Life span in the wild: the role of activity and climate in natural populations of bees

Abstract

Summary1. Animal life span is constrained by ecology and physiology. The latter has been studied under controlled conditions, but little is known about determinants of life span under natural conditions. 2. We studied the relationships between length of adult life, magnitude of foraging activity, and environmental abiotic conditions in two bee species: a pollen specialist Andrena vaga (Andrenidae) and a pollen generalist Anthophora plumipes (Apidae). 3. Our research indicates that life span is driven both directly by climate and indirectly through climate-dependent activity patterns. We found a negative relationship between proportion of active days and length of life; in contrast, a high activity rate within the active days had no negative effect on longevity. 4. Individuals active during warm and/or wet days lived longer, with precipitation being a more important determinant of life span than temperature. 5. Timing of the first appearance at the site was also an important predictor of bee life span. Individuals that first appeared closer to the end of season (critical time horizon) lived a shorter time than individuals observed earlier. The first observed active day in the season was also correlated with seasonal temperature and precipitation. 6. We demonstrate that life span and activity patterns of wild populations of insects are regulated by a tractable interplay of ecological (mostly climatic) variables that were previously studied only in isolation or in vitro.

Wild bees as winners and losers: Relative impacts of landscape composition, quality, and climate

“…Concurrent with land‐use change, climate change is driving increasingly unpredictable weather patterns (Lynch et al, 2016; Thibeault & Seth, 2014), which could influence communities of wild bees in several ways (Forrest, 2016; Rafferty, 2017). Changes in seasonal weather patterns coupled with increased frequency of extreme weather events could alter availability of floral resources (Phillips et al, 2018), cause phenological mismatches between plants and their pollinators (Bartomeus et al, 2011, 2013a; Kudo & Ida, 2013), shift weather‐dependent activity patterns and foraging behavior (Straka et al, 2014), and potentially increase pathogen spread and dominance of non‐native species (Settele et al, 2016). Heat and drought stress can reduce flower number and nectar volume and concentration, with significant implications for plant–pollinator interactions (Descamps et al, 2018; Gallagher & Campbell, 2017; Mu et al, 2015).…”

Special Significance of Non-Drosophila Insects in Aging

“…For instance, flight restriction leads to increased oxidative damage in brains of honey bees and early senescence of flight performance in fruit flies (Tolfsen et al, 2011;Lane et al, 2014). A high flight activity rate within the activity days has no negative effects on longevity in two bee species in the fields (Straka et al, 2014). In Glanville fritillary butterfly (Melitaea cinxia), peak flight metabolic rates are positively associated with lifespan (Niitepõld and Hanski, 2013).…”

Ergonomic skew and reproductive queuing based on social and seasonal variation in foraging activity of eastern carpenter bees (Xylocopa virginica)

“…Minimally, there is the time and wing wear cost of flying from nest to nest investigating the social status of previous occupants and the possibility that this will reduce bee lifespan (Foster and Cartar 2011;Straka et al 2014). Some transient females do not ever manage to find a nest and spend the entire brood-provisioning season flying about the aggregation, seeking nests to join.…”

“…However, the similar proportions of residents and transients among principal foragers in social nests, and the observation that transients can even establish solitary nests, implies that transients do no worse than residents, at least insofar as reproductive success can be measured by foraging rates. However, residents did not incur the metabolic and survival costs of flight involved in finding new nests (Cartar 1992;Straka et al 2014) and so might have lived longer or laid more eggs. This possibility bears further investigation.…”