The secret wildlife of golf courses

The cool morning air has strewn the lawn with small dewdrops. The green is bathed in flickering mist and shining dewdrops. Soon the green is filled with the sibilant sound of golf balls and walking golfers, but for a while, the course still belongs to someone else.

Water hazards of Hiekkaharju Golf in Vantaa (in the Helsinki metropolis area) provide suitable habitats for diverse species. Picture borrowed from http://www.hieg.fi

Keimola Golf, located in Vantaa (in the Helsinki metropolis area in Finland), is a true paradise for birds and amphibians. Whooper swan (Cygnus cygnus), common goldeneye (Bucephala clangula), and horned grebe (Podiceps auritus) pairs nest in the largest water hazard. In addition, the black woodpecker (Dryocopus martius) nests nearby. The number of horned grebes has declined worldwide, and the species is considered vulnerable in Finland. The Finnish population has decreased from 3000 to 6000 nesting pairs in the 1980s to the present 1200–1700 nesting pairs.

On the other hand, all Finnish amphibian species, except one, can be found living in one of the smallest water hazards of Keimola Golf. Only the Northern crested newt (Triturus cristatus) does not occur there. The Northern crested newt is critically endangered in Finland, and can only be found in a few places in eastern Finland. In spring, the common frog (Rana temporaria), the moor frog (Rana arvalis), and the common toad (Bufo bufo) croak vigorously. The smooth newt (Lissotriton vulgaris) does not croak, but mating males bring tropical colors into an otherwise brownish landscape.

Mating smooth newt males are springtime color spots in a wetland. ©Mia Vehkaoja

By Midsummer, golf courses are swarming. On dry land, golfers enjoy their sport in warm summer weather, while hatched ducklings and tadpoles are concurrently going through growth spurts around the water hazards. Golf courses provide lots of nutrition for ducklings and tadpoles. Water hazards, as most wetlands, are habitats for several invertebrates, such as mosquito (Culicidae), nematocera (Nematocera), and trichoptera larvae, as well as for phyto- and zooplankton. Amphibians prefer open and sunny wetlands because higher temperatures escalate tadpole development. Ducklings, on the other hand, prefer wetlands with luxuriant shoreline vegetation (for example club rushes and sedges). Vegetation provides cover against predation.

Luxuriant shoreline vegetation provides cover for ducklings against predation, whereas openness increases water temperature and escalates tadpole development. ©Mia Vehkaoja

Golf courses are oases for wetland-associated species, especially in urban environments, where most wetlands are isolated from each other. For numerous species, water hazards and golf greens offer nearly free access between wetlands and other habitats. Golf courses are currently not planned to consider nature and its needs. What if nature were taken into account during planning, with at least a 10% effort? Keimola Golf’s extraordinary biodiversity has arisen through chance. Waterfowl diversity is due to an island left in the middle of the largest water hazard. The island has some ten trees and bushes. The whooper swan and common goldeneye nest on this island.

Both national and international designers have planned Finnish golf courses. Keimola Golf was planned in Great Britain. More and more, architects plan golf courses by initially outlining the routes, after which the planning is continued on-site concurrently while the course is being constructed. This method enables taking nature into account during the planning process.

Architects could pay attention to small things that benefit animal and plant species when planning water hazards and groves. For example, bushes and shoreline vegetation could be left next to the shoreline that is not close to the green. This has been done at Keimola Golf. Paying attention to such small details does not even cause additional costs. Furthermore, most golfers enjoy the sport because they can be outside and “enjoy” nature. If nature were actually taken into account during planning, golfers could actually play their sport “in the wild”.

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What do ducklings eat?

Ducklings grow rapidly. In just a couple of months, an egg becomes a bird with feathers that enable flying thousands of kilometres. Growing feathers requires a lot of protein. Where do ducklings get the protein?

Ducklings can reach their food using different methods.

If you have ever visited a wetland, you may have noticed a lot of invertebrates, for example mosquitoes and dragonflies. Many invertebrates flying around the wetlands actually lay their eggs in water. The larvae will develop in the water and emerge when ready to fly. Often these flying invertebrates rest on wetland vegetation. Swimming and flying invertebrates are duck food.

Mosquito larvae in various phases of their development. Larvae develop in water and emerge as flying invertebrates.

Wetlands are occupied by many kinds of aquatic invertebrates from small zooplankton to large beetles. They are all duck food, but ducks also help them disperse from one pond to another: invertebrates and their propagules can be carried over long distances in duck feathers or intestines.

What type of food a duck consumes depends on the duck species. Ducks are specialised to eat various types of nutrition, and for example the size of the lamellar (teeth like structures used for filtering or straining food) in the bills differs between species. Diving and dabbling ducks have diverging ways of reaching their food. Diving ducks, even their small ducklings, dive under water and can utilise swimming and benthic aquatic invertebrates.

Duck bill lamellar (tooth-like structure on the sides of a bill) density differs between species. Lamellar are used to sieve food.

 

Females should find good foraging spots for their broods. Broods can move long distances from the nesting site to find proper food patches. Most European ducks breed in the boreal zone, but many lakes lack enough invertebrate food for ducklings. Thus many of the lakes are empty of duck broods.

The common goldeneye (Bucephala clangula), a diving duck, is associated with boreal lakes with large numbers of free-swimming aquatic invertebrates (e.g. dytiscidae) and large emerging invertebrates (caddisflies and mayflies). Of these, mayfly larva live in the bottom of the wetlands.

Dytiscidae are diving beetles.

Of the dabbling ducks, the mallard (Anas platyrhynchos), common teal (A. crecca) and Eurasian wigeon (Mareca penelope) are sympatric species with a shared niche. However, the habitat use of their broods differ. While mallard broods prefer lakes with luxuriant vegetation and large emerging invertebrates, teal broods utilise lakes with smaller emerging invertebrates, such as flies (diptera). Flies are abundant especially in newly created wetlands and flowages, and teals are considered pioneering species.

Productive wetlands can be full of small invertebrates such as copepodas, cladocerans and isopodas.

Adult wigeons are vegetarians, and also appear to prefer lakes with luxuriant vegetation during the brood stage, but small flies are also important for them. Beavers are important for mallards and wigeons in the boreal landscape: lakes that typically lack luxuriant vegetation can establish large and shallow well-vegetated areas during the beaver flood. Thus beavers can provide habitat enhancement. Without them less lakes would be available in the boreal landscape for wigeons and mallards.

 

Read more:

Nummi, Paasivaara, Suhonen & Pöysä 2013: Wetland use by brood-rearing female ducks in a boreal forest landscape: the importance of food and habitat

Nummi & Holopainen 2014: Whole-community facilitation by beaver: ecosystem engineer increases waterbird diversity

Do ducks have teeth?

Beavers facilitate Teals at different scales

Wetland ecology group_University of Helsinki_Teal

Teal broods utilize beaver ponds.

Blog text by Petri Nummi, Eeva-Maria Suontakanen, Sari Holopainen and Veli-Matti Väänänen “Beavers facilitate Teals at different scales” is now available on the Ibis website.

There and back again – a mire’s tale

In a remote country lived a rich mire species community. But that was once upon a time, when Finland was a land of mires. Nowadays, only fragmented pieces are left in the southern region, while large natural mires can still be found in Lapland. Nevertheless, only one third of historical levels remain. Most mireswere dried due to farming and forestry. Ditches were dug to gather water from ca. 6 million hectares of mires. This affected the hydrology and further the ecology of these wet ecosystems. Several plant and animal species are adapted to mires, and have thus suffered from habitat loss and fragmentation. For example, forest grouse and bean geese (Anser fabalis) utilize mires during their breeding period. Due to ditching, mires stop producing their ecosystem services, because berry production and game bird populations (these are cultural and provisioning ecosystem services), decrease, and thus the recreational values of the areas lessen.

Wetland ecology group_University of Helsinki_Mire_Cloudberry

Cloudberry (Rubus chamaemorus) grows on mires and benefits from restoration activities.

Finland has about 10 million hectares of dried mires, more than half of which have been utilized by forestry. However, about a fifth of this area does not produce wood well enough for it to be profitable. After several centuries of mire destruction,  a change is now in the air. Finnish mires are being restored with increasing effort. For example, in 2017 Metsähallitus (the Park and Forest Service) began an EU-funded project called Hydrology LIFE. The project aims to safeguard not just mires, but also small water bodies and important bird lakes in 103 Natura 2000 areas. The project restores and protects mires.

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Mire hydrology can be restored by blocking ditches.

Hydrology is the most important issue to consider when restoring a mire. Blocking ditches leads to changes in water balance, and eventually to active peat formation, which is basically the definition of a mire. After the ditches are blocked, water levels normally rise rapidly to correspond with the natural situation. However, actual peatland processes return at a much slower speed. Forest vegetation is slowly replaced by mire vegetation, starting from the ditches. The processes take a long time, so whether or not the original mire ecosystem returns is yet to be seen. It is also possible that we are actually just creating new mire types.

Wetland ecology group_University of Helsinki_Elimyssalo_mire_peatland_forest reindeer

Elimyssalo nature conservation area in Eastern Finland consists of various peatland types. The area is an important calving place for wild forest reindeer (Rangifer tarandus fennicus).

Helping forest grouse

Wetland ecology group_University of Helsinki_hazel grouse

Forest grouse utilize peatland-forest ecotones. The hazel grouse (Tetrastes bonasia) population in Finland has suffered from peatland loss.

Peatland-forest ecotones are key environments for forest grouse, but unfortunately these areas are becoming very rare. The willow ptarmigan (Lagopus lagopus) has suffered from mire fragmentation in Finland. Ptarmigan habitats are fragmented especially in Southern Finland, and thus there are small populations living far from each other. Luckily, local people are usually interested in peatland restoration that helps species such as the willow ptarmigan. Several good examples exist of how ptarmigans have accepted restored peatlands. The Finnish Association for Nature Conservation has a project “SuoMaa”, which began in 2016, and targets protecting and restoring taiga nature. One of the aims is to restore peatlands to support and enlarge a ptarmigan breeding peatland network and create connections between strong and threatened populations.

 

Read more

Hydrologia-Life

Suomen metsäkanalintukantojen hoitosuunnitelma

Restoration of peatlands, Luke

 

Helping out or avoiding risks

Social insects have numerous pathogens that can spread simultaneously in a densely packed colony. Mild exposure to one disease may not increase an individual’s risk of dying, but it does increase the individual’s risk of concurrently contracting another pathogen. Such double diseases are called superinfections, and they lead to death significantly more often than contracting one disease at a time does.

Preventing the spread of a pathogen within a colony is highly important for social insects. Other individuals can treat their sick counterparts either by helping them or by being aggressive. Help can come in the form of grooming, which serves to clean sick individuals of a potential pathogen, or spraying, where infected individuals are hosed off with antimicrobial chemicals. These chemicals are produced in the bodies of certain ant species, which spray the antimicrobials into their surroundings by increasing their internal pressure. On the other hand, aggression appears as biting and dragging of infected animals, which is done to prevent pathogens from spreading deeper into a colony by removing sick individuals from the colony.

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Ants are social insects. They live in colonies that can grow to tens of thousands of individuals © Sari Holopainen

To test how colony mates react to sick individuals, Austrian scientists conducted a study on Lasius neglectus ants. The scientists placed mildly sick ants, infected with one of two fungal pathogens, into a colony. The colony also housed healthy individuals used as controls. Sick individuals could therefore encounter healthy individuals, individuals with the same disease, or individuals suffering from the different pathogen. The controls on the other hand ran into other healthy ants or ants suffering from one of the two diseases. The researchers wished to see whether previous infection altered the behavior of the ants when meeting an infected individual. They were also interested in testing whether the ants reacted differently to individuals infected by the same pathogen as to individuals carrying the other pathogen.

The studied ant species is usually not aggressive towards its colony mates. However, during the experiment, infected individuals often began biting and dragging encountered individuals if they were also sick. Healthy individuals did not react to their diseased counterparts in the same way. Diseased individuals also sprayed other infected ants more often than healthy individuals did. Spraying was more common if the diseased individual suffered from the different fungus than did the sprayer. Grooming was most common when sick individuals with the same pathogen crossed paths.

In other words, infected ants are more aggressive towards other disease carriers, but concurrently they can alter their behavior according to the situation, and choose the safest decontamination method available. This is determined by whether the encountered ant is infected by the same or the other pathogen. Grooming requires individuals to be close to each other, but if both ants have the same infection, the risk of a new infection is minimal. Spraying can be done from a greater distance, in which case individuals don’t come into close contact. This helps sick individuals from contracting a superinfection, which would most probably be lethal.

The scientists were also able to determine that this risk aversion pays off, as mildly sick ants were successful at avoiding a superinfection. Both individuals therefore benefit from altering their behavior, also known as behavioral plasticity. This is extremely important for social insects in densely inhabited colonies, where sick individuals cannot be avoided.

Cleaning is not the only way in which colony insects help each other out. Another recent example comes from German scientists, who observed an African ant species (Megaponera analis) to tend to its injured individuals by licking. Their saliva is believed to contain antimicrobial substances that assist healing. The species often raids termite mounds, so an individual’s injury risk is great. Uninjured ants must make the choice of either helping injured counterparts back to the colony for medical assistance or not. Helping increases an uninjured individual’s risk of suffering injury. However, it is in the colony’s interest to treat as many individuals as possible.

A YouTube video showing uninjured ants tending to injured individuals

Hawks for hunting

Falconry is a centuries-old form of hunting in numerous countries around the world. It is considered an integral aspect of many cultures, and was therefore added to the UNESCO Lists of Intangible Cultural Heritage as a living human heritage element in 2010.

Falconry involves a trained bird of prey that is instructed by a falconer to hunt its natural prey species. The birds can be falcons, hawks, or eagles: even a few owl species have successfully been used. The falconer releases his bird once he has seen a potential prey animal. The bird flies after the prey, and pins it to the ground. The falconer follows, kills the prey, and gives the hawk a compensatory food reward. Falconry can be practiced during regular hunting seasons.

Wetland ecology group_Stella Thompson_University of Helsinki_falconry

Several cultures utilize birds of prey for hunting. Lotta the goshawk hunts in Finland. ©Markku Kallinen

Falconry is practiced in many Arab nations, European countries (e.g. Great Britain and the Czech Republic), and in most US states, to name a few examples. The International Association for Falconry (IAF) carefully regulates falconry. The association’s objective is to advance the protection and conservation of birds of prey through falconry and awareness raising.

Despite conservation efforts, many people harbor negative feelings towards falconry. And true problems do exist; certain countries allow the crossbreeding of species. If hybrid hunting hawks manage to escape from captivity, they can weaken the genetic purity of local birds. Alien species are also used in certain areas. For example, Britain has imported Harris’s hawks (Parabuteo unicinctus) into the country for pheasant hunting, but escapees have been reported nesting in the wild. The ethics behind captive wild bird species and breeding them in captivity also remains an issue. On the other hand, falconry has also managed to lessen prejudices that people have harbored against birds of prey in many countries, and falconry organizations further the conservation of both birds of prey and other bird species by e.g. raising awareness and campaigning against illegal animal trafficking.

At one time, falconry was also popular in Finland, where the goshawk (Accipiter gentilis) was the bird of prey most used. Falconry is technically legal according to Finnish hunting legislation, but actually obtaining a hunting hawk is not easy in practice. Goshawks are protected in the country, so a native bird cannot be captured. Therefore a bird must be brought in from abroad. The bird cannot be an alien species, and individuals brought in must also be sterile, as goshawks in other countries are of different populations than in Finland.

Wetland ecology group_Stella Thompson_University of Helsinki_falconry

Markku and Lotta mainly hunt mountain hare. ©Pia Kallinen

However, Finland certifiably has one pair of hunting goshawk and falconer. Markku Kallinen and Lotta the goshawk uphold an old hunting tradition that disappeared during the 1960s. Markku and Lotta mainly hunt mountain hare (Lepus timidus). See a video of Lotta feeding, filmed by Pia Kallinen.

Lotta’s activities can be followed (in Finnish) at https://www.facebook.com/haukkametsastys/

Colour matters

Colour change is a surprisingly widespread feature in the animal kingdom. Rapid colour change occurs in both invertebrates and vertebrates. The feature has been observed in crustaceans, insects, cephalopods, amphibians, reptiles and fish.

There are two main methods for changing colour: morphological and physiological colour change. Morphological colour change is based on changes in the number and quality of pigmentophores, whereas physiological colour change is based on changes in the number of organella within the pigmentophores. Melanophores are the most common pigmentophores to have melanosomes. Physiological colour change is much faster than morphological colour change. It can happen in microseconds. Physiological colour change is regulated by the neuromuscular system in cephalopods and by the neuroendocrine system in other classes. Environmental factors, such as background, lighting conditions, temperature and moisture, along with behaviour and stress can trigger physiological colour change.

Animals capable of changing colour usually have more than one colour-change strategy. Environment, the number of predators, predator species and the presence of individuals of the same species influence the colour-change strategy. For example, the daisy parrotfish (or bullethead parrotfish, Chlorurus sordidus) has three different colourations: individuals have stripes, are all black or have an eye-dot on the tail. The purpose of the eye-dot is to frighten predators, whereas the all-black daisy parrotfish tries to blend in with its background and the striped daisy parrotfish tries to bluff or dazzle its predators. The occurrence of these colourations is influenced by environmental background, the body size of the daisy parrotfish and its social relationships. On the other hand, the common cuttlefish (Sepia officinalis) chooses its strategy by whether a predator hunts using vision or chemical signals (watch how the common cuttlefish changes its colour). Chameleons (Chamaeleonidae), however, change their colour according to the environmental background rather than to mimic or to frighten.

The common octopus (Octopus vulgaris) can change its colour. © Sari Holopainen

Temperature affects the melanocyte-stimulating hormone (MSH) in many colour-changing animals such as fish, amphibians, reptiles and crustaceans. MSH is in charge of dispersing melanin. Changing to a dark or light colour helps an animal to either reflect or absorb heat. On the other hand, changing colour can concurrently predispose the animal to predation, because the animal is unable to blend in with its environment. The colour change of over 25 desert reptile species has been proven to depend on both environmental temperature and body temperature regulation. When it gets very warm (over +40°C) reptiles change to a lighter colour despite their background being somewhat dark. The reptiles usually still escape from predation because predators are inactive at such high temperatures. In proportion, when it gets cooler reptiles become darker than their environment, especially if they are near to cover.