Mismatches in Scale Between Highly Mobile Marine Megafauna and Marine Protected Areas

Marine protected areas (MPAs), particularly large MPAs, are increasing in number and size around the globe in part to facilitate the conservation of marine megafauna under the assumption that large-scale MPAs better align with vagile life histories; however, this alignment is not well established. Using a global tracking dataset from 36 species across five taxa, chosen to reflect the span of home range size in highly mobile marine megafauna, we show most MPAs are too small to encompass complete home ranges of most species. Based on size alone, 40% of existing MPAs could encompass the home ranges of the smallest ranged species, while only \u3c 1% of existing MPAs could encompass those of the largest ranged species. Further, where home ranges and MPAs overlapped in real geographic space, MPAs encompassed \u3c 5% of core areas used by all species. Despite most home ranges of mobile marine megafauna being much larger than existing MPAs, we demonstrate how benefits from MPAs are still likely to accrue by targeting seasonal aggregations and critical life history stages and through other management techniques

Mismatches in Scale Between Highly Mobile Marine Megafauna and Marine Protected Areas

Marine protected areas (MPAs), particularly large MPAs, are increasing in number and size around the globe in part to facilitate the conservation of marine megafauna under the assumption that large-scale MPAs better align with vagile life histories; however, this alignment is not well established. Using a global tracking dataset from 36 species across five taxa, chosen to reflect the span of home range size in highly mobile marine megafauna, we show most MPAs are too small to encompass complete home ranges of most species. Based on size alone, 40% of existing MPAs could encompass the home ranges of the smallest ranged species, while only \u3c 1% of existing MPAs could encompass those of the largest ranged species. Further, where home ranges and MPAs overlapped in real geographic space, MPAs encompassed \u3c 5% of core areas used by all species. Despite most home ranges of mobile marine megafauna being much larger than existing MPAs, we demonstrate how benefits from MPAs are still likely to accrue by targeting seasonal aggregations and critical life history stages and through other management techniques

Variation intraspécifique du système d'accouplement du mâle chez le phoque gris (relation entre le phénotype, le comportement et le succès reproducteur)

Cette étude a mesuré l'étendue et le succès des variations comportementales du système d'accouplement chez le phoque gris male. Elle a été conduite sur l'île de Sable, Canada, pendant 6 saisons de reproduction. L'étude a révélé des variations comportementales plus importantes que précédemment documenté. Le succès a été évalué pour deux tactiques d'accouplement. La tactique principale (dite du conjoint) a peu de succès mais elle s'avère plus performante que la tactique alternative (opportuniste). Quelques jeunes mâles utilisent la tactique principale et d'autres plus âges à la fois la tactique principale et celle alternative. Les mâles 'conjoints' sont plus corpulents, disposent de plus de réserves énergétiques et prolongent leur reproduction, suggérant que l'état est plus important que l'âge dans la détermination de la performance. Les tactiques alternatives d'accouplement pourraient avoir d'importantes dans le schéma des flux géniques et de la sélection sexuelle.This study has measured the extent and success of behavioural variation in the mating system of the grey seal. The study was conducted on Sable Island, Canada during 6 breeding seasons. The study revealed much greater variation in behaviour than previously recognised. The success of two mating tactics was measured. Although the principal tactic (i.e. consort) revealed low success it was higher than that of an alternative tactic. Some young males exhibited both primary and alternative tactics. Consort males were larger and arrived with absolutely more energy reserves and sustained breeding for longer suggesting that state was more important than age in determining performance. Alternative mating tactics may have important implications for the pattern of gene flow and for sexual selection.LA ROCHELLE-BU (173002101) / SudocSudocFranceF

State-dependent male mating tactics in the grey seal: the importance of body size

The purpose of this study was to examine the importance of body size and body composition as determinants of conditional mating tactics exhibited in male grey seals. We combined behavioral observations with measures of energy expenditure and success on 42 known-age individuals during the breeding seasons of 1997--2001 at Sable Island, Canada. Males with a large body mass arrived at the breeding grounds with more body fat and body energy and catabolized less body protein than smaller males. Males consumed 1.9 � 0.2 MJ day-super- - 1, and those with a smaller percentage of body fat had higher rates of food energy intake. The amount of body energy on arrival was positively correlated with the duration of the breeding period. Males that exhibited the primary mating tactic of consortship were heavier, had absolutely more body fat and body energy, and sustained breeding longer than those males that did not exhibit the primary tactic. Amongst all males, body mass showed a quadratic relationship with the number of female consorts mated and the estimated number of pups sired. Thus, intermediate-sized males mated with the most consorts and achieved the highest success. Intermediate body size may be optimal during breeding due to greater agility in male combat. Body size was an important determinant of mating tactics used by male grey seals. A large body size provided an energetic advantage of greater endurance while an intermediate body size may provide greater competitive ability in acquiring consortships. Copyright 2005.body size; conditional mating tactics; endurance rivalry; energetics; Halichoerus grypus; pinnipeds; reproductive behavior

Animal-borne acoustic transceivers reveal patterns of at-sea associations in an upper-trophic level predator

Satellite telemetry data have substantially increased our understanding of habitat use and foraging behaviour of upper-trophic marine predators, but fall short of providing an understanding of their social behaviour. We sought to determine whether novel acoustic and archival GPS data could be used to examine at-sea associations among grey seals (Halichoerus grypus) during the fall foraging period. Fifteen grey seals from Sable Island, Canada were deployed with Vemco Mobile Transceivers and Satellite-GPS transmitters in October 2009, 13 of which were recaptured and units retrieved 79±2.3 days later during the following breeding season, December 2009–January 2010. An association between two individuals was defined as a cluster of acoustic detections where the time between detections was <30 min. Bathymetry, travel rate, and behavioural state (slow and fast movement) were determined for each GPS archival point (3.7±0.1 locations recorded per hour). Behavioural state was estimated using a hidden Markov model. All seals had been involved in associations with other instrumented seals while at sea, with a total of 1,872 acoustic detections recorded in 201 associations. The median number of detections per association was 3 (range: 1–151) and the median duration of an association was 0.17 h (range: <0.1–11.3 h). Linear mixed-effects models showed that associations occurred when seals were exhibiting slow movement (0.24±0.01 ms−1) on shallow (53.4±3.7 m) offshore banks where dominant prey is known to occur. These results suggest the occurrence of short-term associations among multiple individuals at foraging grounds and provide new insights into the foraging ecology of this upper-trophic marine predator.8 page(s

Number of associations (detections) between adult grey seals (<i>n</i> = 14) deployed on Sable Island for the period 15^th October 2009 to 7^th January 2010.

<p>• Telemetry instruments not recovered.</p

Ontogeny of movement patterns in naïve grey seal pups inhabiting a complex continental shelf ecosystem.

Most vertebrate offspring must transition from the relative security of parental care (nutrition and protection) to independent foraging. Offspring face many challenges during this critical period, particularly in species where parental care ends at weaning, such as the grey seal (Halichoerus grypus). We studied the development of movement behaviour in naïve grey seal pups from their first trips to sea to about five months of age. Twenty-five (12 males and 13 females) newly-weaned pups were fitted with satellite-linked GPS tags on Sable Island, Nova Scotia, Canada in January 2016. The influence of fixed effects (pup size, sex, week) and the random effect of pup identity on trip characteristics were examined. Movement behaviour was analyzed using a move persistence mixed-effects model. Habitat use was highly variable among individuals and covered much of the geographic distribution of the population. Unlike older juveniles, subadults, and adults in this population, most naïve pups used multiple haulout sites to begin and end trips. There was little evidence of area-restricted search behaviour during trips, suggesting that naïve pups were using an opportunistic foraging tactic that may result in more variable foraging success than that of older, experienced animals. Naïve pups made longer trips with longer haulout durations between them than observed for older greys seals. Males and females differed in some trip characteristics, but sex effects were small over the first few months of life. Offspring size at weaning was not a useful predictor of trip characteristics. Move persistence of grey seal pups was initially high and then decreased over time as individuals gained experience. Both intrinsic and extrinsic factors were influential on the movements of grey seal pups. Greater body length at weaning, longer duration spent on shore after weaning, shallower water column depth, and farther distance from shore were all associated with lower move persistence. Female grey seal pups had lower move persistence than males. Overall, the movements of naïve grey seal pups during the first few months of life were characterized by extensive exploration, but move persistence decreased over time suggesting they may be using an exploration-refinement foraging tactic

A time-series plot showing the occurrence of associations between grey seals (<i>n</i> = 13).

<p>Two-way associations (i.e., both VMTs collected detections during the association) are shown by the grey lines (receiver 1) with a matching blue line (receiver 2). The occurrence of one-way associations (i.e. only one VMT collected detections) are shown by the grey lines (receiver 1) with no matching blue line (receiver 2).</p

Box plots showing the distribution of A) all depths (m) and B) all travel rates (ms⁻¹) according to the occurrence of associations between grey seals.

<p>A also shows the distribution of depths from 5000 randomly selected points taken from 2D kernel density plots generated from each seal track. Plus sympbols (+) are the median depth/speed for each seal, filled circles and error bars are the GLMM-estimated mean depth/speed across all seals +/−1 SE.</p