{"id":{"repo_id":"brock","oai_identifier":"oai:brocku.scholaris.ca:10464/19426"},"canonical_url":"https://search.dev.ndltd.org/etd/brock/oai:brocku.scholaris.ca:10464/19426","repository":{"repo_id":"brock","name":"Brock University","base_url":"https://brocku.scholaris.ca/server/oai/request"},"display":{"title":"Physiological and behavioural responses to temperature and humidity in fossorial amphibians","abstract":"Amphibians have been the focus of research investigating physiological and behavioural responses to temperature and humidity for over two centuries. However, fossorial (i.e., underground-dwelling) amphibians remain comparatively understudied despite the unique environmental pressures that they experience. The overarching goal of this thesis was to understand how temperature and humidity affected the physiology and behaviour of fossorial amphibians. By combining phylogenetic methods and laboratory experiments, my chapters address the topics of energetics, hydroregulation, thermoregulation, and overwintering emergence. First, I tested the prevailing hypothesis that fossorial amphibians should have reduced metabolic rates compared to non-fossorial ones. My results did not support this hypothesis, highlighting that a reduction in amphibian metabolism would be evolutionary unlikely given the limited energetic benefit. Next, I assessed the effect of seasonal acclimatisation (spring versus autumn) on the thermal sensitivity of metabolism and water loss in Ambystoma maculatum. My findings suggested that acute changes in temperature affected energy and water budgets. However, acclimatory changes in temperature affected metabolism but not water loss. I then examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in A. maculatum. I found that salamanders defended a constant vapour pressure deficit between temperatures, which was achieved by targeting higher relative humidity at 22°C than at 17°C. This suggests that salamanders can detect their rates of evaporative water loss, and employ behaviours to limit increased evaporative demand at warmer temperatures. I also evaluated how behavioural thermoregulation differed between seasons (active versus overwintering), and found that A. maculatum engaged in active behavioural thermoregulation despite the prediction that fossorial ectotherms should show little thermoregulatory motivation. Lastly, I assessed how extrinsic (temperature and negative geotaxis) and intrinsic (migration restlessness) factors influenced overwintering emergence in A. maculatum. My results suggested that migration restlessness and negative geotaxis collectively influenced overwintering emergence, shedding light on how fossorial amphibians may navigate complex underground environments. Together, my chapters underscore the intricate coupling between physiology and behaviour in mediating how fossorial amphibians respond toshort- and long-term environmental variation.","abstract_html":"Amphibians have been the focus of research investigating physiological and behavioural responses to temperature and humidity for over two centuries. However, fossorial (i.e., underground-dwelling) amphibians remain comparatively understudied despite the unique environmental pressures that they experience. The overarching goal of this thesis was to understand how temperature and humidity affected the physiology and behaviour of fossorial amphibians. By combining phylogenetic methods and laboratory experiments, my chapters address the topics of energetics, hydroregulation, thermoregulation, and overwintering emergence. First, I tested the prevailing hypothesis that fossorial amphibians should have reduced metabolic rates compared to non-fossorial ones. My results did not support this hypothesis, highlighting that a reduction in amphibian metabolism would be evolutionary unlikely given the limited energetic benefit. Next, I assessed the effect of seasonal acclimatisation (spring versus autumn) on the thermal sensitivity of metabolism and water loss in Ambystoma maculatum. My findings suggested that acute changes in temperature affected energy and water budgets. However, acclimatory changes in temperature affected metabolism but not water loss. I then examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in A. maculatum. I found that salamanders defended a constant vapour pressure deficit between temperatures, which was achieved by targeting higher relative humidity at 22°C than at 17°C. This suggests that salamanders can detect their rates of evaporative water loss, and employ behaviours to limit increased evaporative demand at warmer temperatures. I also evaluated how behavioural thermoregulation differed between seasons (active versus overwintering), and found that A. maculatum engaged in active behavioural thermoregulation despite the prediction that fossorial ectotherms should show little thermoregulatory motivation. Lastly, I assessed how extrinsic (temperature and negative geotaxis) and intrinsic (migration restlessness) factors influenced overwintering emergence in A. maculatum. My results suggested that migration restlessness and negative geotaxis collectively influenced overwintering emergence, shedding light on how fossorial amphibians may navigate complex underground environments. Together, my chapters underscore the intricate coupling between physiology and behaviour in mediating how fossorial amphibians respond toshort- and long-term environmental variation.","abstract_has_math":false,"creators":["Danilo Giacometti"],"institution":"Brock University","degree_name":"Ph.D. Biological Sciences","degree_level":"Doctoral","degree_discipline":"Faculty of Mathematics and Science","degree_department":"Department of Biological Sciences","school":null,"contributors":[],"advisors":["Glenn Tattersall"],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-06-10T16:58:16Z","date_published":"2025-06-10T16:58:16Z","updated_at":"2026-07-24T01:23:02Z","subjects":["Amphibian","Behaviour","Hydroregulation","Physiology","Thermoregulation"],"languages":["eng"],"rights":["Attribution-NonCommercial-NoDerivatives 4.0 International"],"rights_urls":["http://creativecommons.org/licenses/by-nc-nd/4.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10464/19426","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Glenn Tattersall"]},{"key":"dc:contributor.department","label":"Department","values":["Department of Biological Sciences"]},{"key":"dc:creator","label":"Author","values":["Danilo Giacometti"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-06-10T16:58:16Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-06-10T16:58:16Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-06-10T16:58:16Z"]},{"key":"dc:publisher","label":"Institution","values":["Brock University"]},{"key":"dc:type","label":"Dc Type","values":["Electronic Thesis or Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Faculty of Mathematics and Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D. Biological Sciences"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Amphibian","Behaviour","Hydroregulation","Physiology","Thermoregulation"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Attribution-NonCommercial-NoDerivatives 4.0 International"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://creativecommons.org/licenses/by-nc-nd/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10464/19426"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Amphibians have been the focus of research investigating physiological and behavioural responses to temperature and humidity for over two centuries. However, fossorial (i.e., underground-dwelling) amphibians remain comparatively understudied despite the unique environmental pressures that they experience. The overarching goal of this thesis was to understand how temperature and humidity affected the physiology and behaviour of fossorial amphibians. By combining phylogenetic methods and laboratory experiments, my chapters address the topics of energetics, hydroregulation, thermoregulation, and overwintering emergence. First, I tested the prevailing hypothesis that fossorial amphibians should have reduced metabolic rates compared to non-fossorial ones. My results did not support this hypothesis, highlighting that a reduction in amphibian metabolism would be evolutionary unlikely given the limited energetic benefit. Next, I assessed the effect of seasonal acclimatisation (spring versus autumn) on the thermal sensitivity of metabolism and water loss in Ambystoma maculatum. My findings suggested that acute changes in temperature affected energy and water budgets. However, acclimatory changes in temperature affected metabolism but not water loss. I then examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in A. maculatum. I found that salamanders defended a constant vapour pressure deficit between temperatures, which was achieved by targeting higher relative humidity at 22°C than at 17°C. This suggests that salamanders can detect their rates of evaporative water loss, and employ behaviours to limit increased evaporative demand at warmer temperatures. I also evaluated how behavioural thermoregulation differed between seasons (active versus overwintering), and found that A. maculatum engaged in active behavioural thermoregulation despite the prediction that fossorial ectotherms should show little thermoregulatory motivation. Lastly, I assessed how extrinsic (temperature and negative geotaxis) and intrinsic (migration restlessness) factors influenced overwintering emergence in A. maculatum. My results suggested that migration restlessness and negative geotaxis collectively influenced overwintering emergence, shedding light on how fossorial amphibians may navigate complex underground environments. Together, my chapters underscore the intricate coupling between physiology and behaviour in mediating how fossorial amphibians respond toshort- and long-term environmental variation."]},{"key":"dc:title","label":"Title","values":["Physiological and behavioural responses to temperature and humidity in fossorial amphibians"]}]}],"canonical_facts":{"dc:contributor.advisor":["Glenn Tattersall"],"dc:contributor.department":["Department of Biological Sciences"],"dc:creator":["Danilo Giacometti"],"dc:date.accessioned":["2025-06-10T16:58:16Z"],"dc:date.available":["2025-06-10T16:58:16Z"],"dc:date.issued":["2025-06-10T16:58:16Z"],"dc:description.abstract":["Amphibians have been the focus of research investigating physiological and behavioural responses to temperature and humidity for over two centuries. However, fossorial (i.e., underground-dwelling) amphibians remain comparatively understudied despite the unique environmental pressures that they experience. The overarching goal of this thesis was to understand how temperature and humidity affected the physiology and behaviour of fossorial amphibians. By combining phylogenetic methods and laboratory experiments, my chapters address the topics of energetics, hydroregulation, thermoregulation, and overwintering emergence. First, I tested the prevailing hypothesis that fossorial amphibians should have reduced metabolic rates compared to non-fossorial ones. My results did not support this hypothesis, highlighting that a reduction in amphibian metabolism would be evolutionary unlikely given the limited energetic benefit. Next, I assessed the effect of seasonal acclimatisation (spring versus autumn) on the thermal sensitivity of metabolism and water loss in Ambystoma maculatum. My findings suggested that acute changes in temperature affected energy and water budgets. However, acclimatory changes in temperature affected metabolism but not water loss. I then examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in A. maculatum. I found that salamanders defended a constant vapour pressure deficit between temperatures, which was achieved by targeting higher relative humidity at 22°C than at 17°C. This suggests that salamanders can detect their rates of evaporative water loss, and employ behaviours to limit increased evaporative demand at warmer temperatures. I also evaluated how behavioural thermoregulation differed between seasons (active versus overwintering), and found that A. maculatum engaged in active behavioural thermoregulation despite the prediction that fossorial ectotherms should show little thermoregulatory motivation. Lastly, I assessed how extrinsic (temperature and negative geotaxis) and intrinsic (migration restlessness) factors influenced overwintering emergence in A. maculatum. My results suggested that migration restlessness and negative geotaxis collectively influenced overwintering emergence, shedding light on how fossorial amphibians may navigate complex underground environments. Together, my chapters underscore the intricate coupling between physiology and behaviour in mediating how fossorial amphibians respond toshort- and long-term environmental variation."],"dc:identifier.uri":["https://hdl.handle.net/10464/19426"],"dc:language.iso":["eng"],"dc:publisher":["Brock University"],"dc:rights":["Attribution-NonCommercial-NoDerivatives 4.0 International"],"dc:rights.uri":["http://creativecommons.org/licenses/by-nc-nd/4.0/"],"dc:subject":["Amphibian","Behaviour","Hydroregulation","Physiology","Thermoregulation"],"dc:title":["Physiological and behavioural responses to temperature and humidity in fossorial amphibians"],"dc:type":["Electronic Thesis or Dissertation"],"thesis:degree_discipline":["Faculty of Mathematics and Science"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Ph.D. Biological Sciences"]},"updated_at":"2026-07-24T01:23:02Z"}