Energy and Water Budgets of Larks in a Life History Perspective: Parental Effort Varies With Aridity

Abstract

Abstract. We compared physiological, demographic, and ecological variables of larks to gain insights into life history variation along an aridity gradient, incorporating phylogenetic relationships in analyses when appropriate. Quantifying field metabolic rate (FMR) and water influx rate (WIR) of parents feeding nestlings as measures of parental effort, we found that parental FMR and WIR of larks decreased with increasing aridity. Water and energy requirements of 6-8 d old nestlings were reduced in desert species. Nestling growth rate, clutch size, and number of clutches decreased with increasing aridity, and nest predation rates increased with increasing aridity. We combined FMR and WIR of parents and chicks, energy and water accumulated during growth, and brood size to establish energy and water budgets of parent-brood units. Parent-offspring energy budgets equaled 261 kJ/d for Hoopoe Lark, 164 kJ/d for Dunn's Lark, 388 kJ/d for Skylark, and 347 kJ/d for Woodlark, a 27% reduction in the desert species when taking into account mass differences. Family unit WIRs were 46.6 g/d for Hoopoe Lark, 37.3 g/d for Dunn's Lark, 101.6 g/d for Skylark, and 83.2 g/d for Woodlark. Parent-brood units of arid-zone species used 28-51% less water per gram mass than species from mesic areas. These results support the hypothesis that decreasing food and water availability favor lower energy and water requirements of parents and young, reduced growth rates, and smaller clutch sizes with increasing aridity. The decrease in parental effort with increasing aridity might reflect a lower fitness value of a single brood for arid-zone species than for larks from mesic habitats, suggesting that the probability of adult survival is higher in arid than in mesic areas.

Morphology, Diet Composition, Distribution and Nesting Biology of Four Lark Species in Mongolia

“…Unfortunately, we did not collect data for these variables to understand how the clutch size responds to environmental and intrinsic factors. Further, clutch size in larks has been associated with aridity, being smaller in the species inhabiting the most arid environments (Tieleman et al, 2004). In the present study, four larks species showed similar patterns in spatial distribution as the majority of their locations being occurred in steppe ecosystem.…”

Seasonal patterns in immune indices reflect microbial loads on birds but not microbes in the wider environment

“…Body masses were also higher in birds sampled in spring 2007 (Table 2). Larks in the desert skip breeding during lean years, favoring self-maintenance activities over reproduction during such times (Tieleman and Williams 2002, Tieleman et al 2003c, Tieleman et al 2004. In spring 2007, decreased food availability in Mahazat reduced breeding activities among residents and increased dispersal of nomads (B. I. Tieleman, personal observation).…”

Nest Site Selection in a Hot Desert: Trade-Off Between Microclimate and Predation Risk?

“…Hoopoe Larks (Alaemon alaudipes) in the Arabian Desert provide a unique system to study this tradeoff between thermoregulation and predation risk because the variation in their nest sites is large, nest predation is high (Tieleman et al 2004), and their desert environment is harsh (Tieleman andWilliams 2002, Tieleman et al 2003). In addition, the increasingly high temperatures through the course of the season provide natural variation in thermal challenges to which the larks have to respond when selecting nest sites.…”