Foraging height levels and the risk of gastro-intestinal tract parasitic infections of wild ungulates in an African savannah eco-system

Abstract

SummaryGrazing herbivores mainly feed at low feeding height levels, while browsers select food items above ground level. Previous studies on gastrointestinal tract (GIT) nematode parasite burdens of African ungulates have suggested that browsing species hereby minimise the risk of infection with parasites. Here, we investigated the influence of feeding height levels on the pasture larval contamination level (PCL) in a natural African savannah eco-system in Queen Elizabeth National Park, western Uganda. The prevalence and mean abundance of infectious GIT nematode larvae on the pasture were used as measures of pasture contamination. Vegetation samples were examined following standard larval isolation, concentration and counting techniques. We found the feeding height level to be significantly related to the occurrence of infectious GIT nematode larvae, and the contamination was highest at low feeding levels. There was no statistically significant seasonal variation in the prevalence or mean abundance of the contamination of pastures with nematode larvae.

Linking social and pathogen transmission networks using microbial genetics in giraffe (Giraffa camelopardalis)

“…Thus, the importance of social interactions in transmitting E. coli seems counter‐intuitive at first glance. It is possible that the role of environmental transmission may be reduced in giraffe because they rarely forage on the ground (Young & Isbell ), and forage contamination by gastrointestinal parasites is minimized at higher feeding heights (Apio, Plath & Wronski ). Perhaps more likely, however, is that social associations led to synchronous space use.…”

Seasonal variation in reproductive behaviour of bushbuck (Tragelaphus scriptus Pallas, 1766) in an equatorial savannah ecosystem

“…The rainy seasons last from March to May and from September to December, with a monthly mean of more than 50 mm rainfall (daily precipitation, wet season: 3.2 ± 7.1 mm; dry season: 0.5 ± 2.4 mm). Mean annual rainfall in the study period was 680 mm (Deutsch, 1992; Apio, Plath & Wronski, 2006).…”

Spacing behaviors and spatial recruitment of a wild rodent in response to parasitism

“…Host spacing could be a form of anti-parasite behaviors (reviewed in Hart 1990Hart , 1992Hart , 2011, a result of host manipulation by parasites to enhance their own transmission (reviewed in Hart 1990, Poulin 2010, or a by-product of infection (e.g., Kavaliers and Colwell 1995). Whereas host manipulation typically involves parasites with complex life cycles, anti-parasite behaviors are common across diverse host-parasite systems, such as grooming/preening in mammals and birds to remove ecto-parasites (Mooring et al 2004, Hart 2011, grouping in vertebrates and invertebrates to lower individual risks of being attacked by parasitic flies Hart 1992, Fauchald et al 2007), roosting/nesting/foraging site selection in mammals to reduce contacts with parasites such as ticks, fleas, lice, parasitic flies, intestinal protozoa, and intestinal helminths (Freeland 1980, Butler and Roper 1996, Hutchings et al 2002, Ezenwa 2004, Apio et al 2006, Fleurance et al 2007, Reckardt and Kerth 2007, Garnick et al 2009), and even incorporation of plants as nest materials in insects, birds, and rodents to repel parasites and pathogens (Hart 2005, Chapuisat et al 2007, Ontiveros et al 2008.…”