For a comparative study of electrophoretic mobility of mitochondrial malate dehydrogenase (M-MDH), red cells or breast muscle (in some cases) from 185 species (57 families, 22 orders) of birds were subjected to starch-gel electrophoresis at pH7. The cathodal M-MDH mobility of Anas platyrhynchos was used as standard, a value of 100, and relative mobilities of other birds were estimated. Thus far tested, the M-MDH enzyme mobilities did not vary within species and genera. Even within families and orders mobilities were very conservative when compared with other enzymes. Terrestrial and aquatic bird orders following the Wetmore's system showed the standard enzyme mobility 100; i. e. Struthioniformes, Procellariiformes, Sphenisciformes, Podicipediformes, Pelecaniformes, Ciconiiformes, Phoenicopteriformes, Anseriformes, Galliformes, Gruiformes and Charadriiformes. Among these, 4 orders (Pelecaniformes, Ciconiiformes, Galliformes and Charadriiformes) included families with mobilities higher than 100. Exceptional orders were Tinamiformes (160) and Falconiformes (140). On the other hand, arboreal bird orders generally had mobilities exceeding 100, ranging 140-360. The values increased progressively toward smaller bodied orders; i. e. Columbiformes (140, 190), Cuculiformes (200), Strigiformes (200), Caprimulgiformes (200), Apodiformes (220), Coraciiformes (220, 250), Piciformes (230, 300) and Passeriformes (360). An especially high mobility was found in Psittaciformes (300-360). The variations of M-MDH mobility in birds, should have evolutionary as well as eco-physiological implications.

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The present breeding status of the endangered Short-tailed Albatross Diomedea albatrus, on Torishima, the Izu Is. was investigated. In the 1979/80 season, more than 50 eggs were laid and 20 young fledged. In 1980/81, 54 eggs laid and 32 fledged. Breeding success was similar to that in the early 1960s. About 130 adults and sub-adults were observed. The population is still increasing. The rats Rattus rattus, inhabiting much of Torishima were very numerous in 1979/80 but seemed to be decreasing in 1980/81. Although the rats are present on the albatross' nesting grounds in appreciable numbers, the species is primarily a herbivor and might be less harmful to the eggs and hatchlings than previously supposed. Recent observations on the status of the Short-tailed Albatross on Torishima, the Senkaku Is., and Hawaiian Is. suggest that the world population is at least 250 individuals.

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(1) The influence of predation by Slaty-backed Gulls Larus schistisagus on the fledging success of Black-tailed Gulls L. crassirostris was studied on Teuri Island off Haboro, Hokkaido, in 1980 and 1981. (2) Four quadrats were set in the breeding colony of Black-tailed Gulls in which 326 chicks were colour ringed and their biomass was measured. The analysis of food remains collected from forty nests of Slaty-backed Gulls was made for the estimation of the amount of predation. (3) The amount of predation reached a maximum later than the time when the biomass of prey reached a maximum. (4) Slaty-backed Gulls selectively hunt smaller chicks because of low hunting successs of large prey. (5) Later broods of Black-tailed Gulls were exposed to higher predation pressure by Slaty-backed Gulls. (6) The fledging success of Black-tailed Gulls was lower in late (14%) than in early (31%) and middle broods (41%). This trend could partly be explained by predation by Slaty-backed Gulls.

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The significance of the reoccupation of non-breeding birds of Adelie Penguins Pygoscelis adeliae had not been known much. We observed their behaviour during Adelies' breeding period in 1978-79 and got the results that the reoccupation have a positive role for breeding; colonial defence-enforcement, and being proxies for parents to incubate eggs or to guard chicks. So the reoccupation is thought to be adaptive for the chick-raising of breeders, and the creche system is the communal breeding which is developed in the Antarctic penguins.

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1. Census effectivities of bird species so far not treated in my previous papers are analysed by quantification method, type 1, of Hayashi (1961). 2. This method predicts Y_i from X₁, X₂, … X_m. Where Y_i (called outsider) is the census effectivity of i species given with quantitative value and X₁, X₂, … X_m (called items) are given with categorized ranks of each X property, such as, call note, song, body size, etc.. A value (called score) is given to each categorized rank by computer calculation so as to minimize
NΣi=1(Y_i-Y_i)² where Y_i is observed and Y_i is estimated (by Y_i=X₁+X₂+…+X_m) values of the census effectivity for i species. 3. In this study, four items and several categories in each item were selected as follows; 1) call: the synthetical value of strength and frequency of call note, 2) song: frequency of song syllables, 3) vegetation: forest profile which a bird inhabits or in which it was recorded in census, 4) size: the synthetical value of body size, home range size and velocity of bird's movement. 4. Category ranking of items was decided for each bird species based on these categorized items. As an exception, a vegetation category in which a bird species was mostly recorded by strong song was always given the first rank. In categorizing size item, three ranks for 50m and two for 25m observation radii were set. In call and song categories of some species, lower rank were selected from analytical base. 5. Computer analyses of quantification, type 1, were made and the results are shown by 50m and 25m observation radii. Observed Y_i and estimated Y_i census effectivities, with standard deviation σ of the difference are tabled. Observed census effectivities were calculated under standard conditions, which are: about 150 minutes after sunrise, fine weather and census speed 1.5km per hour. Scores given to each category rank are tabled with multi-correlations coefficient Ro between Y_i and Y_i. 6. In each cases, Ro was very significant (ca. 98%), and σ was rather small. Namely, 96% (=Ro²) of variation of Y_i can be explained by these items and categories. Suppose that samples of Y_i-Y_i fit normal distribution, then 95.4% of samples should fall between 0+2σ and 0-2σ. Namely, Y_i can be estimated significantly with ±9.14% (50m) or ±12.56% (25m) differences. In conclusion, application of quantification theory to estimation of census effectivity is considered

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On 19-20 October, 1980, we kept bird watching on the Marimo (9000t), a ferry-boat of Kinkaiyusen Co., from Kushiro, southeastern Hokkaido, for Ariake pier, Tokyo port. On 19 October, 1980, at 12:30 hours, the Marimo left Kushiro in the rain and haze. At about 13:10 hours, the weather changed. The ship was surrounded by a dense fog and fine rain and went on a calm sea at the speed of 20 knots. At 13:10 hours, we began to watch the birds as usual. After ten minutes, we heard the calls of many thrushes and buntings flying overhead in the dense fog. They were probably flying some hundred meters above the water, but we could not find out them. At 13:25 hours, throughout the dense fog, some of them began to fall on the ship in groups. The flights continued until 13:55 hours and headed between SW and W. From 13:25 to 13:45 hours, seventy birds of sixteen species fell on the deck. The position of the ship was 42°54'N, 144°15'E at 13:10 hours and 42°40'N, 144°05'E at 14:00 hours; these positions were about 10-21km from the nearest coast. Between 13:55 hours and evening, no calls were heard and no flights were observed. The fallen birds had damped feathers, and most of them were apparently exhausted. At first they alighted on the upper, middle and lower decks. Then, after two hours, they gathered on the lower deck and adjecent garage to take shelter from winds and rain. We kept watching and gave them avairable food, such as crumbs of potato croquettes, biscuits, sembei (Japanese rice biscuits) and rice. Soon the thrushes and buntings fed these foods, and on 20 October the bramblings joined them. On 20 October, when we began watching at 7:00 hours, we found new comers settled on the lower deck. We estimated that twelve birds of seven species had alighted on the ship during the previous night or in the early morning. About a half of birds fallen on the ship died. These were exhausted buntings and insectivores. Judging from the weather conditions of 18-20 October in their northern breeding areas, it seems that these birds started southward in better weather, but encountered with an unexpected rainy zone which was extending northward. Furthermore, the dense fog caused by a prevailing warm front, must obstruct their course.

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1) Hooded Cranes (Grus monacha Temminck) were observed in the vicinity of the Hachiro-gata and in Wakimoto, Oga city, Akita Pref. during December 1980 to February 1981. 2) A flock of six birds was first found on rice field of Wakami-machi, 19 December 1980. Two were seen at Hachirogata-machi, 13 January, two at Hitoichi, 17 January, four birds at Wakimoto, 30 January, and four at Wakami-machi, 30 January 1981 (Tables 1 and 2). We also saw a solitary bird in rice fields of Wakami-machi during 4 to 25 February 1981. 3) Its feces collected from rice field (by Mr. K. Tanba and Mr. T. Nishide) and analysed by Dr. T. Naito (Botanical Garden of Tohoku University, Sendai) contained many fragments and seeds of rice plant (Oryza sativa).

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The first breeding record in Japan of Bridled Tern Sterna anaethetus is reported from Nakanokami-shima, Okinawa prefecture, South Ryukyus (Abe and Mano 1980). In this paper, we report two other breeding localities of the species. One is Fude Rock where we have already suggested its breeding. The survey of this area was made on 27 and 28 June 1981. Fude Rock is a small rocky islet situated 12km NE of Seto-zaki, Miyako-jima, Okinawa prefecture, having an area of 140m×70m and the altitude, 9m. There is a lighthouse on the islet. Sterna anaethetus, Sterna sumatrana, Anous stolidus and Sula leucogaster settled on Fude Rock and adjacent tiny rocks. About sixty Bridled Terns were breeding, and some of them were in incubation. Another breeding locality is "Panari" commonly called, "Gunkan-jima", is situated near the southeastern end of Miyako-jima. We visited this area on 9 July 1981. The area is a small ring-shaped coral reef, and there are many small rocks at the eastern side of the area. Sterna anaethetus, Sterna sumatrana and Anous stolidus were observed on these rocks. About one hundred or one hundred and fifty Bridled Terns were counted, and their eggs and early chicks were found. The measurements of the Bridled Terns captured on Nakanokami-shima are given.

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