Could an AN/APG-79 AESA radar "lock-on" a single bird?
Depending on the radar, the accuracy fallow might be too big for a smaller object as radar resolution and accuracy matter a great deal in detecting and hitting a small target, that is why usually birds do not show up on radar or are actually filtered out as they could not hit targets that small anyway…
Resolution refers to the size, meaning electromagnetic size or radar cross section (RCS), of the objects a radar can detect. The smaller the minimum detectable RCS of a radar system, the better its resolution. A radar with poor resolution might see a supertanker sailing past but not a tugboat, for example.
Accuracy is referring to the degree of uncertainty in the radar’s calculation of the target’s location. A very accurate radar, for example, might tell you that it’s detected a target at a distance (range) of 87.118km ±10cm from the radar antenna. A much less accurate radar seeing the same target might report its range as 90km ±100m.