Albatross, petrel egg sizes, new research

This video says about itself:

Egg Laid By World’s Oldest Banded Wild Albatross

18 December 2014

Wisdom, a 63-year-old Laysan albatross living in Hawaii, has lain yet another egg.

Wisdom, a Laysan albatross estimated to be around 63 years old, has laid yet another egg at her home on an atoll about 1200 miles northwest of Honolulu.

She is the oldest known banded bird living in the wild, and is believed to have already raised about 35 offspring.

Mating and child rearing isn’t a casual affair among the species.

Only one egg is laid at a time, so it’s particularly important that everything goes well.

Males and females couple for life, and once the egg is produced they share in the early incubation responsibilities.

It’s an all or nothing process, as if something goes awry and the shelled embryo doesn’t make it, there will not be another attempt until the mating season rolls around again in the following year.

If it does succeed, a great deal of time is spent preparing the little one to go and live on its own.

The whole process takes about a year.

Wisdom has enjoyed a phenomenal chick survival rate in recent years, with 8 of her 9 most recent attempts being successful.

Officials from the Midway Atoll National Wildlife Refuge are anticipating that the latest will emerge in early February.

From the Canadian Journal of Zoology:

Does feeding zone influence egg size in slow-breeding seabirds?

F. Stephen Dobson, Pierre Jouventin

20 June 2015

Abstract

In several bird species, mothers that endow their eggs with additional resources benefit from more rapid development and more robust offspring. We examined egg size and associated life-history traits in 44 species of the slow-breeding procellariiform seabirds (albatrosses and petrels).

The far distant foraging of some of the species should subject them to difficult ecological conditions and perhaps delays in return to the nest. Such delays might lead to poorer egg care by the remaining parent. To compensate, we predicted a positive association of egg size with foraging zone (offshore, near pelagic, far pelagic), and both with the length of incubation shifts.

We tested this hypothesis and also examined egg size and fitness-related reproductive traits. Egg size scaled significantly and tightly with female body mass (β = 0.72, R2 = 0.98). After influences of both size and phylogeny were removed, however, egg size was positively and significantly associated with both mean length of incubation shift and feeding zone (r = 0.45 and 0.46, respectively), perhaps indicating a life-history syndrome of egg size, incubation, and distance that species go to forage during the breeding season, and supporting the compensation hypothesis.