Personality of hosts and their brood parasites

Brood parasites such as the common cuckoo Cuculus canorus exploit the parental abilities of their hosts,hosts avoid brood parasitism and predation by showing specific behavior such as loss of feathers,emission of fear screams and contact calls,displaying wriggle behavior to avoid hosts or potential prey,pecking at hosts and prey,and expressing tonic immobility(showing behavior like feigning death or rapid escape from predators and brood parasites).These aspects of escape behavior are consistent for individuals but also among sites,seasons,and years.Escape behavior expressed in response to a broad range of cuckoo hosts and prey are consistently used against capture by humans,but also hosts and brood parasites and predators and their prey.An interspecific comparative phylogenetic analysis of escape behavior by hosts and their brood parasites and prey and their predators revealed evidence of consistent behavior when encountering potential parasites or predators.We hypothesize that personality axes such as those ranging from fearfulness to being bold,and from neophobic to curiosity response in brood parasites constitute important components of defense against brood parasitism that reduces the overall risk of parasitism.

Plant diversity promotes soil fungal pathogen richness under fertilization in an alpine meadow

Aims The effects of fertilization on fungal plant pathogens in agricultural soils have been studied extensively.However,we know little about how fertilization affects the relative abundance and richness of soil fungal plant pathogens in natural ecosystems,either through altering the soil properties or plant community composition.Methods Here,we used data from a 7-year nitrogen(N)addition experiment in an alpine meadow on the Qinghai-Tibetan Plateau to test how N addition affects the relative abundance and richness of soil fungal plant pathogens,as determined using Miseq sequencing of ITS1 gene biomarkers.We also evaluated the relative importance of changes in soil properties versus plant species diversity under N addition.Important Findings Using general linear model selection and a piecewise structural equation model,we found that N addition increased the relative abundance of soil fungal plant pathogens by significantly altering soil properties.However,higher host plant species richness led to higher soil fungal plant pathogen richness,even after excluding the effects of N addition.We conclude that the relative abundance and richness of soil fungal plant pathogens are regulated by different mechanisms in the alpine meadow.Continuous worldwide N inputs(through both fertilizer use and nitrogen deposition)not only cause species losses via altered plant species interactions,but also produce changes in soil properties that result in more abundant soil fungal plant pathogens.This increase in pathogen relative abundance may seriously threaten ecosystem health,thus interrupting important ecosystem functions and services.