View source for Monk seal

{{Short description|Tribe of earless seals}}
{{Automatic taxobox
| name = Monk seals
| image =  Anim2601 (33910324514).jpg
| image2 = Monachus monachus DSC 0274.jpg
| image2_caption = Hawaiian monk seal (top) and Mediterranean monk seal (bottom)
| taxon = Monachini
| authority = [[Victor Blanchard Scheffer|Scheffer]], 1958
| subdivision_ranks = Species
| subdivision = 
''[[Mediterranean monk seal|Monachus monachus]]''<br/>
''[[Hawaiian monk seal|Neomonachus schauinslandi]]''<br/>
†''[[Caribbean monk seal|Neomonachus tropicalis]]''
| range_map = Hawaiian Monk Seal area.png
| range_map_caption = Hawaiian monk seal range
| range_map2 = Monachus monachus distribution.png
| range_map2_caption = Mediterranean monk seal range
}}

'''Monk seals''' are [[earless seal]]s of the [[tribe (biology)|tribe]] '''Monachini'''. They are the only earless seals found in tropical climates. The two [[genus|genera]] of monk seals, ''Monachus'' and ''Neomonachus'', comprise three species: the [[Mediterranean monk seal]], ''Monachus monachus''; the [[Hawaiian monk seal]], ''Neomonachus schauinslandi''; and the [[Caribbean monk seal]], ''Neomonachus tropicalis'', which became extinct in the 20th century. The two surviving species are now rare and in imminent danger of extinction. All three monk seal species were classified in genus ''Monachus'' until 2014, when the Caribbean and Hawaiian species were placed into a new genus, ''Neomonachus''.

Monk seals have a slender body and are agile. They have a broad, flat snout with nostrils on the top. Monk seals are [[polygyny in animals|polygynous]], and group together in [[Harem (zoology)|harems]]. They feed mainly on [[bony fish]] and [[cephalopod]]s, but they are opportunistic. The skin is covered in small hairs, which are generally black in males and brown or dark gray in females. Monk seals are found in the [[Hawaiian archipelago]], certain areas in the east Atlantic and Mediterranean Sea (such as [[Ras Nouadhibou|Cabo Blanco]] and [[Gyaros]] island), and formerly in the tropical areas of the west Atlantic Ocean.

All species experienced overhunting by [[seal hunters|sealers]]. The Hawaiian monk seal experienced population drops in the 19th century and during [[World War II]], and the Caribbean monk seal was exploited since the 1500s until the 1850s, when populations were too low to hunt commercially. The Mediterranean monk seal has experienced both commercial and illegal hunting since the [[Middle Ages]] and has always been threatened with eradication by fishermen. As of 2022, it is estimated and agreed upon that not more than 600–700 Mediterranean monk seals remain, concentrated primarily along the coasts of Turkey, Cyprus, and Greece. The Hawaiian monk seal appears to be faring somewhat better; the 2021 monk seal population count by the National Oceanic and Atmospheric Association (NOAA) numbered 1,570 animals, an encouraging increase from 1,453 seals in 2019. This marked the first time the Hawaiian monk seal's population exceeded 1,500 in 20 years; their numbers have been recorded and observed to increase approximately 2% each year from 2013 to 2021.<ref>{{cite web|url=https://www.fisheries.noaa.gov/feature-story/hawaiian-monk-seal-population-surpasses-1500 |title=Hawaiian Monk Seal Population Surpasses 1,500! |date=3 May 2022 |access-date=20 December 2022 |publisher=NOAA Fisheries |author=Pacific Islands Fisheries Science Center}}</ref> Some of this successful growth is undoubtedly due to numerous rescue-and-release operations and the relocating of weaned pups to quieter beaches (with lower numbers of predatory sharks and less human interactions), enabling  more seals to mature naturally and safely.<ref>{{cite web|url=https://www.fisheries.noaa.gov/pacific-islands/endangered-species-conservation/hawaiian-monk-seal-updates#more-information |title= Monk Seal Pup Koalani to Be Relocated to Remote Beach Away from People After Weaning |date=19 August 2022 |access-date=20 December 2022 |publisher=NOAA Fisheries |author=Pacific Islands Fisheries Science Center}}</ref>

==Etymology==
The name "monk seal" (German ''Münchs-Robbe'') was suggested by naturalist [[Johann Hermann]], who claimed that the seal was popularly known as ''moine'' (French for "monk") in [[Marseille]], and speculated that the seal looks from behind like a monk wearing a cape and hood.<ref>[https://monachus-guardian.org/wordpress/2013/12/02/the-curious-case-of-the-monk-seal-why-monk/ The Curious Case of the Monk Seal — Why 'Monk'?]</ref>

==Taxonomy and evolution==
{{cladogram|align=left|title=
|clade=
{{clade
|style=font-size:75%;line-height:50%;width:330px;
|label1=[[Phocidae]]
      |1={{clade
         |1={{clade
            |1={{clade
               |1={{clade
                  |1={{clade
                     |1={{clade
                        |1={{clade
                           |1={{clade
                              |1={{clade
                                 |1={{clade
                                    |1=[[ringed seal]]
                                    |2=[[Baikal seal]]
                                    }}
                                 |2=[[Caspian seal]]
                                 }}
                              |2={{clade
                                 |1=[[spotted seal]]
                                 |2=[[harbor seal]]
                                 }}
                              }}
                           |2=[[grey seal]]
                           }}
                        |2={{clade
                           |1=[[ribbon seal]]
                           |2=[[harp seal]]
                           }}
                        }}
                     |2=[[hooded seal]]
                     }}
                  |2=[[bearded seal]]
                  }}
               |2={{clade
                  |1={{clade
                     |1={{clade
                        |1=[[Weddell seal]]
                        |2=[[leopard seal]]
                        }}
                     |2=[[crabeater seal]]
                     }}
                  |2=[[Ross seal]]
                  }}
               }}
            |2={{clade
               |1=[[southern elephant seal]]
               |2=[[northern elephant seal]]
               }}
            }}
         |2={{clade
            |1='''Mediterranean monk seal'''
            |2={{clade
            |1='''Hawaiian monk seal'''
            |2='''†Caribbean monk seal'''
              }}
            }}
         }}
}}|caption=Phylogenetic relations between monk seals and other earless seals <ref name=Berta2012/>}}
Monk seals are [[earless seal]]s (true seals) of the [[tribe (biology)|tribe]] Monachini.<ref name = MSW3>{{MSW3 Carnivora | id = 14001050 | page = 598 | heading = Genus ''Monachus''}}</ref> The tribe was first conceived by [[Victor Blanchard Scheffer]] in his 1958 book ''Seals, Sea Lions, and Walruses: A Review of the Pinnipedia''.<ref>{{cite book|url={{Google books|plainurl=yes|id=tG2mAAAAIAAJ|page=47}}|first=Victor B.|last=Scheffer|year=1958 |title=Seals, Sea Lions, and Walruses: A Review of the Pinnipedia|publisher=Stanford University Press|location=Stanford, California|isbn=978-0-8047-0544-8|page=47}}</ref> The two genera of monk seals, ''Monachus'' and ''Neomonachus'', comprise three species: the Mediterranean monk seal (''Monachus monachus''), the Hawaiian monk seal (''Neomonachus schauinslandi''), and the Caribbean monk seal (''N. tropicalis''), which became extinct in the 20th century. All three monk seal species were classified in genus ''Monachus'' until 2014, when comparison of the species' mitochondrial [[cytochrome b]] [[mitochondrial DNA|DNA]] sequences led biologists to place the Caribbean and Hawaiian species in a new genus, ''Neomonachus''.<ref>{{cite journal|url=https://zookeys.pensoft.net/articles.php?id=3807|first1=Dirk-Martin|last1=Scheel|first2=Graham J.|last2= Slater|first3=Sergios-Orestis|last3=Kolokotronis|first4=Charles W.|last4=Potter|first5=David S.|last5=Rotstein|first6=Kyriakos|last6=Tsangaras|first7=Alex D.|last7=Greenwood|first8=Kristofer M.|last8=Helgen|year=2014|title= Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology|journal=ZooKeys|issue=409|pages=1–33|doi=10.3897/zookeys.409.6244|pmid=24899841|pmc=4042687|doi-access=free}}</ref><ref>{{cite web| last = Jemison | first = M. | title = Too valuable to lose: Extinct relative reveals rarity of last two remaining monk seal species| work = Smithsonian Science website | publisher = [[Smithsonian Institution]] | date = 15 May 2014| url = http://smithsonianscience.org/2014/05/extinct-relative-reveals-rarity-last-two-remaining-monk-seal-species/| archive-url = https://web.archive.org/web/20140515224257/http://smithsonianscience.org/2014/05/extinct-relative-reveals-rarity-last-two-remaining-monk-seal-species/ | archive-date = 2014-05-15| access-date = 15 May 2014}}</ref>

Fossils of the Mediterranean and Caribbean species are known from the [[Pleistocene]].<ref name=Berta2012>{{cite journal |author1=Berta, A.  |author2=Churchill, M.  |name-list-style=amp | year = 2012 | title = Pinniped Taxonomy: evidence for species and subspecies | journal = Mammal Review | volume = 42 | issue = 3 | pages = 207–234 | doi = 10.1111/j.1365-2907.2011.00193.x}}</ref> The time of divergence between the Hawaiian and Caribbean species, 3.7 million years ago (Mya), corresponds to the closing of the [[Central American Seaway]] by the formation of the [[Isthmus of Panama]]. The divergence between Mediterranean seals and the New World clade was dated to 6.3 Mya ago.<ref name="Scheel2014">{{Cite journal | doi = 10.3897/zookeys.409.6244| pmid = 24899841| pmc = 4042687| title = Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology| journal = ZooKeys| issue = 409| pages = 1–33| date = 14 May 2014| last1 = Scheel | first1 = D. M. | last2 = Slater | first2 = G. | last3 = Kolokotronis | first3 = S. O. | last4 = Potter | first4 = C. | last5 = Rotstein | first5 = D. | last6 = Tsangaras | first6 = K. | last7 = Greenwood | first7 = A. | last8 = Helgen | first8 = K. M. | doi-access = free}}</ref>

Fossils of a Pliocene species of monk seal, ''[[Eomonachus|Eomonachus belegaerensis]]'', have been found in Taranaki region of New Zealand. This could possibly place the origins of the group in the Southern Hemisphere.<ref>{{Cite journal|last1=Rule|first1=James P.|last2=Adams|first2=Justin W.|last3=Marx|first3=Felix G.|last4=Evans|first4=Alistair R.|last5=Tennyson|first5=Alan J. D.|last6=Scofield|first6=R. Paul|last7=Fitzgerald|first7=Erich M. G.|date=2020-11-11|title=First monk seal from the Southern Hemisphere rewrites the evolutionary history of true seals|journal=Proceedings of the Royal Society B: Biological Sciences|volume=287|issue=1938|page=20202318|doi=10.1098/rspb.2020.2318|pmid=33171079|pmc=7735288|doi-access=free}}</ref><ref name="INV-20201113">{{cite news |last=Yarlagadda |first=Tara |title=Unusual Teeth Reveal A New Species And A Twist On Evolution |url=https://www.inverse.com/science/unusual-teeth-reveal-species |date=13 November 2020 |work=[[Inverse (website)|Inverse]] |access-date=14 November 2020 }}</ref> The only other fossil monk seal is ''Pliophoca etrusca'', from the late Pliocene of Italy.<ref>{{Cite journal|last1=Berta|first1=Annalisa|last2=Kienle|first2=Sarah|last3=Bianucci|first3=Giovanni|last4=Sorbi|first4=Silvia|date=2015-01-02|title=A Reevaluation of Pliophoca Etrusca (Pinnipedia, Phocidae) from the Pliocene of Italy: Phylogenetic and Biogeographic Implications|journal=Journal of Vertebrate Paleontology|volume=35|issue=1|pages=e889144|doi=10.1080/02724634.2014.889144|bibcode=2015JVPal..35E9144B |s2cid=84460049|issn=0272-4634}}</ref>

==Habitat==
[[File:Monachus schauinslandi Hollingsworth.jpg|thumb|Hawaiian monk seal hauled out on volcanic rock]]
The Hawaiian monk seal, as the name suggests, lives solely in the [[Hawaiian archipelago]]. Monk seals migrated to Hawaii between 4–11 Mya through an open-water passage between North and South America called the Central American Seaway. The Isthmus of Panama closed the seaway 3 Mya. The species may have evolved in the Pacific or Atlantic, but in either case, came to Hawaii long before the first [[Polynesians]].<ref name="FIPR HMS timeline">{{cite web |url=http://www.fpir.noaa.gov/Library/PRD/Hawaiian%20monk%20seal/HMS_natural_history_timelineWEB.pdf |title=Historical Timeline of the Hawaiian Monk Seal |work=Pacific Islands Regional Office (NOAA)|publisher=[[National Marine Fisheries Service]], Pacific Islands Regional Office |location=Honolulu, HI, USA|date=June 29, 2011 |access-date=19 November 2012}}</ref> When monk seals are not hunting or eating, they generally [[hauling-out|bask]] on the beaches; Hawaiian monk seals tend to bask on sandy beaches and volcanic rock of the [[Northwest Hawaiian Islands]].<ref name=Baker>{{cite journal|last1=Baker|first1=J|title=Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands|journal=Biological Conservation |year=2004 |volume=116|series=1|pages=103–10|doi=10.1016/S0006-3207(03)00181-2|last2=Johanos|first2=Thea C.}}</ref>

The habitat of the Mediterranean monk seal has changed over the years. Prior to the 20th century, they had been known to congregate, give birth, and seek refuge on open beaches. Since [[seal hunting|sealing]] had ended, they have left their former habitat and now only use sea caves for such behavior. More often than not, these caves are rather inaccessible to humans due to underwater entries, and because the caves are often along remote or rugged coastlines. Scientists have confirmed this is a recent adaptation, most likely due to the rapid increase in human population, tourism, and industry, which have caused increased disturbance by humans and the destruction of the species' natural habitat. Because of these seals' shy nature and sensitivity to human disturbance, they have slowly adapted to try to avoid contact with humans completely within the last century, and perhaps, even earlier. The coastal caves are, however, dangerous for newborns, and are causes of major mortality among pups when sea storms hit the caves.<ref name=guardian>{{Cite journal|first1=William|last1=M. Johnson |first2=Alexandros|last2=A. Karamanlidis|first3=Panagiotis|last3=Dendrinos|first4=Pablo|last4=Fernández de Larrinoa|first5=Manel|last5=Gazo|first6=Luis|last6=Mariano González|first7=Harun|last7=Güçlüsoy|first8=Rosa |last8=Pires|first9=Matthias|last9=Schnellmann|year=2006|title=Monk Seal Fact Files|journal=The Monachus Guardian|url=http://www.monachus-guardian.org/factfiles/medit01.htm}}</ref>

Caribbean monk seals were found in warm temperate, subtropical, and tropical waters of the Caribbean Sea, Gulf of Mexico, and the west Atlantic Ocean. They probably preferred to haul out at sites (low sandy beaches above high tide) on isolated and secluded atolls and islands, but occasionally visited the mainland coasts and deeper waters offshore. This species may have fed in shallow lagoons and reefs.<ref name=NOAAC/>

==Description==
[[File:Monachus schauinslandi.jpg|thumb|Hawaiian monk seal swimming (note the red eyes are due to the [[red-eye effect]])]]
Monk seals are part of the family [[Phocidae]] (earless seals), the members of which are characterized by their lack of external ears, the inability to rotate the hind [[Flipper (anatomy)|flipper]]s under the body,<ref name=Gilmartin>{{cite journal |last=Gilmartin |first=William |author2=Forcada, J. |title=Monk Seals |journal=Encyclopedia of Marine Mammals, Eds|year=2002|pages=756–759}}</ref> and shed their hair and the outer layer of their skin in an annual [[molt]].{{sfn|Encyclopedia of Marine Mammals|loc=[https://books.google.com/books?id=2rkHQpToi9sC&pg=PA741 p. 741]}} Monk seals as a whole vary minutely in size, with all adults measuring on average {{convert|8|ft|m}} and {{convert|500|lb|kg}}. They exhibit [[sexual dimorphism]], in that male Mediterranean monk seals are slightly larger than females, while in Hawaiian monk seals, females are larger. Its white belly, gray coat, and slender physique distinguish it from the [[harbor seal]] (''Phoca vitulina''), another earless seal.<ref name="NOAAC">{{cite web|title=Caribbean Monk Seal (''Monachus tropicalis'')|url=http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/caribbeanmonkseal.htm|publisher=NOAA – Office of Protected Resources|access-date=16 January 2016}}</ref><ref name="NOAAM">{{cite iucn |author1=Karamanlidis, A.|author2=Dendrinos, P.| title = ''Monachus monachus'' | volume=2015 | page = e.T13653A45227543  | year =2015 | doi = 10.2305/IUCN.UK.2015-4.RLTS.T13653A45227543.en }}</ref><ref name="NOAAH">{{cite web|url=http://www.fisheries.noaa.gov/pr/species/mammals/seals/hawaiian-monk-seal.html|title=Hawaiian Monk Seal (''Neomonachus schauinslandi'')|publisher=NOAA – Office of Protected Resources|access-date=16 January 2016|archive-url=https://web.archive.org/web/20160113030040/http://www.fisheries.noaa.gov/pr/species/mammals/seals/hawaiian-monk-seal.html|archive-date=13 January 2016}}</ref>

The Mediterranean monk seal has a short, broad, and flat snout, with very pronounced, long nostrils that face upwards. The flippers are relatively short, with small, slender claws. The monk seal's physique is ideally suited for hunting its prey: [[fish]], [[octopus]], [[lobster]], and [[squid]] in [[deep-water coral]] beds.<ref name=Goodman>{{cite journal|last=Goodman-Lowe |first=GD |title=Diet of the Hawaiian Monk Seal (''Monachus schauinslandi'') from the Northwestern Hawaiian Islands during 1991 to 1994 |journal=Marine Biology |year=1998 |volume=132 |series=3 |pages=535–46 |url=http://www.csulb.edu/~ggoodman/files/DietHMS.pdf|doi=10.1007/s002270050419|issue=3 |s2cid=84310964 }}</ref> The fur coats of males is generally black, and brown or dark gray in females. Pups are about {{convert|1|m|ft|order=flip}} long and weigh around {{convert|15|–|18|kg|lb|order=flip}}, their skin being covered by {{convert|1.0|to|1.5|cm|in|order=flip|adj= on|sigfig=1}} fur, usually dark brown or black. On their bellies,  a white stripe occurs, which differs in color between the two sexes. This hair is replaced after 6–8 weeks by the usual short hair adults carry.<ref name="NOAAM"/>
[[File:Monachus skeleton.JPG|thumb|left|Mediterranean monk seal skeleton]]

The Hawaiian monk seal (whose Hawaiian name means "the dog that runs in rough waters")<ref name=mmc>{{cite web|url=http://www.marinemammalcenter.org/education/marine-mammal-information/pinnipeds/hawaiian-monk-seal/?referrer=https://www.google.com/|title=Hawaiian Monk Seal|work=Marine Mammal Center|access-date=16 June 2016}}</ref> has a short, broad, and flat snout, with long nostrils that face forward. It has a relatively small, flat head with large, black eyes, eight pairs of teeth, and a short snout with the nostrils on top of the snout and [[vibrissae]] on each side.<ref name="NOAAH"/> The nostrils are small, vertical slits, which close when the seal dives under water. Additionally, their slender, torpedo-shaped body and hind flippers allow them to be very agile swimmers.<ref name=Kenyon>{{cite journal|last=Kenyon |first=KW |author2=Rice, DW |title=Life History Of the Hawaiian Monk Seal |journal=Pacific Science |volume=13 |url=http://scholarspace.manoa.hawaii.edu/handle/10125/7958 |date=July 1959 |hdl=10125/7958 }}</ref> Adult males are {{convert|300|to|400|lb}} in weight and {{convert|7|ft}} in length, while adult females tend to be, typically, slightly larger, at {{convert|400|to|600|lb}} and {{convert|8|ft}} in length. When monk seal pups are born, they weigh {{convert|30|to|40|lb}} and are {{convert|40|in|m}} in length.  As they nurse for about 6 weeks, they grow considerably, eventually weighing between {{convert|150|and|200|lb}} by the time they are [[weaning|weaned]], while the mother loses up to {{convert|300|lb}}.

Caribbean monk seals had a relatively large, long, robust body, and could grow to nearly {{convert|8|ft|m}} in length and weighed {{convert|375|to|600|lb|kg}}. Males were probably slightly larger than females, which is similar to Mediterranean monk seals. Like other monk seals, this species had a distinctive head and face. The head was rounded with an extended, broad muzzle. The face had relatively large, wide-spaced eyes, upward-opening nostrils, and fairly big whisker pads with long, light-colored, and smooth whiskers. When compared to the body, the animal's foreflippers were relatively short with little claws and the hindflippers were slender. Their coloration was brownish and/or grayish, with the underside lighter than the dorsal area. Adults were darker than the paler and more yellowish younger seals. Caribbean monk seals were also known to have algae growing on their pelages, giving them a slightly greenish appearance, which is similar to Hawaiian monk seals.<ref name="NOAAC"/>

==Behavior==

===Diet and predation===

Hawaiian monk seals mainly prey on reef-dwelling [[bony fish]], but they also prey on [[cephalopods]] and [[crustaceans]]. Juveniles and subadults prey more on smaller octopus species, such as ''[[Octopus leteus]]'' and ''[[O. hawaiiensis]]'' (nocturnal octopus species), and eels than do adult Hawaiian monk seals. Adult seals feed mostly on larger octopus species such as ''[[O. cyanea]]''. Hawaiian monk seals have a broad and diverse diet due to [[foraging]] [[Phenotypic plasticity|plasticity]], which allows them to be opportunistic predators that feed on a wide variety of available prey.<ref name=Goodman/> [[Tiger shark]]s, [[great white shark]]s, and [[Galapagos shark]]s are all predators of the Hawaiian monk seal.<ref name=Bertilsson>{{cite journal|last=Bertilsson-Friedman |first=P |title=Distribution and Frequencies of Shark-inflicted Injuries to the Endangered Hawaiian Monk Seal (Monachus Schauinslandi)|journal=Journal of Zoology|year=2006 |volume=268 |issue=4 |pages=361–68 |doi=10.1111/j.1469-7998.2006.00066.x }}</ref>

Mediterranean monk seals are [[diurnality|diurnal]] and feed on a variety of fish and [[mollusk]]s, primarily octopus, squid, and [[eel]]s, up to {{convert|6.5|lb|kg}} per day. They are known to forage mostly at depths of {{convert|150|to|230|ft|m}}, but some have been observed by [[NOAA]] submersibles at a depth of {{convert|500|ft|m}}. They prefer hunting in wide-open spaces, enabling them to use their speed more effectively. They are successful bottom-feeding hunters; some have even been observed lifting slabs of rock in search of prey. They have no natural predators.<ref name="NOAAM"/>

===Reproduction and development===
[[File:Sanc1297 - Flickr - NOAA Photo Library.jpg|thumb|Two young Hawaiian monk seals]]
Very little is known of the Mediterranean monk seal's reproduction. They are thought to be [[polygyny in animals|polygynous]], with males being very territorial where they mate with females. Although no breeding season exists, since births take place year round, a peak occurs in October and November. This is also the time when caves are prone to wash out due to high surf or [[storm surge]], which causes high mortality rates among pups, especially at the key Cabo Blanco colony. Pups make first contact with the water 2 weeks after their birth and are weaned around 18 weeks of age; females caring for pups go off to feed for an average of 9 hours.<ref name="NOAAM"/> Most individuals are believed to reach maturity at 4 years of age. The gestation period lasts close to a year. However,  monk seals of the Cabo Blanco colony may have a gestation period lasting slightly longer than a year.<ref name="FAO">{{cite book|chapter-url=https://books.google.com/books?id=OIvn4Zo0PU0C&pg=PA97|author=Food and Agriculture Organization of the United Nations|title=Mammals in the Seas: Report volume 2|chapter=Pinnipeds species summaries|isbn=978-92-5-100512-5|year=1978|publisher=Food & Agriculture Org. }}</ref>{{rp|97}} Mediterranean monk seals generally live to be 25 to 30 years old.<ref name=guardian/>

Hawaiian monk seals are polygynous. The breeding season takes place throughout the year, excluding the fall, but peaks during April and May. Shark attacks cause a high pup mortality, from 19% to 39%. Pups are thought to be weaned around 6 weeks and  reach sexual maturity at 3 years.<ref name="FAO"/>{{rp|104–105}} Their typical lifespan is 25 to 30 years.<ref name=mmc/>

Not much is known of the Caribbean monk seal's reproduction. They likely bore a single pup every two years. Their gestation period, lactation period, and sexual maturity age are unknown.<ref name="FAO"/>{{rp|102}}

==Interactions with humans==

===Hawaii===
[[File:Sleeping seal.JPG|thumb| Hawaiian monk seal sleeping on a beach in [[Kauai]]]]
[[File:Anim2605 (34712516486).jpg|thumb| Hawaiian monk seal swimming above a [[coral reef]]]]
[[File:Anim2600 (34712516246).jpg|thumb|Young monk seal underwater]]

====Threats====
In the 19th century, many seals were killed by [[Whaling|whalers]] and [[Seal hunting|sealers]] for meat, oil, and skin.<ref name="EllisNTB194">
{{cite book| last = Ellis| first = Richard| author-link = Richard Ellis (biologist) | title = No Turning Back: The Life and Death of Animal Species| url = https://archive.org/details/noturningbacklif00elli| url-access = registration| publisher = Harper Perennial | year = 2004| location = New York| page = [https://archive.org/details/noturningbacklif00elli/page/194 194]| isbn =978-0-06-055804-8 }}</ref> U.S. military forces hunted them during World War II, while occupying [[Laysan Island]] and [[Midway Island]].<ref name="EllisNTB194"/> Human disturbances have had immense effects on the populations of the Hawaiian monk seal. They tend to avoid beaches where they are disturbed; after continual disturbance, the seals may completely abandon the beach, thus reducing habitat size, subsequently limiting population growth.  For instance, large beach crowds and beach structures limit the seal's habitat. The WWII military bases in the northwestern islands were closed, but minimal human activities can be enough to disturb the species.<ref name=Antonelis>{{cite journal |last=Antonelis |first=GA |title=Hawaiian monk seal (''Monachus schauins-landi''): status and conservation issues |journal=Atoll Res Bull |year=2006 |volume=543 |pages=75–101|display-authors=etal}}</ref> The current population is only around 1,400 individuals.<ref>{{cite web|url=http://animals.nationalgeographic.com/animals/mammals/hawaiian-monk-seal/|archive-url=https://web.archive.org/web/20100129002642/http://animals.nationalgeographic.com/animals/mammals/hawaiian-monk-seal/|url-status=dead|archive-date=January 29, 2010|title=Hawaiian Monk seal ''Monachus schauinslandi''|date=10 March 2011|publisher=National Geographic|access-date=31 July 2016}}</ref>

The Hawaiian monk seal has the lowest level of genetic variability among the 18 pinniped species, allegedly due to a [[population bottleneck]] caused by intense hunting in the 19th century. This limited genetic variability reduces the species's ability to adapt to environmental pressures and limits [[natural selection]], thus increasing their risk of extinction. Given the monk seal's small population, the effects of disease could be disastrous.<ref name=Schultz>{{cite journal|last1=Schultz J|author2=Baker J |author3=Toonen R |author4=Bowen B |title=Extremely Low Genetic Diversity in the Endangered Hawaiian Monk Seal (''Monachus schauinslandi'') |journal=Journal of Heredity |year=2009 |volume=100 |series=1 |pages=25–33 |doi=10.1093/jhered/esn077 |issue=1|first1=J. K.|pmid=18815116|doi-access=free }}</ref><ref name=Kretzmann1997>{{cite journal | author = Kretzmann, M.| year = 1997 | title = Low Genetic Variability in the Hawaiian Monk Seal | journal = Conservation Biology | volume = 11 | issue = 2 | pages = 482–490 | doi = 10.1046/j.1523-1739.1997.96031.x| s2cid = 73628238 | url = http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-36204 |display-authors=etal}}</ref>

Entanglement can result in mortality, because when the seals get trapped in [[marine debris]] such as fishing nets, they cannot maneuver or reach the surface to breathe.<ref name=Schultz/> Marine fisheries can potentially interact with monk seals by direct and indirect relationships. Directly, the seal can become snared by fishing equipment, entangled in discarded debris, and even feed on fish refuse.<ref name=Antonelis/> International law prohibits the intentional discarding of debris from ships at sea. Monk seals have one of the highest documented rates of entanglement of any pinniped species.<ref name=Antonelis/>

====Conservation====
In 1909, [[Theodore Roosevelt]] created the [[Hawaiian Islands National Wildlife Refuge]] (HINWR), which is under the jurisdiction of the [[U.S. Fish and Wildlife Service]].<ref name=Antonelis/> Throughout the 1980s, the [[National Marine Fisheries Service]] completed various versions of an [[environmental impact statement]] that designated the Northwest Hawaiian Islands as a critical habitat for the Hawaiian monk seal. The designation prohibited lobster fishing in the northwest Hawaiian Islands and Laysan Island. In 2006, a Presidential proclamation established the [[Papahanaumokuakea Marine National Monument]], which incorporated the [[Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve]], the [[Midway Atoll|Midway Atoll National Wildlife Refuge]], the HINWR, and the [[Battle of Midway National Memorial]], thus creating the largest marine protected area in the world and affording the Hawaiian monk seal further protection.<ref name="HMS Recovery Plan">{{cite web |url=http://www.nmfs.noaa.gov/pr/pdfs/recovery/hawaiianmonkseal.pdf |title=Second Revision of Recovery Plan for the Hawaiian Monk Seal (Monachus schauinslandi) |work=NOAA PIFSC Hawaiian Monk Seal Research|publisher=Pacific Islands Fisheries Science Center (NOAA)|location=Honolulu, HI, USA |date=January 28, 2010 |orig-date=2007 |access-date=16 January 2016}}</ref>

[[NOAA]] cultivated a network of volunteers to protect the seals while they bask or bear and nurse their young. NOAA is funding considerable research on seal population dynamics and health in conjunction with the [[Marine Mammal Center]]. From NOAA, several programs and networks were formed. Community programs such as PIRO have helped to improve community standards for the Hawaiian monk seal. The program also creates networks with the native Hawaiians on the island to network more people in the fight for conservation of the seals. The Marine Mammal Response Network  is partnered with NOAA and several other government agencies that deal with land and marine wildlife.<ref>Protected Resources Division." NOAA. N.p., n.d. Web. 21 Oct. 2013.</ref>

To raise awareness of the species' plight, on June 11, 2008, a state law designated the Hawaiian monk seal as [[Hawaii]]'s official state mammal.<ref>{{cite web |author=Gladden, Tracy |url=http://www.khnl.com/Global/story.asp?S=8483697 |archive-url=https://archive.today/20130127130132/http://www.khnl.com/Global/story.asp?S=8483697  |archive-date=27 January 2013 |publisher=KHNL NBC 8 Honolulu Hawaii |title=Hawaiian monk seal is the new state mammal |access-date=23 May 2011 }}</ref>

===Mediterranean===
[[File:Mediterranean Monk Seal.jpg|thumb|One of the first sightings of a monk seal in the [[Strait of Gibraltar]], 2012]]

====Threats====

Several causes provoked a dramatic population decrease over time: on one hand, commercial hunting (especially during the Roman Empire and Middle Ages) and during the 20th century, eradication by fishermen, who used to consider it a pest due to the damage the seal causes to fishing nets when it preys on fish caught in them; and on the other hand, coastal urbanization and pollution. Currently, its entire population is estimated to be less than 600 individuals scattered throughout a wide distribution range, which qualifies this species as endangered. Its current very sparse population is one more serious threat to the species, as it only has two key sites that can be deemed viable. One is the [[Aegean Sea]] (250–300 animals in Greece, with the largest concentration of animals on Gyaros,<ref>{{cite journal|last1=Karamanlidis|first1=A.A.|first2=P.|last2=Dendrinos|last3= P.F. de Larrinoa|first3=A.C. Gücü|first4=W.M.|last4=Johnson|first5=C.O.|last5=Kiraç|first6=R.|last6=Pires|year=2015|title=The Mediterranean monk seal ''Monachus monachus'': status, biology, threats, and conservation priorities|journal=Mammal Review|volume=45|issue=4|page=92|doi=10.1111/mam.12053|hdl=11511/29839|hdl-access=free}}</ref> and some 100 in Turkey); the other important subpopulation is the [[Western Sahara]]n portion of Cabo Blanco (around 200 individuals which may support the small, but growing, nucleus in the [[Desertas Islands]] – roughly 20 individuals<ref name="NOAAM"/>). Some individuals may be using coastal areas along other parts of Western Sahara, such as in [[Cintra Bay]].<ref name=FootPrintBook>{{cite book|author=Tiwari M. |author2=Aksissou M. |author3=Semmoumy S. |author4=Ouakka K. |year=2006|title=Morocco Footprint Handbook|url=https://books.google.com/books?id=LtXcAgAAQBAJ&pg=PA265|publisher=Footprint Travel Guides|page=265|isbn=978-1-907263-31-6}}</ref> These two key sites are virtually in the extreme opposites of the species' distribution range, which makes natural population interchange between them impossible. All the other remaining subpopulations are composed of less than 50 mature individuals, many of them being only loose groups of extremely reduced size – often less than five individuals.<ref name="NOAAM"/> Consequently, low genetic variability exists.<ref name=Pastor2004>{{cite journal | author = Pastor, T.| year = 2004 | title = Low Genetic Variability in the Highly Endangered Mediterranean Monk Seal | journal = Journal of Heredity | volume = 95 | issue = 4 | pages = 291–300 | doi = 10.1093/jhered/esh055| pmid = 15247308 |display-authors=etal| doi-access = free }}</ref>

[[File:Colonia de focas monje de Cabo Blanco (1945).jpg|thumb|left|180px|A colony of Mediterranean monk seals on [[Ras Nouadhibou|Cabo Blanco]], 1945]]
Cabo Blanco, in the Atlantic Ocean, is the largest surviving single population of the species, and the only remaining site that still seems to preserve a colony structure.<ref name="NOAAM"/> In the summer of 1997, a disease killed more than 200 animals (two-thirds of its population) within 2 months, extremely compromising the species' [[viable population]]. While opinions on the precise causes of this epidemic remain divided, the most likely cause is a [[Phocine distemper virus|morbilivirus]] or a [[Red tide|toxic algae bloom]].<ref name=NOAAM/>

====Conservation====

In the [[Aegean Sea]], Greece has allocated a large area for the preservation of the Mediterranean monk seal and its habitat. The Greek [[Alonissos Marine Park]], that extends around the Northern [[Sporades]] islands, is the main action ground of the Greek MOm organisation.<ref>{{cite web|url=http://www.mom.gr |title=MOm Website |publisher=mom.gr |language=el|access-date=11 June 2012}}</ref> MOm is greatly involved in raising awareness in the general public, fundraising for the helping of the monk seal preservation cause, in Greece and wherever needed. Greece is currently investigating the possibility of declaring another monk seal breeding site as a national park, and also has integrated some sites in the NATURA 2000 protection scheme. The legislation in Greece is very strict towards seal hunting, and in general, the public is very much aware and supportive of the effort for the preservation of the Mediterranean monk seal.<ref>{{cite web|url=http://www.mom.gr/displayITM1.asp?ITMID=146&LANG=GR|title=Important Moments for NMPANS|publisher=mom.gr|language=el|access-date=16 January 2016|archive-url=https://web.archive.org/web/20160305010709/http://www.mom.gr/displayITM1.asp?ITMID=146&LANG=GR|archive-date=5 March 2016}}</ref>

One of the largest groups among the foundations concentrating their efforts towards the preservation of the Mediterranean monk seal is the Mediterranean Seal Research Group (''Akdeniz Foklarını Araştırma Grubu'') operating under the Underwater Research Foundation (''Sualtı Araştırmaları Derneği'') in [[Turkey]] (also known as SAD-AFAG). The group has taken initiative in joint preservation efforts together with the [[Foça]] municipal officials, as well as phone, fax, and email hotlines for sightings.<ref>{{cite web|url=http://sadafag.org/uluslararasi-akdeniz-foku-muttefikligi/|title=International Monk Seal Alliance|work=Sualtı Araştırmaları Derneği: Akdeniz Foku Araştırma Grubu|access-date=15 June 2016}}</ref>

===Caribbean===
[[File:Cms-newyorkzoologicalsociety1910.jpg|thumb|Caribbean monk seal in the [[New York Aquarium]], 1910]]
The extinction of the Caribbean monk seal was mainly triggered by overhunting in the eighteenth and nineteenth centuries to obtain the oil held within their blubber,<ref name=Adam>{{cite journal|last=Adam|first=Peter|title=''Monachus tropicali''|journal=Mammalian Species|volume=747|pages=1–9|date=July 2004|doi=10.1644/747|doi-access=free}}</ref> fueled by the large demand for seal products.{{sfn|Encyclopedia of Marine Mammals|loc=[https://books.google.com/books?id=2rkHQpToi9sC&pg=PA585 pp. 585–588]}} As early as 1688, sugar plantation owners sent out hunting parties to kill hundreds of seals every night for blubber oil to lubricate  machinery.<ref name=Gray>{{cite book|last=Gray|first=J|title=Catalogue of the Specimens of Mammalia in the Collection of the British Museum|url=https://archive.org/details/cataloguemammalia03britrich|year=1850|location=London|page=v}}</ref> The Caribbean monk seals' docile nature and lack of an instinctive fear of humans made it an easy target,<ref>{{cite journal|last=Ward|first=H|title=The West Indian Seal (Monachus Tropicalis)|journal=Nature|year=1887|volume=35|issue=904|page=392|doi=10.1038/035392a0|bibcode=1887Natur..35..392W|s2cid=4065385|url=https://zenodo.org/record/1429301}}</ref> and hunting only ended (in the 1850s) because the population was too low for commercial use.<ref>Gray, J (1850). ''Catalogue of the Specimens of Mammalia in the Collection of the British Museum''. London. p. v. {{doi|10.5962/bhl.title.20968}}</ref> Overfishing of the reefs that sustained the Caribbean monk seal population also contributed to their extinction. Fish stock decline in the Caribbean starved the remaining populations.<ref>{{cite journal |last1=McClenachan |first1=Loren |last2=Cooper |first2=Andrew B. |title=Extinction rate, historical population structure and ecological role of the Caribbean monk seal |journal=Proc. R. Soc. B |year=2008 |volume=275 |pages=1351–1358 |pmc=2602701 |pmid=18348965 |doi=10.1098/rspb.2007.1757 |issue=1641}}</ref> Little was done to protect the Caribbean monk seal; by the time it was placed on the endangered species list in 1967, it was likely already extinct.<ref name=Adam />

==References==
{{Reflist|30em}}

== Further reading ==
* {{citation | author = Ronald M. Nowak | title = Walker's Mammals of the World | isbn = 978-0-8018-5789-8 | year = 1999 | publisher = Johns Hopkins University Press | location = Baltimore | edition = 6th | lccn = 98023686 | language = en <!--| GBS-id = T37sFCl43E8C | Ltwork = 257350 -->}}
* {{cite book|last1=Perrin|first1=William F.|author2=Bernd Wursig|author3=J. G. M. Thewissen|title=Encyclopedia of Marine Mammals|url={{Google books|plainurl=yes|id=2rkHQpToi9sC}}|year= 2008|publisher=Academic Press|isbn=978-0-12-373553-9|ref={{harvid|Encyclopedia of Marine Mammals}}}}

==External links==
{{Commons category|Monachus}}
* [http://monachus-guardian.org The ''Monachus'' Guardian]
* [https://web.archive.org/web/20121113141118/http://www.monksealfoundation.org/ Monk Seal Foundation]
* [http://www.fpir.noaa.gov/PRD/prd_hawaiian_monk_seal.html NOAA Monk Seal Info]

{{Carnivora|C1.}}
{{Pan-Pinnipedia|P.|state=autocollapse}}
{{Taxonbar|from=Q33176727}}
{{Good article}}

[[Category:True seals]]
[[Category:Monachines]]