THE REEF OR BLUE HERON

Forest and Bird, Issue 52, 1 May 1939, Page 4

THE REEF OR BLUE HERON

By David H. Graham.

Some Interesting Observations in Otago Harbour

DURING my term of office as biologist to . the Marine Fisheries Investigation and Biological Station at Portobello, Dunedin, I had many favoured opportunities of observing and studying some of the habits of these interesting birds and the following is ample proof of how they learned, to some extent, to trust man. The blue heron, known as the reef heron by some and as Matukumoana by the Maori, is considered to be a wary suspicious bird trusting no man. It was while collecting marine life in and around Quarantine and Goat Islands that I made their acquaintance. At times two would be seen together and then months would go by and only one would appear. Just where its mate went to was not discovered.

Searching round the rocky shore, turning over every moveable rock looking for marine life to study and to stock the aquarium tanks, I soon found that the blue heron came to regard me as part and parcel of the locality. When it found that there was no intention of disturbing or shooting it, it soon became easier to approach. As soon as it found that my custom was to lay bare the undersurface of rocks below high tide which was the hiding places of crabs, worms and other choice morsels, it began to follow and feed on whatever animal life had been left exposed and had not returned to the hiding places. The birds soon made a habit of following me more and more closely, allowing me to make many first-hand records and observations, to note the peculiarities of resting, yawning arid stalking over rocks and mud flats, and to observe closely the method of flying. One feature, which is quite understandable when one considers the practice of so many men to shoot or frighten all birds, was that they would never let me approach closer than about twenty yards, but they would at times decrease the distance in order to feed. If a false step was made or one slipped they would rise rather awkwardly and make a detour round the headland and back again behind me where I had left upturned rocks. As far as could be seen by their colourings, the same one or two birds visited Quarry Point; never at any time in the two years were any

young birds seen. It was not often that the two herons would occupy one vantage point, but when they did it was quite amusing to watch them . performing the same movements at the same time. Both birds might sleep with heads slouched between their shoulders; then both would wake up, and, throwing back their heads, yawn several times in succession. They would stand for long periods on one leg, or they would both hold one leg in front. At other times they appeared to be “marking time” by changing from one foot to the .other. These antics from such stately, though dull-looking birds, seemed quite out of keeping. When sprats and pilchards were abundant in the harbour they could be seen catching and swallowing them one after the other. Rarely was one seen to catch its food on the wing, but occasionally one would be seen to dart down into shallow water and fly to the nearest rock to eat his meal. One very favoured daylight habitat of these birds was a dark wet cave and they could often be seen standing in that part between the light and dark, hunched up and motionless. If in a few months, two blue herons could learn to trust and follow me while I turned over rocks and supplied them with easily found food, what could be done if everyone took the same line of thought and treated all our native birds as our friends?