{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T04:18:27Z","timestamp":1777522707437,"version":"3.51.4"},"reference-count":36,"publisher":"SAGE Publications","issue":"3","license":[{"start":{"date-parts":[[2014,5,1]],"date-time":"2014-05-01T00:00:00Z","timestamp":1398902400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Adaptive Behavior"],"published-print":{"date-parts":[[2014,6]]},"abstract":"<jats:p>Eastern gray squirrels produce alarm calls\u2014vocalizations used in the presence of danger that influence the behavior of some receivers. This influence is possible because the alarm calls\u2019 rate, duration, and structure contain information about the threat and the caller. Gray squirrels\u2019 mix of different structural call types (kuks and quaas) could contain information on potential internal influences within the squirrel. Hidden Markov models (HMMs) are ideal tools to investigate whether hidden states explain the frequencies of kuks versus quaas throughout an alarm call sequence. In this study, we compare the ability of an iid (independent and identically distributed) model and two- to six-state HMMs to represent observed sequences of kukking, quaaing, and periods of silence. Audio recordings of 44 gray squirrels were collected and the first 30 s of each alarm call sequence was coded based on spectrograms. A number of HMMs were fitted, and the overall fit of the observed sequences to each model was assessed using Akaike\u2019s Information Criterion (AIC) and Bayesian Information Criterion (BIC), and Monte Carlo methods. The five-state HMM fit the observed call frequencies better than the other models, suggesting that the squirrels\u2019 alarm calling sequences are influenced by a more complex temporal sequencing of acoustic units.<\/jats:p>","DOI":"10.1177\/1059712314529981","type":"journal-article","created":{"date-parts":[[2014,5,1]],"date-time":"2014-05-01T23:50:39Z","timestamp":1398988239000},"page":"180-188","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":2,"title":["Hidden Markov models of eastern gray squirrel (\n                    <i>Sciurus carolinensis<\/i>\n                    ) alarm calls"],"prefix":"10.1177","volume":"22","author":[{"given":"B Alexander","family":"Simmons","sequence":"first","affiliation":[{"name":"Department of Biology, University of Miami, Coral Gables, Florida, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thaddeus R","family":"McRae","sequence":"additional","affiliation":[{"name":"Department of Biology, University of Miami, Coral Gables, Florida, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2014,5,1]]},"reference":[{"key":"bibr1-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/j.paid.2006.09.018"},{"key":"bibr2-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1086\/286062"},{"key":"bibr3-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1163\/156853985x00316"},{"key":"bibr4-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1086\/283206"},{"key":"bibr5-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1046\/j.1439-0310.2002.00816.x"},{"key":"bibr6-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1006\/anbe.1997.0620"},{"key":"bibr7-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1046\/j.1439-0310.2001.00659.x"},{"key":"bibr8-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/j.paid.2006.10.001"},{"key":"bibr9-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1086\/516719"},{"key":"bibr10-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/j.anbehav.2009.07.021"},{"key":"bibr11-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1111\/1467-9876.00136"},{"key":"bibr12-1059712314529981","first-page":"169","volume":"4","author":"Jia Y.","year":"2000","journal-title":"ICSLP 2000"},{"key":"bibr13-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0024516"},{"key":"bibr14-1059712314529981","unstructured":"Kenny D. A., Kaniskan B., McCoach D. B. (2011). The performance of RMSEA in models with small degrees of freedom. Unpublished paper, University of Connecticut."},{"key":"bibr15-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1111\/j.1439-0310.1984.tb01365.x"},{"key":"bibr16-1059712314529981","doi-asserted-by":"publisher","DOI":"10.2307\/1380274"},{"key":"bibr17-1059712314529981","doi-asserted-by":"publisher","DOI":"10.2307\/1380852"},{"key":"bibr18-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2001.1773"},{"key":"bibr19-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/s1364-6613(00)01840-4"},{"key":"bibr20-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1006\/anbe.1996.0192"},{"key":"bibr21-1059712314529981","volume-title":"Predator-specificity of multimodal alarm signals in the eastern gray squirrel","author":"McRae T. R.","year":"2012"},{"key":"bibr22-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/s0092-8240(83)80017-2"},{"key":"bibr23-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1111\/j.1439-0310.1978.tb01438.x"},{"key":"bibr24-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1093\/czoolo\/56.3.313"},{"key":"bibr25-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/j.anbehav.2008.12.029"},{"key":"bibr26-1059712314529981","doi-asserted-by":"publisher","DOI":"10.3390\/a2041410"},{"key":"bibr27-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1007\/bf00299364"},{"key":"bibr28-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1126\/science.7433999"},{"key":"bibr29-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1016\/s0003-3472(80)80097-2"},{"key":"bibr30-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1126\/science.197.4310.1246"},{"key":"bibr31-1059712314529981","unstructured":"Turner R., Liu L. (2013). Hidden Markov models with discrete non-parametric observation distributions. From CRAN Repository http:\/\/www.math.unb.ca\/~rolf\/"},{"key":"bibr32-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1155\/2002\/874560"},{"key":"bibr33-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1111\/j.1541-0420.2005.00372.x"},{"key":"bibr34-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1007\/s11263-006-4329-6"},{"key":"bibr35-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1006\/anbe.2001.1914"},{"key":"bibr36-1059712314529981","doi-asserted-by":"publisher","DOI":"10.1111\/j.1541-0420.2007.00939.x"}],"container-title":["Adaptive Behavior"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/1059712314529981","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/1059712314529981","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/1059712314529981","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T16:18:27Z","timestamp":1777393107000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/1059712314529981"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,5,1]]},"references-count":36,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2014,6]]}},"alternative-id":["10.1177\/1059712314529981"],"URL":"https:\/\/doi.org\/10.1177\/1059712314529981","relation":{},"ISSN":["1059-7123","1741-2633"],"issn-type":[{"value":"1059-7123","type":"print"},{"value":"1741-2633","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,5,1]]}}}