  We derive a sufficient condition for asymptotic flocking in the Cucker-Smale
model with self-delay (also called reaction delay) and with non-symmetric
interaction weights. The condition prescribes smallness of the delay length
relative to the decay rate of the inter-agent communication weight. The proof
is carried out by a bootstrapping argument combining a decay estimate for the
group velocity diameter with a variant of the Gronwall-Halanay inequality.
