“There is plenty of research showing what happens to ecosystems when Argentine ants invade: many native ant species decline, and other native species that depend on them follow<\/a>,” says Donaldson-Matasci. “Yet relatively little is known about what causes this decline<\/a> and what might prevent it especially for harvester ants. <\/p>\n\n\n\n “Part of the problem is that the vast majority of this research has been done in cool, coastal regions of California where Argentine ants seem to have the upper hand,” Donaldson-Matasci explains. “For example, my collaborator David Holway at UC San Diego, says that at the field site where he has studied harvester ants for decades, less than a handful of colonies remain. This makes it incredibly hard to study the behavioral interactions between native harvester ants and invasive Argentine ants. Instead, here at the Bernard Field Station, we have a thriving population of native harvester ants where I can observe daily conflict between the species. The frequency of interactions makes it possible for us to study how harvester ants are responding, and whether there is anything they are doing to limit the Argentine ant’s impact.”<\/p>\n\n\n\n Donaldson-Matasci will develop new expertise in chemical ecology and analytical chemistry while expanding her work in field ecology. She will work with students to document the timing and pace of natural foraging activity in colonies of both species and relate those patterns to microclimate conditions. They will also test how individual harvester ants respond to chemical cues indicating the presence of Argentine ants and experimentally assess whether entire colonies adjust the timing or direction of their foraging in response to those cues.<\/p>\n\n\n\n The research will test the hypothesis that harvester ants survive invasion partly by avoiding Argentine ants, for example by limiting their foraging activity in space or time. Hot, dry conditions may help make that possible by restricting Argentine ant activity to cooler, moister microclimates.<\/p>\n\n\n\n The question is particularly captivating because competition for food does not readily explain the decline of native harvester ants. Argentine ants are highly effective competitors, using large colonies and sophisticated communication to exploit resources and exclude other species. However, harvester ants primarily eat seeds, giving their diet little overlap with that of Argentine ants. The mechanism behind their decline in invaded areas therefore remains unclear.<\/p>\n\n\n\n Donaldson-Matasci\u2019s research could help reveal how environmental conditions and behavior influence the effects of biological invasion by focusing on a less-studied inland site where the two species still interact. The project is intended to lay the groundwork for a larger collaborative study comparing interactions between Argentine and harvester ants across an environmental gradient, from cooler coastal regions where harvester ant populations are declining to dry inland regions where they continue to thrive.<\/p>\n\n\n\n The ecological implications extend beyond the two ant species. Harvester ants are important seed dispersers in natural ecosystems, which is a role Argentine ants do not fulfill. Understanding how behavioral and climate factors affect their ability to persist could provide broader insight into how biological invasion, climate change and increasing urbanization shape native harvester ant communities and potentially the vegetation communities that depend on them.<\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" Harvey Mudd College Professor of Biology Matina Donaldson-Matasci has received a $363,000 National Science Foundation (NSF) grant to investigate how […]<\/p>\n","protected":false},"author":25,"featured_media":4605,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[967,26],"class_list":["post-15805","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general-feed","category-research"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts\/15805","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/users\/25"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/comments?post=15805"}],"version-history":[{"count":2,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts\/15805\/revisions"}],"predecessor-version":[{"id":15808,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts\/15805\/revisions\/15808"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/media\/4605"}],"wp:attachment":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/media?parent=15805"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/categories?post=15805"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"student](\"https:\/\/www.hmc.edu\/about\/wp-content\/uploads\/sites\/2\/2026\/10\/student-ant-research.jpg\")
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