Data from: Breeding phenological response to spring weather conditions in common Finnish birds: resident species respond stronger than migratory species

National bird-nest record schemes provide a valuable data source to study
large-scale changes in basic breeding biology and effects of climate
change on birds. Using nest-record scheme data from 26 common Finnish
breeding bird species from whole Finland, we estimated the laydate of the
first egg for 129 063 nesting attempts. We then investigated the
relationship of mean spring temperature and spring precipitation sum to
changes in the onset of laying over the period 1961–2012. In addition, we
examine differences in response to these climatic variables for species
grouped for different life history strategies; migration, diet and
habitat. Finally, we test whether body size is related to the strength of
phenological response. We show that 26 common Finnish breeding bird
species have advanced their laying dates over time and to an increase in
the mean spring temperature over the study period. When species are
grouped according life history strategies, we find that breeding
phenological change is negatively associated with changes in the mean
spring temperature where residents respond strongest to changes in mean
spring temperature, but also short- and long-distance migrants advance
laydates with increasing spring temperatures. Breeding phenological change
is also associated with spring precipitation, where resident species delay
and short-distance migrants advance the onset of breeding. In addition we
find that omnivorous species respond stronger than insectivorous species
to changes in spring temperature. In contrast to results from an earlier
study, we do not find evidence that small-sized species respond stronger
to spring temperature than large-sized species. As climate warming is
predicted to continue in the future, long-term citizen science schemes,
such as the Finnish nest-card scheme, prove to be a valuable
cost-effective way to monitor the environment and allow investigation into
how species are responding to changes in their environment.