As the state of biodiversity worsens, the dynamics of species
interactions is a growing conservation concern. However, estimating and
monitoring species interactions across large spatial and temporal scales
remain challenging. Here, we assess changes in the number and type of
pairwise associations using large-scale spatial and temporal data on the
French avifauna. We estimate species associations through space and time
for 109 species monitored across 1,969 sites during 17 years, and we
show their ecological significance by testing their relationships with
species functional proximity or shared habitat preference. We finally
track temporal changes in reconstructed association networks. We show
that birds' local association networks were less and less connected
through the study period. This decrease in network connectance does not
similarly affect the different types of species associations. Overall,
we show that large-scale temporal monitoring of species association
networks can reveal overlooked consequences on how communities can cope
with global change.