Host Specialization and Dispersal in Avian Haemosporidians

Abstract

In order to be able to understand the ecological and evolutionary processes involved in the emergence of infectious diseases, one needs to comprehend how parasites arrive at new geographical ranges and how they manage to maintain viable populations and even expand their ranges. We discuss host specificity in avian haemosporidians and how encounter and compatibility filters affect the dispersal of avian haemosporidians, and how these filters affect avian haemosporidian assemblages at different spatial and evolutionary scales. There are at least three important barriers to the dispersal of avian haemosporidians:(i) geographic barriers, (ii) environmental barriers and, (iii) interspecies barriers. In this chapter, we discuss the factors involved in these barriers and their effects on the structure of avian haemosporidian assemblages. Host specificity plays an important role in parasite dispersal, and in the case of avian haemosporidians that are vector-borne parasites, it needs to be evaluated both at the vector and bird host level. Understanding the effects of these factors on host-vector-parasite dynamics is important to unravel the dispersal and diversification mechanisms of avian haemosporidians. We end this chapter reviewing host specialization in avian haemosporidians of tropical regions, discussing the mechanisms involved in the dispersal and specialisation of these parasites and point out important research gaps that need attention.

The drivers of avian‐haemosporidian prevalence in tropical lowland forests of New Guinea in three dimensions

“…Plasmodium prevalences were low (5%) in the longitudinal study, consistent with findings by Bodawatta et al ( 2020 ). This could be explained by hosts being less susceptible to this genus (Lima & Pérez‐Tris, 2020 ) or geographic variation in the distribution and density of Plasmodium vectors (Ferreira et al, 2020 ).…”

Infection intensity shapes specialization and beta diversity of haemosporidian–bird networks across elevations

“…The Haemosporida Order is a multihost, multiparasite system conformed of intracellular protozoans that infect vertebrates via Diptera vectors (Valkiūnas, 2005). The host specificity of haemosporidian parasites is associated with specific biotic and abiotic factors (Clark et al, 2017; Fecchio et al, 2018; Lima & Pérez‐Tris, 2020; Svensson‐Coelho et al, 2014). Several studies indicate that temperature and humidity along with their seasonality are the major drivers affecting the distribution of three common haemosporidian genera (i.e., Plasmodium , Haemoproteus , and Leucocytozoon ) (Clark et al, 2017; Fecchio et al, 2017; Scordato & Kardish, 2014).…”

“…In these antagonistic networks species are represented by nodes and host–parasite relationships are represented by network links (Dáttilo et al, 2020). When considering interaction intensity, it is expected that specialist parasites within antagonistic networks will infect their preferred host species more often than generalists infecting those same species; at the same time, it would be expected that specialists will show a higher infection intensity in their preferred host species than generalists (Huang et al, 2020; Lima & Pérez‐Tris, 2020; Poulin et al, 2011), indicating both a parasite preference and a degree of infection tolerance by the preferred host species. Thus, considering infection intensity may improve our understanding of parasite coexistence, species turnover, and parasite transmission (Dallas et al, 2019; Hellgren et al, 2004; Runghen et al, 2021).…”

“…When parasite specialization studies are conducted at different spatial scales, the results may show signs of host phylogenetic conservatism, where specialists parasites infect closely related host species (de Angeli Dutra et al, 2021; Fallon et al, 2005). Additionally, parasite communities may be shaped by the distribution of their hosts, and if parasite–host specialization is common then parasite communities may have similar alpha and beta diversity patterns to those of their vertebrate hosts (e.g., parasite infecting an abundant and widely distributed avian host may be similarly locally abundant and widely distributed) (Lima & Pérez‐Tris, 2020). One of the most consistent predictors of haemosporidian community turnover is host community turnover (Barrow et al, 2021; Clark et al, 2017; Fecchio et al, 2018).…”