blue tit 
noun
A small tit (songbird) with a blue cap, greenish-blue back, and yellow underparts, widespread in Eurasia and NW Africa.
- Parus caeruleus, family Paridae.
- The garden attracts a number of birds including finches, blue tits, sparrows and jackdaws.
- The proportion of monogamous females that breed at the same time as primary females was high in lapwings, starlings, pied flycatchers, and blue tits.