Underwater vocalizations of ice breeding grey seals

1993 ◽  
Vol 71 (11) ◽  
pp. 2211-2219 ◽  
Author(s):  
Sylvie Asselin ◽  
Mike O. Hammill ◽  
Cyrille Barrette
Keyword(s):  
Breeding Season ◽  
Seasonal Variations ◽  
Temporal Structure ◽  
Social Activity ◽  
Low Frequency ◽  
Ice Cover ◽  
Halichoerus Grypus ◽  
Vocal Repertoire ◽  
Night And Day

Grey seals (Halichoerus grypus) breed both on land and on the ice. In January 1991, 36 h of underwater recordings were made from Amet Island, located in ice-covered waters in the southern Gulf of St. Lawrence. All vocalizations were examined for spectral and temporal structure and then classified into 1 of 7 call types. The majority of calls consisted of guttural "rups" and "rupes" (frequency = 100–3000 Hz), and low-frequency growls (100–500 Hz). Other less common vocalizations were low-frequency clicks (3000 Hz), as well as loud knocks, similar to knocking vocalizations recorded in walrus, and which had not been described previously for grey seals. The total number of vocalizations and the number of specific call types showed seasonal variations. The rate of vocalizations increased with the intensity of social activity and with the number of agonistic behaviors during the progression of the breeding season. Comparisons between night and day showed some changes in the vocal repertoire. Low-frequency clicks were recorded more often during darkness (17.1% of calls) than in daylight (1.9%), and when ice cover was more extensive.

New underwater and aerial vocalizations of captive harp seals (Pagophilus groenlandicus)

2001 ◽  
Vol 79 (1) ◽  
pp. 75-81 ◽  
Author(s):  
A Serrano
Keyword(s):  
Fundamental Frequency ◽  
Breeding Season ◽  
High Frequency ◽  
Low Frequency ◽  
Time Of Day ◽  
Vocal Repertoire ◽  
Maximum Frequency ◽  
Pagophilus Groenlandicus ◽  
Vocal Activity ◽  
The Mean

Pinnipeds are ecologically and socially diverse, attributes that are reflected in their systems of communication. The purpose of this investigation was to document the vocal repertoire and annual cycle of vocal activity in the harp seal (Pagophilus groenlandicus), a species that communicates mainly under water, but whose social and communicative systems outside the breeding season are poorly known. The repertoire comprised 18 vocal classes, or call types; 7 that had not been described previously are described here. Vocal activity varied seasonally and with time of day. Calls of low frequency and with few pulse repetitions were predominantly used outside the breeding season, and calls of high frequency and with a high number of pulse repetitions predominated in the breeding season. The new vocalizations described here differed in several ways from those described previously. First, calls were relatively brief, with an average duration of 1.75 s (except call types 22 and 23, which averaged >2 s in duration). Second, some calls differed in mean fundamental frequency, the average being 677 Hz. Call types 22 and 23 differed the most, with an average of 838 Hz. The vocal repertoire described previously comprise calls with a fundamental frequency of approximately 400–500 Hz. Third, call types 22 and 25 differed from the rest of the vocalizations. The mean maximum frequency of call types 22 and 25 was 3.4 kHz, while the mean maximum frequency of the other call types is around 7.7 kHz.

scholarly journals Low-frequency bursts of horizontally polarized waves in the Arctic sea-ice cover

2011 ◽  
Vol 57 (202) ◽  
pp. 231-237 ◽  
Author(s):  
David Marsan ◽  
Jérôme Weiss ◽  
Jean-Philippe Métaxian ◽  
Jacques Grangeon ◽  
Pierre-François Roux ◽  
...  
Keyword(s):  
Sea Ice ◽  
Regional Scale ◽  
Low Frequency ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Strong Activity ◽  
Temporal Sampling ◽  
Polarized Waves ◽  
Arctic Sea

AbstractWe report the detection of bursts of low-frequency waves, typically f = 0.025 Hz, on horizontal channels of broadband seismometers deployed on the Arctic sea-ice cover during the DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies) experiment in spring 2007. These bursts have amplitudes well above the ambient ice swell and a lower frequency content. Their typical duration is of the order of minutes. They occur at irregular times, with periods of relative quietness alternating with periods of strong activity. A significant correlation between the rate of burst occurrences and the ice-cover deformation at the ∼400 km scale centered on the seismic network suggests that these bursts are caused by remote, episodic deformation involving shearing across regional-scale leads. This observation opens the possibility of complementing satellite measurements of ice-cover deformation, by providing a much more precise temporal sampling, hence a better characterization of the processes involved during these deformation events.

A small vocal repertoire during the breeding season expresses complex behavioral motivations and individual signature in the common coot

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Changjian Fu ◽  
Atul Kathait ◽  
Guangyi Lu ◽  
Xiang Li ◽  
Feng Li ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Breeding Season ◽  
Function Analysis ◽  
Vocal Repertoire ◽  
Call Type ◽  
Temporal Parameters ◽  
Fulica Atra ◽  
Individual Signature ◽  
Behavioral Activities ◽  
Types Of Information

Abstract Background Although acoustic communication plays an essential role in the social interactions of Rallidae, our knowledge of how Rallidae encode diverse types of information using simple vocalizations is limited. We recorded and examined the vocalizations of a common coot (Fulica atra) population during the breeding season to test the hypotheses that 1) different call types can be emitted under different behavioral contexts, and 2) variation in the vocal structure of a single call type may be influenced both by behavioral motivations and individual signature. We measured a total of 61 recordings of 30 adults while noting the behavioral activities in which individuals were engaged. We compared several acoustic parameters of the same call type emitted under different behavioral activities to determine how frequency and temporal parameters changed depending on behavioral motivations and individual differences. Results We found that adult common coots had a small vocal repertoire, including 4 types of call, composed of a single syllable that was used during 9 types of behaviors. The 4 calls significantly differed in both frequency and temporal parameters and can be clearly distinguished by discriminant function analysis. Minimum frequency of fundamental frequency (F0min) and duration of syllable (T) contributed the most to acoustic divergence between calls. Call a was the most commonly used (in 8 of the 9 behaviors detected), and maximum frequency of fundamental frequency (F0max) and interval of syllables (TI) contributed the most to variation in call a. Duration of syllable (T) in a single call a can vary with different behavioral motivations after individual vocal signature being controlled. Conclusions These results demonstrate that several call types of a small repertoire, and a single call with function-related changes in the temporal parameter in common coots could potentially indicate various behavioral motivations and individual signature. This study advances our knowledge of how Rallidae use “simple” vocal systems to express diverse motivations and provides new models for future studies on the role of vocalization in avian communication and behavior.

The effect of management history and time of mating on ovulation and lambing rates in mule ewes

1995 ◽  
Vol 1995 ◽  
pp. 95-95
Author(s):  
Linda M Mitchell ◽  
Margaret E King ◽  
R.P. Aitken ◽  
Jacqueline M Wallace
Keyword(s):  
Breeding Season ◽  
Seasonal Variations ◽  
Ovulation Rate ◽  
Endogenous Rhythm ◽  
Nutritional Requirements ◽  
Embryo Survival ◽  
Management History ◽  
Reproductive Response ◽  
Per Se ◽  
Natural Breeding

There is increasing interest in the development of later lambing systems for crossbred ewes which more closely match ewe nutritional requirements with herbage growth (Stone, 1988; Mitchell, 1990). It has long been recognised however that at extremes of the natural breeding season fecundity is reduced, a possible consequence of seasonal variations in ovulation rate, fertilisation and/or embryo survival (Hammond, 1944). Daylength is the factor which entrains the endogenous rhythm of reproduction in sheep (Donovan, O’Callaghan, Karsh, Boland and Roche, 1992) and daylength changes per se may be responsible for variations in reproductive response throughout the breeding season. Associated environmental and management factors may also be of importance. The objective of the present study was to determine the effect of management history and month of mating on ovulation and lambing rates in Mule ewes.

Maternal behaviour and energy investment by grey seals (Halichoerus grypus) breeding on land-fast ice

1996 ◽  
Vol 74 (8) ◽  
pp. 1531-1541 ◽  
Author(s):  
Martha A. Haller ◽  
Kit M. Kovacs ◽  
Mike O. Hammill
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Halichoerus Grypus ◽  
Maternal Behaviour ◽  
Similar Amount ◽  
Lactation Period ◽  
Energy Investment ◽  
Fast Ice

The grey seal (Halichoerus grypus) is a sexually dimorphic polygynous phocid that breeds in a synchronous fashion, within populations, on both sides of the North Atlantic Ocean. This study was designed to examine factors that may influence maternal behaviour and energy investment of females breeding on land-fast ice. The study was conducted on the ice around Amet Island, Nova Scotia, during the breeding seasons of 1992, 1993, and 1994. Scan sampling and ad libitum observation techniques were used to record behaviour. Mass transfer from mothers to pups was determined using serial mass records for pairs. Rate of pup mass gain was 2.5 ± 0.6 kg/day and pup mass at weaning 50.0 ± 7.3 kg. The duration of lactation was 15.2 ± 1.6 days. Maternal mass at parturition was 210.6 ± 23.8 kg and female mass loss during the lactation period was 75.0 ± 16.0 kg. This mass loss represented 35.7 ± 6.1% of their parturition mass. Efficiency of mass transfer was 0.52 ± 0.12. Breeding habitat influenced maternal behaviour. Compared with land-breeding grey seals, ice-breeding females had an intensified nursing period, during which females transferred a similar amount of energy to their pups over a shorter time frame. Additionally, females on land-fast ice gave birth more synchronously than is the case in land-breeding colonies. Date of parturition within the breeding season had some influence on female behaviour; females giving birth late in the season were more active than females breeding earlier. The behaviour of males may play a role in determining the optimum time for birthing. Adult males spent more time engaged in agonistic behaviours late in the breeding season and the resultant disruption of adjacent females may serve as a selective force maintaining birthing synchrony. These influences also apply in land-breeding situations and are not likely to contribute to the contraction of the nursing period and the more synchronous breeding observed among females on ice. The more condensed lactation and birthing periods are likely a response to the higher risk of premature separation on the ice.

Diving behaviour during the breeding season in the terrestrially breeding male grey seal: implications for alternative mating tactics

2003 ◽  
Vol 81 (6) ◽  
pp. 1025-1033 ◽  
Author(s):  
Damian C Lidgard ◽  
Daryl J Boness ◽  
W Don Bowen ◽  
Jim I McMillan
Keyword(s):  
Nova Scotia ◽  
Reproductive Success ◽  
Breeding Season ◽  
Foraging Behaviour ◽  
Diving Behaviour ◽  
Halichoerus Grypus ◽  
Phenotypic Traits ◽  
Alternative Mating Tactics ◽  
Grey Seal ◽  
Mating Tactics

We examined the diving behaviour of breeding male grey seals (Halichoerus grypus) at Sable Island, Nova Scotia, from 1997 to 2001. The proportion of time spent at sea varied between 0 and 78% (N = 30). Males engaged in deep (43.4 ± 3.3 m (mean ± SE), N = 27) diving, and these dives were clustered into bouts, which mostly occurred during long trips (62.2 ± 14.7 h). We suggest that males spent time foraging during deep dives. Shallow diving (5.9 ± 0.1 m, N = 27) accounted for 40.8% of dives, which were also clustered into bouts that mostly occurred during short trips (2.1 ± 0.37 h). We suggest that shallow diving comprised a suite of behaviours, but included little foraging behaviour. Phenotypic traits had little influence on diving behaviour. Further work is required to understand the extent to which foraging behaviour enhances reproductive success, and whether shallow diving is a component of the mating tactics of male grey seals at Sable Island.

scholarly journals Seasonal Variations In The Surface Energy Exchanges Over Antarctic Sea Ice and Coastal Waters

1982 ◽  
Vol 3 ◽  
pp. 12-16 ◽  
Author(s):  
I. Allison ◽  
C.M. Tivendale ◽  
G.J. Akerman ◽  
J.M. Tann ◽  
R.H. Wills
Keyword(s):  
Heat Transfer ◽  
Sea Ice ◽  
Seasonal Variations ◽  
Lower Boundary ◽  
Open Water ◽  
Ice Cover ◽  
Turbulent Fluxes ◽  
Turbulent Heat ◽  
Radiative Heat Loss ◽  
Antarctic Sea Ice

Seasonal variations in radiative and turbulent fluxes at the surface of, and in the heat transfer within, sea ice are discussed from results of energy balance studies at a site of annual ice cover near Mawson, Antarctica. In mid-summer, the open water gains heat mostly by radiation but by early February the ocean is cooling predominantly by strong turbulent losses, with some radiative heat loss occurring also by March. When an ice cover forms, turbulent fluxes decrease from several 100 W m−2over open water to only 40 w m−2over ice less than 0.2 m thick and even less over thicker ice.Net radiative losses over mature ice in mid-winter are balanced mostly by conduction through the ice cover but with some turbulent heat gain at the surface. By mid-spring, there is a net radiative gain, the turbulent fluxes are again outgoing, and there is little total heat transfer through the ice. At break-out, the albedo increase from ice to open water causes a large increase in the net radiative gain.At the lower boundary of the ice, the oceanic heat flux provides an important contribution. A net advection of heat into the region is shown from temperature profiles in the water under the ice. Salinity changes in the water during the period of ice melt are also discussed.

scholarly journals A study of seasonal variations of gravity wave intensity in thelower thermosphere using LF D1 wind observations and a numerical model

2004 ◽  
Vol 22 (1) ◽  
pp. 35-45 ◽  
Author(s):  
N. M. Gavrilov ◽  
Ch. Jacobi
Keyword(s):  
Numerical Model ◽  
Drift Velocity ◽  
Seasonal Variations ◽  
Middle Atmosphere ◽  
Low Frequency ◽  
Internal Gravity Waves ◽  
Short Period ◽  
Summer Maximum ◽  
E Region ◽  
Standard Deviations

Abstract. The data of the regular low-frequency D1 E-region observations at Collm, Germany (52°N, 15°E) in 1983–1999 are used for estimations of the intensity of short-period perturbations of the horizontal drift velocity at 85–110 km altitude. A simple half-hourly-difference numerical filter is used to extract perturbations with time scales of 0.7–3 h. The average monthly standard deviations of short-period perturbations of the zonal velocity near altitude 83 km have a main maximum in summer, a smaller maximum in winter, and minimum values at the equinoxes. At higher altitudes the summer maximum is shifted towards the spring months, and a second maximum of perturbation amplitudes appears in autumn at altitudes near and above 100 km. The seasonal changes in the standard deviations of meridional velocity show the maxima in spring and summer. A numerical model describing the propagation of a set of harmonics modeling a spectrum of internal gravity waves in the atmosphere is used for the interpretation of observed seasonal variations of wind perturbation intensity. Numerical modeling reveals that the observed altitude changes in the seasonal variations of the drift velocity standard deviations may be explained by a superposition of IGWs generated at different levels in the troposphere and middle atmosphere. IGWs generated in the stratospheric and mesospheric jet stream may have substantial amplitudes at altitudes near and above 100 km, where they may modify the seasonal variations, which are typical for IGWs propagating from the troposphere. Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides) – Ionosphere (ionospheric irregularities)

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