| dc.description.abstract | Parasites thrive by consuming host resources, causing a decline in host fitness. This burden drives host evolution, exerting selective pressure on both. The main objective of the
study was to investigate parasitic profile and host immune responses in avian hosts along
altitudinal gradients in Sri Lanka. This research took place in the Issengard Biosphere
Reserve, located in Belihuloya, Sri Lanka. which features a 1 km altitudinal gradient from
480 - 1420 m. A total of 49 adult birds representing 18 species from 13 families, were
mist netted and blood samples were collected to assess the host response against blood
parasites in avian communities at 100 m intervals along this altitudinal gradient. The
research employed weight-normalized seven parameters to evaluate host response in birds
at each elevation, which included Red Blood Cell (RBC) count, hemoglobin concentration,
White Blood Cell (WBC) count, WBC differential count, thrombocyte count, RBC shape
index, and body temperature. Blood parasites were found in 26.53% (13/49) of the birds
from 6 different species when blood smears were examined. Microfilaria larvae were found
in 12.24% (6/49) of the birds from 3 species, while Haemoproteus sp. was found in 14.28%
(7/49) of the birds from 4 species. The multiple multivariate linear regression findings
reveal a notable inverse association between total WBC count and elevation, while body
temperature increases significantly with elevation. Moreover, as elevation increases, there
is a significant rise in the elongation ratio of RBCs, particularly in response to higher
intensity of Haemoproteus infection. | en_US |
