scholarly journals Can harbor seals (Phoca vitulina) discriminate familiar conspecific calls after long periods of separation?

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12431
Author(s):  
Mila Varola ◽  
Laura Verga ◽  
Marlene Gunda Ursel Sroka ◽  
Stella Villanueva ◽  
Isabelle Charrier ◽  
...  
Keyword(s):  
Group Living ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Experimental Conditions ◽  
Repeated Interaction ◽  
Significant Difference ◽  
To Come ◽  
Vocal Discrimination

The ability to discriminate between familiar and unfamiliar calls may play a key role in pinnipeds’ communication and survival, as in the case of mother-pup interactions. Vocal discrimination abilities have been suggested to be more developed in pinniped species with the highest selective pressure such as the otariids; yet, in some group-living phocids, such as harbor seals (Phoca vitulina), mothers are also able to recognize their pup’s voice. Conspecifics’ vocal recognition in pups has never been investigated; however, the repeated interaction occurring between pups within the breeding season suggests that long-term vocal discrimination may occur. Here we explored this hypothesis by presenting three rehabilitated seal pups with playbacks of vocalizations from unfamiliar or familiar pups. It is uncommon for seals to come into rehabilitation for a second time in their lifespan, and this study took advantage of these rare cases. A simple visual inspection of the data plots seemed to show more reactions, and of longer duration, in response to familiar as compared to unfamiliar playbacks in two out of three pups. However, statistical analyses revealed no significant difference between the experimental conditions. We also found no significant asymmetry in orientation (left vs. right) towards familiar and unfamiliar sounds. While statistics do not support the hypothesis of an established ability to discriminate familiar vocalizations from unfamiliar ones in harbor seal pups, further investigations with a larger sample size are needed to confirm or refute this hypothesis.

Hormonal changes and enforced diving in the harbor seal Phoca vitulina. II. Plasma catecholamines

1982 ◽  
Vol 242 (5) ◽  
pp. R528-R532 ◽  
Author(s):  
A. J. Hance ◽  
E. D. Robin ◽  
J. B. Halter ◽  
N. Lewiston ◽  
D. A. Robin ◽  
...  
Keyword(s):  
Recovery Period ◽  
Control Period ◽  
Plasma Catecholamines ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Hormonal Changes ◽  
Inotropic Effects ◽  
Arterial Constriction

Plasma epinephrine and norepinephrine concentrations were measured in five harbor seals, Phoca vitulina, during a control period, during a 6-min dive, and during a 30-min postdiving recovery period. Measurements were performed with and without prior glucose administration. Control epinephrine concentrations [189 +/- 118 (SD) pg/ml] and norepinephrine concentrations (340 +/- 191 pg/ml) were similar to resting values in humans. During diving there are dramatic increases in both epinephrine and norepinephrine concentrations, which returned to control values by 30 min of the postdiving recovery period. A similar pattern was found after glucose infusion. The increased catecholamines were not the primary mechanism responsible for arterial constriction during the dive. Persistent diving bradycardia suggests obliteration of the chronotropic effects of catecholamines during the dive. An unchanged stroke volume suggests obliteration of the inotropic effects of catecholamines during the dive. Catecholamines do not appear to be involved in postdiving hyperglycemia and hyperglucogenemia. Neither the regulatory role of increased catecholamines nor the physiological function of increased catecholamines was apparent from the studies. However, dramatic increases in plasma catecholamines during diving appear to be an important component of the hormonal response to prolonged diving in aquatic mammals.

scholarly journals Morphological characteristics of harbor seal (Phoca vitulina) whiskers and their use in dietary reconstruction using stable isotope ratios

2018 ◽  
Vol 96 (11) ◽  
pp. 1255-1263 ◽  
Author(s):  
Justin Smith ◽  
Shawna Karpovich ◽  
Greg A. Breed ◽  
Diane M. O’Brien
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Whisker Growth ◽  
Morphological Characteristics ◽  
Isotope Ratios ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Dietary Reconstruction ◽  
Whisker Morphology

We investigated whether inferences about harbor seal (Phoca vitulina Linnaeus, 1758) whisker shed status and growth rates based on whisker morphology could improve dietary time series from whisker isotopic profiles. We identified morphometric characteristics of Alaskan harbor seal whiskers, including a smooth root section (SRS) and a bumpy section. The SRS was longer for spring versus fall-collected whiskers and matched the length of fully grown, shed whiskers. Thus, SRS length can differentiate whisker shed and growth status, and we used it to determine the sequence of whisker shedding by cohort in summer-captured harbor seals. The mean interbump length (IBL) correlated with whisker length, potentially providing a proxy for whisker growth rate. We compared carbon isotope ratios (expressed as δ13C values) along the three longest whiskers from 10 harbor seals, using two approaches for converting whisker position to date: (1) a standard growth rate constant based on captive studies and (2) individually adjusted growth rates based on whisker morphology. Intraindividual patterns of whisker δ13C values became more synchronous when expressed by deposition date rather than by position; however, adjusting growth rates based on IBL did not improve synchrony further. These findings suggest that whisker morphology can contribute whisker growth rate and shedding information for dietary reconstruction.

Morphological Changes of Intercellular Junctions in the Rat Submandibular Gland Treated by Long-term Repeated Administration of Isoproterenol

1987 ◽  
Vol 66 (8) ◽  
pp. 1303-1309 ◽  
Author(s):  
T. Inoue ◽  
H. Yamane ◽  
T. Yamamura ◽  
M. Shimono
Keyword(s):  
Gap Junctions ◽  
Tight Junctions ◽  
Morphological Changes ◽  
Freeze Fracture ◽  
Acinar Cells ◽  
Intercellular Junctions ◽  
Repeated Administration ◽  
Experimental Conditions ◽  
Significant Difference

Long-term repeated administration of isoproterenol (lPR) 2 mg/100 g bw, once daily for ten days, resulted in morphological changes in the intercellular junctions of rat submandibular glands, which were investigated by means of the freeze fracture technique. A significantly increased number of tight-junctional strands was present. These junctional strands extended much deeper toward the basal membrane than those in normal acinar cells. The basal frontier strands that branched from the networks of tight junctions were elongated and had either free-endings or terminal loops, which were more frequently observed in the IPR-treated acinar cells than in untreated acinar cells. Some of the strands of tight junctions were connected to small gap junctions. The diameters of gap junctions were not significantly different from those of control acinar cells. However, smooth areas devoid of particles were found intermingling with the usual packed particles in irregularly shaped small gap junctions. There was no significant difference between the desmosomes of IPR-treated and untreated acinar cells, in terms of either morphology or distribution. These changes in junctional morphology in the IPR-treated acinar cells resemble those seen in salivary glands during development, and in some experimental conditions including tumorous changes.

A METHOD FOR PREDICTING HARBOR SEAL (PHOCA VITULINA) HAULOUT AND MONITORING LONG-TERM POPULATION TRENDS WITHOUT TELEMETRY

2013 ◽  
Vol 26 (4) ◽  
pp. 605-627 ◽  
Author(s):  
JONATHAN D. COWLES ◽  
SHANDELLE M. HENSON ◽  
JAMES L. HAYWARD ◽  
MATTHEW W. CHACKO
Keyword(s):  
Harbor Seal ◽  
Phoca Vitulina ◽  
Population Trends

scholarly journals Descriptive account of long-term health and behavior of two satellite-tagged captive harbor seals Phoca vitulina

2009 ◽  
Vol 10 ◽  
pp. 159-163 ◽  
Author(s):  
LM Mazzaro ◽  
JL Dunn
Keyword(s):  
Phoca Vitulina ◽  
Harbor Seals ◽  
Descriptive Account ◽  
And Behavior

Influence of storms and maternal size on mother–pup separations and fostering in the harbor seal, Phoca vitulina

1992 ◽  
Vol 70 (8) ◽  
pp. 1640-1644 ◽  
Author(s):  
Daryl J. Boness ◽  
Don Bowen ◽  
Sara J. Iverson ◽  
Olav T. Oftedal
Keyword(s):  
Surface Current ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Frequency Of Occurrence ◽  
Lactation Period ◽  
Maternal Size ◽  
Proximate Causes ◽  
Previous Location

Fostering behavior has been documented in a large number of mammals and birds, but its frequency of occurrence and proximate causes are poorly understood in most species. Ten percent of a sample of 76 paint-marked female harbor seals (Phoca vitulina) fostered pups for some portion of the lactation period. Fostering appears to be associated with females having lost their own pup. In a subsample of 30 pairs that were followed closely, 3 of 16 females that lost their pups fostered, but none of 14 females that maintained continuous association with their pups throughout lactation did so. Smaller, and presumably younger, females were significantly more likely to become separated from their pups than were larger, and presumably older, females (73 vs. 33%). A high proportion (68%) of 35 separations observed occurred during the same day as, or within 1 day following, a storm. In 7 of 8 instances where we relocated pups after they were separated from their mothers during a storm, we found them in the direction of the surface current, 4.9 km from their previous location, on average. These data suggest that storms were the primary cause of separation of harbor seal mothers from their pups, and that younger mothers may be more likely to become separated from their pups. As fostering only occurs after a mother has lost her pup, we suggest that fostering, too, may be more likely among younger females.

scholarly journals The Influence of LED Lighting on Attention and Long-Term Memory

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Chung Won Lee ◽  
Jin Ho Kim
Keyword(s):  
Retention Volume ◽  
Word Fragment ◽  
Long Term Memory ◽  
Memory Retention ◽  
Experimental Conditions ◽  
Term Memory ◽  
Led Lighting ◽  
Significant Difference ◽  
Led Lights

The fact that the illuminance of LED lights affects human attention and long-term memory has been verified through various studies, but there are no consistent research results about what level of illuminance is effective. The aims of this study were to systematically verify the effects of LED lighting on attention and long-term memory. The experiment was designed with four illuminance levels—300 lx, 400 lx, 500 lx, and 1,000 lx—as experimental conditions to determine the effects of LED lights on attention and long-term memory. Participants in the experiment were 18 college students. The attention task was performed using a handmade attention measuring instrument. Long-term memory was measured by the word fragment completion (hereinafter, referred to as “WFC”) task on the memory retention volume of the learning task that was learned exactly 24 hours before. Of the total 20 tasks, the ratio of correctly retrieval tasks was used as a dependent variable. As a result, attention showed the highest performance with a mean performance of 19.39 (SD = 3.78) at 1,000 lx. A statistically significant difference was also found between the 1,000 lx and 300  lx conditions (p=0.01). On the contrary, long-term memory showed the highest retrieval rate at an average of 58.06% (SD = 22.57) at 400 lx, and long-term memory performance was better in the order of 500 lx (mean = 48.89, SD = 20.33), 1,000 lx (mean = 45.83, SD = 23.53), and 300 lx (Mean = 43.33, SD = 19.10). Statistically, there was a significant difference between 300 lx and 400 lx (p=0.01), 400 lx and 1,000 lx (p=0.01). Through this study, it was verified that the effects of attention and long-term memory are different according to the illuminance of LED lighting, and these results can be important data to clarify the influence of light on human memory in the future.

Adaptations to diving in the harbor seal— gas exchange and ventilatory response to CO2

1963 ◽  
Vol 205 (6) ◽  
pp. 1175-1177 ◽  
Author(s):  
Eugene D. Robin ◽  
H. Victor Murdaugh ◽  
William Pyron ◽  
Edgar Weiss ◽  
Peter Soteres
Keyword(s):  
Gas Exchange ◽  
Ventilatory Response ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Pulmonary Gas Exchange ◽  
Respiratory Center ◽  
Harbor Seals ◽  
Response Curves ◽  
Ventilatory Response To Co2

Pulmonary gas exchange and the ventilatory response to CO2 were measured in six female harbor seals, Phoca vitulina. Mean Paco2 (48 ± 6 mm Hg) is higher in the seal and mean Pao2 (88 ± 9 mm Hg) is lower than the corresponding value in man. The seal shows a depressed ventilatory response to CO2 both in terms of slope and intercept of CO2 response curves. The depressed respiratory center sensitivity to CO2 presumably is an adaptative mechanism permitting prolonged diving in this species.

scholarly journals Distance Estimation in Reproduction Tasks in a Harbor Seal (Phoca vitulina)

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 938
Author(s):  
Eric Maaß ◽  
Frederike D. Hanke
Keyword(s):  
Visual Information ◽  
Path Integration ◽  
Visual Cues ◽  
Distance Estimation ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Experimental Paradigm ◽  
Feeding Grounds ◽  
Specific Distance

Harbor seals commute between haul-out places and feeding grounds close to the shore or in the open ocean, which is considered a low structured environment, at first sight not providing many cues for orientation/navigation. Nevertheless, seals are well-oriented. For returning to a specific location, seals may use both external and internal cues to, for example, perform path integration requiring the integration of distances traveled and angles steered. We herein assessed the seal’s ability to estimate distances, previously swum or unknown, in reproduction tasks. Reproduction tasks refer to an experimental paradigm in which the experimental animal is required to swim a specific distance first and subsequently reproduce this distance, with visual cues present or absent. The seal was able to estimate and then reproduce distances (0.5–18.5 m) with the smallest error below 10% of the actual distance, and its precision was higher with distances repeatedly swum compared to its performance with unfamiliar distances. In the absence of visual cues, the seal’s performance slightly dropped; however, it was still able to perform the task with an error of 21%. In conclusion, distance estimation may help seals to navigate precisely towards their goals, even if, for example, visual information is not available.

Pulmonary circulation of the harbor seal

1978 ◽  
Vol 45 (5) ◽  
pp. 718-727 ◽  
Author(s):  
E. E. Sinnett ◽  
G. L. Kooyman ◽  
E. A. Wahrenbrock
Keyword(s):  
Cardiac Output ◽  
Atmospheric Pressure ◽  
Pulmonary Blood Flow ◽  
Pulmonary Arterial Pressure ◽  
Ambient Pressure ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Right Atrial ◽  
Harbor Seals ◽  
Pulmonary Arterial

Cardiac output (Q) and pulmonary arterial pressure (Ppa) were measured under various conditions in four harbor seals (Phoca vitulina) weighing 35--52 kg. In seals anesthetized with halothane, Q averaged 3.47 l/min; in awake resting seals, Q averaged 11.5 l/min; and during surface dives (i.e., at atmospheric pressure) Q averaged 1.99 l/min. Stroke volume was one-third and two-thirds of the awake resting value during anesthesia and diving, respectively. Systolic Ppa was usually 40--50 Torr in anesthetized and awake resting seals, but was about 10 Torr lower during both surface and compression (i.e., elevated ambient pressure) dives. Diastolic Ppa was constant and high during anesthesia and quite variable in awake resting seals. During both surface and compression dives the diastolic Ppa often fell to the same level as right atrial pressure. We conclude that Q and Ppa are high in awake resting seals and that pulmonary blood flow may cease between beats during diving.

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