Authors: Jeremy Cohen and Walter Jetz
Publication: Global Ecology and Biogeography
Publication Link: https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.13722
Keywords: big data, birds, climatic niche, environmental niche, functional trait groups, hypervolume, migration, phylogenetic signal, seasonal niche tracking, seasonality
Aim: Species depend upon a constrained set of environmental conditions, or environmental
niches, for survival and reproduction that are being increasingly perturbed
or lost under rapid climatic change. Seasonal environments, which require species to
withstand shifting conditions or track their niches via movement, can offer an important
system to study the range of biological responses to potentially cope with
climate change. Here, we develop a novel methodological framework to identify
niche-tracking strategies, including the tracking of niche position and breadth, using a
uniquely well-sampled system of 619 New World bird species.
Location: Western Hemisphere.
Time period: 1980–2020.
Major taxa studied: Birds (Aves).
Methods: At continental scales, we identify the tracking of both environmental
niche position and breadth and assess its phylogenetic and functional underpinning.
Partitioning niche position and breadth tracking can inform whether climatic means
or extremes constrain seasonal niches.
Results: We uncover four primary niche-tracking strategies, including the tracking
of environmental niche position, niche breadth, both or neither. Species that track
niche position most often also track niche breadth, but nearly 40% only track one
component and 26% only track niche breadth and not position. There is only limited
phylogenetic determinism to this variation, but a strong association with ecological
and functional attributes that differs between niche position versus niche breadth
Main conclusions: The observed diversity in type and strength of environmental
niche-tracking strategies points to highly differing sensitivity to ongoing climatic
change, with narrow trackers of both position and breadth particularly susceptible.
The trait associations of niche tracking imply significant functional consequences for
communities and ecosystems as impending climate change affects some strategies
more strongly than others. Seasonal environments and their diversity of niche-tracking
strategies offer exceptionally dynamic systems for understanding the biological responses
and consequences of climate change.