Energy is the currency of life, where a surplus allows survival and reproduction and a longstanding debt leads to death, yet monitoring energy expenditures in free-living animals has been relatively limited by available technology. Radio transmitters that have been specially modified to detect heart rate, however, allow for real-time estimation of energy expense in free-living, behaving animals. Red crossbills live at northern latitudes year-round and breed opportunistically throughout much of the year. They therefore offer a unique opportunity to examine the ecophysiology of different life cycle stages under drastically variable seasonal conditions. Here we present heart rate data of free-living, non-breeding and breeding red crossbills in the summer and winter. We discuss these variables in the context of red crossbills’ unique opportunistic and nomadic annual schedules and the highly seasonal conditions of our field site in Grand Teton National Park.
","abstract_html":"<p>Energy is the currency of life, where a surplus allows survival and reproduction and a longstanding debt leads to death, yet monitoring energy expenditures in free-living animals has been relatively limited by available technology. Radio transmitters that have been specially modified to detect heart rate, however, allow for real-time estimation of energy expense in free-living, behaving animals. Red crossbills live at northern latitudes year-round and breed opportunistically throughout much of the year. They therefore offer a unique opportunity to examine the ecophysiology of different life cycle stages under drastically variable seasonal conditions. Here we present heart rate data of free-living, non-breeding and breeding red crossbills in the summer and winter. We discuss these variables in the context of red crossbills’ unique opportunistic and nomadic annual schedules and the highly seasonal conditions of our field site in Grand Teton National Park.</p>","abstract_has_math":false,"creators":["Draud, Travis"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Open Access Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Jamie Cornelius, Ph.D.","Peter Bednekoff Ph.D.","Cara Shillington Ph.D."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-01-01T08:00:00Z","date_published":"2019-01-01T08:00:00Z","updated_at":"2026-07-24T02:17:33Z","subjects":["Breeding costs","Heart Rate","Loxia curvirostra","Opportunistic","Red Crossbill","Seasonal","Biology","Ecology and Evolutionary Biology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://commons.emich.edu/theses/1004","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Jamie Cornelius, Ph.D.","Peter Bednekoff Ph.D.","Cara Shillington Ph.D."]},{"key":"dc:creator","label":"Author","values":["Draud, Travis"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2020-02-24T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Open Access Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Breeding costs","Heart Rate","Loxia curvirostra","Opportunistic","Red Crossbill","Seasonal","Biology","Ecology and Evolutionary Biology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://commons.emich.edu/theses/1004"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Energy is the currency of life, where a surplus allows survival and reproduction and a longstanding debt leads to death, yet monitoring energy expenditures in free-living animals has been relatively limited by available technology. Radio transmitters that have been specially modified to detect heart rate, however, allow for real-time estimation of energy expense in free-living, behaving animals. Red crossbills live at northern latitudes year-round and breed opportunistically throughout much of the year. They therefore offer a unique opportunity to examine the ecophysiology of different life cycle stages under drastically variable seasonal conditions. Here we present heart rate data of free-living, non-breeding and breeding red crossbills in the summer and winter. We discuss these variables in the context of red crossbills’ unique opportunistic and nomadic annual schedules and the highly seasonal conditions of our field site in Grand Teton National Park.
"]},{"key":"dc:title","label":"Title","values":["The cost of breeding in the winter versus the summer in an opportunistic, northtemperate songbird, the red crossbill (Loxia curvirostra)"]}]}],"canonical_facts":{"dc:contributor":["Jamie Cornelius, Ph.D.","Peter Bednekoff Ph.D.","Cara Shillington Ph.D."],"dc:creator":["Draud, Travis"],"dc:date.available":["2020-02-24T08:00:00Z"],"dc:description.abstract":["Energy is the currency of life, where a surplus allows survival and reproduction and a longstanding debt leads to death, yet monitoring energy expenditures in free-living animals has been relatively limited by available technology. Radio transmitters that have been specially modified to detect heart rate, however, allow for real-time estimation of energy expense in free-living, behaving animals. Red crossbills live at northern latitudes year-round and breed opportunistically throughout much of the year. They therefore offer a unique opportunity to examine the ecophysiology of different life cycle stages under drastically variable seasonal conditions. Here we present heart rate data of free-living, non-breeding and breeding red crossbills in the summer and winter. We discuss these variables in the context of red crossbills’ unique opportunistic and nomadic annual schedules and the highly seasonal conditions of our field site in Grand Teton National Park.
"],"dc:identifier":["https://commons.emich.edu/theses/1004"],"dc:subject":["Breeding costs","Heart Rate","Loxia curvirostra","Opportunistic","Red Crossbill","Seasonal","Biology","Ecology and Evolutionary Biology"],"dc:title":["The cost of breeding in the winter versus the summer in an opportunistic, northtemperate songbird, the red crossbill (Loxia curvirostra)"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Open Access Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T02:17:33Z"}