Calonectris Leucomelas Research Articles

A comparative study on the chemical consitutions of some bird eggs and the adaptive significance

1. With the interest to find out the adaptive influence of ecological factors to be reflected in the egg constitution, the eggs of a few species of herons, sea birds as well as some domesticated birds were compared (also referring the known data given by Romanoffs 1949).2. Chemical constitution was analysed at Japan Oil and Vitamin Inspection Institute, Tokyo.3. Eggs of wild birds used were those of the following species: Egretta garzetta and Nycticorax nycticorax (Shinhama colony, Chiba), Larus crassirostris, Uria aalge and Cerorhinca monocerata (Teuri I., Hokkaido) and Calonectris leucomelas (Toshima, Izu Is. Eggs of this species of great interest (Nice 1962) were unfortunately too advanced for chemical analysis).4. A devise for field egg-inspection by means of a long-type cup (of ice-cream) lined inside with silver paper (for strong light reflection), a flashlight (electric torch) and black cloth to work under, is described and by this test the fresh unincubated eggs could be selected. For inspection of thick and colored shelled eggs perfect darkness was necessary.5. Yolk color difference was noticed between Sooty Tern (orange) and Noddy (yellow) (Marcus I., Kuroda 1954), among Larus crassirostris (orange), Uria aalge, Synthliboramphus Cerorhinca (yellow) and Cepphus carbo (orange) breeding on Teuri I., and Calonectris (yellow) of Toshima, and between Egretta garzetta (red) and Nycticorax (yellow) of a same colony. It was suggested that fish eaters have yellow yolks, while crustacean food seems to be responsible for orange or even red yolk according to the amount ingested. However, difference in Sooty Tern and Noddy, both eating squids there, might have involved some other genetic factor.6. The relative yolk weight % for entire egg and egg white is higher in precocial than in altricial birds and in smaller than in larger eggs of the birds of same habit (Romanoffs). The present data support this: the yolk % was low in altricial (semi-altricial by Nice) herons and intermediate in semi-precocial gull, murre and the puffin (Cerorhinca). But, the yolk amount relative to albumen was greater in larger goose eggs than in smaller duck eggs and in larger murre eggs than in smaller puffin eggs. This may reflect the stronger conditions at hatching of goose and murre chicks compared with those of duck and puffin respectively.7. The shell weight % for entire egg is larger in precocial than altricial, and in larger than smaller birds. The shell is thicker in precocial birds, because chicks hatch in stronger condition (Romanoffs). The thick-shelled Guinea Fowl egg should reflect the adaptation of heat prevention devise for they are laid on tropical dryland, while the shell thickness is adaptively different by the murre populations breeding on rough or smooth rocks (Kartaschew) and the eggs of Teuri population belonged to the thick-shelled type; thickest at the pointed end on which the egg rolls.8. The amount of water is higher in the eggs of altricial than precocial birds (least so in ducks and geese (Romanoffs)), in which the solid portion is greater. The present data on heron eggs coincided with the reported amount of altricial song birds and pigeons. In the semi-precocial gull and alcids, eggs had precocial type amount of yolk water and rather altricial type amount of egg white water (if Romanoffs' data are referred), thus being intermediate as a whole.9. The thin-shelled heron eggs were decomposed so soon as three days after having been kept in normal refrigerater. Gull and murre eggs were not affected after 53 days kept in refrigerator, while after 89 days the larger murre egg with extremely thick shell still remained in good shape inspite of the gull egg had been entirely decomposed by this time.

Breeding ecology of the Streaked Shearwa-ter at Kamurijima I

1. The breeding ecology of Calonectris leucomelas at Kamurijima I. on the Japan Sea coast of Honshiu is reported based on 20 visits and 42 days of research. Specimens strayed into inland during post-breeding season was also studied.2. Breeding season sets in from late February and the island is abandoned from early to late November.3. They feed on the ocean during the day, returning to the island one hour after sunset and leaving again one hour before sunrise. The night number of birds on the island varies by night ranging 30, 000-36, 000.4. Preparatory period is from early March to late May during which nestoccupation (old-nests), nest-amendation and forming laying bed with dead leaves are done.5. Total number of nest-hollows on the island was around 128, 000 but usable and actually used nests are about 98, 000 of which only some 12, 000 were breeding nest-hollows. 6. A white egg is laid in middle and late June, measuring 42.0-47.0×64.0-72.2mm., 80g. Total egg number was assumed as 12, 000.7. Incubation period more than 51 days; the hatching dates ranging between August 10 and 20. The new born chicks measure: culmen 20-24 mm, wing 28-33mm, tarsus 19-25mm, middle toe 12-24mm, weight 50-70g.8. The chick is fed once at night and grows at a rate of about 20g per day until middle October, the maximum being 990g. At 30-40 days, the culmen 42-50mm, wing 115-163mm, tarsus 50-60mm, middle toe 55-67mm, weight 515-740g were measured; and at 60 days, culmen 43-57mm, weight 360-990g.9. In middle October, feathers and quills become developed and the feeding by parents become irregular and the weight of chick decreases, though it assumes adult-like feature.10. The chicks leave the island during late October and middle November. The feeding period is 70-100 days with average of 80 days. The chick weight at flying is less than 500g, some still with some down.11. The adult birds leave the island first and the chicks follow them as they grow.12. In early and middle November not few of them are found strayed in the prefectures Kyoto, Fukui, Osaka, and Shiga and these include young of the year and weekened adult birds, just started for migration.13. One hundred chicks and 22 chicks were banded in October 1960 and November 1961 respectively. None of the 1960 chicks recovered in 1961. More banding is being planned.

An albino of Calonectris leucomelas

A total albino of a female young Streaked Shearwater Calonectris leucomelas, obtained in late November, 1960, at the breeding ground on Mikura I., Seven Is. of Izu, Japan, is reported.

A record of Calonectris leucomelas from Hawaii

The author was given a specimen of Calonectris leucomelas obtained in Hawaii, February, 1948. This is its first record from Hawaii.