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Structure and dynamics of minke whale surfacing patterns in the Gulf of St. Lawrence, Canada.

Christiansen F, Lynas NM, Lusseau D, Tscherter U - PLoS ONE (2015)

Bottom Line: The surfacing pattern also differed between feeding and non-feeding whales.Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport.Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles.

View Article: PubMed Central - PubMed

Affiliation: Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Warrnambool, Victoria, Australia; Foundation for Marine Environment Research (ORES), Basel, Switzerland.

ABSTRACT
Animal behavioral patterns can help us understand physiological and ecological constraints on animals and its influence on fitness. The surfacing patterns of aquatic air-breathing mammals constitute a behavioral pattern that has evolved as a trade-off between the need to replenish oxygen stores at the surface and the need to conduct other activities underwater. This study aims to better understand the surfacing pattern of a marine top predator, the minke whale (Balaenoptera acutorostrata), by investigating how their dive duration and surfacing pattern changes across their activity range. Activities were classified into resting, traveling, surface feeding and foraging at depth. For each activity, we classified dives into short and long dives and then estimated the temporal dependence between dive types. We found that minke whales modified their surfacing pattern in an activity-specific manner, both by changing the expression of their dives (i.e. density distribution) and the temporal dependence (transition probability) between dive types. As the depth of the prey layer increased between activities, the surfacing pattern of foraging whales became increasingly structured, going from a pattern dominated by long dives, when feeding at the surface, to a pattern where isolated long dives were followed by an increasing number of breaths (i.e. short dives), when the whale was foraging at depth. A similar shift in surfacing pattern occurred when prey handling time (inferred from surface corralling maneuvers) increased for surface feeding whales. The surfacing pattern also differed between feeding and non-feeding whales. Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport. Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles.

No MeSH data available.


Related in: MedlinePlus

Back transformed prey layer depth recorded near minke whales during three different feeding activities.The depth at the top (dark grey) and bottom (light grey) of the prey layer is shown. SFT1 = surface feeding tactic I, NSF = near-surface foraging, DF = deep foraging. Error bars represent 95% confidence intervals. N = 21.
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pone.0126396.g001: Back transformed prey layer depth recorded near minke whales during three different feeding activities.The depth at the top (dark grey) and bottom (light grey) of the prey layer is shown. SFT1 = surface feeding tactic I, NSF = near-surface foraging, DF = deep foraging. Error bars represent 95% confidence intervals. N = 21.

Mentions: There was a significant difference in both the maximum (LM ANOVA: F2,18 = 51.1, P < 0.0001) and minimum (LM ANOVA: F2,18 = 30.9, P < 0.0001) prey depth between the different feeding activities (Fig 1), which supported the division of feeding activities into SFT1, NSF and DF. The models explained 85 and 77% of the variance (R2) in maximum and minimum prey depth, respectively. Both models fulfilled the assumptions of the LM.


Structure and dynamics of minke whale surfacing patterns in the Gulf of St. Lawrence, Canada.

Christiansen F, Lynas NM, Lusseau D, Tscherter U - PLoS ONE (2015)

Back transformed prey layer depth recorded near minke whales during three different feeding activities.The depth at the top (dark grey) and bottom (light grey) of the prey layer is shown. SFT1 = surface feeding tactic I, NSF = near-surface foraging, DF = deep foraging. Error bars represent 95% confidence intervals. N = 21.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430536&req=5

pone.0126396.g001: Back transformed prey layer depth recorded near minke whales during three different feeding activities.The depth at the top (dark grey) and bottom (light grey) of the prey layer is shown. SFT1 = surface feeding tactic I, NSF = near-surface foraging, DF = deep foraging. Error bars represent 95% confidence intervals. N = 21.
Mentions: There was a significant difference in both the maximum (LM ANOVA: F2,18 = 51.1, P < 0.0001) and minimum (LM ANOVA: F2,18 = 30.9, P < 0.0001) prey depth between the different feeding activities (Fig 1), which supported the division of feeding activities into SFT1, NSF and DF. The models explained 85 and 77% of the variance (R2) in maximum and minimum prey depth, respectively. Both models fulfilled the assumptions of the LM.

Bottom Line: The surfacing pattern also differed between feeding and non-feeding whales.Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport.Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles.

View Article: PubMed Central - PubMed

Affiliation: Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Warrnambool, Victoria, Australia; Foundation for Marine Environment Research (ORES), Basel, Switzerland.

ABSTRACT
Animal behavioral patterns can help us understand physiological and ecological constraints on animals and its influence on fitness. The surfacing patterns of aquatic air-breathing mammals constitute a behavioral pattern that has evolved as a trade-off between the need to replenish oxygen stores at the surface and the need to conduct other activities underwater. This study aims to better understand the surfacing pattern of a marine top predator, the minke whale (Balaenoptera acutorostrata), by investigating how their dive duration and surfacing pattern changes across their activity range. Activities were classified into resting, traveling, surface feeding and foraging at depth. For each activity, we classified dives into short and long dives and then estimated the temporal dependence between dive types. We found that minke whales modified their surfacing pattern in an activity-specific manner, both by changing the expression of their dives (i.e. density distribution) and the temporal dependence (transition probability) between dive types. As the depth of the prey layer increased between activities, the surfacing pattern of foraging whales became increasingly structured, going from a pattern dominated by long dives, when feeding at the surface, to a pattern where isolated long dives were followed by an increasing number of breaths (i.e. short dives), when the whale was foraging at depth. A similar shift in surfacing pattern occurred when prey handling time (inferred from surface corralling maneuvers) increased for surface feeding whales. The surfacing pattern also differed between feeding and non-feeding whales. Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport. Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles.

No MeSH data available.


Related in: MedlinePlus