Breeding and moulting related changes in biomarkers of filarial infected (adult female village weaver, Ploceus cucullatus) birds of Amurum Forest Reserve, Nigeria

Periodic evaluation of body weight, hematological or biochemical parameters are crucial biomarkers (in ecophysiological and conservation research) for understanding the physiological state of wild birds that might serve as reservoir hosts for parasitic infections. We investigated: (i) variations in infected adult female village weaver birds’ body weight and plasma glucose in relation to their moulting status during the breeding and non-breeding periods; (ii) variations in H: L ratio and plasma glucose level in relation to baseline CORT levels during moulting and breeding period of the infected birds; and (iii) how plasma cholesterol correlate to baseline CORT, plasma glucose and H: L ratio during moulting and breeding periods of the infected birds. A total of 240 female birds were trapped, and microfilariae were screened in 155(65%) individuals. In a general linear model analyses (GLMs), we found that breeding status, body and head moult signifcantly correlated with weight of infected birds (P < 0.05), and birds moulting state correlated negatively with the joint interactive effect of both serum baseline CORT and plasma glucose. We observed a negative significant relationship betwee pre-breeding period and plasma cholesterol of infected birds, however, in multiple analyses of variance (MANOVA), breeding and moulting status correlated signifcantly with H: L ratio. Although the infected female village weavers birds were unlikely to exhibit symptoms of filarial diseases, they may have served as reservoirs for the infections, resulting in a decrease in body weight and an increase in the stress biomarkers of the birds.