Curious Finnish fireman rings 16 000 goldeneyes and Danish farmer rings 12 000 starlings – the most amazing examples of citizen science

 

Pentti Runko ringing a small goldeneye duckling.

While scientist struggle with short-term funding periods, the curiosity for nature that the general public shows, can unearth mechanisms that can only be found with long-term datasets. The persistent and systematic observations made by nature enthusts enables research about climate change or life history traits over several generations. Both are issues that require long-term research – and a lot of time and effort. Below are some examples of remarkable work done by citizen scientists curious about nature.

16 000 ringed goldeneyes have passed through the hands of a Finnish fireman

Finnish fireman Pentti Runko has collected systematic data of goldeneyes for several scientific studies. After starting his work in 1984, by 2017 Runko has ringed an amazing 16 000 goldeneyes and checked several hundreds of nest boxes every year.

In a recently published study, the authors utilized data concerning 14 000 of these goldeneyes ringed by Runko between the years 1984-2014. Among these goldeneyes were 141 females that were ringed as ducklings and recaptured later in the area. Based on these data it was possible to follow the recruit females’ lives from hatching to breeding. Thus the early life circumstances of these females are known, and the circumstances can be used to study their effects later on in life. In some cases early life circumstances have severe results on subsequent life, for example on breeding performance (duckling video).

Goldeneyes lay eggs in the nest boxes (video), which Runko checks for eggs several time during the season, to evaluate the hatching dates (video), to catch females and to ring ducklings.

The study was able to show deviations between individuals during the first breeding years and how circumstances during early life affected the breeding statistics of these females. Most females began breeding at the age of 2, but 44% delayed the start of breeding. Winter severity of the first two years affected the timing of breeding, but did not affect which year the females began breeding. As a conclusion, it appears that certain traits buffer the effects that the severity of the first weeks have, so the breeding parameters of females are not affected.  The research also showed that first-time breeders tend to begin breeding later than the yearly specific averages.

After ringing ducklings get back to the nest box.

The authors of another study used a set of 405 females and their offspring’s ringed by Runko, and found that the females’ condition matters when it comes to breeding success. Older, early-nesting females with good body condition and larger broods were able to produce more female recruits for the local population. The later the females bred, the less recruits they produced. The study also showed that females tend to adjust their breeding according to the ice-out dates of lakes. However, differences were observed between the flexibility of the females. Because early-breeding goldeneyes succeed better, the authors conclude that selection favours early-breeding individuals.

The lives and breeding habits of goldeneye females are closely followed at Maaninka (video).

Climate change effects can also be observed from goldeneye phenology. Runko showed that during the last 30 years goldeneyes have advanced their egg-laying dates by 12 days.

45 years of starling surveys in a farmer’s backyard reveal climate warming

Starlings are becoming scarce in Europe.

The Danish Ornithological Society Journal recently published a study that utilized data gathered by a Danish farmer, who ringed starlings for 45 years. Dairy farmer Peder V. Thellesen ringed ca. 12 000 starlings nesting in 27 nest boxes, and measured their phenology systematically. The data showed that during the study period starlings advanced their egg-laying dates by more than 9 days. This advance was observed in both first and second clutches. The result reflects the increase in April temperatures. Another important observation was that while no change was observed in clutch size and hatching rate, nest box occupancy has fallen dramatically in recent years. Starlings used to be common in Europe, but now they have decreased widely in Europe, also in Denmark. Changes in agricultural land use, especially decreased cattle grazing, are suspected as one example affecting starling populations. Loss of cattle-grazed land means less insect-rich foraging lands for the birds.

 

Read more:

Fox, T. and Heldbjerg, H. 2017. Ornithology: Danish dairy farmer delivers data coup. Nature.

Pöysä, H., Clark, R. G., Paasivaara, A. and Runko, P. 2017. Do environmental conditions experienced in early life affect recruitment age and performance at first breeding in common goldeneye females? Journal of Avian Biology.

Clark, R. G., Pöysä, H., Runko, P. and Paasivaara, A. 2014. Spring phenology and timing of breeding in short-distance migrant birds: phenotypic responses and offspring recruitment patterns in common goldeneyes. Journal of Avian Biology.

Kari S. Maattinen Youtube videos about goldeneyes

Thellesen, P.V. Common Starling Sturnus vulgaris clutch size, brood size and timing of breeding during 1971-2015 in Southwest Jutland, Denmark. The Danish Ornithological Society Journal.

YLE 2016: Lintuharrastaja on uhrannut kevätlomansa telkänpoikasille jo 30 vuoden ajan – “Se voisi olla Suomen kansallislintu”. In Finnish.

YLE 2013: Linnut pesivät nyt viikkoja aikaisemmin kuin 1980-luvulla

 

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Traffic flattens billions of frogs every year

Amphibians are run over by cars more often than other vertebrates. Per road kilometer, an average 250 amphibian individuals die every year because of traffic. According to this calculation, over 113.5 million frogs die annually on the Finnish road network (454 000 km). In Brazil, one of the world’s amphibian hot spots, traffic annually kills 9 420 frogs on each road kilometer. This means a total of over 16 billion frogs lost due to traffic.

 

Roads built near wetlands are the most significant cause of frog mortality on all continents, but particularly in Europe. No relief is in sight for this problem, because traffic amounts are increasing every year throughout the world.

 

Fast-moving frog species are somewhat fortunate because their traffic mortality is quite low on roads with little traffic (24–40 cars per hour). Up to 94% of fast-moving frogs survive when crossing a road. Slow-moving species, such as the common toad (Bufo bufo), are not that lucky. Only half of common toads survive to the other side of a road. On busier roads (60 cars in an hour) over 90% of common toads are run over by a car.

A dead common toad (Bufo bufo) hit by a car. © Mia Vehkaoja

Amphibians suffer from both direct and indirect negative effects of road networks and traffic. Mortality is a direct cause, whereas isolation is an indirect cause. Amphibians migrate according to seasons: during spring to their breeding grounds and during autumn to their wintering grounds. These migrations make amphibians vulnerable to traffic mortality. Season migrations occur particularly in the temperate zone, such as in Europe, where traffic has become the greatest threat to amphibian survival in certain places.

 

The traffic mortality of frogs decreases population sizes and reduces migration, which lead to a decreasing gene flow between populations and the disappearance of genetic diversity. Smaller populations are at greater risk of going extinct.

 

Historically thousands of kilometers of roads have been built through wetlands, which leads to the disappearance, isolation and depletion of wetland habitats. Roads also influence the cycle and function of water systems. Road construction has drained and polluted wetlands all over the world.

 

Conservation actions should concentrate not only on restricting road construction laws and regulations, but on preventing frogs from accessing roads by installing culverts and fences. According to a French study, the combination of culverts and fences is the most efficient way for saving frogs from traffic mortality. But this is just one study, and unfortunately we still know too little about which methods are best for amphibian conservation.

Wary bird nests successfully in heavily visited national park – with help from scientists

A mystical, sorrowful yell reverberates far in the Finnish wilderness. The red-throated loon (Gavia stellata) is calling its partner. This wary bird breeds in remote boreal lakes, but its primordial moaning can also be heard near Helsinki, the capital of Finland. How is that possible?

Nuuksio National Park near Helsinki is a jump into wilderness. The forests and lakes host many wild animal species, in addition to the rare red-throated loon. Loons always nest right into the shoreline, and if available, choose the shore of a small island. Oligotrophic lakes of Nuuksio with mire surroundings would be perfect for loon breeding, except for disturbing traffic caused by park visitors. This is a common problem: loon breeding suffers in many boreal areas, mostly due to large-scale anthropogenic factors, such as lake and mire drainage and increased human activity at lakes.

Red-throated loon nesting on man-made raft © Veli-Matti Väänänen

Red-throated loon nesting on the man-made raft © Veli-Matti Väänänen

Scientists of Helsinki University put their hands together, and made peat-rafts for the red-throated loons in Nuuksio. Rafts were made of peat hummock taken from the shore of the lake in question. Their floating was ensured with canisters placed underneath and they were anchored to lakes in opposite sites from the main source of human activity. A nest place on a raft away from the shoreline makes it possible for the loon female to incubate in peace.

Man-made rafts were approved by the loons. The rafts increased loon breeding success, and today Nuuksio national park has several pairs nesting every year. When the study started in 1994 Nuuksio had only one breeding loon pair, which increased to 10 pairs by 2011. A control park located a couple hundred kilometres north did not increase its loon population during the same time. This increase in Nuuksio occurred even though the visitor traffic in the park increased from 60 000 visitors in 1997 to 180 000 in 2009. With a little help from humans, red-throated loons reproduce successfully in this famous park. The same could be tried in other parks and also outside parks, in heavily populated areas, where loon breeding suffers from shore traffic.

 

References

Nummi, P., Väänänen, V-M., Pakarinen, R. & Pienmunne, E. 2013. The Red-throated Diver (Gavia stellata) in human-disturbed habitats – building up a local population with the aid of artificial rafts. — Ornis Fennica. 90: 16-22.

In Finnish: Arka kaakkuri kotiutui Nuuksioon. Helsingin Sanomat 19.7.2014