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Research about Semidi Islands

Source-linked reports with geographic coverage including Semidi Islands.

4 recordsLinked to original sources
USGS1990

Time allocation by northern fulmars during the breeding season

Averaged over the whole breeding cycle (pre-laying through mid-chick stage), breeding fulmars spent about 39% of their time at the breeding site and 61% of their time at sea. Annual means of site occupancy before egg-laying were positively correlated with breeding success, suggesting that time allocation was a sensitive indicator of food availability in different years. Nonbreeding site-holders spent about half as much time at the colony as breeders; their attendance was highest early in the season when pair bonds and site ownership were established. The attendance of failed birds after egg or chick loss was positively correlated with colony-wide breeding success in six years. Males spent more time at the breeding site than females at every stage of the season. Most days were devoted to foraging in the pre-laying period (69% in males, 82% in females). An extended absence from the colony just before laying (the pre-laying exodus) averaged 12.2 d in males and 17.6 d in females. Changes in body weight indicated that neither sex incurred an energy deficit on a seasonal basis. A greater investment by the male in site attendance during incubation offset the female's investment in egg production and assured that both sexes entered the demanding chick-feeding stage in good condition.

Alaska↗
USGS1990

Individual variation in behavior and breeding success of Northern Fulmars

In a sample of breeding Northern Fulmars ( Fulmarus glacialis ) observed in 4-5 years, up to 43% of the variability in 13 attributes of breeding behavior was consistent among individuals or pairs. Sample means for most attributes were correlated in a predictable way with annual levels of breeding success. Except for laying dates, there was little evidence that individual differences in these attributes contributed to variation in breeding success. A test of breeding experience as a contributing factor revealed an interaction between individual and annual components of variation. During years when the whole population did relatively poorly, pairs with no previous breeding experience were affected disproportionately. Late-nesting fulmars were more successful than early layers, possibly because delayed breeding ensured that food availability was adequate for successful incubation.

Alaska↗
USGS1983

Mechanism and ecological significance of sperm storage in the Northern Fulmar with reference to its occurrence in other birds

Sperm-storage glands were found in the uterovaginal (UV) region of the oviduct in Northern Fulmars ( Fulmarus glacialis ), Horned Puffins ( Fratercula corniculata ), and Leach's Storm-Petrels ( Oceanodroma leucorhoa ) collected before or shortly after egg laying. Previously described only in domestic Galliformes, UV sperm-storage glands may prove to be a common feature of the avian reproductive system. There is as yet no compelling explanation of their function in the Horned Puffin. In the Northern Fulmar, and probably in other petrels, however, sperm-storage glands allow the separation of the male and female over pelagic waters for several weeks immediately before egg laying. The likelihood of prolonged viability of sperm in the female reproductive tract should be considered in interpreting the sexual behavior of other wild birds.

Alaska↗