a great deal less bright, but as many of the chicks had not long hatched and some of the parents were in the burrows all day, this factor may account for the high percentage of meals given (73). The full moon periods of January 31 to February 4, and March 2 to 6, 1942, were both quite cloudy, and consequently I was unable to test out properly the effect of the moon. Even so, the percentage was the lowest for the month.

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The periods containing the new moon are very high in 1942, but the one in 1941 is somewhat low. There were, however, only three nights under observation and during the last two of these heavy storms which raged might have kept the birds away. One chick in the period January 12 to 16, 1941, was not fed during the whole five nights which, not taking into account the period between the final feeding and the ultimate departure, is the longest spell I have known, while another was unfed for four nights.

In spite of the evidence given in the above table it is surprisingg the number of chicks which are fed on bright, clear, moonlight nights, and in the field I had formed the opinion that the adults get in somehow. On these moonlight nights there are no Storm Petrels flying about and not a single cry is heard. Occasionally a dark object flits across the sky and lands on the ground—a parent has come home.

A full moon in a cloudless sky marked the night of January 3, 1942, yet all eight chicks weighed next morning had been fed. Two nights later there was a heavy north-west wind accompanied by rain all night, resulting in only three of the eight chicks being fed. From these observations it will be seen that the effects of weather possibly had an influence on the results in Table XIV.

On February 3, 1942, two nights after the full moon, nine of the ten chicks weighed were fed. The early part of the night was dull, but by 10 p.m. the moon began to show up, causing the few Storm Petrels that were flying about to disappear. It remained light and calm all the night. On January 11, 1941, two days before full moon, a bright moon shone till 2 a.m. and on this occasion all the five chicks were fed.

At midnight on January 13–14, 1941, I had an interesting experience. The full moon was shining brightly in a clear sky as I approached nest 51 to discover an adult flitting about over the burrow. Landing near the mouth of the burrow it took some time in getting through the opening. A complete silence pervaded the island and there were no other birds in sight at the time. On weighing the chick next morning I found it was the only one of the five that had been fed. An additional five chicks which were not weighed but across whose burrows I had placed a palisade of sticks had not been visited either. Thus of the ten chicks under observation during this exceptionally bright night, only one was fed.

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The preceding table has been made out to check up whether the average weights of food given are influenced by periods of fast and by successive meals. From the top part of the table the indications are that heavier meals are given as the length of the fast increases. As regards successive meals, the first two after a fast of one day are much the same and then there is a considerable drop. The fourth meal rises again after the light third meal, while the fifth, too, remains high, and then there is another fall. The actual cases for these later meals are somewhat few for reliable inferences.

From January 12 to 16, 1941, a bright moonlight period, out of the possible 25 meals for five chicks, only six were given. On January 17, all five chicks were fed with substantial amounts varying from 6 ½ to 12 ½ grams, the aggregate amounting to 47 ¾ grams, or an average of 9.55 grams. This must surely represent a recuperative quantity. During the previous five nights the six meals given weighed ½ 1, 2, 3, 8, and 18 grams respectively, the last amount being given to a chick which had not been fed for four consecutive nights.

As a rule rough nights appear to keep the adults away, but there occurred on March 7, 1942, the exception that proves the rule. On that night a sudden heavy wind prostrated two Pararas (Pachyp-tila vittata) on the vegetation outside the tent. This was the heaviest wind I had ever experienced on the island, and although the peak period of intensity lasted only ten minutes, it was severe all night. In spite of these rough conditions eight of the eleven chicks that were being weighed were fed that night. Incidents like this and other occasions when feeding occurred on moonlight nights incline me to the opinion, in spite of evidence to the contrary in Table XIV, that parents endeavour to get home somehow. While weighing the chicks in the field I formed the impression that some of the parents gave extra heavy meals to the chicks when the moonlight nights were approaching. For example, when full moon occurred on February 1, chick 71R from January 25 to 29 received 6, 7 ½, 7, 20, and 12 ½ grams respectively. On January 30 it was not fed, and for the next five nights it received only 11 ½ grams altogether.

The influence of moonlight nights on Storm Petrels has been noted by several other writers. Regarding the British Storm Petrel, Lockley (1932, p. 211) states that they shun the land to some extent on very bright moonlight nights, but that they are not so particular as the Manx Shearwater. In my case the position is reversed, for it is the Mutton-bird (Puffinus griseus) which does not object to the moon, whereas the White-faced Storm Petrel does. Gross (1935, p. 387) records that on a night of full moonlight and a clear sky very little activity on the part of Leach's Petrel is noticeable. The birds fly in from the sea to their nests as quickly and as silently as possible. There is only an occasional petrel call. This describes very well the conditions on Whero on moonlight nights, and I would suggest that the birds Gross saw coming in were mainly parents, the unemployed having remained at sea.

Ainslee and Atkinson's records (1937, pp. 242–243) for Leach's Petrel made on North Rona, however, are a little different from