Why does Finland need a change in legislation concerning the raccoon dog?

Guest author: Heidi Krüger

The debate about the ongoing changes in Finnish legislation concerning the status of certain invasive species is reaching bizarre dimensions. People are mixing facts and fiction, becoming confused with terminology, and accusing the counter part of demonization.

Raccoon dogs (Nyctereutes procyonoides) are very cute, and their puppies are even cuter. Like their non-related look-a-likes raccoons, many people see a potential pet in them, and find it difficult to understand why anybody would like to kill these furry cuties. Maybe it was ok before, when people needed hats like Davy Crockett’s, but nowadays that fur is out of fashion, can’t we just let them be?

Raccoon dogs (Nyctereutes procyonoides) are invasive in Finland.

 

The EU says: Harmful invasive alien species must be outed

As a part of the EU 2020 Biodiversity Strategy, regulation of invasive alien species entered into force in 2015. In 2017, the raccoon dog was included on the list of harmful invasive alien species, and now it is time for Finland to act on this matter. The Ministry of Agriculture and Forestry has proposed that the status of the raccoon dog, along with that of some other alien mammals, should be changed from game species to unprotected species.

This change in status would mean that hunting is allowed year-round, using light (e.g. night vision oculars) and that no hunting license is required. Use of poison or instantly killing traps would not be allowed for raccoon dog hunting, even though the former is allowed for the eradication of rats and the latter for example on American minks (Neovison vison) (another species listed as an invasive alien species by the EU).

Many nature conservation and animal rights organizations are now loudly arguing against this change in legislation. One commonly heard quote is: “hunters are demonizing raccoon dogs even though studies have shown them to be quite harmless as predators”.

 

Not so harmless after all

Recent studies have shown that the raccoon dog can be very effective at searching for food and can be responsible for the depredation of ground-nesting bird nests on the mainland and in the archipelago much more severely than previously thought. This was shown with wildlife cameras that captured raccoon dog behavior at the nests.

Raccoon dogs predate the nests of ground-nesting birds.

Earlier studies relied on the fact that egg remains were seldom found in raccoon dog feces or on the clues left by predators at the depredated nest. Studies with cameras showed that raccoon dogs do not consume eggshells and nest predators cannot be identified by analyzing remains at the nests.

Some earlier studies have also tried to prove the harmlessness of raccoon dogs by predator removal experiments. Considering the capability of the raccoon dog in invading new areas, we have to wonder whether these studies were successful in removing the animals. It takes several years of extremely effective eradication before a decline in raccoon dog numbers is reached and an improvement is seen in the nesting success of birds, as shown in a study on a Finnish wetland.

Wildlife cameras were used to show that raccoon dogs are effective at locating eggs in the landscape.

Raccoon dogs spread a multitude of diseases

The raccoon dog is an invasive alien species that has invaded and still is invading our country. The game bag has doubled in the last twenty years, and 2016 was the first year it exceeded 200 000 individuals. There is no natural balance that would limit its population, at least not yet. If we let the population grow so big that it will balance itself, what is the cost? How many frogs and lizards must be eaten? It is not only ground-nesting birds that suffer from predation, most amphibians are doing really badly at the moment, and they don’t need an extra predator either.

The raccoon dog has other harmful properties besides predation. Its presence enabled a serious rabies outbreak in the 1980s in Finland, and we are still spreading vaccinated bates along the eastern border of the country to keep the disease out. And there are other diseases to consider. The raccoon dog is a host for scabies, trichinella, and canine distemper virus. Finland has so far not had any cases of Echinococcus multilocularis, which has already reached the Baltic countries. The raccoon dog will be a very effective vector for its spread and this will have tremendous side effects in a country where practically everyone collects berries from the forests and eats them unwashed.

So, the need to control this species really exists. It is not just the hunters who “hate” the species or who try to blame it for the extinction of birds instead of admitting that habitat loss is a real issue that has to be dealt with.

 

Let’s unite in a campaign for biodiversity

The current situation where raccoon dogs are protected during the summertime helps the population gain its previous strength year after year, as we now have seen in Finland. Yes, some raccoon dog pups may lose both parents and succumb to hunger, but as studies have shown, 90% of the pups will not survive their first winter anyways.

The worries of non-hunters engaging in raccoon dog hunting and employing inappropriate methods to kill these animals are most probably exaggerated. Anyone who has ever met a raccoon dog either in the wild or trapped in a cage, knows they are not as defenseless as often pictured. Euthanizing them requires skills and an effective gun. In Finland, owning a gun usually requires a hunting license. Besides, unprotected species are also covered by animal protection laws, so illegal or unethical methods are not allowed.

The change in legislation will help arrange an effective campaign over larger areas. It will make it easier for hunters to hunt this species. It will lessen the burden of the raccoon dog hunt that is currently placed on local hunters. It will motivate hunters when society finally accepts the removal of this species that does not belong in our nature.

And maybe, with the introduction of an intensive removal program, we can also motivate landowners to restore more habitats. This could help many species hovering on the brink of extinction, or even more, bring back those we lost many years ago. This would mean truly working to increase biodiversity, which is the large issue behind this ongoing debate.

 

References and reading:

Dahl, F & Åhlén, PA (2018) Nest predation by raccoon dog Nyctereutes procyonoides in the archipelago of northern Sweden Biol Invasions 21: 743. https://doi.org/10.1007/s10530-018-1855-4

Kauhala, K, Kowalczyk, R (2011) Invasion of the raccoon dog Nyctereutes procyonoides in Europe: history of colonization, features behind its success, and threats to native fauna. Current Zoology, 2011

Kauhala, K (2004) Removal of medium-sized predators and the breeding success of ducks in Finland. Folia Zoologica 53 (4), 367-378

Krüger, H, Väänänen, V-M, Holopainen, S, Nummi, P (2018) The new faces of nest predation in agricultural landscapes—a wildlife camera survey with artificial nests. Eur J Wildl Res (2018) 64: 76. https://doi.org/10.1007/s10344-018-1233-7

Sutor, A, Kauhala, K, Ansorge, H (2010) Diet of the raccoon dog Nyctereutes procyonoides—a canid with an opportunistic foraging strategy. Acta Theriologica

Väänänen V-M, Nummi P, Rautiainen A, Asanti T, Huolman I, Mikkola-Roos M, Nurmi J, Orava R, Rusanen P (2007) The effect of raccoon dog Nyctereutes procyonoides removal on waterbird breeding success. Suomen Riista 53:49–63 in Finnish with English summary

Government proposal: https://www.eduskunta.fi/FI/vaski/HallituksenEsitys/Sivut/HE_286+2018.aspx

http://www.vieraslajit.fi/fi/content/welcome-invasive-alien-species-portal

Raccoon Dog IUCN Red List: https://www.iucnredlist.org/species/14925/85658776#conservation-actions

Proposal for management measures and pathways of invasive alien species (2019): Ehdotus haitallisten vieraslajien hallintasuunnitelmaksi ja leviämisväyliä koskevaksi toimintasuunnitelmaksi https://julkaisut.valtioneuvosto.fi/bitstream/handle/10024/161270/5-2019-EU-HAVI_2.pdf?sequence=1&isAllowed=y

Game bag statistics: http://statdb.luke.fi/PXWeb/pxweb/fi/LUKE/LUKE__06%20Kala%20ja%20riista__02%20Rakenne%20ja%20tuotanto__16%20Metsastys/9_Mets_saalis_aikasarja.px/table/tableViewLayout1/?rxid=21289640-ded2-4672-8b4f-88454080c4d5

Bringing back the wild forest reindeer

The reindeer (Rangifer tarandus),  a.k.a. the caribou in North America, inhabits a large stretch of the Northern Hemisphere. Fourteen subspecies are currently recognized, several of which live isolated from the other subspecies. The wild forest reindeer (Rangifer tarandus fennicus) lives in Finland and Russia, and it is the only subspecies inhabiting the European Union. Wild forest reindeer were once an important game animal in Finland. However, intensive hunting led to their extinction, first in Sweden, and later, at the turn of the 19^thand 20^thcenturies, also in Finland. During the 1950s, the subspecies made a comeback, when a new population formed naturally in northeastern Finland, made up of individuals that migrated over the border from Russia.

Wild forest reindeer stag

The global reindeer/caribou population is in decline and the species is considered Vulnerable according to the International Union for Conservation of Nature. However, each subspecies also has its own population status, and the wild forest reindeer was classified as Near Threatened in the 2010 Red List of Finnish species. The subspecies is under pressure from human actions such as traffic, habitat change, and snowmobiling. Large carnivores also exert a great deal of predation pressure in certain areas. Finland has conservation obligations, as it is the only country in Europe where the subspecies lives.

2016 saw the beginning of an ambitious EU LIFE project for reintroducing and breeding wild forest reindeer to parts of its former habitats in two Finnish national parks (Seitseminen and Lauhanvuori). The project involved building two reintroduction enclosures, after which wild forest reindeer males (stags) and females (does) were housed in the enclosures. Some of the individuals were caught from the wild, while the rest were brought in from various zoos. More individuals will be brought in over the course of the reintroduction scheme. This will enable keeping the genetic diversity of the breeding and reintroduced populations at high enough levels. The reindeer will be fed lichen and reindeer fodder, to supplement what the individuals are able to forage from nature. The first calves were born in the enclosures last spring (2018). Currently the reindeer still live in the enclosures, but the project goal is to release the first individuals during 2019. They will still be given supplemental food e.g. in the case of a harsh winter.

Wild forest reindeer living in the reintroduction enclosures are given supplemental food.

Widescale mammal reintroduction projects often encounter surprising situations. The birth of five wild forest reindeer calves into the reintroduction enclosures during the spring/summer of 2018 was one such event. Not because the calves were born, but because each of them is most likely a male (their gender has not been 100% determined yet). More males than females are born in reindeer/caribou populations, because they form small groups with one stag and several does. However, chance dealt an unexpected hand in the small reintroduction populations, resulting in several males and no females. Three additional does were brought into the enclosures in October 2018 to deal with this surprise.

Calves born in the reintroduction enclosures during summer 2018.

The project is also committed to restoring several forest and peatland areas suitable for wild forest reindeer. Another task is to ensure that wild forest reindeer and the semidomesticated form of mountain reindeer (Rangifer tarandus tarandus) do not meet in the wild. Both are subspecies of the reindeer/caribou. Semidoemsticated reindeer live in North Finland, where they are cared for by the reindeer herding industry. Reindeer/caribou subspecies can reproduce with each other, which is why the genome of the wild forest reindeer must be kept clean. Otherwise we risk mixing the genomes of the two subspecies.

During the fall rutting season, wild forest reindeer form small herds with one mature stag and several does and their different-aged calves. After the rut, these herds migrate towards their wintering grounds, where several herds congregate.

More information is available on the project website. The life of wild forest reindeer can be followed via a camera set up by WWF Finland (live footage especially during summer). Best recordings from last summer are available on the YouTube site of WWF Finland (text in Finnish, but videos have no sound).

Wishing everyone a Peaceful Christmas and a Happy New Year 2019!

Bohemian waxwings move around Finland in search of plentiful rowanberry stocks. Sometimes these sporadic migrations, known as irruptions, bring waxwings all the way to Great Britain and Continental Europe. Strong waxwing irruptions were observed in southern Finland during autumn 2018.

All cavities are not equal

Come spring (late winter), the forests are bustling. Cavity-dwelling animals search for tree crevices and holes in which to lay their eggs and raise their offspring. Tree cavities provide a stable environment for successful nesting.

Natural cavities are usually found in old wide trees, where the inner temperature of such cavities remains more stable than outside temperatures.

Only one problem remains. Cavities usually form in old or, at the least, decomposing trees, but forestry practices simplify forest cover composition. Fewer trees surpass forestry practice recommendation ages, so our forests have less large aging trees in which fungi can spread. More tree cavities are desperately needed. Nest boxes are our solution to this problem. The idea is simple: anyone can build a nest box and hang it on their own land (or somebody else’s with permission). This has helped boost the populations of certain cavity-nesters such as pied flycatchers (Ficedula hypoleuca) and great tits (Parus major).

It would be nice to think that we have solved the cavity problem, or that the problem will be solved if we raise the number of nest boxes to sufficient levels. But it’s not that simple. Several researchers have studied the functionality of nest boxes over the years. The microhabitats of tree cavities and nest boxes differ from each other in relation to temperature and moisture. Wroclaw University researchers were the most recent group to prove this distinction, but they also demonstrated that these functional differences drive the marsh tit (Poecile palustris) to choose natural cavities over nest boxes. Their study was conducted in two forests; the other had an unlimited number of tree cavities, while nest boxes were the only nesting option in the other forest. The marsh tits preferred natural cavities with thick walls buffering the holes from outside temperatures. And birds are not the only species that have been shown to prefer natural cavities, for example certain bats and the common brushtail possum (Trichosurus vulpecula) will settle in natural cavities due to their more stable microclimates.

The common brushtail possum is an Australian mammal that nests in tree cavities. Picture: Wikimedia Commons. https://upload.wikimedia.org/wikipedia/commons/b/b4/Brush_tail_possum_4-colour_corr.jpg. By user:benjamint444 modified by Tony Wills [GFDL]

Nest box temperatures in the Wroclaw study fluctuated significantly more than the inner temperatures of tree cavities. Nest box temperature also changed at the same rate as outside temperatures. Nest box temperatures can therefore rise to dangerous levels during the summer, to where chicks are at higher risk of dying from excessive heat compared to broods in tree cavities. During the winter, nest box temperatures drop to lower levels than cavity temperatures, decreasing the shelter effect that many small birds utilize to survive the harsh cold.

Nest boxes also average lower air moisture levels compared to natural cavities. This may hinder mold from growing in the nest boxes, but concurrently lower moisture may encourage wasps (Vespidae) and tree bumblebees (Bombus hypnorum) to settle in nest boxes, making them inaccessible for birds. Fleas (Siphonaptera) may also increase in dry and warm conditions, so the number of competitors and ectoparasites may increase.

Woodpeckers excavate cavities in decomposing trees and standing dead wood

To cap, nest boxes and natural cavities do not replace each other from a structural point of view and not all species will nest in boxes. The majority of nest boxes are so-called standard models, i.e. they are copies of each other in terms of dimensions and flight hole diameter. In real life, a standard model nest box is only accepted by a limited number of cavity dwellers. It is therefore imperative to conserve aging and decomposing trees, as their cavities are never of standard shape or size. If nothing else, decomposing trees in our yards should be conserved; trees can always be cut to a height that ensures they are of no danger to nearby buildings or people. Such standing dead wood is very rare in current heavily managed forests. With a standing birch dead wood tree it is even possible to attract the picky willow tit (Poecile montanus) to your yard.

The next best alternative is to ensure the structural heterogeneity of nest boxes, i.e. build boxes that are also suitable for species such as the common redstart (Phoenicurus phoenicurus), owls (Strigidae), treecreepers (Certhiasp.), and even certain mammals such as flying squirrels (Pteromys volans). This may require a little more trial and error, but it is the only way of maximizing the nesting alternatives in managed forests. Ideas for nest box designs abound online, Pinterest for example has a huge selection of box models. However, it is important to follow nest box construction instructions issued e.g. by the BTO and Audubon Society or these general safety instructions, to make sure that the boxes are as safe as possible for birds. Nest box positioning is also important; foliage has a protective effect, and the microhabitat of nest boxes positioned under foliage therefore remains more stable than in sun-exposed areas.

Blue tits often utilize nest boxes.

Adding insulating materials to nest boxes is one way of adding to the inventiveness of nest box construction. To mimic the microclimates of natural cavities, a team of Australian researchers recently compared nest boxes that had been fitted with three types of insulating or heat-reflecting materials. Nest box temperatures remained most stable around the clock in nest boxes insulated with polystyrene foam. The inner temperature of one polystyrene-fitted nest box was nearly six degrees Celsius less than outside temperatures. Nighttime inner temperatures were also higher in the polystyrene nest boxes compared to non-insulated boxes when a heat-producing pillow was placed in the insulated and non-insulated nest boxes, to mimic the effect of birds spending the night in the boxes. The Australian study showed insulation had a more significant effect on nest box temperatures than nest box placement in a shady or sunny location. However, for the environment and breathability, it is probably better to use some type of natural fiber insulation in nest boxes. Also, insulated nest boxes are not enough to fill the void created by the disappearance of natural tree cavities, as the study showed that the temperature fluctuation of even the polystyrene-fitted nest boxes was greater that of natural cavities.

P.S. It is currently trendy to set up cool or “beautiful” nest boxes without thinking about their safety at all. Not a good idea! For example, ceramic bird boxes are much worse insulators than wooden ones, and painted boxes should use lead-free paint. https://www.telegraph.co.uk/news/earth/wildlife/12165505/Novelty-nest-boxes-putting-garden-birds-at-risk-warns-RSPB.html

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.

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.

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.

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/