Agonistic behavior in three species of chipmunks, Tamias merriami, T. obscurus, and T. speciosus, was compared at seven locations in the San Bernardino and San Jacinto Mountains of southern California. The study was conducted during the post-breeding periods in the summers of 1983 and 1984. Chipmunks were attracted to feeding stations baited with sunflower seeds. Their aggressive interactions were classed as displacement, short chase, long chase, or fight. Over 500 encounters were recorded.
Short chase was the most frequent agonistic mode, followed by displacement, with fewer long chases, and rare fights. Observations were made both at areas where T. merriami or T. obscurus was the exclusive species, and at areas where two or all three species were present. T. merriami showed the most intra- and interspecific aggression, followed by T. obscurus, then T. speciosus. Dominance hierarchies were determined at three sites. There were some dominance reversals in both T. merriami and T. obscurus. No correlation was found between dominance and size, sex, or species. It was felt that the unique distribution of these chipmunks is not due merely to habitat preference, because of the overlap of habitats where T. merriami and T. obscurus lived isolated from other species of chipmunks; but rather that aggressive interactions, selected for by both species to protect scarce food supplies, serve to maintain existing isolated distributions.
","abstract_html":"<p>Agonistic behavior in three species of chipmunks, Tamias merriami, T. obscurus, and T. speciosus, was compared at seven locations in the San Bernardino and San Jacinto Mountains of southern California. The study was conducted during the post-breeding periods in the summers of 1983 and 1984. Chipmunks were attracted to feeding stations baited with sunflower seeds. Their aggressive interactions were classed as displacement, short chase, long chase, or fight. Over 500 encounters were recorded.</p> <p>Short chase was the most frequent agonistic mode, followed by displacement, with fewer long chases, and rare fights. Observations were made both at areas where T. merriami or T. obscurus was the exclusive species, and at areas where two or all three species were present. T. merriami showed the most intra- and interspecific aggression, followed by T. obscurus, then T. speciosus. Dominance hierarchies were determined at three sites. There were some dominance reversals in both T. merriami and T. obscurus. No correlation was found between dominance and size, sex, or species. It was felt that the unique distribution of these chipmunks is not due merely to habitat preference, because of the overlap of habitats where T. merriami and T. obscurus lived isolated from other species of chipmunks; but rather that aggressive interactions, selected for by both species to protect scarce food supplies, serve to maintain existing isolated distributions.</p>","abstract_has_math":false,"creators":["Vandervort, Ronald C"],"institution":null,"degree_name":"Master of Arts (MA)","degree_level":"Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Leonard R. Brand","Earl W. Lathrop","Elwood S. McCluskey"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1985,"date_issued":"1985-09-01T07:00:00Z","date_published":"1985-09-01T07:00:00Z","updated_at":"2026-07-24T02:52:59Z","subjects":["Biology","Chipmunks -- Behavior; Aggressive behavior in animals; Rodents -- California."],"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/742","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Leonard R. Brand","Earl W. Lathrop","Elwood S. McCluskey"]},{"key":"dc:creator","label":"Author","values":["Vandervort, Ronald C"]}]},{"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","Chipmunks -- Behavior; Aggressive behavior in animals; Rodents -- California."]}]},{"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/742"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Agonistic behavior in three species of chipmunks, Tamias merriami, T. obscurus, and T. speciosus, was compared at seven locations in the San Bernardino and San Jacinto Mountains of southern California. The study was conducted during the post-breeding periods in the summers of 1983 and 1984. Chipmunks were attracted to feeding stations baited with sunflower seeds. Their aggressive interactions were classed as displacement, short chase, long chase, or fight. Over 500 encounters were recorded.
Short chase was the most frequent agonistic mode, followed by displacement, with fewer long chases, and rare fights. Observations were made both at areas where T. merriami or T. obscurus was the exclusive species, and at areas where two or all three species were present. T. merriami showed the most intra- and interspecific aggression, followed by T. obscurus, then T. speciosus. Dominance hierarchies were determined at three sites. There were some dominance reversals in both T. merriami and T. obscurus. No correlation was found between dominance and size, sex, or species. It was felt that the unique distribution of these chipmunks is not due merely to habitat preference, because of the overlap of habitats where T. merriami and T. obscurus lived isolated from other species of chipmunks; but rather that aggressive interactions, selected for by both species to protect scarce food supplies, serve to maintain existing isolated distributions.
"]},{"key":"dc:title","label":"Title","values":["Intraspecific and Interspecific Agonistic Behavior in Chipmunks, TAMIAS MERRIAMI, T. OBSCURUS, and T. SPECIOSUS (Rodentia: Sciuridae)"]}]}],"canonical_facts":{"dc:contributor":["Leonard R. Brand","Earl W. Lathrop","Elwood S. McCluskey"],"dc:creator":["Vandervort, Ronald C"],"dc:description.abstract":["Agonistic behavior in three species of chipmunks, Tamias merriami, T. obscurus, and T. speciosus, was compared at seven locations in the San Bernardino and San Jacinto Mountains of southern California. The study was conducted during the post-breeding periods in the summers of 1983 and 1984. Chipmunks were attracted to feeding stations baited with sunflower seeds. Their aggressive interactions were classed as displacement, short chase, long chase, or fight. Over 500 encounters were recorded.
Short chase was the most frequent agonistic mode, followed by displacement, with fewer long chases, and rare fights. Observations were made both at areas where T. merriami or T. obscurus was the exclusive species, and at areas where two or all three species were present. T. merriami showed the most intra- and interspecific aggression, followed by T. obscurus, then T. speciosus. Dominance hierarchies were determined at three sites. There were some dominance reversals in both T. merriami and T. obscurus. No correlation was found between dominance and size, sex, or species. It was felt that the unique distribution of these chipmunks is not due merely to habitat preference, because of the overlap of habitats where T. merriami and T. obscurus lived isolated from other species of chipmunks; but rather that aggressive interactions, selected for by both species to protect scarce food supplies, serve to maintain existing isolated distributions.
"],"dc:identifier":["https://scholarsrepository.llu.edu/etd/742"],"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","Chipmunks -- Behavior; Aggressive behavior in animals; Rodents -- California."],"dc:title":["Intraspecific and Interspecific Agonistic Behavior in Chipmunks, TAMIAS MERRIAMI, T. OBSCURUS, and T. SPECIOSUS (Rodentia: Sciuridae)"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Arts (MA)"]},"updated_at":"2026-07-24T02:52:59Z"}