The timing of daily opening of the nest entrance by the red harvester ant Popnomyrmex californicus was studied during all four seasons. Multiple regression analysis of several , environmental variables shows that the variation from day to day in mean opening time can be attributed to temperature differences, with the time that a given temperature was reached being the most important single variable for the autumn days studied. An equation incorporating this and the minimum temperature was sufficient to specify the mean opening time to within a few minutes. For the spring days, it was necessary to combine sunrise time with the time a particular temperature was reached. Standard temperatures from a nearby weather station served essentially as well as those taken at the nests.
On the hottest nights in August over half the nests never closed at all, and on the coldest days in winter most of the nests stayed closed.
Artificial heating of nests after they had closed advanced opening time markedly although several hours passed before most openings occurred; over half opened before dawn. Also in a few cases, nests opened in the dark naturally. Thus light is not necessary for opening.
","abstract_html":"<p>The timing of daily opening of the nest entrance by the red harvester ant Popnomyrmex californicus was studied during all four seasons. Multiple regression analysis of several , environmental variables shows that the variation from day to day in mean opening time can be attributed to temperature differences, with the time that a given temperature was reached being the most important single variable for the autumn days studied. An equation incorporating this and the minimum temperature was sufficient to specify the mean opening time to within a few minutes. For the spring days, it was necessary to combine sunrise time with the time a particular temperature was reached. Standard temperatures from a nearby weather station served essentially as well as those taken at the nests.</p> <p>On the hottest nights in August over half the nests never closed at all, and on the coldest days in winter most of the nests stayed closed.</p> <p>Artificial heating of nests after they had closed advanced opening time markedly although several hours passed before most openings occurred; over half opened before dawn. Also in a few cases, nests opened in the dark naturally. Thus light is not necessary for opening.</p>","abstract_has_math":false,"creators":["Smith, A. Dwight"],"institution":null,"degree_name":"Master of Arts (MA)","degree_level":"Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Elwood S. McCluskey","Raymond E. Ryckman","Jan W. Kuzma"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1968,"date_issued":"1968-12-01T08:00:00Z","date_published":"1968-12-01T08:00:00Z","updated_at":"2026-07-24T02:53:20Z","subjects":["Biology","Entomology","Ants -- Behavior"],"languages":["English"],"rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsrepository.llu.edu/etd/948","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Elwood S. McCluskey","Raymond E. Ryckman","Jan W. Kuzma"]},{"key":"dc:creator","label":"Author","values":["Smith, A. Dwight"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Arts (MA)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology","Entomology","Ants -- Behavior"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:rights","label":"Dc Rights","values":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsrepository.llu.edu/etd/948"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The timing of daily opening of the nest entrance by the red harvester ant Popnomyrmex californicus was studied during all four seasons. Multiple regression analysis of several , environmental variables shows that the variation from day to day in mean opening time can be attributed to temperature differences, with the time that a given temperature was reached being the most important single variable for the autumn days studied. An equation incorporating this and the minimum temperature was sufficient to specify the mean opening time to within a few minutes. For the spring days, it was necessary to combine sunrise time with the time a particular temperature was reached. Standard temperatures from a nearby weather station served essentially as well as those taken at the nests.
On the hottest nights in August over half the nests never closed at all, and on the coldest days in winter most of the nests stayed closed.
Artificial heating of nests after they had closed advanced opening time markedly although several hours passed before most openings occurred; over half opened before dawn. Also in a few cases, nests opened in the dark naturally. Thus light is not necessary for opening.
"]},{"key":"dc:title","label":"Title","values":["Ecological Determination of the Hour of Nest Opening by an Ant"]}]}],"canonical_facts":{"dc:contributor":["Elwood S. McCluskey","Raymond E. Ryckman","Jan W. Kuzma"],"dc:creator":["Smith, A. Dwight"],"dc:description.abstract":["The timing of daily opening of the nest entrance by the red harvester ant Popnomyrmex californicus was studied during all four seasons. Multiple regression analysis of several , environmental variables shows that the variation from day to day in mean opening time can be attributed to temperature differences, with the time that a given temperature was reached being the most important single variable for the autumn days studied. An equation incorporating this and the minimum temperature was sufficient to specify the mean opening time to within a few minutes. For the spring days, it was necessary to combine sunrise time with the time a particular temperature was reached. Standard temperatures from a nearby weather station served essentially as well as those taken at the nests.
On the hottest nights in August over half the nests never closed at all, and on the coldest days in winter most of the nests stayed closed.
Artificial heating of nests after they had closed advanced opening time markedly although several hours passed before most openings occurred; over half opened before dawn. Also in a few cases, nests opened in the dark naturally. Thus light is not necessary for opening.
"],"dc:identifier":["https://scholarsrepository.llu.edu/etd/948"],"dc:language":["English"],"dc:rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"dc:subject":["Biology","Entomology","Ants -- Behavior"],"dc:title":["Ecological Determination of the Hour of Nest Opening by an Ant"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Arts (MA)"]},"updated_at":"2026-07-24T02:53:20Z"}