Diving performance of male and female Japanese Cormorants

1996 ◽  
Vol 74 (6) ◽  
pp. 1098-1109 ◽  
Author(s):  
Yutaka Watanuki ◽  
Akiko Kato ◽  
Yasuhiko Naito
Keyword(s):  
Body Mass ◽  
Dive Duration ◽  
Sexual Differences ◽  
Foraging Efficiency ◽  
Diving Behavior ◽  
Bottom Phase ◽  
Similar Proportion ◽  
Sexually Dimorphic ◽  
Surface Time ◽  
Ascent Phase

Sexual differences in the diving behavior of the sexually dimorphic Japanese Cormorant, Phalacrocorax capillatus (males are 26% heavier than females), were studied at Teuri Island, Hokkaido, using time–depth recorders. A typical dive cycle involved a rapid descent phase, a bottom phase where they remained for a while, an ascent phase, and a postdive surface phase. Depth and duration across individual birds were greater for males (15.1 ± 3.7 (mean ± SD) m, 37 ± 5 s, respectively) than those for females (7.2 ± 2.4 m, 24 ± 4 s, respectively). While submerged, females spent a similar proportion of time during the bottom phase to males, hence foraging efficiency (proportion of time at the bottom to total dive cycle time) did not differ between the sexes. No sexual differences were found in descent and ascent rates, dive bout duration, or time spent underwater per day. No significant effects of dive duration on postdive surface time were observed for either sex, indicating that birds dived within an aerobic dive limit. However, mean dive durations and maximum dive durations for individual birds were a function of body mass to the power 1.49 and 1.87, respectively, suggesting that body mass partly constrains the diving behavior of this opportunistically feeding cormorant.

Diving behavior of an epipelagically feeding alcid, the Rhinoceros Auklet (Cerorhinca monocerata)

2003 ◽  
Vol 81 (7) ◽  
pp. 1249-1256 ◽  
Author(s):  
Maki Kuroki ◽  
Akiko Kato ◽  
Yutaka Watanuki ◽  
Yasuaki Niizuma ◽  
Akinori Takahashi ◽  
...  
Keyword(s):  
Feeding Habits ◽  
Dive Depth ◽  
Diving Behavior ◽  
Bottom Phase ◽  
Cerorhinca Monocerata ◽  
The Hours ◽  
Small Bird ◽  
Rhinoceros Auklet ◽  
Ascent Phase ◽  
Horizontal Bottom

The diving behavior of Rhinoceros Auklets (Cerorhinca monocerata) breeding at Teuri Island, Hokkaido, Japan, was studied using small bird-borne time–depth dataloggers. The eight auklets made dives without an obvious horizontal bottom phase to a median depth of 14.0 ± 1.8 (mean ± SD) m (maximum 57 m) for 53 ± 8 s (maximum 148 s) between the hours of 0300 and 2000. They made undulations (rapid depth changes), considered to represent prey pursuit, in 35% of the dives. Of the undulations, 57% occurred during the deep (>80% of maximum depth) parts of the dives and 26% during the ascent phase. The auklets performed 26 ± 31 dives continuously during dive bouts of 32 ± 34 min. Dive bouts at the end of the day were twice as long as in the morning and at midday. During dive bouts, the auklets showed consistent trends in dive depth, decreasing (23% of bouts), increasing (32%), or stable (19%), but sometimes they showed hectic depth changes (26%). V-shaped dives (with no horizontal bottom phase), potential prey pursuit in both the deep parts and ascent phases of the dives, and variable depth changes within dive bouts indicate the auklets' epipelagic feeding habits.

The development of diving behavior in juvenile Weddell seals: pushing physiological limits in order to survive

1999 ◽  
Vol 77 (5) ◽  
pp. 737-747 ◽  
Author(s):  
Jennifer M Burns
Keyword(s):  
Blood Chemistry ◽  
Weddell Seal ◽  
Dive Duration ◽  
Foraging Strategies ◽  
Foraging Efficiency ◽  
Diving Behavior ◽  
Weddell Seals ◽  
Physiological Limits ◽  
Behavioral Constraints ◽  
Absolute Energy

In juvenile phocids, the successful transition from nursing to independent foraging is contingent upon the development of adequate diving skills within the limited time between weaning and the depletion of body reserves. Yet, because juvenile seals are unable to remain submerged for as long as adults, owing to their smaller size, higher metabolic rates, and lowered oxygen stores, their behavioral options are likely constrained. To determine how such limitations might influence foraging strategies, we studied the development of diving behavior and physiology in Weddell seal (Leptonychotes weddellii) juveniles, using a combination of time-depth recorders, satellite-linked dive recorders, and morphological and physiological measurements (mass and blood chemistry). Time-depth recorder data indicated that the average depth, duration, and frequency of dives made by pups increased rapidly in the period from birth through weaning, but slowed soon thereafter. While preweaning increases in these parameters were correlated with seal age, postweaning increases in dive capacity were gradual and were probably the result of slower changes in mass and body composition. In weaned pups and yearlings, dive frequency and time underwater increased with age and (or) mass. Despite their smaller size and lower absolute energy requirements, the amount of time juveniles spent in the water was similar to that spent by adults. However, because juveniles were unable to remain submerged as long as adults and because most foraging dives were deep, juveniles were unable to spend an equivalent amount of time at the foraging depths. This difference was evident even though juveniles dove much closer to their anaerobic threshold than did adults. These findings support the hypothesis that the foraging efficiency of younger seals is reduced relative to that of adults, owing to physiological and morphological constraints on aerobic dive duration, and suggests that low juvenile survival might result from behavioral constraints.

scholarly journals Dive Performance and Aquatic Thermoregulation of the World’s Smallest Mammalian Diver, the American Water Shrew (Sorex palustris)

2021 ◽  
Author(s):  
Roman W. Gusztak ◽  
Robert A. MacArthur ◽  
Kevin L. Campbell
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Thermal Inertia ◽  
Oxygen Storage Capacity ◽  
Dive Duration ◽  
Oxygen Storage ◽  
Foraging Efficiency ◽  
Diving Behavior ◽  
In The Wild ◽  
Total Body Oxygen

AbstractAllometry predicts that the 12–17 g American water shrew (Sorex palustris)—the world’s smallest mammalian diver—will have the highest diving metabolic rate (DMR) coupled with the lowest total body oxygen storage capacity, skeletal muscle buffering capacity, and glycolytic potential of any endothermic diver. Despite these constraints, the maximum dive time (23.7 sec) and calculated aerobic dive limit (cADL; 10.8–14.4 sec) of wild-caught water shrews match or exceed values predicted by allometry based on studies of larger-bodied divers. The mean voluntary dive time of water shrews in 3, 10, 20, and 30°C water was 5.1±0.1 sec (N=25, n=1584), with a mean maximum dive time of 10.3±0.4 sec. Only 2.3–3.9% of dives in 30 and 10°C water, respectively, exceeded the cADL. Mean dive duration, duration of the longest dive, and total time in water all decreased significantly as temperature declined, suggesting that shrews employed behavioural thermoregulation to defend against immersion hypothermia. As expected from their low thermal inertia, diving shrews had a significantly higher DMR in 10°C (8.77 mL O2 g-1 hr-1) compared to 30°C water (6.57 mL O2 g-1 hr-1). Diving behavior of radio-telemetered shrews exclusively foraging in a simulated riparian environment (3°C water) for 12- to 28-hours suggest that mean (but not maximum) dive times of water shrews in the wild may be longer than predicted from our voluntary dive trials, as the average dive duration (6.9±0.2 sec, n=257) was ∼1.75× longer than during 20-min trials with no access to food at the same water temperature. Notably, free-diving shrews in the 24-hr trials consistently elevated core body temperature by ∼1.0–1.5°C immediately prior to initiating aquatic foraging bouts, and ended these bouts when body temperature was still at or above normal resting levels (∼37.8°C). We suggest this observed pre-dive hyperthermia aids to heighten the impressive somatosensory physiology, and hence foraging efficiency, of this diminutive predator while submerged.

scholarly journals The Influence of Body Mass on the Endurance to Restrained Submergence in the Pekin Duck

1986 ◽  
Vol 120 (1) ◽  
pp. 351-367 ◽  
Author(s):  
DENNIS M. HUDSON ◽  
DAVID R. JONES
Keyword(s):  
Body Mass ◽  
Linear Regression Analysis ◽  
Dive Duration ◽  
Oxygen Storage ◽  
Pekin Duck ◽  
Oxygen Utilization ◽  
Pekin Ducks ◽  
Mass Coefficient ◽  
Relationship Of ◽  
The Relationship

Pekin ducks, ranging in mass from 0.05 to 3.5 kg, were force-dived to determine the maximum tolerance to diving asphyxia. The size of the respiratory and blood oxygen storage compartments and oxygen utilization during the dive were also measured. By the end of a maximum dive, less than 4% of the original O2 store remained in the blood, whereas almost 25% remained in the respiratory system. In contrast, the level of arterial glucose did not change significantly during diving. The relationship of a number of measured variables to body mass was analysed using linear regression analysis on logio-transformed variables to generate power equations of the form Y = aXb (Y, any variable; X, body mass; a, mass coefficient; b, mass exponent). The mass exponent was 1.19 for the total oxygen stores and 0.64 for maximum diving duration. Using measurements of brain and heart mass and literature estimates of the scaling of O2 consumption, it was also possible to predict a mass exponent aerobic metabolism by these organs during a maximum dive. Allometric cancellation of mass exponents for O2 availability and predicted utilization resulted in a residual mass exponent almost identical to the measured value for maximum dive duration. Thus it is possible to predict the relationship of maximum underwater endurance to body mass in Pekin ducks from a knowledge of the oxygen consumption by, and availability to, the central aerobic organs.

scholarly journals Status and biology of ringed seals (Phoca hispida) in Svalbard

1998 ◽  
Vol 1 ◽  
pp. 46 ◽  
Author(s):  
Christian Lydersen
Keyword(s):  
Body Mass ◽  
Dive Duration ◽  
Early Spring ◽  
Ringed Seal ◽  
The Arctic ◽  
Polar Cod ◽  
Net Energy ◽  
Adult Males ◽  
Ringed Seals ◽  
Males And Females

The ringed seal is the most abundant mammal in the Svalbard area. Annual pup production in this area is estimated to be 20,000. No systematic harvest records exist, but some few hundred seals are taken annually, mainly for dog food. The ringed seals in Svalbard are protected from hunting in the period 15 March - 15 April. Peak pupping season is the first week of April. New-born ringed seals weigh an average of 4.6 kg. They are nursed for about 39 days, and weaned at an average body mass of around 22 kg. During the period of maternal care pups consume a total of about 54 litres of milk, that is composed of approximately 38% fat and 10% protein. Asymptotic standard lengths and body masses for adult ringed seal males and females are 131.5 and 127.8 cm, and 52.6 and 59.9 kg,respectively. The maximum values recorded for lengths of males and females in Svalbard are 157 cm and 107 kg, respectively. There is marked seasonal variation in body mass in both sexes with the highest mass records being recorded in early spring before pupping occurs, and with minimum values in the summer after the breeding and moulting seasons. The observed variation in mass is mainly due to changing blubber thickness of the seals. Ringed seal males attain sexual maturity at the age of 5 - 7 years, while females reach maturity when they are 3-5 years of age. The oldest seal collected in Svalbard was aged 45. Ringed seals in the Svalbard area feed on a variety of prey organisms, the most important of which are polar cod (Boreogadus saida) and the crustaceans Parathemisto libellula, Thysanoessa inermis and Pandalus borealis. Ringed seal pups start diving during the nursing period while they are still white-coats, and spend about 50% of the time in thewater prior to weaning. They are capable of diving for up to 12min and dive to the bottom of the study areas (max. 89 m). Nursing females spend more than 80% of their time in the water. Maximum recorded dive duration for mothers was 21.2 min. In order to produce a weaned pup, the net energy expenditure for a ringed seal mother is 1,073 MJ. This energy value corresponds to the consumption of 185 kg of polar cod or 282 kg of P. libellula. The annual gross energy consumption for adult males and females is calculated to be 5,600 MJ and 7,300 MJ, respectively. The main predators of ringed seals in Svalbard are polar bears (Ursus maritimus) and Arctic foxes (Alopex lagopus). In addition, both glaucous gulls (Larus hyperboreus) and walruses (Odobenus rosmarus) are documented as predators of ringed seals in this area. Heavy predation pressure is probably the main factor explaining why pups of this species start diving at such a young age, why they have access to so many breathing holes (8.7 on average) and why they keep their white coat long after its thermoregulatory properties have vanished. Pollution levels in ringed seals from Svalbard are, generally speaking, similar to levels in other areas of the Arctic.

scholarly journals The bottlenose dolphin Tursiops truncatus foraging around a fish farm: Effects of prey abundance on dolphins’ behavior

2009 ◽  
Vol 55 (4) ◽  
pp. 243-248 ◽  
Author(s):  
Bruno Díaz López
Keyword(s):  
Group Size ◽  
Human Activities ◽  
Bottlenose Dolphin ◽  
Bottlenose Dolphins ◽  
Dive Duration ◽  
Fish Farm ◽  
Prey Abundance ◽  
Diving Behavior ◽  
Top Predators ◽  
Feeding Activities

Abstract The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied. The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond, individually and as groups, to the relative abundance of prey around a fish farm. Detailed views of dolphins’ behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data. A total of 2150 dive intervals were analyzed, corresponding to 342 focal samples, lasting over 34 hours. Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds. This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area. This study’s results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding, dolphins did not modify dive duration. Additionally, underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities. Thus, bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey. When top predators display behavioral responses to activities not directed at them, the task of studying all possible effects of human activities can become even more challenging.

scholarly journals Diving Behavior of the Red-Legged Cormorant in Southeastern Patagonia, Argentina

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 440-444 ◽  
Author(s):  
Esteban Frere ◽  
Flavio Quintana ◽  
Patricia Gandini
Keyword(s):  
Environmental Variables ◽  
High Tide ◽  
Dive Duration ◽  
Diving Behavior ◽  
Shallow Waters ◽  
Feeding Time ◽  
Radio Transmitters ◽  
Inshore Waters ◽  
Mean Time ◽  
Foraging Time

Abstract We studied the diving behavior of Red-legged Cormorants (Phalacrocorax gaimardi) in Patagonia, Argentina, using VHF radio-transmitters deployed during incubation. Red-legged Cormorants made foraging trips in inshore waters less than 15 m deep. Mean dive duration was 26.8 ± 2.0 sec while mean time at surface was 9.2 ± 0.9 sec (n = 2217 dives). The birds spent 74% of their foraging time underwater. Diving efficiency was different among individuals, and was among the highest reported for the Phalacrocoracidae. Dive variables were correlated with the height of the tide, suggesting that the birds forage on the seabed. Red-legged Cormorants were efficient divers, investing most of their feeding time underwater and foraging in shallow waters, maximizing bottom time. Our results are consistent with the hypothesis that Red-legged Cormorant diving behavior is strongly influenced by a combination of environmental variables (bottom heterogeneity and high tide width) characteristic of the south coast of Patagonia. Comportamiento de Buceo del Phalacrocorax gaimardi en la Patagonia Sudoriental, Argentina Resumen. Se estudió el comportamiento de buceo del Phalacrocorax gaimardi en Patagonia, Argentina, usando transmisores VHF instalados durante el periodo de la incubación. P. gaimardi realizó sus viajes de alimentación en áreas costeras poco profundas (<15 m). La duración media del buceo fue 26.8 ± 2.0 seg y el tiempo medio en superficie de 9.2 ± 0.9 seg (n = 2217). Las aves pasaron bajo el agua un 74% de su tiempo de alimentación, mostrando una de las eficiencias de buceo más altas mencionadas para los Phalacrocoracidae. Los parámetros de buceo se correlacionaron con la altura de la marea, sugiriendo que las aves se alimentaron en el fondo marino. Los individuos de P. gaimardi fueron eficientes buceadores, invirtiendo la mayoría de su tiempo de alimentación debajo del agua en aguas someras, maximizando el tiempo en el fondo marino. Nuestros resultados apoyan la hipótesis que P. gaimardi tiene un comportamiento de buceo que responde a las características ambientales de la costa sur de la Patagonia (heterogeneidad del fondo marino y grandes amplitudes de marea).

Diving behavior reduces genera richness of lice (Insecta, Phthiraptera) of mammals

2007 ◽  
Vol 52 (1) ◽  
Author(s):  
Bernadett Felső ◽  
Lajos Rózsa
Keyword(s):  
Species Richness ◽  
Body Mass ◽  
Comparative Approach ◽  
Diving Behavior ◽  
Taxonomic Richness ◽  
Entire Life ◽  
Confounding Variables ◽  
The Mean ◽  
The Difference ◽  
Aquatic Mammals

AbstractLice of mammals spend the entire life cycle in the host hair, thus, the microclimate found near the mammal skin is likely to influence the structure of louse communities. Here we use a comparative approach to examine the effect of mammals’ diving behavior on the taxonomic richness of their lice. We compared the mean genera richness of lice, and — as potential confounding variables — the mean species richness of host, and the mean body mass of host between diving clades and their non-diving sister clades. Louse genera richness was significantly lower in clades of aquatic mammals than on their non-diving sister clades. Host species richness was not significantly different between these clades. Body mass was significantly higher in clades of aquatic mammals, however, the direction of this difference cannot explain the difference in parasite taxonomic richness. This study suggests that mammals’ diving behavior can effectively shape their ectoparasite communities.

scholarly journals Behavioral changes in female Swiss mice exposed to tannery effluents

2016 ◽  
Vol 11 (3) ◽  
pp. 519 ◽  
Author(s):  
Sabrina Ferreira De Almeida ◽  
Letícia Martins Rabelo ◽  
Joyce Moreira de Souza ◽  
Raíssa De Oliveira Ferreira ◽  
Abraão Tiago Batista Guimarães ◽  
...  
Keyword(s):  
Body Mass ◽  
Forced Swim Test ◽  
The Body ◽  
Behavioral Changes ◽  
Diving Behavior ◽  
Antidepressant Effect ◽  
Control Group ◽  
Tannery Effluent ◽  
Tannery Effluents ◽  
Swiss Mice

Among the anthropic activities generating potentially toxic residues are those involved with bovine hide processing (tannery industries). However, knowledge is scant regarding the damage caused to the health of various organisms by tannery waste and studies are rare, especially in mammalian experimental models. This study therefore aimed to evaluate the physical and behavioral effects of the exposure of female Swiss mice to tannery effluent. To accomplish this, for a period of 15 days the animals were fed tannery effluent diluted with water in the following concentrations: 0% (control group, received only potable water), 5% and 10%. The body mass of the animals was evaluated at the beginning and end of the experiment, as well as the daily consumption of water and food. After 15 days of exposure to the effluent, the animals were submitted to the elevated plus maze (predictive of anxiety) and the forced swim test (predictive of depression). The treatments did not affect the animals’ body mass, either in eating behavior or in consumption of water. However, it was found that the animals that ingested tannery effluent concentrations of 5% and 10% exhibited an anxiolytic (lower level of anxiety, greater percentage of time in the open arms, longer time and frequency in the diving behavior, less time of lurks and less frequency of freezing) and an antidepressant effect (more time in climbing behavior and less time of immobility) when compared to the control group. It was concluded that the exposure of female Swiss mice to tannery effluents (5% and 10% diluted with water) causes behavioral changes, possibly related to the neurotoxicity of this waste, without causing physical changes in the animals.

Reproductive effort of male hooded seals (Cystophora cristata): estimates from mass loss

1996 ◽  
Vol 74 (8) ◽  
pp. 1521-1530 ◽  
Author(s):  
Kit M. Kovacs ◽  
Christian Lydersen ◽  
Mike Hammill ◽  
David M. Lavigne
Keyword(s):  
Body Composition ◽  
Mass Loss ◽  
Body Mass ◽  
Breeding Season ◽  
Tritiated Water ◽  
Dive Depth ◽  
Dive Duration ◽  
Day Range ◽  
Ice Surface ◽  
Cystophora Cristata

This study investigated mass loss, body composition, and behaviour patterns of male hooded seals during the reproductive season. During the 6 years of study (between 1989 and 1995), 139 records of male mass were obtained that involved 115 individuals. Body masses of males ranged from 147 to 434 kg. Mean mass at first capture was 312.5 ± 53.0 kg (N = 119). Year, date of sampling, and age all significantly influenced mass. Nineteen males were recaptured at least twice during a single season. Mean rate of mass loss among these individuals was 2.5 ± 1.1 kg/day (range 0.7–4.6 kg/day). Body composition early in the breeding season, measured using tritiated water (N = 6), produced mean estimates of 51.6 ± 1.6% water, 29.3 ± 2.4% fat, 16.9 ± 0.7% protein, and 1.9 ± 0.2% ash. Time–depth recorders attached to three males indicated that they spent 84.7 ± 15.4% of their time hauled out on the surface of the ice during the breeding season. Each of these males was on the ice for a few days; they then spent a few hours at sea before returning to the ice surface. Mean dive depth was only 14.1 ± 3.2 m (maximum 66 m) and mean dive duration was only 1.7 ± 0.3 min (maximum 28 min). Extrapolating mean daily rates of body mass loss to encompass a 2.5-week breeding season, males would lose an average of 44 kg, which represents 14% of their mean body mass. Compared with values for males of other phocid species this value is conservative. It appears that the short breeding season among hooded seals is energetically advantageous for both sexes.

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