The birthday of 23 million mutton birds

Every year, around January 15, Australia's 23 million short-tailed shearwaters (mutton birds) hatch their eggs. It's the birthday of tiny chicks covered in grey down. Although the date varies by a couple of days either side of January 15, this is the day when most of the mutton bird eggs hatch; eggs that were laid around November 25.

It's an exciting time in the rookery. The birds are extra noisy as they 'talk' about the hatching and 'discuss' feeding rosters.

From now until maturity in late April, the mutton bird chicks will eat enormous quantities of krill and small fish, delivered to the burrow by the returning parents.

For the first week or so one parent will stay with the chick to keep it warm and safe, while the other goes out fishing -- either in Western Port Bay or Bass Strait.

In our Ventnor rookery we have about 2000 birds. This is one of the smaller rookeries on Phillip Island. Swan Lake also has a rookery. On Cape Woolamai (also on Phillip Island) the mutton bird colony has about three quarters of a million birds. Phillip Island has about 1 1/2 million birds in total; with the Australian population of mutton birds about 23 million.

When we lived on King Island, our property had both mutton bird and penguin rookeries. It was here that I first became interested in these birds and began studying their habits -- and writing about them. One of the first books I wrote was called Moonbird. Written for children aged between eight and 12 years, the book was fiction, based on King Island with a strong mutton bird connection. The book is in many libraries throughout Australia.

Now on Phillip Island we live alongside another mutton bird rookery, so my study and interest continues. I never cease to be amazed by their life cycle and breeding patterns. Therefore, today I celebrate the birthday of all the mutton bird chicks newly hatched and living in sandy burrows on islands in southern Australia -- but especially in Bass Strait.

Come walk with me: Phillip Island

This afternoon was perfect for a dog walk along the beach: a sunny blue sky, a balmy 25°C and no wind at all. On the way down the board-walk, a broken mutton bird egg shell caught my attention. Perched on top of a clump of New Zealand spinach, its contents had been sucked clean -- probably by gulls. Here was evidence of one less chick for the rookery.

The only other person on the entire stretch of beach was a fisherman with a small shade tent and his dog. Consequently, as soon as we passed the man and his dog we let our two German shepherds off their leads for 45 minutes of free running and swimming.

Major found a huge stick on the beach and proudly strutted along the sand. Then he took the stick for a swim. Del stood by, waiting for an opportunity to take the stick, but Major is very possessive and dominant and wouldn't let her anywhere near his prized possession.

With the moon nearly full and the tide extra low, the exposed reef was clear to see with its beds of sea grass and clumps of sea grapes. I observed with disappointment that the diversity of seaweeds, shellfish and other small marine creatures living in the rock pools has diminished over the past 15 years -- at an alarming rate. This is due to the increasing pollution of Western Port Bay from shipping and the run-off from housing estates and industry.

As if on cue, a gas tanker moved up Western Port Bay's narrow shipping channel, its diesel motors remarkably quiet. I have no idea where it's heading. Perhaps Asia?

On King Island, in the 1980s, I remember the richness and diversity of life in the rock pools. Starfish, sea anemones, crabs, tiny silver fish, seaweeds the colours of the rainbow, abalone, mussels, limpets, brittle stars -- -- --.

Walking back up the track to the house, I paused beside a tall flowering dock. Even weeds have beauty.