Picard Baptiste

French National Centre for Scientific Research | CNRS · Centre d'Etudes Biologiques de Chizé (CNRS & La Rochelle Université)

Background Studying animal movement in the context of the optimal foraging theory has led to the development of simple movement metrics for inferring feeding activity. Yet, the predictive capacity of these metrics in natural environments has been given little attention, raising serious questions of the validity of these metrics. The aim of this stu...

The Patagonian slope is the region where Subantarctic waters and bathymetry give raise to physical and ecological processes that support a rich biodiversity and a large-scale industrial fisheries. Unique among the species that depend on this region is the deep diving southern elephant seal, Mirounga leonina. We report here on changes in the foragin...

Rapid and regionally contrasting climate changes have been observed around Antarctica. However, our understanding of the impact of these changes on ecosystems remains limited, and there is an urgent need to better identify habitats of Antarctic species. The Weddell seal ( Leptonychotes weddellii ) is a circumpolar mesopredator and an indicative spe...

The diving behavior of southern elephant seals, Mirounga leonina, is investigated through the analysis of time-depth dive profiles. The originality of this work is to consider dive profiles as continuous curves. For this purpose, a Functional Data Analysis (FDA) approach is proposed for the shape analysis of a collection of dive profiles. Complexit...

Identifying factors influencing survivorship is key to understanding population persistence. Although satellite telemetry is a powerful tool for studying remote animal ecology and behaviour it is rarely used for demographic studies because distinguishing the death of the animal (individual mortality) from failure of the tag (mechanical tag failure)...

Incubating eggs represents a trade-off for parent birds between spending enough time fasting to take care of the clutch and to get enough nutrients for self-maintenance. It is believed that the pituitary hormone prolactin plays an important role in such allocation processes. Incubation does not solely imply the active warming of the eggs but also t...

Animal telemetry is a powerful tool for observing marine animals and the physical environments that they inhabit, from coastal and continental shelf ecosystems to polar seas and open oceans. Satellite-linked biologgers and networks of acoustic receivers allow animals to be reliably monitored over scales of tens of meters to thousands of kilometers,...

Most available CTD–Satellite Relay Data Logger (CTD–SRDL) profiles are heavily compressed before satellite transmission. High-resolution profiles recorded at the sampling frequency of 0.5 Hz are however available upon physical retrieval of the logger. Between 2014 and 2018, several loggers deployed on elephant seals in the Southern Ocean have been...

In birds, incubation-related behaviors and brood patch formation are influenced by hormonal regulation like prolactin secretion. Brood patch provides efficient heat transfer between the incubating parent and the developing embryo in the egg. Importantly, several environmental contaminants are already known to have adverse effects on avian reproduct...

The effect of thermal mass on the salinity estimate from conductivity–temperature–depth (CTD) tags sensor mounted on marine mammals is documented, and a correction scheme is proposed to mitigate its impact. The algorithm developed here allows for a direct correction of the salinity data, rather than a correction of the sample’s conductivity and tem...

Antarctic coastal polynyas are regions of persistent open water and are thought to be key bio-physical features within the sea-ice zone. However, their use by the upper trophic levels of ecosystems remains unclear. A unique bio-physical dataset recorded by southern elephant seals reveals that East Antarctic polynyas are a key winter foraging habita...

Few studies have examined the foraging ecology of top marine predators by taking into account the vertical and horizontal dimensions simultaneously. In this study, thanks to three-dimensional reconstruction of underwater animal paths, we investigated the relationship between area restricted search (ARS) and foraging behaviors in the Southern Elepha...

Marine endotherms living in cold water face an energetically challenging situation. Unless properly insulated these animals will lose heat rapidly. The field metabolic rate of king penguins at sea is about twice that on land. However, when at sea, their metabolic rate is higher during extended resting periods at the surface than during foraging, wh...

Polar oceans are poorly monitored despite the important role they play in regulating Earth’s climate system. Marine mammals equipped with biologging devices are now being used to fill the data gaps in these logistically difficult to sample regions. Since 2002, instrumented animals have been generating exceptionally large data sets of oceanographic...

Marine mammals help gather information on some of the harshest environments on the planet, through the use of miniaturized ocean sensors glued on their fur. Since 2004, hundreds of diving marine animals, mainly Antarctic and Arctic seals, have been fitted with a new generation of Argos tags developed by the Sea Mammal Research Unit of the Universit...

Marine mammals help gather information on some of the harshest environments on the planet, through the use of miniaturized ocean sensors glued on their fur. Since 2004, hundreds of diving marine animals, mainly Antarctic and Arctic seals, have been fitted with a new generation of Argos tags developed by the Sea Mammal Research Unit of the Universit...

Understanding the diving behaviour of diving predators in relation to concomitant prey distribution could have major practical applications in conservation biology by allowing the assessment of how changes in fine scale prey distribution impact foraging efficiency and ultimately population dynamics. The southern elephant seal (Mirounga leonina, her...

Detection of Prey Encounter Events (PEE). (PDF)

Surface horizontal speed. (PDF)

Influence of vertical speed on swimming effort during transit phases. (PDF)

Diving behaviour and device deployment details for the 9 post-breeding female SES. (PDF)

Assessing energy gain and expenditure in free ranging marine predators is difficult. However, such measurements are critical if we are to understand how variation in foraging efficiency, and in turn individual body condition, is impacted by environmentally driven changes in prey abundance and/or accessibility. To investigate the influence of oceano...

Seals help gather information on some of the harshest environments on the planet, through the use of miniaturized ocean sensors glued on their fur. The resulting data – gathered from remote, icy seas over the last decade – are now freely available to scientists around the world from the data portal http://www. meop.net. The Polar oceans are changin...

The circulation in the Western Equatorial Atlantic is characterized by a highly dynamic mesoscale activity that shapes the Guiana continental shelf. Olive ridley sea turtles (Lepidochelys olivacea) nesting in French Guiana cross this turbulent environment during their post-nesting migration. We studied how oceanographic and biological conditions dr...

The circulation in the Western Equatorial Atlantic is characterized by a highly dynamic mesoscale activity that shapes the Guiana continental shelf. Olive ridley sea turtles (Lepidochelys olivacea) nesting in French Guiana cross this turbulent environment during their post-nesting migration. We studied how oceanographic and biological conditions dr...

1.Optimal Diving Models have been developed to investigate how air-breathing predators should adjust their diving behaviour to optimize their foraging efficiency. Using Time-Depth-Recorders and 3D accelerometers, we addressed this question on six free-ranging Southern Elephant Seal (SES) females equipped on Kerguelen Island.2.We hypothesise that se...

It is notoriously difficult to measure physiological parameters in cryptic free-ranging marine mammals. However, it is critical to understand how marine mammals manage their energy expenditure and their diving behavior in environments where the predation risks are low and where survival is mainly linked to capacities to maintain physiological homeo...

Understanding the responses of animals to the environment is crucial for identifying critical foraging habitat. Elephant seals (Mirounga leonina) from the Kerguelen Islands (49° 20’ S, 70° 20’ E) have several different foraging strategies. Why some individuals undertake long trips to the Antarctic continent while others utilise the relatively close...

Under the influence of both tidal and oceanic currents, the Guyana continental shelf is one of the most dynamic coastal ecosystems of the world. Olive ridley Lepidochelys olivacea sea turtles nesting in French Guiana are among the marine species that live in this dynamic ecosystem when migrating. To better understand how this species use mesoscale...

Mature female southern elephant seals come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buo...

Mature female southern elephant seals come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buo...

The distribution of southern elephant seal Mirounga leonina prey encounter events (PEEs) was investigated from the foraging behaviour of 29 post-breeding females simultaneously equipped with a satellite tag, a time−depth recorder and a head-mounted accelerometer. Seal diving depth and PEE were related to water temperature at 200 m (T200), and light...

In situ observation of the marine environment has traditionally relied on ship-based platforms. The obvious consequence is that physical and biogeochemical properties have been dramatically undersampled, especially in the remote Southern Ocean (SO). The difficulty in obtaining in situ data represents the major lim- itations to our understanding, an...

In-situ observation of the marine environment has traditionally relied on ship-based platforms. The obvious consequence is that physical and biogeochemical properties have been dramatically undersampled, especially in the remote Southern Ocean (SO). The difficulty in obtaining in situ data represents the major limitations to our understanding, and...