Shuka, Ravana's aide, describes the individual strengths of the various commanders in the army of monkeys, mentioning their names one by one, in detail, in Yuddha Kanda of Srimad Ramayana.
While describing Sri Hanuman, Shuka says that Sri Hanuman was the eldest son of Kesari.
ज्येष्ठः केसरिणः पुत्रो वात आत्मज इति श्रुतः |
हनूमान् इति विख्यातो लन्घितो येन सागरः || ६-२८-१०
This monkey, by whom the ocean was traversed, is the eldest son of Kesari. He is known as the son of wind-god and famously called as Hanuman.
Can anybody tell me how many sons did Kesari have, other than Sri Hanuman?