{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T15:44:18Z","timestamp":1782747858173,"version":"3.54.5"},"reference-count":46,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T00:00:00Z","timestamp":1782086400000},"content-version":"vor","delay-in-days":21,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T00:00:00Z","timestamp":1780272000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["esajournals.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ecology"],"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Close\u2010kin mark\u2013recapture (CKMR) is a promising approach for assessing population size of species that have been difficult to survey using more traditional methods. Here, we combine individual and close\u2010kin mark\u2013recapture in a single modeling framework (ICKMR) and provide an example of study design using this approach for Pacific walrus (\n                    <jats:italic>Odobenus rosmarus divergens<\/jats:italic>\n                    ). We develop the ICKMR model and test it using simulated datasets, then use properties of the pseudo\u2010likelihood to investigate the expected precision in estimates of abundance with different proposed survey designs. Our motivating example, the Pacific walrus, is an ice\u2010associated marine mammal found in the Bering and Chukchi seas, where it is an important resource for Indigenous peoples. Pacific walrus abundance declined in the late 20th century, and it is currently a species of conservation concern due to potential impacts of climate change, particularly the loss of sea ice. To reduce uncertainty in population size estimates, researchers undertook a genetic mark\u2013recapture sampling campaign from 2013 to 2017 and collected tissue samples from over 8000 individuals. Another campaign of a similar scale is ongoing (2023\u20132028). While sample collection was designed for individual mark\u2013recapture, advances in CKMR methods and associated molecular techniques mean that these samples could also be suitable for CKMR. The advantages of CKMR over mark\u2013recapture include an increased effective sample size (because each individual tags itself and its parents, siblings, and offspring) and additional insights into demographic quantities of interest. To make best use of genetic samples, we combine individual mark\u2013recapture (IMR) with CKMR (ICKMR) and investigate whether different sampling strategies can increase precision in estimates of abundance. Our modeling approach includes special considerations for walrus life history, including a multi\u2010year inter\u2010birth interval. We found that expected coefficients of variation (CVs) of the ICKMR estimates of abundance, adult female survival, juvenile female survival, and proportion of breeding females are lower than those expected from IMR alone, and with ICKMR, fewer years of sampling can be conducted to obtain sufficient precision in estimates of abundance. This work demonstrates the utility of ICKMR and could be applicable across a variety of taxa.\n                  <\/jats:p>","DOI":"10.1002\/ecy.70377","type":"journal-article","created":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T04:12:06Z","timestamp":1782187926000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Combining individual and close\u2010kin mark\u2013recapture to design an effective wildlife population survey"],"prefix":"10.1002","volume":"107","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0147-8367","authenticated-orcid":false,"given":"Eiren K.","family":"Jacobson","sequence":"first","affiliation":[{"name":"Centre for Research into Ecological &amp; Environmental Modelling and School of Mathematics &amp; Statistics, University of St Andrews  St Andrews UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark V.","family":"Bravington","sequence":"additional","affiliation":[{"name":"Estimark Research  Hobart Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rebecca L.","family":"Taylor","sequence":"additional","affiliation":[{"name":"US Geological Survey Alaska Science Center  Anchorage Alaska USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9058-4481","authenticated-orcid":false,"given":"Irina S.","family":"Trukhanova","sequence":"additional","affiliation":[{"name":"North Pacific Wildlife Consulting, LLC  Seattle Washington USA"},{"name":"US Fish and Wildlife Service, Marine Mammals Management  Anchorage Alaska USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David L.","family":"Miller","sequence":"additional","affiliation":[{"name":"Independent Researcher  Dundee UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William S.","family":"Beatty","sequence":"additional","affiliation":[{"name":"US Geological Survey Upper Midwest Environmental Sciences Center  La Crosse Wisconsin USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,6,22]]},"reference":[{"key":"e_1_2_9_2_1","unstructured":"Baylis S. M.2019.\u201cfishSim: R Tool for Simulation of Fish Population Dynamics.\u201dhttps:\/\/github.com\/SMBaylis\/fishSim. Accessed 2025\u201012\u201011."},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.3354\/meps14131"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1093\/jmammal\/gyaa050"},{"key":"e_1_2_9_5_1","unstructured":"Bravington M. V. S.Jarman andH.Skaug.2014.\u201cAntarctic Blue Whale surveys: augmenting via genetics for close\u2010kin and ordinal age. Scientific Committee paper SC\/65b\/SH17. International Whaling Commission.\u201d"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1214\/16-STS552"},{"key":"e_1_2_9_7_1","volume-title":"Matrix Population Models: Construction, Analysis, and Interpretation","author":"Caswell H.","year":"2001"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/ece3.6296"},{"key":"e_1_2_9_9_1","volume-title":"Next\u2010generation Close\u2010kin Mark Recapture: Using SNPs to Identify Half\u2010Sibling Pairs in Southern Bluefin Tuna and Estimate Abundance, Mortality and Selectivity","author":"Davies C.","year":"2020"},{"key":"e_1_2_9_10_1","doi-asserted-by":"crossref","unstructured":"Fay F. H.1982.\u201cEcology and biology of the Pacific walrus Odobenus rosmarus divergensIlliger\u201d. InNorth American Fauna74. 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In Ecology (V1.0).\u201dZenodo.https:\/\/doi.org\/10.5281\/zenodo.18782247","DOI":"10.1002\/ecy.70377"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.3354\/meps10057"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1002\/jwmg.22686"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.3354\/meps14635"},{"issue":"2","key":"e_1_2_9_20_1","first-page":"85","article-title":"Growth and Reproduction of Captive Pacific Walrus (Odobenus rosmarus divergens)","volume":"18","author":"Katsumata E.","year":"2020","journal-title":"Veterinary Integrative Sciences"},{"key":"e_1_2_9_21_1","volume-title":"Applied Mathematical Demography","author":"Keyfitz N.","year":"2005"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1134\/S1062359014080068"},{"key":"e_1_2_9_23_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-023-38639-z"},{"key":"e_1_2_9_24_1","unstructured":"MacCracken J. G. W. S.Beatty J. L.Garlich\u2010Miller M. L.Kissling andJ. 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