Researchers have previously assumed that common diving petrels (Pelecanoides urinatrix) have a limited sense of smell since they have relatively small olfactory bulbs. A recent study, however, showed that adult diving petrels prefer the scent of their own burrow compared to burrows of other diving petrels, implying that personal scents contribute to the burrow's odour signature. Because diving petrels appear to be adapted to use olfaction in social contexts, they could be a useful model for investigating how chemically mediated social recognition develops in birds. A first step is to determine whether diving petrel chicks can detect familiar and unfamiliar odours. We compared behavioural responses of chicks to three natural stimuli in a wind tunnel: soil collected from their burrow or colony, and a blank control. During portions of the experiment, chicks turned the least and walked the shortest distances in response to odours from the nest, which is consistent with their sedentary behaviour within the burrow. By contrast, behaviours linked to olfactory search increased when chicks were exposed to blank controls. These results suggest that common diving petrel chicks can detect natural olfactory stimuli before fledging, and lay the foundation for future studies on the role of olfaction in social contexts for this species.

As a first step towards understanding the development of olfactory behaviours in Antarctic procellariiform seabirds, we recently showed that blue petrel chicks (Halobaena caerulea) could detect both a food-related and a novel odour while asleep. In this current study, we tested chicks in a simple wind tunnel to determine if exploratory behaviours could be initiated by olfactory stimuli as well. We compared the behavioural responses of 30 blue petrel chicks to cod liver oil (a prey-related odour) or phenyl ethyl alcohol (an unfamiliar, rosy-smelling odourant) against a control (distilled water). Six behavioural indices were measured, including head turns, body turns, bites, preening events, wing-stretches, and distance walked. In response to cod liver oil, we found that chicks increased both turning rates and distances walked whereas chicks preened more in response to phenyl ethyl alcohol. Since only cod liver oil initiated behaviours consistent with searching, our results suggest that chicks are attaching biological significance to food-related odours even before they leave the burrow to forage for the first time.

A limited sampling campaign on the main island of Îles Kerguelen revealed 170 freshwater diatom taxa, belonging to 29 genera. Four different communities were distinguished in two major groups, being determined principally by habitat type. The Fragilaria vaucheriae–Fragilaria germainii assemblage occurs exclusively in running waters. The three other communities, observed in standing waterbodies, are separated by their geographical position on the island with the Fragilaria exigua–Aulacoseira alpigena and the Fragilaria exigua–Fragilaria vaucheriae assemblages, mainly found in the Lac Studer area and the Fragilaria pinnata var. pinnata assemblage, recorded near the coastal line and the research station. Analysis of different waterbody types revealed the habitat preference of the various diatom taxa and identified a diatom flora for running waters and one preferring stagnant waterbodies.

Des investigations portant sur le genre Diadesmis (Bacillariophycées), observé à l'aide du microscope photonique et du microscope électronique à balayage, ont été réalisées dans différents biotopes des archipels de Crozet et de Kerguelen : lacs, mares temporaires, mousses et sols. Dix espèces ont été recensées. Diadesmis arcuata Heiden, décrite à l'origine dans l'archipel de Kerguelen, est réexaminée et typifiée. Cinq espèces nouvelles pour la science sont décrites : Diadesmis comperei, Diadesmis costei, Diadesmis crozetikerguelensis, Diadesmis langebertalotii et Diadesmis subantarctica. Les espèces appartenant au sous-genre Paradiadesmis ont une structure particulière : les interstries sont constituées de tubes creux quadrangulaires.

Cette étude de la flore diatomique subfossile dulçaquicole de la Grande Terre (Iles Kerguelen) a été réalisée à partir de six prélèvementseffectués sur des dépôts tourbeux mis à jour après le retrait du Glacier Ampère, à l'ouest de l'archipel. Au total, 107taxons de diatomées (84 espèces, 22 variétés et 1 forme) ont été observés. On constate une grande similitude entre cette floresubfossile, datant d'environ 1000, 5000 ou 10000 ans BP, et la flore diatomique actuelle des Iles Kerguelen. La biogéographiede cette flore et les similitudes avec la flore d'autres îles antarctiques sont brièvement discutées.

Cet inventaire des diatomées d'eau douce des îles Kerguelen (Grande Terre) a été réalisé à partir de prélèvements effectués sur 31 stations représentant divers milieux : ruisseaux, rivières, lacs, rochers suintants. Dans la présente note, 279 taxons ont été déterminés, dont 3 sont considérés nouveaux pour la science. La plupart des espèces et variétés recensées ont une large répartition géographique ; l'endémisme est restreint. De nombreuses espèces sont représentées seulement par quelques individus. Si les Pennales présentent une large gamme de genres et d'espèces, il n'en est pas de même pourles Centrales, non seulement du point de vue diversité, mais également du point de vue abondance (à l'exception de Melosira distans).

Raphe-like vestiges have been found regularly in two new taxa which presumably belong to Fragilaria, one of them livingin several lakes of the Kerguelen Islands, the other in the Yellowstone National Park, Wyoming, U.S.A. The latter onepossesses septa-like elements as integrated parts of a girdle band. Other septa-like elements can occur in different speciesof Fragilaria. They represent appendices of the valvocopula, located beneath the transapical costae. Structures like linkingspines on marginal parts of the valve face occur in an Achnanthes species. Most of these characters seem to havebeen unknown in these taxa until recently.