A new database of 10,000 bird species shows how measurements of
wings, beaks and tails can predict a species' role in an ecosystem. Given that
many bird species perform important ecological functions, such as pollinating
plants, spreading seeds, or controlling pests, the database may help scientists
to understand and predict how the loss of species will affect ecosystem health.
A global team of researchers, led by Imperial College London and
University College London, including Dr. Uri Roll of the Marco and Louise Mitrani Department of Desert Ecology (MDDE)
at the Swiss
Institute for Dryland Environmental and Energy Research (SIDEER), one of
BGU's
Jacob Blaustein Institutes for Desert Research, visited museums around the
world to find specimens of nearly 10,000 species, covering more than 99 percent
of all known bird species. Their results and the database were recently
published in Nature
Ecology and Evolution.
The link between body form of each animal species and aspects of
their lifestyle, including diet, has previously been proposed, but this is the
first time it has been confirmed at such a large scale and with such precise
detail.
The senior author of the study, Dr. Joseph Tobias, from the
Department of Life Sciences at Imperial College, said: “To compile measurements
for all bird species has been a massive undertaking. That's particularly the
case considering the hundreds of explorers and biologists over the last 150
years who collected and curated the 60,000 museum specimens on which this work
is based."
Predictions of a species' contribution to an ecosystem are often
made using estimates of their evolutionary relationships with other species –
relying on the fact that closely related species tend to be more similar in
function than distantly related species. However, the new database shows that
body measurements offer a far better prediction overall, as some very distantly
related species have evolved similar bodies to equip them for similar
lifestyles or dietary preferences. For example, the family of auks, which
includes puffins and guillemots, have very similar body shape to penguins,
despite evolving in opposite hemispheres. Both have beaks, bodies and wings
adapted to swimming and catching fish underwater. The concept – called convergent
evolution – is far from new, but the new dataset provides the clearest picture
yet of its widespread influence across an entire class of animals on a global
scale.
The team looked at nine body measurements including the
dimensions of beaks, tails, wings and legs as well as body mass, and compared
these to a bird's diet and foraging behavior – for example whether it primarily
catches invertebrates in the air, on the ground, or underwater. Further studies
can use the database to predict the effects of climate and land-use change on
ecosystem function and to set appropriate targets for wildlife conservation.
Some associations are obvious, such as longer wings in species that spend much
of their time flying, or longer legs in ground-dwelling species. However, the
team found that the combination of all body measurements was highly predictive
of even subtle differences in lifestyle across all species.
The study's first author, Dr. Alex Pigot of UCL's
Department of Genetics, Evolution & Environment, said: “Our results suggest
that evolution is a predictable process. If we were to 're-run the tape of
life', then evolution likely would once again lead to very similar-looking
organisms to the ones we see today. Being able to quantify each animal's
vital role in the functioning of the biosphere is really important in
understanding the impacts of the current extinction and climate crisis."
Dr. Tobias said: “The link we show between body form and
function has some potentially important applications, and paves the way for the
use of similar data to investigate the role of biodiversity in ecosystems. For
example, further studies can use our database to predict the effects of climate
and land-use change on ecosystem function, and to set appropriate targets for
wildlife conservation."
