Marine Birds

Le gouvernement de Polynésie française s’est
engagé en novembre 2013 à protéger au moins 20%
des eaux polynésiennes d’ici 2020. En juin 2014, plus
de 50 associations de Polynésie française ont
soutenu cet objectif à travers le message de la
pirogue Hokule’a. Les îles Australes présentent des
opportunités de conservation majeures, avec une
richesse extraordinaire des écosystèmes marins et
un intérêt marqué de la population des îles pour la
protection de leur patrimoine. De juin à décembre
2014, les conseils municipaux des cinq îles habitées
des Australes ont voté une délibération appelant à la
création d’une grande Aire Marine Protégée (AMP)
dans les eaux de leur archipel. Le gouvernement a
entendu ce message et annoncé en novembre 2014
la création future d’une grande AMP dans les eaux
des Australes, lors du Congrès Mondial des Parcs à
Sydney. En mai 2014, le gouvernement de Polynésie
française a invité The Pew Charitable Trusts à
travailler sur un état des lieux scientifique de
l’environnement marin des Australes ; le présent
ouvrage vise à répondre à cette requête. L’objectif de
ce rapport est d’établir un diagnostic détaillé et
partagé des connaissances disponibles sur le milieu
marin de l’archipel des Australes, du littoral jusqu’à
l’océan du large, et des relations entre les insulaires
des Australes et leur environnement marin. Cet état
des lieux participatif et pluridisciplinaire offrira un
socle de connaissance solide sur lequel pourront être
définies des mesures de conservation adaptées, par
le gouvernement et les populations locales.

Hundreds of fossil marine vertebrates cropping out at Cerro Colorado (Pisco Basin, Peru) are identified and reported on a 1:6500 scale geological map and in a joined stratigraphic section. All the fossils are from the lower strata of the Pisco Formation, dated in this area to the late middle or early late Miocene. They are particularly concentrated (88%) in the stratigraphic interval from 40 to 75 m above the unconformity with the underlying Chilcatay Formation. The impressive fossil assemblage includes more than 300 specimens preserved as bone elements belonging mostly to cetaceans (81%), represented by mysticetes (cetotheriids and balaenopteroids) and odontocetes (kentriodontid-like delphinidans, pontoporiids, ziphiids, and physeteroids, including the giant raptorial sperm whale Livyatan melvillei). Seals, crocodiles, sea turtles, seabirds, bony fish, and sharks are also reported. Isolated large teeth of Carcharocles and Cosmopolitodus are common throughout the investigated stratigraphical interval, whereas other shark teeth, mostly of carcharinids, are concentrated in one sandy interval. This work represents a first detailed census of the extraordinary paleontological heritage of the Pisco Basin and the basis for future taphonomic, paleoecological, and systematic studies, as well as a much needed conservation effort for this extremely rich paleontological site.

Se presentan los indicadores de edad definidos para cinco elementos del esqueleto post-craneal (húmero, coracoides, fémur, tibiatarso y tarsometatarso) de pingüinos Patagónicos o de Magallanes (Spheniscus magellanicus) a partir de una muestra actual de la especie colectada en el área de nidificación de Punta Entrada, litoral atlántico del sur de Patagonia continental (Argentina). El objetivo es definir indicadores óseos para estimar la edad relativa de estas aves, para aportar a las discusiones sobre la explotación de sus colonias de nidificación por los cazadores-recolectores holocénicos de la región. Para establecer los rasgos diagnósticos se consideraron las variables usualmente utilizadas para determinar edad en el caso de las aves: grado de osificación, textura y porosidad del tejido óseo, grado de fusión de las epífisis y de desarrollo de rasgos anatómicos diagnósticos. Este análisis se hizo en esqueletos correspondientes a las siguientes clases de edad: pichones (0 a 2 meses), “volantones” o independizados (2 a 3,5-4 meses), juveniles (3,5-4 a 12 meses) y adultos (más de 12 meses). Se concluye que a través de estos indicadores es posible establecer la presencia de pichones y adultos, lo cual es clave para determinar la existencia de un área de nidificación. Estos estudios contribuirán a discutir la estacionalidad de las ocupaciones humanas y las estrategias de explotación de la especie en todo su rango de distribución geográfica.
Age indicators defined for five elements of the post-cranial skeleton (humerus, coracoides, femur, tibiotarsus and tarsometatarsus) from a modern sample of Magallanic penguins (Spheniscus magellanicus) carcasses are presented. The sample was collected in the breeding colony at Punta Entrada, southern continental Patagonia (Argentina). The goal is to contribute to the discussion on the exploitation of penguin nesting colonies by the Holocene hunter-gatherers. Variables used for defining the diagnostic features of age were: degree of ossification, texture and porosity of the bone tissue, degree of fusion of the epiphyses, and development of anatomical diagnostic features in elements corresponding to the following age classes: chicks (0 to 2 month), fledglings (2 to 3.5-4 month), juveniles (3.5-4 to 12 month) and adults (more than 12 month). It is concluded that through these indicators it is possible to define the presence of chick bones and breeding adults, which are key to establish the existence of breeding areas. These studies will contribute to discussing issues such as the seasonality of human occupations and exploitation strategies of the species throughout its range of geographical distribution.

Individual specialization in diet or foraging behavior within apparently general-ist populations has been described for many species, especially in polar and temperate marine environments, where resource distribution is relatively predictable. It is unclear, however, whether and how increased environmental variability – and thus reduced predictability of resources – due to global climate change will affect individual specialization. We determined the within-and among-individual components of the trophic niche and the within-individual repeatability of d 13 C and d 15 N in feathers and red blood cells of individual female southern rockhopper penguins (Eudyptes chrysocome) across 7 years. We also investigated the effect of environmental variables (Southern Annular Mode, Southern Oscillation Index, and local sea surface temperature anomaly) on the isotopic values, as well as the link between stable isotopes and female body mass, clutch initiation dates, and total clutch mass. We observed consistent red blood cell d 13 C and d 15 N values within individuals among years, suggesting a moderate degree of within-individual specialization in C and N during the pre-breeding period. However, the total niche width was reduced and individual specialization not present during the premolt period. Despite significant inter-annual differences in isotope values of C and N and environmental conditions, none of the environmental variables were linked to stable isotope values and thus able to explain phenotypic plasticity. Furthermore, neither the within-individual nor among-individual effects of stable isotopes were found to be related to female body mass, clutch initiation date, or total clutch mass. In conclusion, our results emphasize that the degree of specialization within generalist populations can vary over the course of 1 year, even when being consistent within the same season across years. We were unable to confirm that environmental variability counteracts individual specialization in foraging behavior, as phenotypic plasticity in d 13 C and d 15 N was not linked to any of the environmental variables studied. 4488