About this Research Topic
Vagrants form the “fodder of evolution” in the words of R.A. Davis and D.M.Watson, and vagrancy may offer the mechanism to escape from extinction due to the changing climate. We will explore the data in support of this idea for birds, and ask whether birds are likely to disperse over a sufficiently large spatial scale and in a timely manner to be able to exploit new habitats, as these habitats become newly suitable due to climate change. Accumulation of substantial data on bird movement in recent years shows that vagrancy is a broadly typical behavior of birds, as well as many other organisms, and far from being biologically inconsequential, often results in colonization or recolonization of novel breeding sites.
Furthermore, there is increasing evidence that vagrancy is a positive response to improved conditions, rather than a desperate move to escape catastrophe, and is thus carried out by individuals in top physical condition. This contrasts with the view that vagrancy is simply a consequence of incompetent navigation. Putting these ideas together, we suggest that, in order to colonize newly available habitats, pockets of elevated reproduction in response to abundant resources must exist to generate vagrants. To experience whether previously unoccupied areas are suitable for breeding, birds must first travel to these places, and this initial movement of discovery constitutes vagrancy by definition.
In this Research Topic, we will analyze recent data on vagrancy by birds, explore the mechanisms of this behavior, and question how vagrancy may impact the colonization of previously unoccupied habitats that have become habitable due to changes in climate.
Specifically, the papers in this Research Topic will show
1. Significant range expansion by multiple bird species worldwide,
2. What, if any, role changing climate has played in each of these range expansions, and
3. How vagrancy and exploratory behavior led to these changes in range and distribution.
We want to ask
1. Do vagrants differ behaviorally from non-vagrants, or is vagrancy simply a consequence of more juvenile birds available to disperse?
2. Is there a preferred orientation among vagrants?, and
3. Are vagrants in especially good physiological condition at the start of their journey, compared to non-vagrants (as has been suggested by recent studies)?
We will explore this topic using about 15 species of birds for which we have substantial data to support the three main points outlined above. This topic is especially important now, given the prevalence of declining species of birds and other organisms worldwide. We address the question of whether bird species can escape “extinction by climate change” through vagrancy or exploratory behavior to discover newly suitable habitats.
Keywords: Vagrancy, Climate Change, Exploratory Behavior, Birds
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.