Trait Category,Functional Trait,Common Metrics and States,Significance
Morphological,Body size,"Typically measured by proxy, most commonly intertegular distance, but also body length, head width, and wing length. Rarely measured directly as mass. Alternatively, measured categorically (small, medium, large).","Correlates with physiological, ecological, and life history traits including pollination efficiency, foraging distance, mating success, social dominance, fecundity, and thermoregulation."
Morphological,Tongue length,Commonly classified categorically (short vs. long) based on bee family. Less commonly measured numerically as combined length of prementum and glossa. Can also be estimated from an allometric scaling relationship including bee family and ITD (Cariveau et al. 2016).,"Can influence floral choice, efficiency in acquiring floral resources, pollination services, plant-pollinator networks, and plant speciation."
Morphological,Pilosity,"Measured as hair length, hair density, or the proportion of the body surface covered by hair.","Can influence pollen uptake, pollination effectiveness, thermoregulation, and water retention."
Behavioral,Sociality,"Categorized most commonly as solitary vs. social, sometimes including multiple forms of sociality (e.g., subsocial, communal, eusocial, etc.).","Determines intraspecific variation in lifetime reproductive success, longevity, and behavioral repertoire. Generates emergent strategies for defense, foraging, nest construction, thermoregulation, etc."
Behavioral,Nesting biology,"Categorized most commonly as above-ground vs. below-ground, but sometimes more specifically or with reference to substrate (e.g., soil, stem,wood, cavity).","Determines energetic investment in nest initiation, protection against natural enemies, and exposure to environmental conditions."
Behavioral,Diet breadth,"Categorized most commonly as oligolectic vs. polylectic, sometimes including mesoloctic and monolectic. Alternatively, measured numerically as indices incorporating the number and/or phylogenetic breadth of floral host species.","Determines biotic interactions, especially floral resource networks and interspecific competition. Also influences nutritional opportunities, habitat choice, and interactions with pathogens and parasites."
Behavioral,Reproductive strategy (parasitism),"Categorized as cleptoparasite vs. nonparasitic. More commonly, parasitism status is classified under other traits including sociality, nesting biology, and diet breadth.","Determines behavioral repertoire, ecological niche, and pollination services."
Phenological,Seasonality,"Quantified as flight season duration, the month of first activity, or the median date of the flight season. Alternatively, measured categorically at the species level as early-season vs. late season.","Determines ecological niche and biotic interactions, especially with floral resources and competitors. Influences exposure to environmental conditions, especially annual patterns in temperature, photoperiod, and precipitation."
Phenological,Voltinism,"Quantified as the number of generations produced per year, and categorized at the population or species level as univoltine, partially bivoltine, bivoltine, or multivoltine.",Interacts with activity period and access to floral resources. Can influence social strategy.
Physiological,Thermal tolerance,"Can be quantified as an individual’s critical thermal limits (CTmin and CTmax), defined as the point at which flight capability or postural control is lost. Also may be measured as chill-coma recovery time, or inferred from passive heating and cooling rates of dead bees.",Determines ecological niche and species range and likely influences daily and seasonal activity periods.
Physiological,Desiccation resistance,Typically measured as the length of time an individual maintains postural control in low humidity conditions. May be inferred from measurements of water loss rates.,Determines ecological niche and species range. May influence foraging decisions and nectar needs.