Man’s best friend as a field assistant

The dog has been man’s best friend for tens of thousands of years. Our friend has travelled to the moon for us (Laika the dog was the first living organism in space), guards our homes, assists in hunting, helps weed out drug-related crime and helps scan for cancer tumours. Now our intelligent and multifaced companion has become a new use and help.

Dogs are now serving as field assistants in ecological research. Ten years ago, Natural Resources Institute Finland began utilizing game bird dogs in willow ptarmigan (Lagopus lagopus) surveys in Lapland. Previously the surveys were conducted with human help.

Game bird dogs are utilized in willow ptarmigan (Lagopus lagopus) surveys in Lapland. © Veli-Matti Väänänen

In the willow ptarmigan surveys, Lapland is divided into 45 areas and these areas contain 171 survey sectors altogether. Dogs assist in the counting of willow ptarmigans from 670 kilometers. Usually two humans at a time take part in the surveys. One of them guides the dog while the other observes that the human and dog stay in their sector and count all the willow ptarmigans. Only one dog works at a time, although several dogs present may be present.

 

The dog’s purpose is to silently search for willow ptarmigans and after finding birds, the dog will freeze and then flush them into flight. Once the birds are flying, the surveyor counts them. In addition to counting, the person also determines the sex and age of the birds, and estimates the point where the flock was flushed. This method provides an estimate of population density. The population density of Finnish willow ptarmigans is 7.5 individuals per square kilometer. This estimate was received from last year’s surveys. The yearly variation in willow ptarmigan population density is great. Population dynamics are based on reproductive success. The willow ptarmigan population size can vary from tens of thousands to some hundreds of thousands in the Lapland region.

The dog breed makes no difference in the surveys, but game bird dogs are most suitable for the purpose. © Veli-Matti Väänänen

Finland is somewhat behind in utilizing this survey method. Sweden and Norway have used game bird dogs since the 1990s. The dogs must be experienced in flushing birds into flight, rather than being successful in working tests. Dogs usually learn from hunting situations. Game bird dogs are bred and trained for seeking and disturbing birds into flight. The dog breed makes no difference in the surveys, but game bird dogs are most suitable for the purpose.

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Primeval beaver soup

Life on Earth has originated in water, in the so-called primeval soup. Chemical reactions in water produced a series of processes from which life on Earth began evolving. The main components of life are composed of carbon, hydrogen and oxygen.

 

Beavers act as cooks of the primeval soup of water systems in the Northern Hemisphere. Boreal water systems are fairly oligotrophic and infertile. An oligotrophic water system means that it does not provide a habitat for diverse assemblages of plant and animal species. Only a few species are able to live in such habitats. Oligotrophic conditions originate from the chemical conditions of a water system. Furthermore, oligotrophic water systems do not contain that much dissolved organic compounds (organic = carbon-carbon compound).

A beaver flood alters the oligotrophic water systems in the boreal zone into a lush one by changing the habitat’s water chemistry. © Sari Holopainen

A beaver flood alters an oligotrophic water system into a lush one by changing the habitat’s water chemistry. The water level rises into the surrounding land ecosystem because of the dam, and washes various materials and substances from the shore into the water system. Most of these materials originate from organisms, mainly vegetation.

 

Plants consist of various proteins, lipids and carbon hydrates, whose principal components are carbon, hydrate and oxygen, the main elements of life. Therefore, plenty of carbon and hydrate, in addition to some phosphorus, are washed into water systems because of beaver dams.

 

The Carbon in water is usually in a dissolved form, which is called DOC (dissolved organic carbon). When a beaver has dammed a water system, the DOC concentration increases significantly in the water system. The beaver’s effect on the carbon is not permanent, as it converts to initial levels after the flooding has lasted for four to six years. Organic carbon washed from the shores begins gradually sinking to the bottom of the water system and it can also be released into the atmosphere in the form of carbon dioxide and methane.

 

The eutrophic primeval soup cooked by beavers creates a series of events that consequently attracts very versatile plant and animal species to the water system. The beaver effect is evident in several food web levels. Organic carbon and other nutrients are consumed by phytoplankton and aquatic vegetation, which in turn benefit for example aquatic invertebrates and tadpoles. Abundant invertebrate numbers, on the other hand, provide food for fish and ducklings. Oligotrophic water systems in the boreal zone are altered into biodiversity oases by beaver activity.

 

Further reading: Vehkaoja ym. (2015). Spatiotemporal dynamics of boreal landscapes with ecosystem engineers: beavers influence the biogeochemistry of small lakes. Biogeochemisty.

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”.

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.

Wetlands, the Earth’s kidneys

Wetlands are one of the world’s most important ecosystems. They are referred to as the “Earth’s kidneys” and that comparison could not be more accurate. Wetlands truly are as important to the planet as kidneys are to humans, with one exception: humans can survive with only one kidney, but the Earth cannot.

Kidneys are in charge of humans’ fluid balance. If we are dehydrated, our kidneys try to preserve as much water in our bodies as possible, and when we have excess water our bodies, our kidneys work to discharge the extra water. Wetlands work in the same way. They mitigate both floods and droughts by absorbing and recharging water.

A wetland photographed from a drone. © Antti Nykänen

In addition to fluid balance, kidneys are also responsible for removing unnecessary and hazardous substances, such as waste products and medical substances. In resemblance to our kidneys, wetlands purify our natural waters. They filter and remove nutrients and pollutants from our rain and floodwaters. Extra nutrients will sink to the bottom of the wetland and hence are available for wetland vegetation. Kidneys purify 1750 litres of blood every day, but the water purification ability of global wetlands is 30-fold. Wetlands purify 30 cubic litres of water daily.

Unfortunately, the world has lost approximately half of its wetlands, and Europe alone has destroyed and altered two-thirds of its wetlands. We need strong actions to retain the Earth’s functioning.

The value of wetlands is essential in urban environments, where nutrient and pollutant levels are manyfold compared to more natural environments. Urban wetlands should be seen as important and cheap tools to purify our stormwaters, along with maintaining biodiversity within cities.

A Moorhen (Gallinula chloropus) chick at a wetland in Finland. © Mia Vehkaoja

Luckily, the Ramsar Convention has acknowledged the importance of urban wetlands and themed this year’s World Wetland Day as “Wetlands for a Sustainable Urban Future”. Happy World Wetland Day 2018! Let’s appreciate the Earth’s vital organs.

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.

Four reasons why beaver wetlands are paradise for pin lichens

Beaver activity enhances the occurrence and diversity of pin lichens (Caliciales). Both the number of species and individuals is much higher in beaver-created wetlands than in other types of boreal forest landscapes. There are four reasons behind this:

1. High amounts of deadwood. Pin lichens grow on both living trees and deadwood. Decorticated deadwood in particular is preferred by pin lichens. Beaver-induced flooding kills trees in the riparian zone and produces high amounts of decorticated snags.

Pin lichen on decorticated stump. © Mia Vehkaoja

2. Diversity of deadwood types. Beaver activity produces snags, logs and stumps. Snags are created by the flood, whereas logs and stumps are also produced by beaver gnawing. The diversity of deadwood tree species is also wide, containing both deciduous and coniferous tree species. The diversity of deadwood types maintains a high diversity of pin lichen species.

3. High humidity conditions. High humidity conditions are favorable for many pin lichen species. Old-growth forests are usually the only places in the boreal forest belt that contain high humidity conditions. There the shading of trees creates a beneficial microclimate for pin lichens. Lighting, on the other hand, becomes a limiting factor for pin lichens in old-growth forests. Most snags in beaver wetlands stand in water, where steady and continuously humid conditions are maintained on the deadwood surface.

Snags produced by a beaver flood in Evo (southern Finland). © Mia Vehkaoja

4. Sufficient lighting conditions. Because most of the deadwood in beaver wetlands stands in water, it is concurrently in a very open and sunny environment. Many boreal pin lichens are believed to be cheimophotophytic (cheimoon=winter), meaning that they are able to maintain photosynthesis also during winter at very low temperatures. The algae member of pin lichens requires enough light for photosynthesis. Open beaver wetlands make photosynthesis possible for pin lichens during both summer and winter. Snow also enhances light availability during winter.

More information: Vehkaoja, M., Nummi, P., Rikkinen, J. 2016: Beavers promote calicioid diversity in boreal forest landscapes. Biodiversity and Conservation. 26 (3): 579-591.