Meeting Abstract

P3.120  Sunday, Jan. 6  Body condition and heterophil to lymphocyte ratios in urban and rural song sparrow (Melospiza melodia) populations ROSS, A.E.*; ROCK, R.P.; FOLTZ, S.L.; MOORE, I.T.; Virginia Tech; Virginia Tech; Virginia Tech; Virginia Tech allenr15@vt.edu

The environment an organism inhabits may directly or indirectly influence the pressures placed on that organism’s immune system, as well as the amount of energy the organism is able to allocate toward immune activity. Previous studies have shown that the immune activity and body condition of urban birds may differ from those of their non-urban counterparts. Our study was conducted to see whether heterophil to lymphocyte ratio (H/L) and body condition are correlated with urbanization in populations of song sparrows (Melospiza melodia) in southwestern Virginia. Song sparrows are abundant in both rural and urban environments and our previous studies have suggested that glucocorticoid levels are sometimes higher in urban environments. We chose to investigate H/L and body fat score because they are additional organismal-level assessments of general physiological stress. We collected blood samples from 41 free-living males from 3 rural and 3 urban sites. Our data show that urban birds have significantly lower H/L ratios than rural birds. While there was no difference in fat scores between urban and rural birds, there was a trend toward a negative correlation between fat scores and H/L. These results appear to contradict our previous work suggesting that urban habitats are more stressful and may mean that measures such as these are context-dependent and variable.