Influence of the haemosporidian Leucocytozoon spp. over reproductive output in a wild Neotropical passerine, the Thorn‐tailed Rayadito (Aphrastura spinicauda)

Abstract

Life-history theory predicts that hosts may adjust the costs of parasites by altering their reproductive effort. Haemosporidian parasites can affect the reproductive output of wild birds in multiple ways. Thorn-tailed Rayaditos Aphrastura spinicauda breeding in Navarino Island, southern Chile (55°-40°S), experience a high prevalence of the haemosporidian Leucocytozoon spp., which opens the possibility of exploring how these parasites may affect reproductive output in a Neotropical bird species. We compared several variables describing reproductive output (laying date, clutch size, incubation period, brood size, nestling body condition and early-life telomere length) of infected and non-infected parents (individually and as breeding pairs). We found that infected females and breeding pairs with both parents infected showed significantly shorter incubation periods than uninfected Thorn-tailed Rayaditos. Furthermore, breeding pairs where both parents were infected raised nestlings with higher body condition than nestlings for which infection was present in only one or in neither of the parents. Our results suggest that the higher the parental investment, the higher the risk of relapse of chronic infection by Leucocytozoon spp. Thorn-tailed Rayaditos that decrease their incubation period pay the cost of infection to take advantage of early breeding through a greater availability of resources, producing nestlings with higher body condition.

Effects of haemosporidian co-infection and parasitemia on reproductive strategies in a polymorphic species

“…All statistical analyses were performed with R software version V 4.1.2 (R Core Team 2021). We evaluated the impact of morph, sex, pair type, infection status, parasitemia, and population density (explanatory variables) on individual body condition (response variable) using a General Linear Mixed Model (GLMM) with a Gaussian distribution and identity link function.…”

“…Host-parasite interactions play a significant role in the evolution and ecology of organisms (Cuevas et al 2021, Poulin 2011). Parasites inflict substantial fitness costs by impacting host body condition, survival, or reproductive success (Van Rooyen et al 2013).…”

“…Thus, host-parasite and parasite-parasite interactions lead to variation in parasitemia, impacting virulence and infection dynamics (Bose et al 2016, Van Rooyen et al 2013). While the effect of malaria prevalence on host fitness has been widely investigated (Cuevas et al 2021, De La Torre et al 2020, Figuerola et al 1999, Jacobs et al 2015), less often those studies integrated the costs of co-infection on host reproductive success (Marzal et al 2008, Van Rooyen et al 2013, Norte et al 2009, Pigeault et al 2020, Pigeault et al 2018).…”