Anthropogenic Natal Environmental Effects on Life Histories in a Wild Bird Population

Abstract

SummaryRecent work suggests that the environment experienced in early life can alter life histories in wild populations [1–5], but our understanding of the processes involved remains limited [6, 7]. Since anthropogenic environmental change is currently having a major impact on wild populations [8], this raises the possibility that life histories may be influenced by human activities that alter environmental conditions in early life. Whether this is the case and the processes involved remain unexplored in wild populations. Using 23 years of longitudinal data on the Mauritius kestrel (Falco punctatus), a tropical forest specialist, we found that females born in territories affected by anthropogenic habitat change shifted investment in reproduction to earlier in life at the expense of late life performance. They also had lower survival rates as young adults. This shift in life history strategy appears to be adaptive, because fitness was comparable to that of other females experiencing less anthropogenic modification in their natal environment. Our results suggest that human activities can leave a legacy on wild birds through natal environmental effects. Whether these legacies have a detrimental effect on populations will depend on life history responses and the extent to which these reduce individual fitness.

Dispersal as a source of variation in age-specific reproductive strategies in a wild population of lizards

“…Such variation has been shown to be influenced by natal conditions (maternal age, birth date, environmental quality, or natal density, see [10,30]) and early investment in reproduction [15,29,31]. In our study, we show that age-specific life-history traits can also vary depending on the dispersal status of individuals.…”

Full Issue

“…Kestrels from natal territories in agricultural habitat with altered prey community (gray triangles and curve), which suffered increased mortality as young adults, increased their production of recruits (Xþse) in early life compared to kestrels from intact forest (black dots, dashed curve), thereby achieving similar lifetime fitness. (figure 1B in Cartwright et al 2014) The Auk: Ornithological Advances 132:563-576, Q 2015 American Ornithologists' Union years ( Figure 3). Intriguingly however, fledglings produced by juniors in their first 3 years of life (when female juniors, at least, are temporarily underweight) were less likely to recruit than those produced by seniors ( Figure 4).…”

Observational field studies reveal wild birds responding to early-life stresses with resilience, plasticity, and intergenerational effects

“…Kestrels from natal territories in agricultural habitat with altered prey community (gray triangles and curve), which suffered increased mortality as young adults, increased their production of recruits (Xþse) in early life compared to kestrels from intact forest (black dots, dashed curve), thereby achieving similar lifetime fitness. (figure 1B in Cartwright et al 2014) years ( Figure 3). Intriguingly however, fledglings produced by juniors in their first 3 years of life (when female juniors, at least, are temporarily underweight) were less likely to recruit than those produced by seniors ( Figure 4).…”

“…Individuals that fledged in areas where prey populations had been altered by converting natural forest habitat to agriculture probably suffered nutritional stress in the nestling period, and they showed increased mortality in early adult life (Cartwright et al 2014). Nonetheless, they achieved similar lifetime fitness to females raised in natural forest areas by increasing reproductive investment (fledgling/recruit production) in early life at the expense of investment in late life (Figure 1).…”