This section is from the book "Some Contributions Of South India To Indian Culture", by S. Krishnaswami Aiyangar. Also available from Amazon: Some Contributions of South India to Indian Culture.
Of these two sections of people referred to, the term Vadukar is used for those that lived across the Tamil frontier on the north for which Pulikat on the one side and the northern frontier of Nannan's territory, including in it both Tulu and Konkan, provide the limits. The Chief of Vengadam (Tirupati), Pulli by name, comes often in contact with the people who are described in various ways in these poems. The general trend of all this description is to make of them a class of hunters. Their chief occupation was cattle-raiding and they are always said to be accompanied by cruel dogs.1 Entering into their territory language changed.2 This language is referred to by a poet Kari-Kannan of Kaveripattanam3 as unlearned in character and long in sound. The latter characterisation would apply to Telugu even now, if it is the Telugu of the northern districts, from the point of view of the Tamilian. The former characteristic, whatever foundation there was for it in the days of our author, has long since worn off, and Telugu is regarded now-a-days as specially musical among Indian languages. The Vadukar were found on the frontier across the hill of Tirupati. Narkirar speaks of Erumai of Kudanadu as the chief of the cattle-lifting tribe of Vadukar.1 Another poet gives a Chola ruler a victory at Pali against the Vadukar.2 Thus we find the Vadukar all along the northern frontier from sea to sea. When therefore Mamulanar3 says that the Mauryas came to the south, sending in front of them the Vadukar, the natural interpretation is that they came practically into occupation of the territory which was the natural habitat of these Vadukar, and pushed the Vadukar in front of them in their further march southward.
1 Aham 213 and 381. 2 Mamulanar, Aham 295. 3 Aham 107.