Receding ice drove parallel expansions in Southern Ocean penguins.

Climate shifts are key drivers of ecosystem change. Despite the critical importance of Antarctica and the Southern Ocean for global climate, the extent of climate-driven ecological change in this region remains controversial. In particular, the biological effects of changing sea ice conditions are poorly understood.

Dispersal in the sub-Antarctic: king penguins show remarkably little population genetic differentiation across their range.

Background: Seabirds are important components of marine ecosystems, both as predators and as indicators of ecological change, being conspicuous and sensitive to changes in prey abundance. To determine whether fluctuations in population sizes are localised or indicative of large-scale ecosystem change, we must first understand population structure and dispersal. King penguins are long-lived seabirds that occupy a niche across the sub-Antarctic zone close to the Polar Front.

Mother Vocal Recognition in Antarctic Fur Seal Arctocephalus gazella Pups: A Two-Step Process.

In otariids, mother's recognition by pups is essential to their survival since females nurse exclusively their own young and can be very aggressive towards non-kin. Antarctic fur seal, Arctocephalus gazella, come ashore to breed and form dense colonies. During the 4-month lactation period, females alternate foraging trips at sea with suckling period ashore.

Color ornaments and territory position in king penguins.

King penguins exhibit mutual color ornamentation of feathers and beak color. They breed in dense colonies and produce a single chick every 2 years. Thus, males and females must choose partners carefully to be reproductively successful, and auricular patches of males and UV coloration of beak spots have been shown to influence mate choice.

Transcriptome analysis in non-model species: a new method for the analysis of heterologous hybridization on microarrays.

Background: Recent developments in high-throughput methods of analyzing transcriptomic profiles are promising for many areas of biology, including ecophysiology. However, although commercial microarrays are available for most common laboratory models, transcriptome analysis in non-traditional model species still remains a challenge. Indeed, the signal resulting from heterologous hybridization is low and difficult to interpret because of the weak complementarity between probe and target sequences, especially when no microarray dedicated to a genetically close species is available.

Eleven polymorphic microsatellite markers in Cory's shearwater, Calonectris diomedea, and cross-species amplification on threatened Procellariiformes.

For the first time, we describe 11 variable dinucleotide microsatellites and the conditions for multiplexing and simultaneous genotyping sets of loci in Cory's shearwater, Calonectris diomedea. Microsatellite variability was assessed in a colony from the Azores archipelago (Atlantic Ocean). Two to eight alleles were detected per locus, the mean gene diversity being 4.

Individual odor recognition in birds: an endogenous olfactory signature on petrels' feathers?

A growing body of evidence indicates that odors are used in individual, sexual, and species recognition in vertebrates, and may be reliable signals of quality and compatibility. Petrels are seabirds that exhibit an acute sense of smell. During the breeding period, many species of petrels live in dense colonies on small oceanic islands and form pairs that use individual underground burrows.

How slow breeding can be selected in seabirds: testing Lack's hypothesis.

The historical debate of the 1960s between group and individual selection hinged on how the slow breeding of seabirds could be explained. While this debate was settled by the ascendance of individual selection, championed by David Lack, explanations for slow breeding in seabirds remain to be tested. We examined the slowest breeding of these birds, the albatrosses and petrels (order Procellariiformes), using analyses that statistically controlled for variations in body size and phylogeny.

Ultraviolet reflecting photonic microstructures in the King Penguin beak.

King and emperor penguins (Aptenodytes patagonicus and Aptenodytes forsteri) are the only species of marine birds so far known to reflect ultraviolet (UV) light from their beaks. Unlike humans, most birds perceive UV light and several species communicate using the near UV spectrum. Indeed, UV reflectance in addition to the colour of songbird feathers has been recognized as an important signal when choosing a mate.

How to measure information carried by a modulated vocal signature?

Acoustic signaling systems that permit individual recognition are described in an increasing number of species. Evolutionary logic predicts that the efficiency of these signatures is related to the possibilities for confusion. To test this "signature adaptation" hypothesis, one needs a standardized method to estimate and compare the efficiency of different signatures.

Evidence for nest-odour recognition in two species of diving petrel.

In nearly every procellariiform species, the sense of smell appears to be highly adapted for foraging at sea, but the sense of smell among the diving petrels is enigmatic. These birds forage at considerable depth and are not attracted to odour cues at sea. However, several procellariiform species have recently been shown to relocate their nesting burrows by scent, suggesting that these birds use an olfactory signature to identify the home burrow.

Mother-lamb acoustic recognition in sheep: a frequency coding.

Ewes of the domestic sheep ( Ovis aries ) display selective maternal investment by restricting care to their own offspring and rejecting alien young. This trait relies on individual recognition processes between ewes and lambs. Whereas identification at the udder is only olfactory, distance recognition is performed through visual and acoustic cues.

Potential for individual recognition in acoustic signals: a comparative study of two gulls with different nesting patterns.

We test relationships between structure of acoustic signal used for individual recognition and nesting ecology among two gulls: the black-headed gull (Larus ridibundus), in which chicks remain in the nest, and the slender-billed gull (L. genei), in which chicks leave the nest after hatching to form crèches. A striking difference between both species is the presence of two fundamental frequencies in the slender-billed gull's call and only one in the black-headed gull's call.

Homing in pelagic birds: a pilot experiment with white-chinned petrels released in the open sea.

During the breeding period white-chinned petrels (Procellaria aequinoctialis) repeatedly perform long foraging trips in the open ocean from their breeding island, and are able to home with an astonishing precision. The orientation mechanisms involved are not yet known. By analogy with those used by desert ants moving in a similarly "featureless" environment, one can hypothesise that petrels may home using path-integration.

How mothers find their pups in a colony of Antarctic fur seals.

In Antarctic fur seals, Arctocephalus gazella, mothers must identify their own young among hundreds or even thousands of pups, if they are to invest in their own offspring and avoid misdirecting their parental care. When returning to their breeding colony from a foraging trip of several days at sea, mothers have to find and identify their young before suckling can occur. There appears to be little confusion about which pup belongs to a mother, and adoption is absent or rare.

Localisation of an acoustic signal in a noisy environment: the display call of the king penguin Aptenodytes patagonicus.

King penguin chicks identify their parents by an acoustic signal, the display call. This call consists of a succession of similar syllables. Each syllable has two harmonic series, strongly modulated in frequency and amplitude, with added beats of varying amplitude generated by a two-voice system.

Why breed every other year? The case of albatrosses.

Albatrosses exhibit extremely low reproductive rates, each pair brooding only one egg and subsequent chick at a time. Furthermore, in several of the species, the majority of successful pairs breed only once every second year (termed 'biennial' breeding). Thus, on average, these latter species have an annual fecundity of about half an offspring per year, while other albatrosses produce an egg and chick every year.

How does a fur seal mother recognize the voice of her pup? An experimental study of Arctocephalus tropicalis.

In the subantarctic fur seal Arctocephalus tropicalis, mothers leave their pups during the rearing period to make long and frequent feeding trips to sea. When a female returns from the ocean, she has to find her pup among several hundred others. Taking into account both spectral and temporal domains, we investigated the individual vocal signature occurring in the 'female attraction call' used by pups to attract their mother.

Effect of sea-ice extent on adult survival of an Antarctic top predator: the snow petrel Pagodroma nivea.

The snow petrel Pagodroma nivea is an obligate associate of sea-ice and one of the most abundant seabird species of the Southern Ocean. Time- and sex-specific annual variation in adult survival was estimated using capture-mark-recapture of petrels nesting at Pétrels Island, Terre Adélie, 1981-1997. On the basis of a regression analysis, 44% of the variation was linked inversely to the latitudinal extent of sea-ice during winter (June) in the region offshore of the study colony, where this population is likely to spend the non-breeding season.