Woodland birds living amongst native trees produce more chicks - University of Glasgow

Native trees, such as oaks, have long held a special place in our culture and countryside. Now, researchers have shown that these trees are also important to woodland birds and their offspring.

A new study, led by the University of Glasgow and published in the journal Ecology, shows that common woodland birds, such as blue tits, produce more chicks when surrounded by a greater abundance of native tree foliage.

Using nine years of data from blue tits breeding at 20 locations, extending from the city centre of Glasgow to the banks of Loch Lomond, the research team looked at a range of factors that differed across the sites. These factors included the amount of tree foliage, the type of trees, the density of people and the local temperature. The research team then teased apart the impact of these different factors on how well the birds did.

The key finding was that the abundance of native trees, in particular oak trees, really matter to the overall wellbeing of woodland birds and their ability to produce more chicks. In areas where more oak trees were present blue tits laid more eggs, laid them earlier in the year and overall bred more successfully.

The researchers believe this is because our native trees support more insect life. In the case of oak trees, this means more caterpillars of moths and butterflies – the food that blue tits’ prefer. The team confirmed this by recording caterpillar numbers during the birds breeding season and found more food for breeding birds where there were more oak trees.

The findings highlight the importance of carefully considering what trees we should be planting, particularly in our urban areas where there are fewer native trees.