The Ferocity Merit detailed on page 40 of Ars Magica Houses of Hermes: Mystery Cults.
It says that "...take 3 confidence points and confidence score of 1 to use when those circumstances are met".
The issue is that some beasts such as Lions already have a confidence pool of higher than one.
Does Ferocity mean that a Lion defending its self gains a further +1 to its base confidence and an additional 3 confidence points?
If the next day it defends its self again, does it gain 3 more confidence points with its ferocity?
Or does the Ferocity Confidence not reset?
I've always read Ferocity as a "restricted" form of Confidence possessed by some beasts that would otherwise lack Confidence. If a beast lacks Confidence, then Ferocity is treated exactly like Confidence with the sole limitation that it can only be used in some specific situations.
But if you are already playing a beastly companion (such as a magical animal) that has a Confidence score, you can't "purchase" Ferocity - or more precisely purchasing it does you no good: your "baseline" with or without Ferocity is Confidence 1 with 3 starting Confidence points.
I read their stat blocks to mean given that this NPC beast has Ferocity, it has a Confidence score (that it otherwise would not have), as per description of the Ferocity Virtue. In other words, the Confidence you see in the stat block is not "normal" Confidence, it's "restricted" Ferocity Confidence.
In this sense note that, in the chapter you are referring to, only animals with Ferocity have a Confidence score of 1+, and every animal with Ferocity has a Confidence score of 1+. In fact, every animal has a Confidence score of exactly 1, except for the Lion, that has the Self-Confident Virtue. I read this to modify the "Ferocity" Confidence, however, that thus remains wholly "restricted" (in the case of the Lion, to self-defense use).
ezzelino is quite right. Although I was initially confused by some animals that had confidence but not Ferocity and some animals that had both confidence and ferocity.
Ah I did a bit more reading and I have found the answers:
In the textbox: "Cunning Characters" on pg 33, it clarifies that Magical creatures with Cunning instead of intelligence, "They cannot use Confidence Points unless they have the Ferocity Virtue."
On Page 36 it says: "If the character is intelligent, is not a grog and does not have the Low Self Esteem Flaw, or if the character has the Ferocity Virtue, give it a Confidence Score of 1 and 3 Confidence Points to start"
So this is more about intelligence vs cunning than anything else.
Most animals of virtue do have Intelligence rather than cunning. This is why the Lion of Virtue does have confidence (Because it also has intelligence), but not ferocity (unlike a standard lion which has Ferocity but is cunning). This also means that Magical animals which become familiars should have Confidence when they are bound as they automatically become intelligent and would lose Ferocity if they had it.)
As it states under Ferocity, it can only only be taken by magic characters played as grogs, or who do not have Intelligence, or who have the Low Self Esteem Flaw.
Which means that Bjornear can't have it and neither can Familiars. This also clarifies that this doesn't grant Confidence points, it only gives people access to confidence points that already exist.