JYUnity

Good news! A nice bunch of returning migratory pied flycatchers and local tits moving to their summer territories accepted the birdhouses for nesting that researchers had placed around Jyväskylä. The University’s long-term bird study investigates what kind of food the different species favour in this environment and what kind of a diet keeps the birds best resistant against diseases. 

The busiest ornithology season is underway, as evidenced by the researchers’ alert demeanour.

Researchers brought birdhouses to Haukanniemi and they were accepted for nesting by pied flycatchers and tits.

Right after parking her car, Associate Professor Suvi Ruuskanen is already in full speed with her work. A pied flycatcher is fluttering amidst the branches of a willow near a birdhouse that Ruuskanen’s research team has placed on a birch trunk at Haukanniemi in Jyväskylä.

Ruuskanen tries to see with the naked eye whether the bird is male or female. Would it like to settle in the research birdhouse, which is located fairly low on the tree trunk?

”Have the females already arrived?”, asks Ruuskanen from Doctoral Researcher Martta Liukkonen, who has just checked the birdhouses at Haukanniemi.

Pied flycatcher males arrive to the nesting places about a week before females.

An important criterion that the females use in selecting their partner pertains to the potential nesting place the male has discovered.

The male pied flycatcher fluttering around this particular birdhouse at the edge of forest may have arrived too late for this site. It is found out that a blue tit has already occupied this birdhouse.

The flycatcher has still some hope for moving in, however.

”Tits make several nests at first and choose then one of these. Thus, the pied flycatcher may get a chance to start building a nest on a moss bed prepared by the tit. It is common that flycatchers are watching for nests no longer occupied by tits. The flycatchers need to be cautious with this, however, since in a possible fight for the nest the bigger tit would win”, Ruuskanen tells.

The large ornithological study brought 500 birdhouses placed low and visible on trees

The first summer for the project in Jyväskylä began reasonably well: Of the altogether 500 birdhouses, 117 were occupied, says Associate Professor Suvi Ruuskanen.

The birdhouses at Haukanniemi are part of a long-term bird study of the University of Jyväskylä, which the research team led by Suvi Ruuskanen started this spring. After five years – and perhaps still further on – we will receive research data on blue and great tits as well as on pied flycatchers, from which we can already see some annual variations.

Climate change and the rise in the average temperatures in spring have prompted many birds to start nesting earlier.

The now launched research in Jyväskylä will yield evidence on the annual variation of nesting for tits and pied flycatchers. Comparative data will be gained from elsewhere in Europe, where similar studies are underway.

The first summer for the project in Jyväskylä began reasonably well: Of the altogether 500 birdhouses, 117 were occupied by the end of May: 65 by tits and 52 by pied flycatchers.

The researchers thank local people who have been smart enough to leave the nesting birds and the birdhouses in peace, although the birdhouses are placed fairly low on the tree trunks so as to make researchers’ work slightly easier.

The researchers monitor the nesting of small perching birds and as the study progresses, can also analyse the diet and the composition of intestine microbiome of these birds.

In the next few years, Martta Liukkonen can tell what kind of intestine microbiome composition the nesting birds have and what it reveals about the birds’ immunological resistance, in other words, protective capacity against pathogens.

There are interesting connections to prove: What do these birds eat? How does it show in their intestines? Is there any regional variation in the intestine microbiome? How does the microbiome composition affect the birds’ fitness?

”Genetic sequencing methods reveal a bird’s diet so that we can define the specific species of insects or plants fed on. I am interested, above all, in the mutual relationships of intestine microbes as well as the geographical and seasonal differences in the intestine microbiome, Liukkonen says.

According to Liukkonen, the microbiome is formed in young birds so that changes in their diet may have long-term effects on the composition of their intestine microbiome.

The fieldwork in summer enhances researchers’ skills for bird handling

As the nesting progresses, Martta Liukkonen will head more frequently for checking the nests.

As the nesting progresses, Martta Liukkonen will head more frequently for checking the nests. If she finds eggs in a nest, she needs to be able to estimate when the hatching will take place.

”When the young birds are about seven days old, we will take a faeces and blood sample from the bird mother. By sequencing the genes from the faeces sample, we can find out what bacteria the birds have in their intestine microbiome and what the birds have eaten. Similarly, we can also analyse regional or annual variations in this respect. From the blood samples, in turn, we can examine, for instance, the composition of short-chained fatty acids”, Liukkonen tells.

This blue tit choose an old birdhouse.

As yet, there is only scarce research knowledge about the composition of birds’ intestine microbiome. Based on studies conducted on other species, it is already known, however, that diet is connected to the composition of intestine microbiome of animals, which in turn is connected to the condition of the individual animal.

Will the data eventually show how diet is connected to a bird’s health?

”I hope that the data helps us find out whether diet has any significance for the health of these tits and pied flycatchers”, Martta Liukkonen states.

Key indicators of bird health include the bird’s weight, reproductive capacity, and the survival of the offspring. Especially in winter, the meaning of weight is highlighted, since to survive through the frosty weathers in Finland, birds need sufficient nutrition.

Pied flycatchers tolerate changes

The pied flycatcher is a viable and vital species in Finland. It is a famous eater of insects, not only airborne ones but also various arthropods on the ground.

According to Suvi Ruuskanen, pied flycatchers are good helpers for a researcher.

”Pied flycatchers have a calm character and are therefore favourable research objects for a researcher. They do not get easily disturbed and they also tolerate transfers related to research, for example. Summertime is short for them; nesting must be successful at the first attempt. For this reason, these birds must also tolerate changes in their environment, Ruuskanen explains.

It is also fascinating to watch the life of tits, which learn new things easily and solve problems aptly. Blue tits make skilful nests and decorate them with feathers – or with other soft material found in the environment.

”Besides, both tits and pied flycatchers are really beautiful”, rejoices Martta Liukkonen over her fieldwork, where she can study these birds for the whole summer.

As the study progresses, Liukkonen will gain good experience in bird handling for research purposes. With sufficient experience, Liukkonen will be eligible to apply for a licence to ring birds, which is granted by Luomus, the Finnish Museum of Natural History. All young birds from the research nests in Jyväskylä will be ringed.