Deforestation and avian infectious diseases

Abstract

SummaryIn this time of unprecedented global change, infectious diseases will impact humans and wildlife in novel and unknown ways. Climate change, the introduction of invasive species, urbanization, agricultural practices and the loss of biodiversity have all been implicated in increasing the spread of infectious pathogens. In many regards, deforestation supersedes these other global events in terms of its immediate potential global effects in both tropical and temperate regions. The effects of deforestation on the spread of pathogens in birds are largely unknown. Birds harbor many of the same types of pathogens as humans and in addition can spread infectious agents to humans and other wildlife. It is thought that avifauna have gone extinct due to infectious diseases and many are presently threatened, especially endemic island birds. It is clear that habitat degradation can pose a direct threat to many bird species but it is uncertain how these alterations will affect disease transmission and susceptibility to disease. The migration and dispersal of birds can also change with habitat degradation, and thus expose populations to novel pathogens. Some recent work has shown that the results of landscape transformation can have confounding effects on avian malaria, other haemosporidian parasites and viruses. Now with advances in many technologies, including mathematical and computer modeling, genomics and satellite tracking, scientists have tools to further research the disease ecology of deforestation. This research will be imperative to help predict and prevent outbreaks that could affect avifauna, humans and other wildlife worldwide.Key words: deforestation, birds, infectious diseases, disease ecology, global change. THE JOURNAL OF EXPERIMENTAL BIOLOGY956 Brownstein et al., 2005; Killilea et al., 2008), and cutaneous leishmaniasis is increasing with deforestation in Costa Rica (Chaves et al., 2008). Deforestation has also been associated with the increased emergence of viral pathogens, such as SARS, Ebola and other viruses of bats (Field, 2009; Leroy et al., 2005; Looi and Chua, 2007). In addition, deforestation can indirectly result in increased human contact with wildlife, increasing the exposure to zoonoses (Wolfe et al., 2005;Wolfe et al., 2007). For example, it is now clear that human/chimpanzee contacts led to the HIV pandemic (Keele et al., 2006; Keele et al., 2009), and may have provided the first transmission of Falciparum malaria (Rich et al., 2009).Birds are affected by viral, bacterial, parasitic and fungal infectious pathogens, and can also act as reservoirs of numerous zoonotic pathogens (Davis, 1971;Hubalek, 2004;Thomas and Hunter, 2007). It is likely that the direct and indirect effects of deforestation could affect the transmission of all the four major classes of avian pathogens. Viruses Avian influenzaThe most topical virus of birds is the highly pathogenic avian influenza H5N1. Avian influenza viruses reside in wild aquatic birds; they are the natural reservoir for all influenza A viruses (Ol...

Mosquito Communities and Avian Malaria Prevalence in Silvereyes (Zosterops lateralis) Within Forest Edge and Interior Habitats in a New Zealand Regional Park

“…Similar results have been demonstrated for avian malaria, with deforestation producing variable prevalence patterns at both local and regional scales (see Sehgal 2010, LaPointe et al 2012). For example, recent studies in Africa by Bonneaud et al (2009) and Loiseau et al (2010) found higher Plasmodium prevalence in birds inhabiting pristine forests, whereas Chasar et al (2009) revealed one parasite species was more abundant in disturbed sites and another more so in pristine sites.…”

“…), primarily through their effect on vector species (Patz et al 2000;Harvell et al 2002). In many parts of the world, deforestation for agricultural development is a common anthropogenic driver of changes in parasite transmission rates (Yasuoka and Levins 2007;Sehgal 2010;LaPointe et al 2012). Studies of human malaria in Asia, Africa and the Amazon region have shown that forest fragmentation and increasing edge habitat produce complex host-vector responses; these can either increase or decrease malaria prevalence depending on subsequent land use and the breeding ecology of local vector species (see Yasuoka andLevins 2007, Stefani et al 2013).…”

Use of Poisson spatiotemporal regression models for the Brazilian Amazon Forest: malaria count data

“…Deforestation is associated with loss of biodiversity, the alteration of many fundamental aspects of ecosystems, and an increase in the prevalence and incidence of many human vector-borne diseases 25 . The year-round high rainfall and temperatures in tropical forests are ecological characteristics that favor the development of many kinds of mosquitoes that transmit pathogens that cause disease in humans 26 .…”

Assessing the Effects of Logging Activities on Avian Richness and Diversity in Different Aged Post-Harvested Hill Dipterocarp Tropical Rainforest of Malaysia

“…Forest logging directly or indirectly reduced the habitat suitability of forest fauna (Potts, 2011) such as butterflies and mammals (Brook et al, 2003;Sehgal, 2010) and monkeys (Collins, 2008). Due to logging, the forest becomes fragmented, more irregular and isolated (Echeverria et al, 2007) which affects on distribution, richness and diversity of avian species (McCarthy, 2012).…”