Editing Caspian seal (section)

==Behavior and ecology==
Caspian seals are shallow divers, typically diving {{cvt|50|m|ft|-1}} for about one minute, although scientists have recorded Caspian seals diving deeper and for longer periods of time. After foraging during a dive, they rest at the surface of the water.<ref name="Chanticlear Press">{{cite book|last1=Reeves|first1=R|last2=Stewart|first2=B|last3=Clapham|first3=P|last4=Powell|first4=J|title=Guide to Marine Mammals of the World|date=2002|publisher=Chanticlear Press|location=New York}}</ref>

In the summer and winter, during mating season, Caspian seals tend to live in large groups. At other times of the year, these seals are solitary. During the summer, however, they make aggressive snorts or use flipper waving to tell other seals to keep their distance. Little else is known about their behavior.<ref name="Chanticlear Press"/>

===Reproduction===
Male and female Caspian seals are monogamous. Among breeding seals, a lack of fighting for a mate seems prevalent. In late autumn, Caspian seals travel to the northern part of the Caspian Sea where the water is shallow and frozen to give birth in secluded areas on ice sheets after a gestation period of 11 months. Normally, pregnancy rates are  40 to 70%, but are currently at an all-time low of 30%. In late January to early February, female seals give birth to one pup each. Similar to other ringed seals, these pups are born with white [[pelage]]s and weigh about {{cvt|5|kg}}. Caspian seals employ a [[capital breeding]] lactation strategy, where the mother will fast while nursing the pup, sometimes with a small amount of supplemental feeding. Pups are weaned after a few weeks.<ref>{{Cite journal |last1=Wilson |first1=Susan C. |last2=Dolgova |first2=Evgeniya |last3=Trukhanova |first3=Irina |last4=Dmitrieva |first4=Lilia |last5=Crawford |first5=Imogen |last6=Baimukanov |first6=Mirgaliy |last7=Goodman |first7=Simon J. |date=2016-11-15 |title=Breeding behavior and pup development of the Caspian seal,''Pusa caspica'' |journal=Journal of Mammalogy |pages=gyw176 |doi=10.1093/jmammal/gyw176 |issn=0022-2372|doi-access=free }}</ref> The pups' white coats are [[molt]]ed at around three weeks to a month. Male pups become sexually mature after six to seven years, whereas female pups sexually mature after five to seven years. Newborn pups are not fully grown until 8 to 10 years after they are born.<ref>{{cite journal|last1=Easley-Appleyard |first1=B. |title=Pusa Caspica Caspian Seal|journal=Animal Diversity Web |date=2006 |url=http://animaldiversity.ummz.umich.edu/accounts/Pusa_caspica/#757c91a32120facf8ff6bc9e83c87ac3|access-date=23 October 2014}}</ref> Breeding begins a few weeks after the birth of last year's pup around late February to mid March. Breeding usually occurs after weaning of a newborn pup, but can begin while the pup is still nursing. Caspian seals migrate back to the southern part of the Caspian Sea after the breeding season and molting in late April because the north begins to warm with constant ice melting. The southern region of the Caspian Sea has deep, colder waters where the seals spend the summer months.<ref>{{cite journal|editor1-last=Hogan|editor1-first=Michael C.|title=Caspian Seal|journal=The Encyclopedia of Earth|date= 2010 |url=http://www.eoearth.org/view/article/150951/|access-date=24 October 2014}}</ref>

===Diseases===
Several recent cases of large numbers of Caspian seals dying due to [[canine distemper]] virus have been reported, in 1997, 2000 and 2001.<ref name=role /> In April 2000, a mass die-off of Caspian seals was first reported near the mouth of the [[Ural River]] in Kazakhstan. It spread south to the [[Mangistau]] region, and by the end of May, more than 10,000 seals had died along the Kazakhstan coast. High death rates were also recorded in May and June along the [[Apsheron peninsula]] of Azerbaijan and the Turkmenistan coast.<ref name=mass>{{cite journal |last1=Kennedy |first1=Seamus |last2=Kuiken |first2=Thijs |last3=Jepson |first3=Paul |last4=Deaville |first4=Robert|last5=Forsyth|first5=Morag|last6=Barrett|first6=Tom|last7=van de Bilt |first7=Marco |last8=Osterhaus |first8=Albert |last9=Eybatov |first9=Tariel |last10=Callan |first10=Duck |last11=Kydyrmanov |first11=Aidyn|last12=Mitrofanov|first12=Igor|last13=Wilson|first13=Susan|title=Mass die-off of Caspian Seals by Canine Distemper Virus |journal=Emerging Infectious Diseases|date=2000 |volume=6|issue=6|pages=637–639 |pmid=11076723 |doi=10.3201/eid0606.000613 |pmc=2640919}}</ref>

Clinical signs of infected seals included debilitation, muscle spasms, ocular and nasal exudation, and sneezing.  Necropsies performed in June 2000 on eight Azerbaijan seals revealed microscopic lesions, including bronchointerstitial [[pneumonia]], [[encephalitis]], [[pancreatitis]] and lymphocytic depletion in lymphoid tissues.  Similar lesions were also discovered on four seals from Kazakhstan. ''Morbillivirus'' antigen was also detected in multiple tissues, including lung, [[lymph nodes]], spleen, brain, pancreas, liver, and [[epithelial tissue]] of the reproductive, urinary, and gastrointestinal tracts. Such tissue lesions are characteristic of distemper in both terrestrial and aquatic mammals.<ref name=mass />

Tissues from 12 carcasses found in [[Kazakhstan]], [[Azerbaijan]], and [[Turkmenistan]] were examined for [[morbillivirus]] nucleic acid. Sequences from the examination showed that canine distemper virus, which is part of the genus ''Morbillivirus'', was the primary cause of death. The sequences also proved that seals from widely separated regions of the Caspian Sea were infected by the same virus. This finding established spatial and temporal links between the seal deaths in these regions. The sequences were also identical to that of canine distemper virus found in the brain tissue of a seal that died in 1997 and showed no morbillivirus lesions. This suggests persistence of canine distemper virus in the Caspian seal population over a span of several years or repeated spillover from the same terrestrial reservoir.<ref name=mass />

Another study in 2000 using 18 Caspian seal corpses found several concurrent bacterial infections that could have contributed to the illness of the affected seals. These include ''[[Bordetella bronchiseptica]]'', ''Streptococcus phocae'', ''Salmonella dublin'', and ''S. choleraesuis''. ''Corynebacterium caspium'', a new bacterium, was identified in one of the seals, and poxvirus, ''Atopobacter phocae'', ''[[Eimeria]]''- and ''[[Sarcocystis]]''-like organisms, and a ''[[Halarachne]]'' species were identified in Caspian seals for the first time. The study also asserts that the "unusually mild" winter that preceded the die-off in 2000 could have contributed to its cause "through increased ambient air pressure and accelerated disappearance of ice cover at the breeding areas in the northern Caspian Sea."<ref name=canine>{{cite journal |last1=Kuiken |first1=T. |last2=Kennedy |first2=S. |last3=Barrett |first3=T.|last4=Van de Bilt |first4=M.W.G. |last5=Borgsteede |first5=F.H. |last6=Brew |first6=S.D. |last7=Codd |first7=G.A.|last8=Duck|first8=C.|last9=Deaville|first9=R.|last10=Eybatov|first10=T. |last11=Forsyth |first11=M.A. |last12=Foster |first12=G. |last13=Jepson |first13=P.D. |last14=Kydyrmanov |first14=A. |last15=Mitrofanov |first15=I. |last16=Ward |first16=C.J. |last17=Wilson |first17=S. |last18=Osterhaus |first18=A.D.M.E. |title=The 2000 Canine Distemper epidemic in Caspian Seals (''Phoca caspica''): Pathology and analysis of contributory factors |journal=Veterinary Pathology |date=2006 |volume=43 |issue=3|pages=321–338 |pmid=16672579 |doi=10.1354/vp.43-3-321|doi-access=free}}</ref>