Birchstar is politely talking with Redstar, ThunderClan's leader, before a Gathering. She questions Cloudstar on why he brought his whole Clan to the Gathering, and Cloudstar reveals that SkyClan's home has been destroyed by Twolegs. When Cloudstar asks for help, Birchstar states that she would like to help SkyClan, but that the river is very low, and that it is harder than ever to catch any fish. She also says that SkyClan doesn't know how to catch fish.
Much later, Birchstar appears during Leafstar's leadership ceremony with the other leaders at the time of SkyClan's departure: Redstar of ThunderClan, Swiftstar of WindClan, and Dawnstar of ShadowClan. Firestar notes that she looks like Heavystep from RiverClan and a bit like Clovertail. She tells Cloudstar that RiverClan feels the same as ThunderClan, admitting that they should never have driven SkyClan out. Birchstar admits that she felt compassion for SkyClan, but did nothing and says that it makes her actions worse, and she is sorry. Birchstar gives Leafstar a life for sympathy and understanding, to use for the weakest in SkyClan, and for all the others who need help and protection.
When she talks to Firestar with the other leaders, she admits that there should always have been five Clans in the forest. She stands close to the other leaders, Skywatcher, Spottedleaf, and Leafstar's mother for the rest of the leadership ceremony.
Although unnamed, Birchstar is mentioned by Firestar, when the old ThunderClan leader is talking to Bramblestar about SkyClan. He says that the leaders of ThunderClan, WindClan, ShadowClan, and RiverClan had to deal with the consequences of their actions after being responsible for driving out SkyClan. Firestar goes on to tell Bramblestar that each of these leaders had come to visit Leafstar during her leadership ceremony, and in turn, gave her a life. Firestar says that this served as not only an apology, but a reminder that one Clan is not able to survive alone.
When Cloudstar and the entire whole of SkyClan come to the gathering to beg for territory, Birchstar says that she would like to help, but the river was low in RiverClan, and that SkyClan didn't know how to fish anyway.
Although not mentioned by name, it is mentioned on Cloudstar's and Skywatcher's page that when Twoleg dens started to destroy SkyClan territory, Cloudstar looked to his rival Clans to help him and his Clan survive. Instead, Birchstar and the other leaders protested that sharing territory would be impossible, that SkyClan could not catch different prey, and that if there were only four Great Oaks in the hollow, perhaps there were only meant to be four Clans.
She has been noted to look very similar to Heavystep and Clovertail.