Pretty Clear

I've been leafing through Suetonius, starting at the backs of the chapters (ergo the Deaths rather than the Lives of the Caesars). One aspect of history which the Roman writers seldom neglect is the record of the signs and portents which illuminate the gathering clouds with flashes of lightning.

Agrippina reproaches Nero for the death of Britannicus

The race of the Caesars ended with Nero. That this would be so was shown by many portents and especially by two very significant ones.

Years before, as Livia was returning to her estate near Veii, immediately after her marriage with Augustus, an eagle which flew by dropped into her lap a white hen, holding in its beak a sprig of laurel, just as the eagle had carried it off. Livia resolved to rear the fowl and plant the sprig, whereupon such a great brood of chickens was hatched that to this day the villa is called Ad Gallinas, and such a grove of laurel sprang up, that the Caesars gathered their laurels from it when they were going to celebrate triumphs.

Moreover it was the habit of those who triumphed to plant other branches at once in that same place, and it was observed that just before the death of each of them the tree which he had planted withered.

Now in Nero's last year the whole grove died from the root up, as well as all the hens.

Furthermore, when shortly afterwards the temple of the Caesars was struck by lightning, the heads fell from all the statues at the same time, and his sceptre, too, was dashed from the hand of Augustus.

From the opening of the Life of Galba