About

Natasha Tigreros leads The Stressed Herbivore Lab at The University of Arizona, focusing on the behavioral and physiological stress responses of organisms as they persist under new environmental conditions. Her research addresses the complexities of studying stress responses in changing environments, particularly those altered by human activities. She highlights two main challenges: the connection between environmental stressors and stress responses across broad time scales, including minutes to years and across life stages, seasons, and generations; and the need to establish the significance of these responses in real-world settings where human-altered landscapes introduce new stressors or modify existing ones in frequency and magnitude. To tackle these challenges, her lab combines laboratory experiments with greenhouse and field observations, integrating tools and approaches from diverse fields such as nutritional ecology, behavior and physiology, evolutionary ecology, and landscape ecology. Her work primarily involves insects, especially those herbivorous at some point in their life cycle, including many beetles and butterflies.

Research topics

• Ecology
• Biology
• Zoology
• Animal science
• Endocrinology
• Genetics
• Physics
• Evolutionary biology
• Astronomy
• Geography
• Art

Selected publications

• Oxidation and allocation of nectar amino acids during butterfly flight

  Journal of Experimental Biology · 2026-01-02

  articleOpen access1st authorCorresponding

  Flying animals face extreme energetic demands, relying mainly on carbohydrates and lipids, with occasional contributions from proteins and amino acids. In nectar-feeding species such as butterflies and hummingbirds, sugars are the primary fuel, yet the extent to which nectar-derived amino acids support flight versus other functions remains unclear. Using 13C-labelled nectar, we tracked the metabolic fate of sugars and amino acids during flight in Pieris rapae butterflies. We found that proline and glycine, two abundant nectar amino acids, were oxidized alongside sugars. We also compared females subjected to low- versus high-intensity flight. High flight intensity females incorporated less glycine into tissues, implying greater diversion toward energy use during flight. In contrast, they deposited more threonine - an essential amino acid - into their abdomens, prioritizing reproduction and storage. These findings reveal the role of nectar-derived nutrients in supporting locomotion and reproduction, while showing how nectar use can modulate trade-offs between flight and fecundity.

  PublisherOA PDFDOI

• Oxidation and allocation of nectar amino acids during butterfly flight

  DRYAD · 2026-01-22

  datasetOpen access1st authorCorresponding

  Flying animals face extreme energetic demands, relying mainly on carbohydrates and lipids, with occasional contributions from proteins and amino acids. In nectar-feeding species such as butterflies and hummingbirds, sugars are the primary fuel, yet the extent to which nectar-derived amino acids support flight versus other functions remains unclear. Using 13C-labelled nectar, we tracked the metabolic fate of sugars and amino acids during flight in Pieris rapae butterflies. We found that proline and glycine, two abundant nectar amino acids, were oxidized alongside sugars. We also compared females subjected to low- versus high-intensity flight. High flight intensity females incorporated less glycine into tissues, implying greater diversion toward energy use during flight. In contrast, they deposited more threonine – an essential amino acid – into their abdomens, prioritizing reproduction and storage. These findings reveal the role of nectar-derived nutrients in supporting locomotion and reproduction, while showing how nectar use can modulate trade-offs between flight and fecundity.

  PublisherDOI

• Oxidation and allocation of nectar amino acids during butterfly flight

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-10-01

  preprintOpen access1st authorCorresponding

  ABSTRACT Flying animals face extreme energetic demands, relying mainly on carbohydrates and lipids, with occasional contributions from proteins and amino acids. In nectar-feeding species like butterflies and hummingbirds, sugars are the primary fuel, yet the extent to which other nectar-derived nutrients, like amino acids, are used for flight or retained for other functions remains unclear. Using 13 C-labeled nectar, we tracked the metabolic fate of sugars and amino acids during flight in Pieris rapae butterflies. We found that proline and glycine, two of the most abundant nectar amino acids, were oxidized alongside sugars. Importantly, flight intensity modulated nutrient allocation from nectar: high-flight females incorporated less glycine into tissues, implying diversion toward flight, while threonine deposition in abdomens increased, reflecting prioritization for reproduction and storage. These findings reveal the complex role of nectar-derived nutrients in supporting locomotion and reproduction, while showing how nectar use can modulate trade-offs between flight and fecundity.

  PublisherOA PDFDOI

• Shifts in nutrient allocation in a gift-giving butterfly: A hidden consequence of water balance?

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-07-22

  preprintOpen accessSenior author

  ABSTRACT As climate change intensifies drought, understanding how animals maintain fitness under water stress is key to predicting species persistence. Animals use diverse behavioural and physiological adjustments to avoid dehydration. However, the physiological and fitness costs of these mechanisms are often overlooked, despite their potential to shift nutrient acquisition and allocation. We hypothesized that maintaining water balance, through increased water intake and/or decreased water loss, leads to nutrient shifts and trade-offs in Pieris rapae butterflies. In this species, females receive a protein- and water-rich nuptial gift (NG), known to enhance fecundity and possibly mitigate dehydration. We quantified the impact of dry conditions on female hydration and fitness, using stable isotopes to trace nutrient allocation to storage, fecundity, and catabolism. We found that the NG, combined with reduced respiratory water loss, contributed to maintaining female water balance in dry conditions. Importantly, while dry environments did not impact potential fecundity, nutritional shifts and trade-offs that could affect long-term fitness were evident: females allocated more lipids to eggs at the expense of long-term storage, while reducing catabolism of NG-derived leucine. This interplay among water balance, nutrient allocation, and fitness emphasizes the importance of linking water balance mechanisms with broader nutrient-use strategies under environmental stress.

  PublisherOA PDFDOI

• Shifts in nutrient allocation in a gift-giving butterfly: a hidden consequence of water balance?

  Journal of Experimental Biology · 2025-12-29

  articleOpen accessSenior author

  As climate change intensifies drought, understanding how animals maintain fitness under water stress is essential for predicting ecological resilience. Terrestrial animals use diverse behavioural and physiological strategies to avoid dehydration, yet the associated physiological and fitness costs remain poorly understood. Because water balance is tightly linked to nutrient acquisition and metabolism, mechanisms that enhance hydration may alter how animals allocate key macronutrients across vital functions. Here, we investigated how maintaining water balance - via increased water intake or reduced water loss - shapes nutrient allocation and trade-offs in the cabbage white butterfly (Pieris rapae), a species in which males transfer nutrient- and water-rich nuptial gifts to females during mating. Using controlled humidity treatments and stable-isotope tracing, we quantified how the hydric environment and mating status influence female allocation of nutrients - including nuptial gift-derived amino acids - to storage, fecundity and catabolism. We found that females in dry environments maintained water balance largely by acquiring nuptial gifts and by reducing respiratory water loss. However, dry conditions still altered nutrient allocation: females invested more lipids into eggs at the expense of long-term storage, and they reduced catabolism of an essential amino acid derived from the nuptial gift. These results show that mechanisms supporting water balance can indirectly reshape nutrient-use strategies, revealing physiological trade-offs that may influence longer-term fitness. More broadly, our findings highlight the tight coupling between water and nutrient economies and emphasize the need for a nutrient-explicit framework for understanding how animals cope with increasing aridity.

  PublisherOA PDFDOI

• Influence of the direct and indirect effects of habitat fragmentation, via microclimate change, on animal locomotion

  Landscape Ecology · 2023-01-13 · 3 citations

  article1st authorCorresponding
  PublisherDOI

• Impact of body size on critical thermal maxima in female solitary desert bees

  Ecological Entomology · 2023 · 11 citations

  • Biology
  • Animal science
  • Ecology

  Abstract Solitary, size‐variable bees are adapted to a wide range of thermal environments (e.g., through critical thermal maxima, or CT max ) and are important, understudied subjects for research on species' vulnerability to climate change. Centris pallida are solitary, ground‐nesting desert bees with females varying two‐fold in body mass. We hypothesized that body size would affect CT max in female C. pallida, predicting that an increase in body size would result in increased thermal tolerance . We tested the effects of female body mass on CT max using a ramping CT max assay while controlling for age. We used flow‐through respirometry to confirm that the behavioural indicator of CT max correlated with the metabolic indicator of lethality. Body mass correlated positively with CT max ; every 100 mg increase in body mass resulted in a 1.5°C increase in CT max . Female age (as assessed by an index score based on wing, thorax hair and mandibular wear) did not affect CT max . Flow‐through respirometry confirmed that loss of muscle control correlated with the metabolic ‘mortal fall’, or a decline in CO 2 production. As insect body sizes typically decline with higher temperatures, our data suggest rising temperatures could magnify thermal stresses on desert bee populations.

  PublisherOA PDFDOI

• Size-dependent fitness trade-offs of foraging in the presence of predators for prey with different growth patterns

  Theoretical Ecology · 2022-06-07 · 2 citations

  article
  PublisherDOI

• Adaptive Variation in Sex and Male Size Morph Critical Thermal Maxima in Centris Pallida Desert Bees

  SSRN Electronic Journal · 2022 · 7 citations

  • Biology
  • Ecology
  • Zoology
  PublisherDOI

• Influence of the direct and indirect effects of landscape fragmentation, via microclimate change, on animal locomotion

  Research Square · 2022-04-01

  preprintOpen access1st authorCorresponding
  PublisherOA PDFDOI

Frequent coauthors

• Goggy Davidowitz

  University of Arizona

  7 shared

• Jennifer S. Thaler

  Cornell University

  6 shared

• Sara M. Lewis

  Tufts University

  5 shared

• Paul Switzer

  Stanford University

  4 shared

• Giorgi Kozhoridze

  Czech University of Life Sciences Prague

  3 shared

• Yaron Ziv

  Ben-Gurion University of the Negev

  3 shared

• Rashmi T Jadhav

  Eastern Illinois University

  2 shared

• Britto P. Nathan

  Eastern Illinois University

  2 shared