A sufficient number of jet engines suffer bird strikes that cause damage to the aircraft and occasionally loss of human life. Other than using methods to try and deter birds from gathering around airports, there is nothing that can save the birds once they are in the air intake stream. However, a deflection grill should be considered for jet intakes. Such a grill could be quite thin along the axis of the air flow even while having sufficient depth for strength. If properly angled, with a greater overhang on the top, most debris would slough off. If necessary where the intake of air was too great to allow the debris to slough of, the grill could be sharpened so that if, for instance, a large bird struck it, the bird would not enter the engine blades whole but rather in piecemeal fashion. It's not a pretty thought but, once the bird had entered the air stream of the jet, it is done for already and now the hope would be to save the engine the bird has entered. The cost to retrofit most jet engines would be small compared to even one aircraft crashing, which has happened. Even the jet which crash landed in the Hudson is considered to have been a result of bird strike, as far as I recall. A Jet Intake Grill could have averted that, amongst others.