Does the diversification rate of endemic birds of mainland China follow abrupt, gradual shifting or constant patterns?

In this brief report, time-varying (including both gradual and abrupt change) and time-constant diversification models are fitted on a phylogeny of endemic birds of mainland China to test the diversification patterns of endemic birds in the region. The results show that phylogeny of endemic birds is best quantified by a constant-rate diversification model through model comparison. Limitations of the study are discussed. In particular, ignorance of non-endemic taxa and the limited sampling of endemic taxa could influence the conclusions of the study.