Body condition is negatively associated with infection with Syngamus trachea in the ring-necked pheasant (Phasianus colchicus).
The role that parasites play in regulating animal populations is debated, however recent research hints at their pervasiveness among free-living animal populations. Parasites exert both direct and indirect effects on host populations, and can act to regulate populations. The Ring-necked pheasant is an important game-bird species in the UK, and large numbers of birds are released annually. The impact of the ubiquitous tracheal nematode, Syngamus trachea on pheasant populations through effects on host condition was assessed on two pheasant estates in the south west of England. Pheasants infected with S. trachea demonstrated a significant reduction in host condition compared with uninfected controls, with as few as one pair of worms per bird. Although there was no difference in worm burden between sexes, analysis of regression slopes revealed there was a significant difference between sexes in the magnitude of the effect of increasing worm burden on host condition, with detectable effects observed in hosts with one and three pairs of worms for males and females respectively. The observed reductions in host condition in birds with even sub-clinical infections could be the cause of poor reproductive success and survival of pheasants post-release.
Department of Crop & Environment Sciences, Harper Adams University, Edgmond, Newport, TF10 8NB, UK. Electronic address: owengethings@hotmail.co.uk.
O J
OJ
Gethings
Game & Wildlife Conservation Trust, Burgate Manor, Fordingbridge, SP6 1EF, UK.
R B
RB
Sage
University of Bristol, School of Veterinary Sciences, Langford House, Langford, North Somerset, BS40 5DU, UK.
E R
ER
Morgan
Department of Crop & Environment Sciences, Harper Adams University, Edgmond, Newport, TF10 8NB, UK.
S R
SR
Leather
D000818:Animals; D001715:Bird Diseases / Q000469:parasitology*; D004739:England; D005260:Female; D046094:Galliformes / Q000469:parasitology* / Q000502:physiology; D008297:Male; D012098:Reproduction; D017206:Strongylida Infections / Q000469:parasitology / Q000662:veterinary*; D013320:Strongyloidea / Q000502:physiology*; D014132:Trachea / Q000469:parasitology
Body condition; Gapeworm; Phasianus colchicus; Pheasant; Reproduction; Syngamus trachea