. The Importance of Birds to Ecosystems and Culture
Birds contribute toward many ecosystem services that either directly or indirectly benefit hu-
manity. These include provisioning, regulating, cultural, and supporting services. Functional roles
of birds within ecosystems as pollinators, seed-dispersers, ecosystem engineers, scavengers and
predators not only facilitate accrual and maintenance of biodiversity but also support human en-
deavors such as sustainable agriculture via pest control, for example, of phytophagous insects in
coffee plantations (25) and rodents in cropland (26). The high vagility of most bird species, es-
pecially migratory species, leads to environmental teleconnections linking ecosystem fluxes and
processes, sometimes in geographically disparate locations. For example, coral reef fish produc-
tivity has been shown to increase as seabird colonies recovered following rat eradication in the
Chagos Archipelago (27). Wild birds and products derived from them are also economically
important as food (meat, eggs and, in some cases, nests) or guano as fertilizer. By far the most
abundant bird on Earth is the domestic chicken (Gallus gallus domesticus), of which an estimated
19.6 billion are estimated to be alive at any one time (28). This domesticated form of the Red Jun-
glefowl (Gallus gallus)—a tropical forest species from Southeast Asia—outnumbers its wild ances-
tors by several orders of magnitude.
The status of birds as a model taxon to ask questions in ecology and evolutionary biology
is owed in part to aspects of their life history—largely diurnal, conspicuous, and usually easy to
identify and study in life—as well as a “manageable” number of described species, which means
that our knowledge of their distribution in space and time is far better than for other groups of
organisms in the tree of life. Consequently, birds have been used as models to understand many
macroecological patterns, such as the theory of island biogeography, and their codistributions used
to inform conservation priority setting. The ornithological academic corpus is vast in scale, with
an average of 1,177 bird conservation papers published in English annually (33). This rapid rate of
publication has been helped by the proliferation of open access datasets that provide information
on phylogeny (https://birdtree.org), functional traits (34), and species distributions (35). These
endeavors are informed by ongoing digitization of museum collections through sites like GBIF
(https://www.gbif.org//), including scans of specimens, as well as mobilization of vast numbers
of citizen scientists through platforms like eBird (https://ebird.org/), which has amassed signifi-
cantly more than a billion bird records across 64 million checklists collected by more than 750,000
users. These data on bird abundance in space and time have enabled assessments of bird abundance
distribution in regions where systematic surveys have not yet been possible, along with a collec-
tion of rich media useful for addressing a broad range of ecological questions (36). The growth in
public participation in bird monitoring and the advent of easy-to-use tools such as eBird enable
continental-scale breeding bird surveys, distribution atlases, and development of spatiotemporal
abundance models.