Animals need to synchronise their reproductive phenologies
with the seasonal availability of resources, so that they’re reproducing at the
time of maximum resource abundance. Plants and insects have advanced their
spring phenologies as spring temperature has increased. The animals which rely
on them for food need to advance their reproductive phenologies in step, in
order to cope with this change.
Migratory birds have been heavily studied in this regard. Some species have not advanced their timing of breeding. Unsurprisingly, European migratory bird species which
advanced their spring migration phenology in the past decades have stable or
increasing populations, but those which have failed to respond have decreasing
populations.
The migratory pied flycatcher,
Ficedula hypoleuca, is one
example. It has had trouble adapting to climate change because
the timing of its migration is controlled by “endogenous rhythms”, such as day
length, which are not affected by climate change. The pied flycatcher populations with the largest declines are those where its prey’s population peaks early in the spring – because it
hasn't been arriving earlier, it’s missed the time of peak food availability.
When prey population peaks later, the birds do better.
No comments:
Post a Comment