Life history diversity in terrestrial animals is associated with metabolic response to seasonally fluctuating resources

Abstract

Physiological and behavioral processes interact with environmental conditions to strongly influence organismal life history strategies which covary with latitude. However, few studies have articulated explicit linkages between metabolism and life history across latitudinal gradients. Interactions between metabolism and resource dynamics may give rise not only to patterns of variation in mean life history traits, but also to patterns in the ranges (diversity) of those traits across the same gradients. Here we show that the range of viable and realized metabolic/life history strategies covaries with the amplitude of seasonal resource fluctuations and, thus, latitude. Using a theoretical metabolic model we predicted that aseasonal environments support a greater diversity of life-history strategies than those subject to strong seasonality, where only 'fast' strategies were successful. We analyzed a global database of organismal metabolic parameters (estimated using a standard dynamic energy budget model) and found empirically derived evidence supporting our theoretical prediction that life history diversity negatively covaries with resource seasonality. These results comprise a novel framework for exploring covariation of life history with latitude at global scales, which may in turn help to explain other fundamental ecological patterns such as species diversity across gradients of seasonality.

Seasonal migration alters energetic trade-off optimization and shapes life history

“…Interestingly, we found that phylogenetic effects explained a substantial proportion of variation in relative energetic allocation to self. Models fitted without a phylogenetic random effect (not shown) exhibited a strong negative effect of breeding latitude on POL, in keeping with previous reports (Muller & Nisbet 2000; Yanco et al 2022). That phylogenetic effects are apparently confounded with biogeography offers an intriguing avenue for future research taking a macroevolutionary approach to these questions but extends beyond the scope of the present analysis.…”

“…Because we expect POL to be constrained to [0, 1], we modeled it as beta distributed. We also included niche dissimilarity as a predictor on the precision parameter for the beta distribution (φ) based on previous reports (Yanco et al 2022). To control for phylogenetic relatedness among the species in our sample we implemented a phylogenetic generalized mixed model approach (Lynch 1991; Garamszegi 2014).…”

“…In this study we sought to explore how migratory behavioral mitigation of seasonality can affect dynamics of metabolic and temporal trade-offs to shape POL and life history based on a model of avian migration. To model energetic and temporal trade-offs we combined an individual-based model (IBM) of one-dimensional movement within a simulated environment of seasonally fluctuating energy with a generalized Dynamic Energy Budget (Kooijman 2010) model of metabolism (sensu Yanco et al 2022). We compared life-history optimization tradeoffs between migratory and stationary strategies using a heuristic optimization algorithm to solve for fitness-optimized IBM parameterizations across a gradient of seasonality and migration strategies.…”

“…In this study we sought to explore how migratory behavioral mitigation of seasonality can affect dynamics of metabolic and temporal trade-offs to shape POL and life history based on a model of avian migration. To model energetic and temporal trade-offs we combined an individual-based model (IBM) of one-dimensional movement within a simulated environment of seasonally fluctuating energy with a generalized Dynamic Energy Budget (Kooijman 2010) model of metabolism (sensu Yanco et al . 2022).…”

Size-dependence of food intake and mortality interact with temperature and seasonality to drive diversity in fish life histories

“…For example, while polar oceans may increase in temperature, they will remain strongly seasonal. This result is one of the novel predictions of our model that warrants further investigation; while there is increasing attention to latitudinal trends in physiological processes in terrestrial systems (Yanco et al 2022), the role of seasonality in driving life history evolution is still poorly understood.…”