10.5061/DRYAD.51C59ZW7F
Schlesinger, Christine
0000-0002-2676-3925
Charles Darwin University
Pascoe, Bruce
Charles Darwin University
Data from: Dynamics of bird assemblages in response to temporally and
spatially variable resources in arid Australia
Dryad
dataset
2021
2022-01-24T00:00:00Z
2022-01-24T00:00:00Z
en
285142 bytes
2
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Bird assemblages in arid Australia are often characterised as being highly
variable through time in response to boom and bust dynamics, although the
importance of habitat in structuring assemblages at a local scale is also
recognised. We use a novel approach to investigate the importance of
rainfall variability in structuring bird assemblages in a resource-limited
environment. Monthly bird surveys were conducted at ten plots for eight
years at a botanical and zoological park in central Australia, including
five irrigated plots within a fenced area and five natural plots outside.
Irrigation – used to promote growth, flowering, and fruiting of plants –
created an artificial resource-enhanced environment against which the
response of birds to natural fluctuations in season and rainfall were
compared. Species richness was generally maintained at a higher level in
resource-enhanced plots during dry times but was higher in natural sites
when rainfall was high, mainly due to increases in granivores and
insectivores. Honeyeaters were consistently more abundant at irrigated
sites. Rainfall was important in structuring bird assemblages at all
plots; however, assemblages were more stable in irrigated plots and did
not respond as dramatically to a period of very high rainfall. The
comparative smoothing of fluctuations in the composition and abundance of
birds in irrigated areas highlights the importance of primary
productivity, normally tied to rainfall, in driving temporal change in
arid-zone bird communities. There was also evidence that different plots
in differing habitats supported distinct bird assemblages and that this
spatial distinctiveness persisted irrespective of rainfall and determined,
to some extent, the response to rainfall. Our study is one of few
long-term studies of arid bird assemblages and highlights the importance
of both long-term cycles of productivity driven by rain and season as well
as site differences in the dynamics of arid zone bird communities. These
insights are particularly valuable as climate change further exacerbates
rainfall variability worldwide and initiatives to conserve avifauna in
increasingly extreme environments may be required.
Data represent 30-minute area searches conducted simultaneously at 10
sites by citizen scientists. Surveys were conducted on 94 occasions
between February 2004 and December 2011. Five sites were inside the Alice
Springs Desert Park in an area that is irrigated and maintained as a
botanical/zoological garden and five are outside the park in surrounding
bushland and are natural (with no irrigation).
Labels are in the form Feb04I1 and represent the month of survey, year of
survey, 'treatment' I/N, site number. I = Irrigated sites N =
Natural sites (no irrigation)