scholarly journals Maternal responses to pup calls in a high-cost lactation species

2021 ◽  
Vol 17 (12) ◽  
Author(s):  
Juliette Linossier ◽  
Caroline Casey ◽  
Isabelle Charrier ◽  
Nicolas Mathevon ◽  
Colleen Reichmuth
Keyword(s):  
Individual Recognition ◽  
Social Systems ◽  
Social Factor ◽  
Reproductive Behaviour ◽  
Response Strength ◽  
Elephant Seal ◽  
Lactation Period ◽  
Northern Elephant Seal ◽  
Growth And Survival ◽  
Individual Fitness

Bonding between mothers and their young is fundamental to mammalian reproductive behaviour and individual fitness. In social systems where the risk of confusing filial and non-filial offspring is high, mothers should demonstrate early, strong and consistent responses to their kin throughout the period of offspring dependence, irrespective of maternal traits. We tested this hypothesis through playback experiments in the northern elephant seal Mirounga angustirostris , a phocid species that breeds in high-density colonies. We found that mothers recognized their offspring throughout lactation and as early as 1–2 days after parturition. Measures of experience (age) and temperament (aggressivity) did not predict their response strength to filial playback treatments, nor did pup age or sex. Some mothers showed great consistency in behavioural responses throughout the lactation period, while others were less predictable. The strength of a female's response did not influence her pup's weaning weight; however, more consistent females weaned pups of higher mass. This is a rare demonstration of individual recognition among phocid mothers and their offspring, and suggests that consistency in maternal responsiveness may be an important social factor influencing the pup's growth and survival.

Glucose metabolism during lactation in a fasting animal, the northern elephant seal

2006 ◽  
Vol 291 (4) ◽  
pp. R1129-R1137 ◽  
Author(s):  
Cory D. Champagne ◽  
Dorian S. Houser ◽  
Daniel E. Crocker
Keyword(s):  
Glucose Production ◽  
Elephant Seal ◽  
Endogenous Glucose Production ◽  
Molar Ratio ◽  
Life History Trait ◽  
Lactation Period ◽  
Northern Elephant Seal ◽  
Body Tissues ◽  
Production Values ◽  
Glucose Cycle

Fasting is associated with a series of physiological responses that protect body tissues from degradation by efficiently using expendable energy reserves while sparing protein. Lactation requires the mobilization of maternal nutrients for milk synthesis. The rare life history trait of fasting simultaneous with lactation results in the conflicting demands of provisioning offspring while meeting maternal metabolic costs and preserving maternal tissues for her own survival and future reproduction. Certain tissues continue to require glucose for operation during fasting and might constrain tissue mobilization for lactogenesis due to a need for gluconeogenic substrates. This study investigated glucose flux, glucose cycle activity, and the influence of regulatory hormones in fasting lactating northern elephant seals. Measurements were taken early (5 days) and late (21 days) during the lactation period and, as a nonlactating comparison, after the completion of molting. Glucose cycle activity was highly variable in all study groups and did not change over lactation ( P > 0.3), whereas endogenous glucose production decreased during lactation ( t = −3.41, P = 0.008). Insulin and insulin-to-glucagon molar ratio decreased across lactation ( t = 6.48, 4.28; P = 0.0001, 0.002), while plasma cortisol level increased ( t = 4.15, P = 0.002). There were no relationships between glucose production and hormone levels. The glucose production values measured exceeded that predicted from available gluconeogenic substrate, indicating substantial glucose recycling in this species.

Twinning in southern elephant seals: the implications of resource allocation by mothers

2003 ◽  
Vol 30 (1) ◽  
pp. 35 ◽  
Author(s):  
Clive R. McMahon ◽  
Mark A. Hindell
Keyword(s):  
Reproductive Success ◽  
Rare Event ◽  
Elephant Seal ◽  
Lactation Period ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Growth And Survival ◽  
Southern Elephant Seals ◽  
Lactation Duration ◽  
Pup Growth

Southern elephant seals (Mirounga leonina) typically give birth to a single pup and raise it over a short 24-day lactation period. Lactation is characterised by: maternal fasting, rapid pup growth and abrupt weaning after which the weaned pups rely on stored fat for growth and survival. Females are not able to transfer all of their stored resources to their pups because they themselves need to use some to return to their remote foraging grounds after the breeding effort. Therefore the amount of energy expended by a female during lactation may affect not only the survival of her pup, but her own survival and future reproductive success. Female southern elephant seals are therefore under strong selective pressure to allocate finite amounts of resources to their pups. In the rare event of producing twins, females that wean both pups are likely to experience reduced reproductive success. Twin births accounted for 0.38% of all the observed elephant seal births at Macquarie Island in 1999. The mean birth masses, weaning lengths and lactation duration for twin and singleton pups did not differ significantly but weaning mass, weaning girths and lactation growth rates did differ significantly. In all cases, singleton pups were larger and grew faster than twin pups. Twin pups suffered greater pre-weaning mortality than singletons (16.7% and 4.6% respectively) and fewer were seen alive after 18 months (20% compared with 47% respectively).

Agonistic Behavior in the Male Northern Elephant Seal

Behaviour ◽  
1976 ◽  
Vol 57 (1-2) ◽  
pp. 136-157 ◽  
Author(s):  
Finn E. Sandegren
Keyword(s):  
Individual Recognition ◽  
Elephant Seal ◽  
Low Rank ◽  
Overt Aggression ◽  
Adult Males ◽  
Northern Elephant Seal ◽  
Aggressive Interactions ◽  
Submissive Behavior ◽  
High Ranking ◽  
Agonistic Display

AbstractAt least 10 behavioral elements were involved in aggressive behavior. The frequency of nine of these among five males was determined. High ranking males were involved in more aggressive interactions than those of low rank, but overt fights were very rare. At least six elements of submissive behavior were observed among males and the frequency of these were determined. Submissive display among males (involving female mimicking behavior) effectively inhibited most overt aggression. Erection and maximal size of the proboscis always coincided with dominance and aggression while a small retracted proboscis coincided with the display of subdominance defence and submission. By the shape of the proboscis and no other criteria alone can the mood of the male be read at any moment. It is suggested that the proboscis has evolved mainly as an agonistic display organ. Adult males recognize each other vocally. It is suggested that the criterium for individual recognition is the structure of the pulse and not the number of pulses they emit in the most characteristic of the four distinct vocalizations that were recorded among males (VO 2). The high ranking males were active 11,5% of the day while the low ranking were significantly less active (6,4%).

Sexual Behavior in the Northern Elephant Seal Mirounga Angustirostris

Behaviour ◽  
1972 ◽  
Vol 41 (1-2) ◽  
pp. 1-26 ◽  
Author(s):  
Burney J. Leboeuf
Keyword(s):  
Social Systems ◽  
Elephant Seal ◽  
Social Hierarchy ◽  
Mirounga Angustirostris ◽  
Northern Elephant Seal ◽  
Female Behavior ◽  
Elephant Seals ◽  
Sea Lions ◽  
The Social ◽  
Breeding Seasons

AbstractThe mating behavior of Northern elephant seals, Mirounga angustirostris, was studied during the I968, I969 and I970 breeding seasons at Año Nuevo Island, I9 miles north of Santa Cruz, California. Copulation takes place primarily on land, from January to March; it is initiated and terminated by the male and lasts approximately 5 minutes. A few males do most of the breeding and the higher a male's rank in the social hierarchy, the more frequently he copulates. Some bulls may maintain high rank and participate in mating for 3 breeding seasons. Low ranking males are kept out of the harem so they attempt to copulate with females on the periphery or in the water with departing females. Males prevent subordinates from mounting females and disrupt copulations in progress. The higher a male's rank, the more freedom he has to copulate without interference, and the more frequently he interferes with the copulation of others. The highest ranking males interrupt their own copulations prematurely to attack other males and prevent them from copulating. Males mount weaned pups, yearlings, and non-estrous females in addition to estrous females; the latter are mounted most frequently. Females come into estrus 24 days after parturition. They are receptive for about 3 days (range I-I3 days), during which they may copulate several different times with one or more males. Females are usually in estrus when they leave the rookery and return to sea. The greatest difference in the copulatory pattern of the elephant seal, a true seal, and members of the sea lion family, is that the former interfere with the copulations of other males while the latter do not. This may he due to differing social systems, a social hierarchy in elephant seals and a territorial system in sea lions. In elephant seals, where copulations are interrupted, mating may be incomplete. This is not as likely with sea lions where copulations are never interrupted because males honor the boundaries of their neighbors. The differences in female behavior and sexual physiology - a long promiscuous estrous period in elephant seals as opposed to a brief estrus with only one copulation in sea lions - may have evolved as a compensation for the consequences of the social behavior of males.

Feeding Habits and Feeding Grounds of the Northern Elephant Seal

1984 ◽  
Vol 65 (2) ◽  
pp. 281-290 ◽  
Author(s):  
R. Condit ◽  
B. J. Le Boeuf
Keyword(s):  
Feeding Habits ◽  
Elephant Seal ◽  
Northern Elephant Seal ◽  
Feeding Grounds

scholarly journals In-air hearing in Hawaiian monk seals: implications for understanding the auditory biology of Monachinae seals

2021 ◽  
Author(s):  
Brandi Ruscher ◽  
Jillian M. Sills ◽  
Beau P. Richter ◽  
Colleen Reichmuth
Keyword(s):  
Marine Mammals ◽  
Elephant Seal ◽  
Critical Ratio ◽  
Mirounga Angustirostris ◽  
Northern Elephant Seal ◽  
Hearing Ability ◽  
Highly Sensitive ◽  
Monk Seals ◽  
Management And Conservation ◽  
Hearing Abilities

AbstractThe auditory biology of Monachinae seals is poorly understood. Limited audiometric data and certain anatomical features suggest that these seals may have reduced sensitivity to airborne sounds compared to related species. Here, we describe the in-air hearing abilities of a Hawaiian monk seal (Neomonachus schauinslandi) trained to participate in a psychophysical paradigm. We report absolute (unmasked) thresholds for narrowband signals measured in quiet conditions across the range of hearing and masked thresholds measured in the presence of octave-band noise at two frequencies. The behavioral audiogram indicates a functional hearing range from 0.1 to 33 kHz and poor sensitivity, with detection thresholds above 40 dB re 20 µPa. Critical ratio measurements are elevated compared to those of other seals. The apparently reduced terrestrial hearing ability of this individual—considered with available auditory data for a northern elephant seal (Mirounga angustirostris)—suggests that hearing in Monachinae seals differs from that of the highly sensitive Phocinae seals. Exploration of phylogenetic relationships and anatomical traits support this claim. This work advances understanding of the evolution of hearing in amphibious marine mammals and provides updated information that can be used for management and conservation of endangered Hawaiian monk seals.

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