Changes in climate can disrupt the synchrony of phenological events by altering the environmental cues that trigger the events

• Two of the main environmental cues are temperature and the length of sunlight during a day (photoperiod)

Arctic Mouse-Ear and Reindeer

• Reindeer are migratory animals that rely on day length as the environmental cue for their seasonal movement

• The Arctic mouse-ear chickweed is a plant that forms part of the diet of the reindeer and its germination pattern is regulated by temperature (typically spring growth)
  

• Climate change (due to human activity) is resulting in higher global temperatures but does not affect the daylength
  

• This is creating a temporal mismatch between the reindeers normal migratory timing and the availability of their food source
  

Great Tits and Caterpillars

• Great tits are a small bird that rely on caterpillars as a food source for their hatchlings

• While both the timing of egg hatching and caterpillar activity is controlled by temperature cues, the caterpillars are more susceptible to temperature changes
  

• Climate change is causing the timing of peak caterpillar activity to occur prematurely, reducing the rates of survival among the hatchlings
  

Climate Disruptions

Spruce Bark Beetle 

• Spruce bark beetles are insects that lay their eggs within the bark of spruce trees in Europe and North America

• The larvae will feed on the tree phloem and other tissues while they mature, which causes damage to the plant
  

• The life cycle of the beetle is regulated by temperature – climate change is increasing the number of life cycles per year
  

• The increase in beetle population within the spruce trees is causing higher amounts of damage and increasing the rate of tree death