INVESTIGADORES
BELDOMENICO Pablo Martin
congresos y reuniones científicas
Título:
Dynamics of gastrointestinal parasitism in free-ranging guanacos (Lama guanicoe)
Autor/es:
MORENO, P; OVEJERO, R; COLOMBO, VC; RAGO, V; MACEDO, A; GUTIERREZ, GL; ROCHI, M; WELSCHEN, N; ISSA, M; BELDOMENICO, PM; CARMANCHAHI, P
Lugar:
Puerto Iguazú
Reunión:
Conferencia; LVII Annual International Conference of the Wildlife Disease Association; 2010
Institución organizadora:
Wildlife Disease Association
Resumen:
The guanaco (Lama guanicoe) is the dominant herbivore of South American arid lands. In Reserva
Provincial La Payunia (Argentina) there is a population of 10,000 individuals, part of which is livesheared
as part of a sustainable use program. Recently, the importance of parasites for wildlife
population dynamics has been increasingly recognized. Moreover, stress can affect a populations
ability to thrive, as it jeopardizes the immunity of individuals, increasing their vulnerability to
parasites. With the aim of investigating factors associated with variability in gastrointestinal
parasitism in guanacos, faeces collected during eight sampling sessions in Payunia were analized with
cualitative and cuantitative copro-parsitological techniques. Additionally, plasmatic cortisol was
determined by radioimmunoassay. Parasites found belonged to the Genera Eimeria, Nematodirus,
Trichuris, and Capillaria, but the two former largely prevailed. Prevalence of Nematodirus spp. and
oocyst counts of Eimeria spp. were significantly higher in spring, and had their lowest values in
summer. Bachelor groups had lower Eimeria spp. intensities than family and mixed groups, while the
latter had higher prevalence of Nematodirus spp. than other social groups. In males, oocyst counts
and plasmatic cortisol were negatively correlated. Faeces from dung piles have lower loads of
Eimeria spp. oocysts than those shed away from piles, even within the same host age group.
Guanacos with higher intensities of Nematodirus spp. and Eimeria spp. had significantly lower body
condition. These results are important to better understand how parasite ecology may influence
guanaco population dynamics, which may be key knowledge for effective management and
conservation programs