow-eyed, white flippered and Fiordland crested penguins, blue petrels, storm petrels, fulmars, kerguelen petrels and white-chinned petrels.

Land birds sometimes turn up as well: thrushes, magpies and native pigeons. A pair of white wings that eventually turned out to be a royal spoonbill created a lot of discussion -- we thought we had a red-tailed tropic bird for a while.

I tell the children to collect anything that is more than two feathers joined together, as this constitutes a dead bird. They also tend to bring back a range of interesting dead things that are definitely not avian. Seals, sharks, fish and sheep skulls. One boy left a penguin behind on the grounds that, as it couldn't fly, it wasn't a bird. Another one arrived with what he said was a sack of chickens. "Not chickens" I said, "we call them seagulls, shearwaters and things like that". He tipped out a pile of real dead chickens -- origin unknown.

You wouldn't think it was possible to lose kids on a beach but I have had to call out the police three times. They overshoot the mark, take short cuts through the dunes or get disoriented and head off the wrong way, but despite the few setbacks and moments of panic, it's great exercise and a really good learning experience. I recommend it.

Lloyd Esler can be found wandering the beaches near Invercargill in the interests of science.

Lloyd Esler can be found wandering the beaches near Invercargill in the interests of science.