All the markers previously suggested are share with macrophages and other myeloid cells. If you are studying healthy tissues they should suffice, but under inflammatory conditions you should consider markers like P2ry12, 4d4 and Tmem119. Best !
Jorge: also the markers suggested are for either Flow cyto or IP. I wanted to know microgllia cell marker suitable for immunoflorescence in brain tissue of chicken
There are antibodies suitable for both techniques. You should always consider testing Abs yourself to see if they work in your hands and particularly in your tissues.
Check this paper: http://www.ncbi.nlm.nih.gov/pubmed/24316888
From published work: We mapped the distribution of the three neuroglial cells, oligodendrocytes, astrocytes and microglia, in the chicken optic tectum using their specific markers, transferrin binding protein (TfBP), glial fibrillary acidic protein (GFAP), and Ricinus communis agglutinin-1 (RCA-1), respectively.