scholarly journals Status of the harbour seal (Phoca vitulina) along the Murman coast of Russia

2010 ◽  
Vol 8 ◽  
pp. 37 ◽  
Author(s):  
Sergey V Zyryanov ◽  
Sergey A Egorov
Keyword(s):  
Activity Pattern ◽  
Daily Activity ◽  
Breeding Site ◽  
Phoca Vitulina ◽  
Adult Males ◽  
Breeding Colony ◽  
Harbour Seals ◽  
By Catch ◽  
Two Peaks ◽  
Gender Specific

Harbour seals are observed along the Murmansk coast of Russia, but they are not very abundant there. The estimated abundance for this area was about 500 individuals in 1998. The number of seals observed during winter months is less than during summer. During summer, the main habitats are the Pechenga inlet, the Motovsky and Kola Bays of the Western Murman coast and the Ivanovskaya Bay in the Eastern Murman coast. The Ivanovskaya Bay was thought to be the easternmost breeding colony of the subspecies Phoca vitulina vitulina. However, recent sightings may indicate the establishment of a breeding site further to the east, which then becomes the easternmost known habitat for this subspecies. A substantial, recent decrease in abundance has been observed in the Ivanovskaya Bay. The population numbered about 120 seals in the early 1990s, but only about 20 seals were seen in 2007 and 2008. It is presumed that the reasons for this reduction include hunting, fishery by-catch, disturbance and depletion of the food supply in this semi-enclosed inlet. A gender-specific daily activity pattern was observed in the IvanovskayaBay. The highest number of single animals (primarily adult males) hauled out during mid day, while hauled out females with pups showed two peaks per day associated with low tides.

scholarly journals Observations on seals on the island of Surtsey in the period 1980-2012

2015 ◽  
Vol 13 ◽  
pp. 41-43
Author(s):  
Erlingur Hauksson
Keyword(s):  
Breeding Site ◽  
Phoca Vitulina ◽  
The Other ◽  
South Coast ◽  
Harbour Seal ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
The South ◽  
Breeding Sites ◽  
Harbour Seals

Grey seals (Halichoerus grypus Fabricius) and harbour seals (Phoca vitulina L.) have been surveyed on the coasts of Iceland since 1980. During the period 1980-2012, both seal species have declined markedly in numbers at the Icelandic coast. The grey seal has established a considerable breeding site on the northern spit of the Surtsey island. This is at present one of the biggest grey seal rookeries on the southern shores of Iceland, with estimated about 60 pups born there in the autumn of 2012. On the other hand, the harbour seal has not been numerous on Surtsey during breeding time in the summer. Breeding sites of harbour seals on the south coast of Iceland closest to Surtsey are in the estuaries of the glacial rivers Ölfusá, Þjórsá, Markarfljót and Kúðafljót. Harbour seals, however, haul-out in great numbers on the northern shores of Surtsey during the winter, presumably using the island as a resting place after foraging in the adjacent waters.

The influence of body size and sex on the characteristics of harbour seal foraging trips

1998 ◽  
Vol 76 (6) ◽  
pp. 1044-1053 ◽  
Author(s):  
Paul M Thompson ◽  
Ann Mackay ◽  
Dominic J Tollit ◽  
Simon Enderby ◽  
Philip S Hammond
Keyword(s):  
Body Size ◽  
Activity Pattern ◽  
Diet Composition ◽  
Phoca Vitulina ◽  
Trip Duration ◽  
Energy Requirements ◽  
Endogenous Factors ◽  
Foraging Range ◽  
Harbour Seals ◽  
Size Population

Most pinnipeds disperse from centralised terrestrial sites to forage at sea, but the factors that result in variation inforaging-trip characteristics remain unclear. We investigated the influence of sex and body size on the summer foraging activityof radio-tagged harbour seals (Phoca vitulina) from Scotland. Mean foraging-trip duration (range 17–257 h) was stronglycorrelated with mean foraging range (range 4.3–55.0 km), but both were significantly shorter for females. The proportion oftime spent at sea, mean trip duration, and mean foraging range were all positively related to body size. Comparison with datafrom other study areas suggests that both environmental and endogenous factors shape foraging characteristics in this species.These sex and body size related differences in activity pattern and foraging range have important implications for themethodologies currently used to assess the population size, population energy requirements, and diet composition of coastalpinnipeds.

scholarly journals Effect of sex, age, and reproductive status on daily activity levels and activity patterns in jaguars (Panthera onca)

2021 ◽  
Author(s):  
Włodzimierz Jędrzejewski ◽  
Ilad Vivas ◽  
Maria Abarca ◽  
Margarita Lampo ◽  
Luis G. Morales ◽  
...  
Keyword(s):  
Activity Pattern ◽  
Daily Activity ◽  
Activity Patterns ◽  
Activity Level ◽  
Reproductive Status ◽  
Activity Levels ◽  
Adult Males ◽  
Movement Activity ◽  
Daily Movement ◽  
Reproductive Females

AbstractAll animals, including carnivores, adapt their daily activity duration and distribution to satisfy food demands, breed, or avoid mortality risk. We used the kernel density method to estimate daily movement activity levels and movement activity patterns of jaguars in Hato Piñero, in Venezuelan Western Llanos, based on 3,656 jaguar detection time records from two and a half years of camera trapping. Jaguars were active for 11.7 h per day on average and exhibited mostly nocturnal and crepuscular activity pattern, however, with marked differences between sex/age/reproductive groups. Reproductive females had the highest daily activity level (13.2 h/day), followed by adult males (10.9 h/day), non-reproductive females (10.5 h/day), and cubs (8.7 h/day). Activity patterns also differed, with males and reproductive females having activity peaks at the same hours after sunset and before sunrise, cubs in the night and after sunrise, while non-reproductive females were most active during night hours. This study was the first to document the effect of sex, age, and reproductive status on daily level and activity pattern in the jaguar.

In-air and underwater vocalizations of eastern Canadian harbour seals, Phoca vitulina

2002 ◽  
Vol 80 (7) ◽  
pp. 1173-1179 ◽  
Author(s):  
Sofie M Van Parijs ◽  
Kit M Kovacs
Keyword(s):  
Phoca Vitulina ◽  
Nearest Neighbour ◽  
Adult Males ◽  
Mating Season ◽  
Agonistic Interactions ◽  
Age Classes ◽  
Harbour Seals ◽  
The World ◽  
Pinniped Species ◽  
Vocalization Type

Harbour seals, Phoca vitulina, have long been thought to be one of the least vocal pinniped species both in air and under water. However, recent studies have shown that males use underwater vocalizations intensively during the mating season. In air, harbour seals are still thought to be relatively silent. In this study we describe the vocal repertoire of Eastern Canadian harbour seals during the breeding season. Harbour seals from this area produced seven vocalization types in air and one vocalization type under water. In-air vocalizations are predominantly used by adult males during agonistic interactions. Other sex and age classes also vocalize, but less frequently. Nearest neighbour responses to in-air vocalizations were primarily agonistic when any age or sex class vocalized. In this study, seals produced an underwater roar vocalization closely resembling that produced by adult males during the mating season at other sites. Eastern Canadian harbour seals appear to be considerably more vocal when hauled out than is the norm for this species at other sites around the world.

Dive shapes reveal temporal changes in the foraging behaviour of different age and sex classes of harbour seals (Phoca vitulina)

2002 ◽  
Vol 80 (9) ◽  
pp. 1569-1577 ◽  
Author(s):  
J Baechler ◽  
C A Beck ◽  
W D Bowen
Keyword(s):  
Foraging Behaviour ◽  
Direct Evidence ◽  
Function Analysis ◽  
Water Flux ◽  
Phoca Vitulina ◽  
Adult Males ◽  
Additional Information ◽  
Harbour Seals ◽  
And Function ◽  
The Relationship

Classifying dives into two-dimensional shapes based on time and depth is an attempt to extract additional information about the behaviour of aquatic air-breathing predators. In some species, there is considerable circumstantial evidence that different dive shapes represent different behaviours. However, few studies have provided direct evidence of the relationship between dive shape and function. We classified over 283 000 dives of adults (31 males and 45 females) and suckling (13) and recently weaned (15) harbour seal (Phoca vitulina) pups into seven shapes using supervised discriminant function analysis. Changes in the percentage of U-shaped dives over time within adults and weaned pups were associated with changes in food intake derived from water-flux studies on subsets of the same individuals. The changes in the percentage of U-shaped dives were accompanied by roughly reciprocal changes in V-shaped dives, whereas there was little change in other dive shapes, indicating that V-shaped dives are not generally exhibited during foraging. Video of adult males (from an animal-borne video system) also showed that there was a strong but not exclusive association between foraging and U-shaped dives. Our results indicate that changes in the percentage of U-shaped dives may serve as a reasonable index of changes in foraging behaviour. However, behaviours of suckling pups and adult males during the breeding season cannot be easily inferred from dive shape alone.

Long-distance movements of harbour seals (Phoca vitulina) from a seasonally ice-covered area, the St. Lawrence River estuary, Canada

2004 ◽  
Vol 82 (7) ◽  
pp. 1070-1081 ◽  
Author(s):  
Véronique Lesage ◽  
Mike O Hammill ◽  
Kit M Kovacs
Keyword(s):  
River Estuary ◽  
Distribution Patterns ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Adult Males ◽  
Long Distance ◽  
Adequate Food ◽  
Harbour Seals ◽  
Ice Conditions ◽  
St Lawrence River

Previous studies of harbour seal (Phoca vitulina L., 1758) movements indicate that this species is relatively sedentary throughout the year. However, few investigations have examined their movements and seasonal distribution patterns in ice-covered areas. This study used spatial analysis of ice data and movement data from harbour seals collected via satellite (n = 7) and VHF radiotelemetry (n = 15) to explore this species' spatial use patterns in a seasonally ice-covered region, the St. Lawrence River estuary, Canada. When solid ice formed within the bays of the estuary, four of the seven satellite-tagged animals (all adult males) left their summer haul-out areas, migrating 266 ± 202 km (range 65–520 km) to over-wintering sites. The seals exhibited preference for areas of light to intermediate ice conditions during the winter months; at least six of the seven seals occupied areas with lighter ice conditions than those that prevailed generally in the study area. Evidence of high abundance of potential prey for harbour seals in the estuary during winter suggests that reduced availability of adequate food resources is not the primary factor which influences the movement and distribution patterns of harbour seals. Movement patterns observed during the ice-free period concur with previously reported harbour seal behaviour; the seals remained near the coast (<6.1–11.0 km from shore) in shallow water areas (<50 m deep in 100% VHF and 90% SLTDRs (satellite-linked time-depth recorders)) and travelled only short distances (15–45 km) from capture sites. None of the VHF- or satellite-tagged seals crossed the 350 m deep Laurentian channel, which suggests that this deep body of water might represent a physical barrier to this coastal population.

scholarly journals Review on utilization and research on harbour seal (Phoca vitulina) in Iceland

2010 ◽  
Vol 8 ◽  
pp. 341 ◽  
Author(s):  
Erlingur Hauksson ◽  
Sólmundur T Einarsson
Keyword(s):  
Phoca Vitulina ◽  
Economic Resources ◽  
Harbour Seal ◽  
Legal Rights ◽  
Large Dataset ◽  
Harbour Seals ◽  
Seal Population ◽  
By Catch ◽  
Catch Statistics ◽  
Anisakid Nematodes

Harbour seals (Phoca vitulina) have been harvested in Iceland since the first settlers arrived in the 9th century. Pups were generally netted, clubbed and harpooned until 1875 when general use of guns for hunting began. Seal-hunting has been traditional amongst the farms legal rights. Seal hunting was an important supplement to other economic resources. Harbour seal skins, salted ordried, were exported and large dataset of catch statistics is available from trading logbooks since the late 19th century. In the early 20th century catch was about 6,000. In the ‘bounty’ period 1982 – 1989, maximum catches were of 4,000 animals with about 350 hunters participated; in 2006 catches were only about 100 animals with 18 hunters. After 1989 the population continued to decline even though catches decreased markedly. Unreported by-catch in fishing gear, hunt for local consumption and shooting of seals swimming in salmon rivers estuaries may have kept the total removal from the stock above sustainable levels. A considerable Icelandic knowledge base had been compiled about the biology of the harbour seal since the late 16th century, with the first written reference in 1588-1589. In the last decades, research on various aspects of its biology and monitoring have been intensified, with focus on abundance, distribution, diet and nematode infestation. The main results show that the Icelandic harbour seal population - has declined annually about 5% in the period 1980-2006, - was most abundant on the NW-coast, - feeds mainly on sand-eels and gadoids, - and was less infected with anisakid nematodes than grey seals. Seal watching, as a low-consumptive indirect utilization, may represent a new economical opportunity if properly regulated.

The influence of underwater data transmission sounds on the displacement behaviour of captive harbour seals (Phoca vitulina)

2006 ◽  
Vol 61 (1) ◽  
pp. 19-39 ◽  
Author(s):  
Ronald A. Kastelein ◽  
Sander van der Heul ◽  
Willem C. Verboom ◽  
Rob J.V. Triesscheijn ◽  
Nancy V. Jennings
Keyword(s):  
Data Transmission ◽  
Phoca Vitulina ◽  
Harbour Seals

Underwater acoustic displays and individual variation in male harbour seals, Phoca vitulina

1994 ◽  
Vol 48 (6) ◽  
pp. 1275-1283 ◽  
Author(s):  
Evelyn B. Hanggi ◽  
Ronald J. Schusterman
Keyword(s):  
Individual Variation ◽  
Phoca Vitulina ◽  
Underwater Acoustic ◽  
Harbour Seals
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