The effect of local weather conditions on the behaviour of moulting southern elephant seals,Mirounga leonina(L)

Abstract

NOTES 427confirmed so close to a station that has been occupied for 35 years, the likelihood that more emperor colonies are waiting to be discovered along the largely unexplored Wilkes Land coast between Casey Station and Dumont d'Urville is very strong. The presence of more breeding emperor colonies in Wilkes Land could significantly raise the present estimates of emperor penguin numbers. AcknowledgmentsWe thank voyage leader Martin Betts, station leader Angie Rhodes, and chief pilot Tony Scolari for their support in obtaining helicopter time during the base changeover operations. Barbara Wienecke and Knowles Kerry provided valuable information and advice.

Local weather and body condition influence habitat use and movements on land of molting female southern elephant seals (Mirounga leonina)

“…Our model also estimated an increase in individual distances moved each day when solar radiation was high at the final stage of molt. Despite effects of windchill, high solar radiation may therefore have influenced thermal comfort of elephant seals, leading animals to seek water for thermoregulation (Codde et al., ; Cruwys & Davis, ; White & Odell, ). The fact that distances moved on land were influenced by weather conditions only for elephant seals at mid‐ to final stages of their molt may be due to the fact that location of suitable habitat for molting may have dominated movement patterns, rather than weather constraints.…”

“…Our results may suggest that molting elephant seals increased their movements in response to temperature sensation (i.e., windchill), in order to change habitat, as different habitats (topography, substrate) offer different thermal environments (Cruwys & Davis, 1995;Twiss et al, 2002), or to join an aggregation if they were not aggregated before (Cruwys & Davis, 1994). Indeed, we also found a tendency for elephant seals to decrease their distances moved per day when they were aggregated in groups.…”

“…Our model also estimated an increase in individual distances moved each day when solar radiation was high at the final stage of molt. Despite effects of windchill, high solar radiation may therefore have influenced thermal comfort of elephant seals, leading animals to seek water for thermoregulation (Codde et al, 2016;Cruwys & Davis, 1995;White & Odell, 1971).…”

“…Mainly solar radiation, air temperature, and wind speed influenced haul‐out numbers, while in other studies, there was no consistent effect of meteorological parameters. In elephant seals, behavior on land and physical activity was linked to weather conditions (northern elephant seal: Norris, Houser, & Crocker, ; southern elephant seal Mirounga leonina : Cruwys & Davis, , ). In general, during the molt, elephant seals often aggregate in wallows (mud pools), when the nature of the colony's substrate allows their formation (Boyd et al., ; Carlini et al., ).…”

Environmental and physiological determinants of huddling behavior of molting female southern elephant seals (Mirounga leonina)

“…Elephant seals show high fidelity to breeding and molting sites (Laws, 1956) and we do not yet understand how aggregation behavior may be influenced by relatedness and other social aspects of conspecifics. We also measured body mass loss as an indirect measure of total energy expenditure during the molt as elephant seals were supposed fasting while on land (Crocker and Costa, 2002). However, some studies have questioned the possibility of fast-breaking during the molt (Boyd et al, 1993;Chaise et al, 2018).…”