Editing Grey seal

{{Short description|Species of pinniped}}
{{other uses|Grey Seal (disambiguation)}}
{{Use dmy dates|date=January 2025}}
{{Use British English|date=December 2015}}
{{speciesbox
| name = Grey seal
| image = Donna Nook NNR - Grey Seal pupping and breeding season - 38804871202.jpg
| image_caption = Male
| image2 = Focas grises (Halichoerus grypus), playa de Horsey, Norfolk, Inglaterra, 2022-11-20, DD 11.jpg
| image2_caption = Female with pup
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Bowen, D. |date=2016 |title=''Halichoerus grypus'' |volume=2016 |page=e.T9660A45226042 |doi=10.2305/IUCN.UK.2016-1.RLTS.T9660A45226042.en |access-date=19 November 2021}}</ref>
| genus = Halichoerus
| parent_authority = [[Sven Nilsson (zoologist)|Nilsson]], 1820
| species = grypus
| authority = ([[Otto Fabricius|O. Fabricius]], 1791)
| range_map = Halichoerus grypus map.svg
| range_map_caption = Grey seal range<ref name="iucn status 19 November 2021" />
}}

The '''grey seal''' ('''''Halichoerus grypus''''') is a large [[pinniped|seal]] of the [[family (biology)|family]] [[Phocidae]], which are commonly referred to as "true seals" or "earless seals". The only species classified in the [[genus]] '''''Halichoerus''''', it is found on both shores of the North [[Atlantic Ocean]]. In [[Latin]], ''Halichoerus grypus'' means "hook-nosed sea pig". Its name is spelled '''gray seal''' in the [[United States]]; it is also known as '''Atlantic seal'''<ref name="sokolov1984">{{cite book|last=Sokolov|first=Vladimir|title=Пятиязычный словарь названий животных. Млекопитающие.|year=1984|place=Moscow}}</ref> and the '''horsehead seal'''.<ref name="sokolov1984"/><ref name=Mowat>{{cite book |last1=Mowat |first1=Farley |title=Sea of Slaughter |publisher=Atlantic Monthly Press Publishing |edition=First American |year=1984 |isbn=0871130130}}</ref>

==Taxonomy==
There are two recognized subspecies of this seal:<ref name=msw3>{{MSW3 Wozencraft | pages = | id = 14001036}}</ref>
{| class="wikitable "
|-
! Image !! Subspecies !!  Distribution
|-
|[[File:Two seals in the water.jpg|120px]]|| ''Halichoerus grypus grypus'' {{small|Fabricius, 1791}} || Baltic Sea
|-
|[[File:Farne Grey seal.jpg|120px]]|| ''Halichoerus grypus atlantica'' {{small|Nehring, 1886}}|| western North Atlantic stock (eastern Canada and the northeastern United States), the eastern North Atlantic stock (British Isles, Iceland, Norway, Denmark, the Faroe Islands, and Russia)<ref name="NOAA 2019">{{cite web | title=Gray Seal | website=NOAA | date=2019-07-08 | url=https://www.fisheries.noaa.gov/species/gray-seal | access-date=2021-01-05}}</ref>
|-
|}

The type specimen of ''H.&nbsp;g.&nbsp;grypus'' ([[University of Copenhagen Zoological Museum|Zoological Museum of Copenhagen]] specimen ZMUC M11-1525, caught in 1788 off the island of [[Amager]], Danish part of the [[Baltic Sea]]) was believed lost for many years, but was rediscovered in 2016, and a DNA test showed it belonged to a Baltic Sea specimen rather than from Greenland, as had previously been assumed (because it was first described in [[Otto Fabricius]]' book on the animals in Greenland: ''Fauna Groenlandica''). The name ''H.&nbsp;g.&nbsp;grypus'' was therefore transferred to the Baltic subspecies (replacing ''H.&nbsp;g.&nbsp;macrorhynchus''), and the name ''H.&nbsp;g.&nbsp;atlantica'' resurrected for the Atlantic subspecies.<ref>{{cite journal|last1=Olsen|first1=Morten Tange|last2=Galatius|first2=Anders|last3=Biard|first3=Vincent|last4=Gregersen|first4=Kristian|last5=Kinze|first5=Carl Christian|title=The forgotten type specimen of the grey seal [''Halichoerus grypus'' (Fabricius, 1791)] from the island of Amager, Denmark|journal=Zoological Journal of the Linnean Society|volume=178|issue=3|pages=713–720|date=April 2016|doi=10.1111/zoj.12426|doi-access=free}}</ref>

Molecular studies have indicated that the eastern and western Atlantic populations have been genetically distinct for at least one million years, and could potentially be considered separate subspecies.<ref name=Boskovic1996>{{cite journal | author = Boskovic, R.| year = 1996 | title = Geographic distribution of mitochondrial DNA haplotypes in grey seals (''Halichoerus grypus'') | journal = Canadian Journal of Zoology | volume = 74 | issue = 10 | pages = 1787–1796 | doi = 10.1139/z96-199| bibcode = 1996CaJZ...74.1787B |display-authors=etal}}</ref>

==Description==
[[File:Juvenilegreysealswimmingfarneislands.jpg|thumb|A juvenile grey seal swims in the Farne Islands, UK.]]
This is a fairly large seal, with bulls in the eastern Atlantic populations reaching {{convert|1.95|–|2.3|m|ftin|0|abbr=on}} long and weighing {{convert|170|-|310|kg|lb|abbr=on}}; the cows are much smaller, typically {{convert|1.6|–|1.95|m|ftin|0|abbr=on}} long and {{convert|100|–|190|kg|lb|abbr=on}} in weight.<ref name= FAO>{{cite book |last=Working Party on Marine Mammals |date=1978 |title=Mammals in the Seas, Volume 4 |url=https://books.google.com/books?id=j-Je25qovO8C&q=Halichoerus |location=Rome |publisher=Food & Agriculture Org. |page=257 |isbn=9251005141}}</ref> Individuals from the western Atlantic are often much larger, with males averaging up to {{convert|2.7|m|ftin|0|abbr=on}} and reaching a weight of as much as {{convert|400|kg|lb|abbr=on}}  and females averaging up to {{convert|2.05|m|ftin|0|abbr=on}} and sometimes weighing up to {{convert|250|kg|lb|abbr=on}}. Record-sized bull grey seals can reach about {{convert|3.3|m|ftin|0|abbr=on}} in length.<ref>{{cite book |last1=Naughton |first1=D. |year=2014 |title=The Natural History of Canadian Mammals: Opossums and Carnivores |publisher=University of Toronto Press |url=https://utorontopress.com/9781442622319/the-natural-history-of-canadian-mammals/}}</ref><ref>{{cite book |last1=Bjärvall |first1=A. |last2=Ullström |first2=S. |year=1986 |title=The mammals of Britain and Europe |location=London |publisher=Croom Helm |isbn=0709932685}}</ref> A common average weight in [[Great Britain]] was found to be about {{convert|233|kg|lb|abbr=on}} for males and {{convert|154.6|kg|lb|abbr=on}} for females whereas in [[Nova Scotia]], [[Canada]], adult males averaged {{convert|294.6|kg|lb|abbr=on}} and adult females averaged {{convert|224.5|kg|lb|abbr=on}}.<ref name= FAO/><ref>{{cite journal |last1=Lidgard |first1=D. C. |last2=Boness |first2=D. J. |last3=Bowen |first3=W. D. |year=2001 |url=https://repository.si.edu/handle/10088/343 |title=A novel mobile approach to investigating mating tactics in male grey seals (''Halichoerus grypus'') |journal=Journal of Zoology |volume=255 |issue=3 |pages=313–320|doi=10.1017/S0952836901001418 |hdl=10088/343 |url-access=subscription }}</ref><ref>{{cite journal | url=https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.1995.tb02730.x | doi=10.1111/j.1469-7998.1995.tb02730.x | title=Mass transfer during lactation of an ice-breeding pinniped, the grey seal (''Halichoerus grypus''), in Nova Scotia, Canada | year=1995 | last1=Baker | first1=S. R. | last2=Barrette | first2=C. | last3=Hammill | first3=M. O. | journal=Journal of Zoology | volume=236 | issue=4 | pages=531–542 | url-access=subscription }}</ref> It is distinguished from the smaller [[harbor seal]] by its straight head profile, nostrils set well apart, and fewer spots on its body.<ref name="How to identify British seals">{{cite web|title=How to identify British seals|url=http://www.discoverwildlife.com/british-wildlife/how-identify-british-seals|publisher=BBC Wildlife|access-date=23 October 2015|archive-date=4 September 2018|archive-url=https://web.archive.org/web/20180904143757/http://www.discoverwildlife.com/british-wildlife/how-identify-british-seals|url-status=dead}}</ref><ref name="Get the lowdown on seals">{{cite web|last1=Middleton|first1=Kevin|title=Get the lowdown on seals|url=http://www.rspb.org.uk/community/wildlife/b/notesonnature/archive/2012/08/17/get-the-lowdown-on-seals.aspx|publisher=[[RSPB]]|access-date=23 October 2015}}</ref> Wintering [[hooded seal]]s can be confused with grey seals as they are about the same size and somewhat share a large-nosed look but the hooded has a paler base colour and usually evidences a stronger spotting.<ref>{{cite book |editor-last1=Perrin |editor-first1=W. F. |editor-last2=Würsig |editor-first2=B. |editor-last3=Thewissen |editor-first3=J. G. M. |year=2009 |url=https://books.google.com/books?id=2rkHQpToi9sC&q=%22gray%20seal%22%20OR%20%22grey%20seal%22 |title=Encyclopedia of marine mammals |publisher=Academic Press |isbn=9780080919935 |chapter=Grey Seal (''Halichoerus gryphus'') |last1=Hall |first1=Ailsa |last2=Thompson |first2=David |pages=500–502}}</ref> Grey seals lack external ear flaps and characteristically have large snouts.<ref>{{Cite book|title = Marine Science: The Dynamic Ocean|author = Schuster, Marreno|author2 = Glen, Megan|publisher = Pearson|year = 2011|isbn = 978-0-13-317063-4|location = US Satellite Laboratory|pages = 107}}</ref> Bull greys have larger noses and a less curved profile than harbor seal bulls. Males are generally darker than females, with lighter patches and often scarring around the neck. Females are silver grey to brown with dark patches.

==Ecology and distribution==
[[File:Grey seals, Stiffkey, Norfolk.jpg|thumb|Group of grey seals on sands at [[Stiffkey]], Norfolk]]
[[File:Gråsäl (Halichoerus grypus) - Ystad -2018.jpg|thumb|A dead grey seal that drowned after being caught in a [[fishing net]] in [[Ystad]]]]

In the [[United Kingdom]] and [[Ireland]], the grey seal breeds in several colonies on and around the coasts.  Notably large colonies are at [[Blakeney Point]] in [[Norfolk]], [[Donna Nook]] in [[Lincolnshire]], the [[Farne Islands]] off the [[Northumberland Coast National Landscape|Northumberland Coast]] (about 6,000 animals), [[Orkney]] and [[North Rona]].<ref name=Stewartetal2014>{{cite journal | author = Stewart, J.E.| year = 2014 | title = Finescale ecological niche modeling provides evidence that lactating grey seals (''Halichoerus grypus'') prefer access to fresh water in order to drink | journal = Marine Mammal Science | volume = 30 | issue = 4 | pages = 1456–1472 | doi = 10.1111/mms.12126| bibcode = 2014MMamS..30.1456S |display-authors=etal| url = http://dro.dur.ac.uk/16508/1/16508.pdf }}</ref> off the north coast of [[Scotland]], [[Lambay Island]] off the coast of [[Dublin]] in the [[Irish Sea]], the [[Isle of Man]], [[Ramsey Island]] (off the coast of [[Pembrokeshire]], [[Wales]]). In the [[German Bight]], colonies exist off the islands [[Sylt]], [[Amrum]] and on [[Heligoland]].<ref>{{cite web |url=http://www.nordseewolf.de/magazin/13-01-2010/kegelrobben-geburtenrekord-auf-helgoland/ |title=Kegelrobben-Geburtenrekord auf Helgoland |language=de |work=Nordseewolf Magazin |date=13 January 2010 |first=Melanie |last=Hahn |access-date=20 November 2011 |archive-url=https://web.archive.org/web/20160331005018/http://www.nordseewolf.de/magazin/13-01-2010/kegelrobben-geburtenrekord-auf-helgoland/ |archive-date=31 March 2016 |url-status=dead }}</ref>

In the western North Atlantic, the grey seal is typically found in large numbers in the coastal waters of the [[The Maritimes|Maritime Provinces]] of [[Canada]] and south to [[Nantucket]] in the United States. In coastal Canada, it is typically seen in areas such as the [[Gulf of St. Lawrence]], [[Newfoundland (island)|Newfoundland]], [[Prince Edward Island]], and [[Quebec]]. The largest colony in the world is at [[Sable Island]], [[Nova Scotia]]. In the United States, it is found year-round off the coast of [[New England]], in particular [[Maine]] and [[Massachusetts]]. It has also been observed in the waters around [[Connecticut]], [[New York (state)|New York]] and [[Rhode Island]]. Archaeological evidence confirms grey seals in southern [[New England]] with remains found on [[Block Island]], [[Martha's Vineyard]], and near the mouth of the [[Quinnipiac River]] in [[New Haven, Connecticut]].<ref>{{cite journal |title=Gray Seal Remains from Southern New England Archeological Sites |author=Waters, Joseph H. |journal=Journal of Mammalogy |volume=48 |issue=1 |date=February 1967 |pages=139–141 |doi=10.2307/1378182 |jstor=137818}}</ref> Its natural range now extends much further south than previously thought, with confirmed sightings off of [[North Carolina]]. Also, there is a report by [[Farley Mowat]] of historic breeding colonies as far south as [[Cape Hatteras]], North Carolina.<ref name=Mowat/>

An isolated population exists in the [[Baltic Sea]],<ref name="iucn status 19 November 2021" /> forming the ''H. grypus balticus'' subspecies.

Besides these very large colonies, many much smaller ones exist, some of which are well-known tourist attractions, despite their small size. Such colonies include one on the [[The Carracks|Carrack rocks]], [[Cornwall]].

During the winter months, grey seals can be seen [[hauling-out|hauled out]] on rocks, islands, and shoals not far from shore, occasionally coming ashore to rest. In the spring, recently weaned pups and yearlings occasionally strand on beaches after becoming separated from their group.

Grey seals are vulnerable to typical predators for a pinniped mammal; their primary predator would be the [[orca]] or killer whale, but certain large species of sharks are known to prey on grey seals in [[North America]]n waters, particularly [[great white shark]]s and [[bull sharks]] but also, upon evidence, additionally [[Greenland shark]]s. Some grey seal carcasses have washed ashore with visible "cookie cutter" bite marks, a telltale sign of attack by a Greenland shark (also called the sleeper shark).<ref>{{cite journal | url=https://cdnsciencepub.com/doi/abs/10.1139/f83-040 | doi=10.1139/f83-040 | title=Predation by Sharks on the Grey Seal (Halichoerus grypus) in Eastern Canada | year=1983 | last1=Brodie | first1=Paul | last2=Beck | first2=Brian | journal=Canadian Journal of Fisheries and Aquatic Sciences | volume=40 | issue=3 | pages=267–271 | bibcode=1983CJFAS..40..267B | url-access=subscription }}</ref><ref>{{cite journal |last1=Lucas |first1=Z. N. |last2=Natanson |first2=L. J. |year=2010 |url=https://ojs.library.dal.ca/nsis/article/view/3987 |title=Two shark species involved in predation on seals at Sable Island, Nova Scotia, Canada |journal=Proceedings of the Nova Scotian Institute of Science |volume=45 |issue=2 |pages=64–88 |doi=10.15273/pnsis.v45i2.3987|doi-broken-date=1 November 2024 }}</ref> In the waters of [[Great Britain]], grey seals are a fairly common prey species for [[killer whale]]s.<ref>{{cite journal |last1=Weir |first1=C. R. |year=2002 |title=Killer whales (''Orcinus orca'') in UK waters |journal=British Wildlife |volume=14 |issue=2 |pages=106–108 |url=https://www.researchgate.net/publication/237714054}}</ref><ref>{{cite journal |last1=Bloc |first1=D. |last2=Lockyer |first2=C. |year=1988 |title=Killer whales (''Orcinus area'') in Faroese waters |journal=Rit Fiskideildar}}</ref> In the Baltic, grey seal pups are prey for [[White-tailed eagle]]s, and [[Great black-backed gull|Great black-backed gulls]].<ref name="iucn status 19 November 2021" />

==Diet==
[[File:Grey seal food web.png|thumb|left| {{center|Grey seal [[food web]] in the [[Baltic Sea]]<ref>{{cite journal |last1=Karlson |first1=A.M. |last2=Gorokhova |first2=E. |last3=Gårdmark |first3=A. |last4=Pekcan-Hekim |first4=Z. |last5=Casini |first5=M. |last6=Albertsson |first6=J. |last7=Sundelin |first7=B. |last8=Karlsson |first8=O. |last9=Bergström |first9=L. |year=2020 |title=Linking consumer physiological status to food-web structure and prey food value in the Baltic Sea |journal=Ambio |volume=49 |issue=2 |pages=391–406 |doi=10.1007/s13280-019-01201-1|pmid=31168701 |pmc=6965491 |bibcode=2020Ambio..49..391K }}</ref>}}]]
[[File:Monitoring grey seals in Pembrokeshire, Wales.webm|thumb|A short video on monitoring and conservation of grey seals at Skomer Island]]
[[File:Grey seal feeding Skansen.jpg|thumb|Captive grey seal being fed, showing snout shape]]

The grey seal feeds on a wide variety of [[fish]], mostly [[benthic]] or [[demersal]] species, taken at depths down to 70&nbsp;m (230&nbsp;ft) or more. [[Sand eel]]s (''Ammodytes spp'') are important in its diet in many localities. [[Cod]] and other [[gadidae|gadids]], [[flatfish]], [[herring]],<ref>{{cite web|url=http://www.ices.dk/sites/pub/CM%20Doccuments/CM-2007/C/C1207.pdf|title=How does hunting grey seals (Halichoerus grypus) on Bothnian Bay spring ice influence the structure of seal and fish stocks? |first=Olavi |last=Stenman |year=2007 |publisher=[[International Council for the Exploration of the Sea]] |access-date=23 January 2017 |quote=Analysis of fish otolithes and other hard particles in the alimentary tract showed clearly that the herring (''Clupea harengus'') was the most important item of prey.}}</ref> [[wrasse]]<ref>{{cite journal |last1= Ridoux|first1=Vincent|last2=Spitz |first2= J.|last3= Vincent|first3=Cecile  |last4=Walton |first4=M. J. |date= 2007|title=Grey seal diet at the southern limit of its European distribution: combining dietary analyses and fatty acid profiles |url=http://archimer.ifremer.fr/doc/2007/publication-3573.pdf |journal= Journal of the Marine Biological Association of the United Kingdom|volume= 87|issue=1 |pages=255–264 |doi=10.1017/S002531540705463X |bibcode=2007JMBUK..87..255R |s2cid=55465507|access-date=24 January 2017 }}</ref> and [[Skate (fish)|skate]]s<ref>{{cite book|first1=Claude |last1=Savenkoff |first2=Lyne |last2=Morissette |first3=Martin |last3=Castonguay |first4=Douglas P. |last4=Swain |first5=Mike O. |last5=Hammill |first6=Denis |last6=Chabot |first7=J. Mark |last7=Hanson|title=Ecosystem Ecology Research Trends |chapter=Interactions between Marine Mammals and Fisheries: Implications for Cod Recovery |editor1-first=Junying |editor1-last=Chen |editor2-first=Chuguang |editor2-last=Guo|publisher=Nova Science Publishers |year=2008 |isbn=978-1-60456-183-8 |page=130 |chapter-url=https://books.google.com/books?id=AH9JghsCN0gC&pg=PA130}}</ref> are also important locally. However, it is clear that the grey seal will eat whatever is available, including [[octopus]]<ref>{{cite web|url=http://www.bbc.co.uk/wales/nature/sites/species/mammals/grey_seals.shtml|title=Grey seal |work=Wales Nature & Outdoors |publisher=[[BBC Wales]] |date=25 February 2011 |access-date=20 November 2011}}</ref> and [[lobster]]s.<ref>{{cite web|url=http://www.askaboutireland.ie/reading-room/environment-geography/flora-fauna/flora-and-fauna-of-wexfor/fauna-of-the-wexford-slob/the-grey-seal/ |title=The Grey Seal |work=Ask about Ireland |access-date=20 November 2011}}</ref> The average daily food requirement is estimated to be 5&nbsp;kg (11&nbsp;lb), though the seal does not feed every day and it fasts during the breeding season.

Recent observations and studies from Scotland, The Netherlands, and Germany show that grey seals will also prey and feed on large animals like [[harbour seal]]s and [[harbour porpoise]]s.<ref>{{cite journal|title=Exposing the grey seal as a major predator of harbour porpoises |first1=Mardik F. |last1=Leopold |first2=Lineke |last2=Begeman |first3=Judith D. L. |last3=van Bleijswijk |first4=Lonneke L. |last4=IJsseldijk |first5=Harry J. |last5=Witte |first6=Andrea |last6=Gröne |journal=[[Proceedings of the Royal Society]] |volume=282 |issue=1798|pages=20142429 |year=2014|doi=10.1098/rspb.2014.2429 |pmid=25429021 |pmc=4262184 }}</ref><ref>{{cite journal|title=Grey seal (''Halichoerus grypus'') predation on harbour seals (''Phoca vitulina'') on the island of Helgoland, Germany |first1=Abbo |last1=van Neer |first2=Lasse F. |last2=Jensen |first3=Ursula |last3=Siebert |journal=[[Journal of Sea Research]] |volume=97 |doi=10.1016/j.seares.2014.11.006 |pages=1–4|year=2015 |bibcode=2015JSR....97....1V }}</ref><ref>{{cite news |title=Kegelrobben mit großem Appetit auf Schweinswale |trans-title=Grey seals with a great appetite for porpoises |language=de |first=Angelika |last=Hillmer |work=[[Hamburger Abendblatt]] |date=16 February 2015}}</ref> In 2014, a male grey seal in the [[North Sea]] was documented and filmed killing and cannibalising 11 pups of his own species over the course of a week. Similar wounds on the carcasses of pups found elsewhere in the region suggest that [[cannibalism]] and [[infanticide]] may not be uncommon in grey seals. Male grey seals may engage in such behaviour potentially as a way of increasing reproductive success through access to easy prey without leaving prime territory.<ref>{{cite web|url=https://www.newscientist.com/article/2077441-first-video-footage-of-seal-drowning-and-eating-a-pup/ |title=First video footage of seal drowning and eating a pup |website=New Scientist |date=15 February 2016 |last1=Gabbatiss |first1=Josh}}</ref><ref>{{cite journal |last1=Bishop |first1=A. M. |title=Cannibalism by a male grey seal (Halichoerus grypus) in the North Sea Cannibalism by a male grey seal (Halichoerus grypus) in the North Sea |journal=Aquatic Mammals |date=2016 |volume=42 |issue=2 |pages=137–143 |doi=10.1578/AM.42.2.2016.137 |url=https://www.aquaticmammalsjournal.org/cannibalism-by-a-male-grey-seal-halichoerus-grypus-in-the-north-sea/|url-access=subscription }}</ref>

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==Communication==
While it was originally understood that marine mammals communicate vocally, new research conducted by researchers at Monash University shows that grey seals clap their flippers as another form of communication. They clap their flippers underwater to deter a predator from attacking. If done during the mating season, the clapping can be used as a way to find a potential mate. The Monash researchers point out that seals are typically known for clapping, so this behaviour may not be a surprise, but the clapping we know typically occurs in captivity. Clapping seals are associated with aquariums and zoos, but were never observed in the wild for this behaviour. They were astonished at how loud these marine mammals were able to clap underwater, but it is logical for the reasons they do this.<ref name="sciencedaily.com">{{Cite web|url=https://www.sciencedaily.com/releases/2020/02/200203104510.htm|title=Grey seals discovered clapping underwater to communicate|website=ScienceDaily|accessdate=19 March 2021}}</ref>

==Reproduction==
[[File:GreySealMating.jpg|thumb|Cow (l) and bull (r) grey seals mating, [[Donna Nook]], Lincolnshire, U.K.]]
Grey seals are capital breeders; they forage to build up stored blubber, which is utilised when they are breeding and weaning their pups, as they do not forage for food at this time. They give birth to a single pup every year, with females' reproductive years beginning as early as 4 years old and extending up to 30 years of age. All parental care is provided by the female. During breeding, males do not provide parental care but they defend females against other males for mating.<ref>{{Cite journal|last1=Bubac|first1=Christine M.|last2=Coltman|first2=David W.|last3=Don Bowen|first3=W.|last4=Lidgard|first4=Damian C.|last5=Lang|first5=Shelley L. C.|last6=den Heyer|first6=Cornelia E.|date=June 2018|title=Repeatability and reproductive consequences of boldness in female gray seals|journal=Behavioral Ecology and Sociobiology|volume=72|issue=6|page=100 |doi=10.1007/s00265-018-2515-5|bibcode=2018BEcoS..72..100B |s2cid=46975859|issn=0340-5443}}</ref> The pups are born at around the mass of 14&nbsp;kg.<ref name="BBC Earth 2014">{{cite web|url=http://www.bbc.com/earth/story/20141009-and-they-called-it-pupping-love|title=Autumn spectacle: grey seal colonies|date=10 October 2014|publisher=BBC Earth|access-date=3 January 2015}}</ref> They are born in autumn (September to December) in the eastern Atlantic and in winter (January to February) in the west, with a dense, soft silky white fur; at first small, they rapidly fatten up on their mothers' extremely fat-rich milk. The milk can consist of up to 60% fat.<ref name="BBC Earth 2014" /> Grey seal pups are precocial, with mothers returning to the sea to forage once pups are weaned. Pups also undergo a post-weaning fast before leaving the land and learning to swim.<ref>{{Cite journal|last1=Bowen|first1=William D.|last2=Heyer|first2=Cornelia E. den|last3=McMillan|first3=Jim I.|last4=Iverson|first4=Sara J.|date=2015-04-01|title=Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals| journal=Ecology and Evolution|language=en|volume=5|issue=7|pages=1412–1424|doi=10.1002/ece3.1450|issn=2045-7758|pmc=4395171|pmid=25897381|bibcode=2015EcoEv...5.1412B }}</ref> Within a month or so they shed the pup fur, grow dense waterproof adult fur, and leave for the sea to learn to fish for themselves. In recent years, the number of grey seals has been on the rise in the west and the U.S.<ref>{{cite news |last1=Bidggod |first1=Jess |date=16 August 2013 |url=https://www.nytimes.com/2013/08/17/us/thriving-in-cape-cods-waters-gray-seals-draw-fans-and-foes.html |title=Thriving in Cape Cod's Waters, Gray Seals Draw Fans and Foes |work=The New York Times}}</ref> and [[Canada]]<ref>{{cite news |url=https://www.cbc.ca/news/canada/newfoundland-labrador/plan-to-cull-70-000-grey-seals-gets-senate-panel-s-approval-1.1221876 |title=Plan to cull 70,000 grey seals gets Senate panel's approval |location=Newfoundland & Labrador |work=CBC News |date=23 October 2012}}</ref> there have been calls for a seal cull.
[[File:Juvenile Grey Seal.jpg|thumb|Seal pup a few days after birth]]

Seal pup first-year survival rates are estimated to vary from 80 to 85%<ref>{{Cite journal | doi=10.1111/j.1365-2656.2001.00468.x|title = Factors affecting first-year survival in grey seals and their implications for life history strategy| journal=Journal of Animal Ecology| volume=70| pages=138–149|year = 2008|last1 = Ailsa j|first1 = Hall| last2=Bernie j| first2=Mcconnell| last3=Richard j| first3=Barker| doi-access=free}}</ref><ref>{{cite journal |url=https://www.researchgate.net/publication/229788805 |doi=10.1111/j.1469-7998.1984.tb06042.x|title=Mortality and morbidity in Grey seal pups (Halichoerus grypus). Studies on its causes, effects on the environment, the nature and sources of infectious agents, and the immunological status of pups |year=1984 |last1=Baker |first1=J. R. |journal=Journal of Zoology |volume=203 |pages=23–48 }}</ref> to below 50%<ref name="friendsofhorseyseals.co.uk">{{Cite web|url=https://www.friendsofhorseyseals.co.uk/|title=Homepage|website=Friends of Horsey Seals|accessdate=19 March 2021}}</ref> depending on location and conditions. Starvation, due to difficulties in learning to feed, appears to be the main cause of pup death.<ref name="friendsofhorseyseals.co.uk"/>

Male grey seals engage in aggressive sexual behaviour, which can lead to severe injuries and even death for the female. Sometimes they will also target females from other seal species.<ref>{{cite journal |last1=Wilson |first1=Susan C. |title=Attempted Mating between a Male Grey Seal and Female Harbor Seals |journal=Journal of Mammalogy |date=1975 |volume=56 |issue=2 |pages=531–534|doi=10.2307/1379389 |jstor=1379389 }}</ref> In the [[North Sea]], multiple cases were recorded of pregnant harbour seals dying as a result of [[forced copulation]] with male grey seals.<ref>{{cite journal |last1=Rohner |first1=Simon |title=Male grey seal commits fatal sexual interaction with adult female harbour seals in the German Wadden Sea |journal=Scientific Reports |date=2020 |volume=10 |issue=1 |page=13679 |doi=10.1038/s41598-020-69986-w |pmid=32792537 |pmc=7426965 }}</ref> 

==Status==
After near extirpation from hunting grey seals for oil, meat, and skins in the United States, sightings began to increase in the late 1980s. Bounties were paid on all kinds of seals up until 1945 in [[Maine]] and 1962 in [[Massachusetts]].<ref name=Lelli>{{cite journal |title=Seal Bounties in Maine and Massachusetts, 1888 to 1962 |author=Barbara Lelli |author2=David E. Harris |author3=AbouEl-Makarim Aboueissa |name-list-style=amp |journal=Northeastern Naturalist |volume=16 |issue=2 |pages=239–254 |year=2009 |doi=10.1656/045.016.0206|s2cid=85652019 }}</ref> One year after Congress passed the 1972 [[Marine Mammal Protection Act of 1972|Marine Mammal Protection Act]] preventing the harming or harassing of seals, a survey of the entire Maine coast found only 30 grey seals.<ref name=Lelli/> At first grey seal populations increased slowly but then rebounded from islands off Maine to [[Monomoy Island]] and [[Nantucket Island]] off of southern [[Cape Cod]]. The southernmost breeding colony was established on [[Muskeget Island]] with five pups born in 1988 and over 2,000 counted in 2008.<ref name=Wood/> According to a genetics study, the United States population has formed as a result of recolonisation by Canadian seals.<ref name=Wood>{{cite journal |title=The genetics of recolonization: an analysis of the stock structure of grey seals (Halichoerus grypus) in the northwest Atlantic |journal=Canadian Journal of Zoology |year=2011 |volume=89 |issue=6 |pages=490–497 |doi=10.1139/z11-012|last1=Wood |first1=S.A. |last2=Frasier |first2=T.R. |last3=McLeod |first3=B.A. |last4=Gilbert |first4=J.R. |last5=White |first5=B.N. |last6=Bowen |first6=W.D. |last7=Hammill |first7=M.O. |last8=Waring |first8=G.T. |last9=Brault |first9=S. |bibcode=2011CaJZ...89..490W }}</ref> By 2009, thousands of grey seals had taken up residence on or near popular swimming beaches on outer Cape Cod, resulting in sightings of [[great white shark]]s drawn close to shore to hunt the seals.<ref>{{cite news |url=http://www.boston.com/news/science/articles/2009/10/03/gray_seals_haul_out_to_new_england_waters_again/ |title=Once again, coastal waters getting seals' approval |work=[[The Boston Globe]] |date=3 October 2009 |last1=Daley |first1=Beth}}</ref> A count of 15,756 grey seals in southeastern Massachusetts coastal waters was made in 2011 by the [[National Marine Fisheries Service]].<ref>{{cite report |title=Gray Seal (Halichoerus grypus grypus): Western North Atlantic Stock |date=April 2014 |publisher=NMFS, NOAA |pages=342–350 |url=http://www.nmfs.noaa.gov/pr/sars/2013/ao2013_grayseal-wna.pdf |access-date=2015-06-15 }}</ref> Grey seals are being seen increasingly in [[New York (state)|New York]] and [[New Jersey]] waters, and it is expected that they will establish colonies further south.

Human noise pollution continues to affect marine-life communication but remains an understudied facet of marine conservation efforts. In more recent years, the potential negative effect of human noise has been highlighted with the discovery of seals using clapping as a form of communication.<ref name="sciencedaily.com"/>

In the UK seals are protected under the [[Conservation of Seals Act 1970]]; however, it does not apply to [[Northern Ireland]]. In the UK there have also been calls for a cull from some fishermen claiming that stocks have declined due to the seals.

The population in the [[Baltic Sea]] increased about 8% per year between 1990 and the mid-2000s, with the numbers becoming stagnant since 2005. As of 2011, hunting grey seals is legal in [[Sweden]] and [[Finland]], with 50% of the quota being used. Other [[Human impact on the environment|anthropogenic]] causes of death include drowning in fishing gear.<ref>{{cite web |title=Health Assessment in the Baltic grey seal (''Halichoerus grypus'') |work=HELCOM Indicator Fact Sheets 2011 |first1=Britt-Marie |last1=Bäcklin |first2=Charlotta |last2=Moraeus |first3=Mervi |last3=Kunnasranta |first4=Marja |last4=Isomursu |publisher=[[HELCOM]] |date=2 September 2011 |url=http://www.helcom.fi/BSAP_assessment/ifs/ifs2011/en_GB/BalticGreySeal |url-status=dead |archive-url=https://web.archive.org/web/20111103030646/http://www.helcom.fi/BSAP_assessment/ifs/ifs2011/en_GB/BalticGreySeal/ |archive-date=3 November 2011 }}</ref>

===Captivity===
Grey seals have proved amenable to life in captivity{{Citation needed|date=April 2024}} and are commonly found as zoo animals around their native range, particularly in Europe. Traditionally they were popular circus animals and often used in performances such as balancing and display acts.

==References==
{{Reflist}}

==External links==
{{Commons}}
{{Wikispecies|Halichoerus grypus}}
{{Portal|Marine life|Mammals}}
*[http://www.bbc.co.uk/wales/nature/mediaexplorer/?theme_group=species&theme=mammals&set=seal BBC Wales Nature: Grey Seal video clips]
*[http://www.pinnipeds.org/seal-information/species-information-pages/the-phocid-seals/grey-seal Grey Seals on pinnipeds.org]
*[https://web.archive.org/web/20060211161126/http://www.arkive.org/species/ARK/mammals/Halichoerus_grypus/ ARKive – images and movies of the grey seal from Atlantic ''(Halichoerus grypus)'']
*[http://www.greyseal.net Grey Seal Conservation Society (GSCS)]
*[https://www.youtube.com/watch?v=2HI1kB3n5F4 The first filming of the grey seal in Eastern Crimea, Ukraine]
* {{sealifephotos|137080}}

{{Carnivora|C1.}}
{{Pan-Pinnipedia|P.|state=autocollapse}}
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[[Category:Phocins]]
[[Category:Pinnipeds of the Arctic Ocean]]
[[Category:Pinnipeds of Europe]]
[[Category:Fauna of the Baltic Sea]]
[[Category:Fauna of the North Sea]]
[[Category:Fauna of Scandinavia]]
[[Category:Mammals of Iceland]]
[[Category:Mammals described in 1791|Grey seal]]
[[Category:Pinnipeds of North America]]
[[Category:Fauna of the Holarctic realm]]
[[Category:Habitats Directive species]]