Prolonged, continuous, deep diving by northern elephant seals

1989 ◽  
Vol 67 (10) ◽  
pp. 2514-2519 ◽  
Author(s):  
Burney J. Le Boeuf ◽  
Yasuhiko Naito ◽  
Anthony C. Huntley ◽  
Tomohiro Asaga
Keyword(s):  
Dive Depth ◽  
Dive Duration ◽  
Mirounga Angustirostris ◽  
Steady State Condition ◽  
Elephant Seals ◽  
Deep Diving ◽  
Physiological Processes ◽  
Northern Elephant Seals ◽  
Extended Surface ◽  
The Mean

An earlier study showed that female northern elephant seals (Mirounga angustirostris) dive deeply and continuously during the first 1–3 weeks at sea following lactation. We report that this dive pattern is maintained for the entire 2½-month period at sea. Time–depth recorders were attached to six adult females at Año Nuevo, California; three instruments recorded continuously and three instruments recorded every 3rd day at sea. The mean dive rate was 2.5–3.3 dives per hour, with a mean of < 3.5 min on the surface between dives. This resulted in females spending 83–90% of the time at sea underwater. Interruption of continuous diving, characterized by extended surface intervals with a mean of 51.9 ± 65.5 min, was rare, following only 0.42% of the dives. Modal dive duration per female was in the range 17.1–22.5 min. The longest dive was 62 min and was followed by a surface interval of < 2.6 min. Modal dive depth per female was in the range 500–700 m; three females had dives that exceeded 1000 m, with the deepest dive estimated at 1250 m. Deep diving to 500 m or more was always preceded by a descending-staircase pattern of initially shallow to increasingly deeper dives. The continuous, deep diving pattern of this pelagic seal is evidently a steady-state condition. This has important implications for understanding diving adaptations and the physiological processes underlying them.

Continuous, deep diving in female northern elephant seals, Mirounga angustirostris

1988 ◽  
Vol 66 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Burney J. Le Boeuf ◽  
Daniel P. Costa ◽  
Anthony C. Huntley ◽  
Steven D. Feldkamp
Keyword(s):  
Mass Gain ◽  
Dive Depth ◽  
Dive Duration ◽  
Mirounga Angustirostris ◽  
Elephant Seals ◽  
Deep Diving ◽  
Northern Elephant Seals ◽  
The Mean ◽  
Free Ranging ◽  
Nearly Continuous

The free-ranging dive pattern of seven adult female northern elephant seals (Mirounga angustirostris) was obtained with time–depth recorders during the first 14 – 27 days at sea following lactation. The instruments were recovered and mass gain at sea determined when the animals returned to the rookery at Año Nuevo, California, to molt. The seals gained a mean of 76.5 ± 13.9 kg during a mean of 72.6 ± 5.0 days at sea. The mean dive rate was 2.7 ± 0.2 dives/h and diving was virtually continuous during the entire period at sea. Mean dive duration was 19.2 ± 4.3 min with the longest submersion lasting 48 min. Mean surface interval between dives was 2.8 ± 0.5 min, so that only 14.4% of the recorded time at sea was spent on the surface. Surface intervals did not vary with the duration of preceding or succeeding dives. Modal dive depth for each female was between 350 and 650 m. The maximum dive depth was estimated at 894 m, a depth record for pinnipeds. The deep, nearly continuous dive pattern of female northern elephant seals differs from the dive pattern of other pinnipeds and appears to serve in foraging, energy conservation, and predator avoidance.

Heart rates of northern elephant seals diving at sea and resting on the beach.

1997 ◽  
Vol 200 (15) ◽  
pp. 2083-2095 ◽  
Author(s):  
R D Andrews ◽  
D R Jones ◽  
J D Williams ◽  
P H Thorson ◽  
G W Oliver ◽  
...  
Keyword(s):  
Heart Rate ◽  
Dive Depth ◽  
Dive Duration ◽  
Cardiac Response ◽  
Elephant Seals ◽  
Heart Rates ◽  
Data Loggers ◽  
Long Duration ◽  
Northern Elephant Seals ◽  
Instantaneous Heart Rate

Heart rates of northern elephant seals diving at sea and during apnoea on land were monitored to test whether a cardiac response to submergence is an important factor in their ability to make repetitive, long-duration dives. Seven juvenile northern elephant seals were captured at Año Nuevo, CA, instrumented and translocated to release sites around Monterey Bay. Heart rate and dive depth were recorded using custom-designed data loggers and analogue tape monitors during the seals' return to Año Nuevo. Heart rates during apnoea and eupnoea were recorded from four of the seals after they hauled out on the beach. Diving patterns were very similar to those of naturally migrating juveniles. The heart rate response to apnoea at sea and on land was a prompt bradycardia, but only at sea was there an anticipatory tachycardia before breathing commenced. Heart rate at sea declined by 64% from the surface rate of 107 +/- 3 beats min-1 (mean +/- S.D.), while heart rate on land declined by 31% from the eupnoeic rate of 65 +/- 8 beats min-1. Diving heart rate was inversely related to dive duration in a non-linear fashion best described by a continuous, curvilinear model, while heart rate during apnoea on land was independent of the duration of apnoea. Occasionally, instantaneous heart rate fell as low as 3 beats min-1 during diving. Although bradycardia occurs in response to apnoea both at sea and on land, only at sea is heart rate apparently regulated to minimise eupnoeic time and to ration oxygen stores to ensure adequate supplies for the heart and brain not only as the dive progresses normally but also when a dive is abnormally extended.

scholarly journals Oxygen minimum zone: An important oceanographic habitat for deep-diving northern elephant seals, Mirounga angustirostris

2017 ◽  
Vol 7 (16) ◽  
pp. 6259-6270 ◽  
Author(s):  
Yasuhiko Naito ◽  
Daniel P. Costa ◽  
Taiki Adachi ◽  
Patrick W. Robinson ◽  
Sarah H. Peterson ◽  
...  
Keyword(s):  
Oxygen Minimum Zone ◽  
Mirounga Angustirostris ◽  
Elephant Seals ◽  
Deep Diving ◽  
Northern Elephant Seals ◽  
Minimum Zone ◽  
Oxygen Minimum

Maternal aggression in northern elephant seals: the effect of the pup

1988 ◽  
Vol 66 (7) ◽  
pp. 1693-1698 ◽  
Author(s):  
Christine A. Ribic
Keyword(s):  
Mirounga Angustirostris ◽  
Maternal Aggression ◽  
Arrival Date ◽  
Elephant Seals ◽  
Aggressive Encounter ◽  
Early Arrival ◽  
Northern Elephant Seals ◽  
The Mean ◽  
Breeding Seasons

Female northern elephant seals (Mirounga angustirostris) were observed for three breeding seasons on Southeast Farallon Island to determine the effect of the pup on maternal aggression. For females that lost their pups before weaning them, the mean percentage of aggressive encounters started and won decreased after the death of the pup. A higher percentage of females moved away at the end of an aggressive encounter from females that ultimately weaned their pups than from females that ultimately lost their pups. There was, however, no difference between the two categories in mean percentage of aggressive encounters started and won. Among females that weaned pups in all three seasons, individuals did not win more encounters but differed in percentage of females that moved away and in mean percentage of aggressive encounters started as they aged. A number of variables were associated with an increased probability that a female would successfully wean her pup: early arrival date, having a high percentage of females that moved away, and a high mean percentage of aggressive encounters won. Raising a pup in an area of high female density or where animals had access to the beach were associated with a decreased probability of weaning a pup.

Extreme hypoxemic tolerance and blood oxygen depletion in diving elephant seals

2009 ◽  
Vol 297 (4) ◽  
pp. R927-R939 ◽  
Author(s):  
Jessica U. Meir ◽  
Cory D. Champagne ◽  
Daniel P. Costa ◽  
Cassondra L. Williams ◽  
Paul J. Ponganis
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Oxygen Depletion ◽  
Dive Duration ◽  
Aerobic Metabolism ◽  
Mirounga Angustirostris ◽  
Dissociation Curve ◽  
Elephant Seals ◽  
Store Depletion ◽  
Northern Elephant Seals

Species that maintain aerobic metabolism when the oxygen (O2) supply is limited represent ideal models to examine the mechanisms underlying tolerance to hypoxia. The repetitive, long dives of northern elephant seals ( Mirounga angustirostris) have remained a physiological enigma as O2 stores appear inadequate to maintain aerobic metabolism. We evaluated hypoxemic tolerance and blood O2 depletion by 1) measuring arterial and venous O2 partial pressure (Po2) during dives with a Po2/temperature recorder on elephant seals, 2) characterizing the O2-hemoglobin (O2-Hb) dissociation curve of this species, 3) applying the dissociation curve to Po2 profiles to obtain %Hb saturation (So2), and 4) calculating blood O2 store depletion during diving. Optimization of O2 stores was achieved by high venous O2 loading and almost complete depletion of blood O2 stores during dives, with net O2 content depletion values up to 91% (arterial) and 100% (venous). In routine dives (>10 min) PvO2 and PaO2 values reached 2–10 and 12–23 mmHg, respectively. This corresponds to So2 of 1–26% and O2 contents of 0.3 (venous) and 2.7 ml O2/dl blood (arterial), demonstrating remarkable hypoxemic tolerance as PaO2 is nearly equivalent to the arterial hypoxemic threshold of seals. The contribution of the blood O2 store alone to metabolic rate was nearly equivalent to resting metabolic rate, and mean temperature remained near 37°C. These data suggest that elephant seals routinely tolerate extreme hypoxemia during dives to completely utilize the blood O2 store and maximize aerobic dive duration.

scholarly journals The rise and fall of dialects in northern elephant seals

2018 ◽  
Vol 285 (1892) ◽  
pp. 20182176 ◽  
Author(s):  
Caroline Casey ◽  
Colleen Reichmuth ◽  
Daniel P. Costa ◽  
Burney Le Boeuf
Keyword(s):  
Mammalian Species ◽  
Structural Complexity ◽  
Mirounga Angustirostris ◽  
Geographical Differences ◽  
Migration Patterns ◽  
Elephant Seals ◽  
The North ◽  
Vocal Behaviour ◽  
Northern Elephant Seals ◽  
The North Pacific

Vocal dialects are fundamental to our understanding of the transmission of social behaviours between individuals and populations, however few accounts trace this phenomenon among mammals over time. Northern elephant seals ( Mirounga angustirostris ) provide a rare opportunity to examine the trajectory of dialects in a long-lived mammalian species. Dialects were first documented in the temporal patterns of the stereotyped vocal displays produced by breeding males at four sites in the North Pacific in 1968 and 1969, as the population recovered from extreme exploitation. We evaluated the longevity of these geographical differences by comparing these early recordings to calls recently recorded at these same locations. While the presence of vocal dialects in the original recordings was re-confirmed, geographical differences in vocal behaviour were not found at these breeding rookeries nearly 50 years later. Moreover, the calls of contemporary males displayed more structural complexity after approximately four generations, with substantial between-individual variation and call features not present in the historical data. In the absence of measurable genetic variation in this species—owing to an extreme population bottleneck—a combination of migration patterns and cultural mutation are proposed as factors influencing the fall of dialects and the dramatic increase in call diversity.

The effect of rehabilitation of northern elephant seals (Mirounga angustirostris) on antimicrobial resistance of commensal Escherichia coli

2009 ◽  
Vol 133 (3) ◽  
pp. 264-271 ◽  
Author(s):  
Robyn A. Stoddard ◽  
E. Rob Atwill ◽  
Patricia A. Conrad ◽  
Barbara A. Byrne ◽  
Spencer Jang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Mirounga Angustirostris ◽  
Elephant Seals ◽  
Northern Elephant Seals

scholarly journals Rival assessment among northern elephant seals: evidence of associative learning during male–male contests

2015 ◽  
Vol 2 (8) ◽  
pp. 150228 ◽  
Author(s):  
Caroline Casey ◽  
Isabelle Charrier ◽  
Nicolas Mathevon ◽  
Colleen Reichmuth
Keyword(s):  
Communication Strategy ◽  
Social Knowledge ◽  
Mirounga Angustirostris ◽  
Alternative Communication ◽  
Elephant Seals ◽  
Acoustic Signatures ◽  
Dominance Relationships ◽  
Northern Elephant Seals ◽  
Rival Assessment ◽  
Male Contests

Specialized signals emitted by competing males often convey honest information about fighting ability. It is generally believed that receivers use these signals to directly assess their opponents. Here, we demonstrate an alternative communication strategy used by males in a breeding system where the costs of conflict are extreme. We evaluated the acoustic displays of breeding male northern elephant seals ( Mirounga angustirostris ), and found that social knowledge gained through prior experience with signallers was sufficient to maintain structured dominance relationships. Using sound analysis and playback experiments with both natural and modified signals, we determined that males do not rely on encoded information about size or dominance status, but rather learn to recognize individual acoustic signatures produced by their rivals. Further, we show that behavioural responses to competitors' calls are modulated by relative position in the hierarchy: the highest ranking (alpha) males defend their harems from all opponents, whereas mid-ranking (beta) males respond differentially to familiar challengers based on the outcome of previous competitive interactions. Our findings demonstrate that social knowledge of rivals alone can regulate dominance relationships among competing males within large, spatially dynamic social groups, and illustrate the importance of combining descriptive and experimental methods when deciphering the biological relevance of animal signals.

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