{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,17]],"date-time":"2026-05-17T02:01:41Z","timestamp":1778983301107,"version":"3.51.4"},"reference-count":22,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2024,1,9]],"date-time":"2024-01-09T00:00:00Z","timestamp":1704758400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"SeaWorld Parks and Entertainment","award":["2017-02-F"],"award-info":[{"award-number":["2017-02-F"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Polar bears (Ursus maritimus) face a number of challenges that threaten the survival of the species. Captive breeding represents one essential facet of species conservation, but aspects of the polar bear\u2019s reproductive physiology, such as follicle maturation, coitus-induced ovulation, and pseudopregnancy, are poorly characterized and present challenges for enhancing natural reproductive success and the application of advanced reproductive techniques. Due to the absence of a reliable transrectal or transabdominal ultrasound method for ovarian examination in the species, the ovaries of two adult female polar bears were examined laparoscopically to evaluate the feasibility of surgical access to the ovaries, oviduct, and uterus. The minimally invasive procedure was easily and rapidly performed in both bears and all procedures. Direct visual assessment of the ovary was possible after dissection of a fatty bursal sac, which completely enclosed the ovaries. In the second bear, laparoscopic manipulation of the ovary to draw it closer to the body wall enabled transcutaneous ultrasound. Laparoscopy may be a valuable tool to aid in the application of advanced reproductive technologies in polar bears.<\/jats:p>","DOI":"10.3390\/life14010105","type":"journal-article","created":{"date-parts":[[2024,1,9]],"date-time":"2024-01-09T10:48:06Z","timestamp":1704797286000},"page":"105","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Laparoscopic Evaluation of the Reproductive Tract in Two Female Polar Bears (Three Procedures) (Ursus maritimus)"],"prefix":"10.3390","volume":"14","author":[{"given":"Ellison D.","family":"Aldrich","sequence":"first","affiliation":[{"name":"School of Veterinary Sciences, Massy University, Palmerston North 4442, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2246-9742","authenticated-orcid":false,"given":"Dean A.","family":"Hendrickson","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7703-1540","authenticated-orcid":false,"given":"Todd L.","family":"Schmitt","sequence":"additional","affiliation":[{"name":"SeaWorld of California, 500 Sea World Drive, San Diego, CA 92109, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1653-9583","authenticated-orcid":false,"given":"Hendrik H.","family":"Nollens","sequence":"additional","affiliation":[{"name":"Sand Diego Zoo Wildlife Alliance, 15500 San Pasqual Valley Road, Escondido, CA 92027, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7791-2428","authenticated-orcid":false,"given":"Gisele","family":"Montano","sequence":"additional","affiliation":[{"name":"Species Preservation Laboratory, SeaWorld Parks and Entertainment Corporation, 2595 Ingraham Road, San Diego, CA 92109, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karen J.","family":"Steinman","sequence":"additional","affiliation":[{"name":"Species Preservation Laboratory, SeaWorld Parks and Entertainment Corporation, 2595 Ingraham Road, San Diego, CA 92109, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2011-9626","authenticated-orcid":false,"given":"Justine K.","family":"O\u2019Brien","sequence":"additional","affiliation":[{"name":"Taronga Conservation Society Australia, Mosman, NSW 2088, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8573-5070","authenticated-orcid":false,"given":"Todd R.","family":"Robeck","sequence":"additional","affiliation":[{"name":"Species Preservation Laboratory, SeaWorld Parks and Entertainment Corporation, 2595 Ingraham Road, San Diego, CA 92109, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"634","DOI":"10.1890\/14-1129.1","article-title":"Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline","volume":"25","author":"Bromaghin","year":"2015","journal-title":"Ecol. Appl."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1111\/gcb.12339","article-title":"Variation in the response of an Arctic top predator experiencing habitat loss: Feeding and reproductive ecology of two polar bear populations","volume":"20","author":"Rode","year":"2014","journal-title":"Glob. Chang. Biol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.scitotenv.2007.07.020","article-title":"Spatial and temporal variation in size of polar bear (Ursus maritimus) sexual organs and its use in pollution and climate change studies","volume":"387","author":"Sonne","year":"2007","journal-title":"Sci. Total Environ."},{"key":"ref_4","first-page":"503","article-title":"Bears as induced ovulators: A preliminary study","volume":"10","author":"Boone","year":"1998","journal-title":"Ursus"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1163","DOI":"10.1016\/j.theriogenology.2003.07.016","article-title":"Evidence that bears are induced ovulators","volume":"61","author":"Boone","year":"2004","journal-title":"Theriogenology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"645","DOI":"10.1638\/2013-0055R1.1","article-title":"Ovulation induction and artificial insemination of a captive polar bear (Ursus maritimus) using fresh semen","volume":"45","author":"Curry","year":"2014","journal-title":"J. Zoo Wildl. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"355","DOI":"10.2307\/3872643","article-title":"Changes in serum progesterone levels and growth of fetuses in Hokkaido brown bears","volume":"7","author":"Tsubota","year":"1987","journal-title":"Bears Their Biol. Manag."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Derocher, A.E. (2012). Polar Bears: A Complete Guide to Their Biology and Behavior, JHU Press.","DOI":"10.56021\/9781421403052"},{"key":"ref_9","first-page":"629","article-title":"Embryonic diapause in vertebrates","volume":"266","author":"Mead","year":"1993","journal-title":"J. Exp. Zool. Part A Ecol. Genet. Physiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"432","DOI":"10.1086\/394493","article-title":"Delayed implantation and discontinuous development in the mammals","volume":"10","author":"Hamlett","year":"1935","journal-title":"Q. Rev. Biol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1111\/j.1469-7998.1988.tb03762.x","article-title":"Reproductive biology and ecology of female polar bears (Ursus maritimus)","volume":"214","author":"Ramsay","year":"1988","journal-title":"J. Zool."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1977","DOI":"10.1016\/j.theriogenology.2012.07.005","article-title":"Longitudinal fecal hormone analysis for monitoring reproductive activity in the female polar bear (Ursus maritimus)","volume":"78","author":"Stoops","year":"2012","journal-title":"Theriogenology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1016\/0093-691X(85)90059-7","article-title":"The evaluation of a laparoscopic insemination technique in ewes","volume":"24","author":"Robinson","year":"1985","journal-title":"Theriogenology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/j.anireprosci.2004.04.027","article-title":"Advanced assisted reproduction technologies (ART) in goats","volume":"82","author":"Baldassarre","year":"2004","journal-title":"Anim. Reprod. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1111\/evj.12486_2","article-title":"Efficacy of Oviductal Flushing with PGE2, in Mares, in and out of the Breeding Season","volume":"47","author":"Martynski","year":"2015","journal-title":"Equine Vet. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1016\/j.jevs.2013.01.003","article-title":"Laparoscopic Application of PGE 2 to the Uterine Tube Surface Enhances Fertility in Selected Subfertile Mares","volume":"33","author":"Ortis","year":"2013","journal-title":"J. Equine Vet. Sci."},{"key":"ref_17","unstructured":"Sitters, S., and McCue, P.M. (2014). Equine Reproductive Procedures, John Wiley & Sons, Inc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/j.cveq.2013.11.007","article-title":"Urogenital surgery performed with the mare standing","volume":"30","author":"Seabaugh","year":"2014","journal-title":"Vet. Clin. N. Am. Equine Pract."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1136\/vr.d4985","article-title":"Laparoscopic cholecystectomy under field conditions in Asiatic black bears (Ursus thibetanus) rescued from illegal bile farming in Vietnam","volume":"169","author":"Pizzi","year":"2011","journal-title":"Vet. Rec.-Engl. Ed."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1016\/S0093-691X(99)00006-0","article-title":"Live birth of a bear cub following nonsurgical embryo collection","volume":"51","author":"Boone","year":"1999","journal-title":"Theriogenology"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"O39","DOI":"10.1111\/vsu.12764","article-title":"Effect of patient rotation on ovary observation during laparoscopic ovariectomy in dogs","volume":"47","author":"Liehmann","year":"2018","journal-title":"Vet. Surg."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1111\/j.1740-8261.2006.00141.x","article-title":"Laparoscopic ultrasonography in six dogs","volume":"47","author":"Spinella","year":"2006","journal-title":"Vet. Radiol. 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