Population decline 34% in roe deer in Denmark from 2009 to 2020 – Course, consequences, cause and solution.
by Jack Hansen
Preserve the roe deer Hunt – Read this and use these Cull Tools and / or this Wild Game Analysis.
It is now up to us hunters, hunting organizations and hunting landlords to act.
This also applies to roe deer and moose in other countries.
Table of Contents:
This is a status statement for our population management of roe deer on the shooting side in Denmark, from 2009 to 2020, in which period a very large stock decline has been registered. Here, the course, consequences, cause and possible solution are reviewed – and the latest seen recommended cull distribution are also reviewed, which according to my calculations will be completely destructive – calculated in a Wild Game Analysis with Cull Tools and Optimization Tools (which I am working on and which will be published soon).
In this status, the topics you read a lot about in the media are reviewed in connection with our ongoing population decline. In order for it to make sense to try to understand the reason behind the decline in the population, to be able to see the consequences of this and how this can be countered, one has to look at many things – and there have to be a number of figures on the table. – Some will think that there is a lot to read here, and others read 50 pages in a book every night. – Please see the hassle of reading this, in relation to reducing your roe deer hunting, perhaps significantly and irrevocably, as a hunter and hunting landlord.
Many of the things described here in this status apply to many of the 50 countries in the world with roe deer – and some also relate to moose.
In the following, we review some important, basic things about game management on the shooting side, which through the ages have been mentioned and written about very much and very differently. This will therefore be a bit long and for some perhaps heavy, but it is probably super necessary to look at this thoroughly – because errors in, and different perceptions of these basic and often discussed topics, very easily lead to wrong and dangerous cull policies.
And I think this has actually happened, to a not insignificant extent, with reference to our registered approx. 34% decrease in the shooting of roe deer in the period 2009 to 2020, which indicates a roughly equal percentage decrease in the roe deer population. – This is a particularly disturbing decline, which if it continues, could mean a very sharp reduction in our roe deer hunting, or even over time could lead to the collapse of our roe deer population in several districts – and could lead to imposed restrictions.
In my opinion, there is a lack of a homogeneous basis for population management on the shooting side, which can most likely be documented correctly and effectively – and fortunately you can count on such a thing, and fortunately it seems that the big and wild changes are not necessary, for us to achieve sustainable hunting. – In short, 2 things are missing: A tool for proper shooting on your hunting areas, and where the results are based on an updatable simulating Wild Game Analysis model over a number of years, just as the Game Yield Statistics should be expanded and optimized (read at the end).
I am well aware that you can step on someone’s toes when you come up with something like this. However, this is not the intention, and I would never sacrifice so much time and gunpowder to just step on someone’s toes – it’s all about the game and its conditions in connection with sustainable hunting, and the quality of our hunting experiences – and that we preserve the roe deer hunt. – And everything is written exactly as I see, perceive and calculate this.
Hunting and Population Management is a huge area
Population management, game biology research, hunting, and game analysis take place in a huge area with a huge number of actors. – Many people are affected by e.g. reductions in hunting.
For example. is believed to be approx. 15,000,000 roe deer in 50 countries and approx. 3,000,000-4,000,000 moose in 20 countries, and that there are e.g. ca. 199 different deer species in the world.
This covers more than 50 countries for 2 animal species alone, and a huge number of other huntable game species in countries all over the world.
In all countries of the world, an unknown and very large number of hunters and their lifestyles and recreational values are directly implicated in – and dependent on hunting and proper population management.
In addition, hunting landlords, stock management authorities, hunting organizations, forestry staff, biologists and researchers, the arms industry and all actors in hunting travel, etc.
Financially, these are also really large amounts.
** Thus, it is seen that it is important to protect the game populations and ensure that there are no repeated, annual population declines – and the most important thing in this is to be able to document sustainable hunting – ie to be able to find and use the correct cull and the correct cull- distribution. – A population decline is, in the first instance, especially affecting both hunting landlords and hunters.
This is probably now it applies/count and what does the future hold?
As a result of the repeated significant decline in our deer population from 2009 to now 2020, hunters and hunting organizations may quickly be required to provide evidence that sustainable hunting is taking place, or be subject to restrictions and limitations that may go beyond what is necessary and which will later be highly difficult to change. Many of the things described here in this status apply to many of the 50 countries in the world with roe deer – and some also relate to moose in the 20 countries with moose.
I think, as a number of others have gradually come to the conclusion, that there will be restrictions on roe deer hunting if the hunting organizations, hunters and hunting landlords cannot find the probable right cull around their own table and demonstrate that sustainable hunting takes place. Sustainable hunting is achieved when for a number of years you can shoot approximately the same number of animals annually, and with roughly the same cull- distribution – without a significant population decline or other unfortunate population development, aside from the expected natural population fluctuations.
In 2008, I tried in several ways to warn various agencies about an impending population decline, and with concrete solution proposals to avoid this, but that no one (except one) would hear of – uuha – a hunter who talks about even a minor reduction in the cull/harvest! – With this here, I try something similar again, because our seen population decline over 11 years can continue. – Nothing is so wrong that it can not get worse, and in Sweden the population decline continued for 26 years, from 1993-2019 – hunting yield in 1993: 382,000 – hunting yield in 2019: 99,000 = decline: 74% and in simple terms: 2.85 pr. year.
Both the Hunting Act and the ‘Hunting Ethical Rules’ are, in their fine but spherical formulations, not at all sufficiently specific, and in general it seems as if the hunting yield is controlled solely by hunting landlords and hunters and not least by supply and demand.
It is good that there are many different perceptions of how to best manage population on the shooting side, and it is also good that this is written about in our indispensable magazines and media (which by the way can not be praised enough) – but if this leads to confusion and if this do not end up in a homogeneous and generally accepted management plan – this will undoubtedly affect the roe deer population, which will affect all roe deer hunters, hunting landlords and the hunting organizations and others. perhaps powerful and indefinite. Measured by our steadily declining yield/harvest over the last 11 years (2009: 132,000 and 2020: approx. 87,000), we are thoroughly and well on our way to this.
Whether it all ends up in a legally permissible number of shot animals per. for example. 5 hectares is not known, but quite objectively considered and on closer consideration, this may not be so stupid and unreasonable in a small country like Denmark, with very many small areas where roe deer hunting is conducted – as long as this is done district by district, and based on correctly performed simulated and updatable population analysis, where all significant variables are included, the right things are calculated and the right key figures are extracted. – I have actually also developed such a cull tool, and this works fine and is simple to use, but preferably we hunters should be able to find out to agree and pull on the same hammer – because it is necessary.
– It is probably now that the hunters, the hunting landlords and the hunting organizations must step into character and act fairly quickly – to avoid reductions and restrictions in the hunting of roe deer.
Has the roe deer population declined?
Yes, without a doubt and this is clearly reflected / proven in the decrease in the hunting yield, as the hunting yield is in a certain (certainly not exactly known) relation to the presumed population size. – The declining hunting yield is not due to the fact that there have been fewer roe deer hunters, that these go hunting less or that they shoot worse – and we have probably not seen fall game on a scale like the population decline.
The cull in a roe deer population is assumed to be between 25 and 33% of the population, ie. that in 2009 we had a population of between approx. 528,000 and 396,000 animals. In 2020, we had a population of between approx. 348,000 and 261,000 animals – ie a population decline of between approx. 135,000 and 180,000 animals over 11 years, against a decrease in hunting yield of approx. 45,000 over 11 years.
In the countries around us, there are also repeated declines in the populations of roe deer and moose, where the decline in the Swedish roe deer population is probably the worst horror seen, and where no one (not even the authorities) reacted to the years-long and repeated declines, which ended in collapse. in several counties. – It is not the responsibility of hunters and hunting landlords alone, that a huntable game species declines or collapses.
The decrease in the number of shot roe deer in Denmark from 2009 to 2020 is similar to the decrease seen in Sweden from 1993 to 2019, namely a decrease of approx. 3% in simple cut per. years on average, which is thought-provoking and alarming, and must worry many with roe deer hunt as a lifestyle or regarding income.
Why has the roe deer population declined?
In a popular huntable game species such as roe deer, there can be only one cause of population decline.
If an ongoing population decline is not desired, and / or even more significant: if the cull- distribution between bucks, does and fawn is incorrect, the hunting yield is too large or incorrect in relation to the population – this regardless of all other causes and influences. Occurs e.g. disease outbreaks, fertility problems or elevated stress levels, the hunting yield and form of hunting must also be adapted to these situations, as there are no other options for a popular huntable game species, where the cull will probably always be the largest and crucial burden.
It is also important to be aware that the hunting yield in a wild game population may actually be unchanged and even increasing, but still the population may be on the way to a significant population decline – just as was seen in the sudden, unexpected and violent population decline in the extremely increasing Swedish roe deer population. The actual population decline occurs when two or more key figures collide with each other and when the roe deer’s well-illuminated self-regulatory ability is no longer sufficient to counteract this. Only by theoretical simulation of a population situation over years, such things can be detected and countered in time.
There is a great deal of talk about overpopulation. A general population decline due to competition for food caused by too high a population density is difficult to imagine, partly because there is plenty of supplementary food in the summer and winter green fields, and partly because fawns are not generally seen with too small weights, which is the first warning on food scarcity. – To this can be added, that on Bornholm in Denmark there are areas with an estimated net population density of 1 animal per. 5-7 acres of land without widespread ‘roe deer disease’, and in all of Denmark the net population density is around 17 acres per. animals, at an estimated population of 356,000 animals.
In Sweden’s counties Skåne, Halland and Blekinge, with roughly the same food resources as in Denmark and even with a larger forest percentage, the net population density in 2010 was approx. 1 animal per 75 acres per. animals – so even here the seen huge population decline can not be explained by density-dependent food shortages. – It is probably rare when flen (ice under surface) does not occur for long periods) that an area’s food carrying capacity is exceeded in areas where hunting takes place, as the browsing and selecting roe deer is not a type of animal species that clears an area for food and because they will emigrate due to food shortages. – It may be different in non-hunted populations in really good deer habitats during the fawn season, where adjacent large areas are not found attractive for the roe deer – but in general it seems that it is the spatial environment such as forest percentage, deciduous tree share, marginal zone lengths , leading wild fences, farmers’ chosen crops, degree of disturbance as well as cover options, hiding / staying – and resting places, which determine the number of animals on an area.
Whether the advance of fallow deer and red deer affects the roe deer population is extremely difficult to prove, and I have several times seen young fallow deer walking with a roe and her fawn, just as yesterday I photographed a buck and a doe goose grazing side by side with 6 fallow deer. But I have also seen roe deer give way to horses and red deer, but never seen roe deer leave an area with fallow deer or red deer or even with both, in an area with ‘normal’ occurrence of fallow deer / red deer.
In some places, a noticeably high level of stress is seen in roe deer, due to a generally high degree of disturbance, created by the sum of various disturbances. Nothing can stress the roe deer (and all other animal species) in a small country more than pürch hunting, which can make the roe deer incredibly more shy, less fertile, less pleasant, much more nocturnal and make the roe deer hunt boring and sad for everyone. Just try to find 2 important positive things about pürch hunting that do not relate to the hunter’s own hunting experience and development. Or try to mention just one thing about pürch hunting that benefits the roe deer population.
– So, as described above, there are several things that can contribute to a current decline in a huntable roe deer population – but it is and will allways be the hunting yield, cull- distribution and hunting form that must adapt to the roe deer population’s current situation, regardless of everything else.
The cull/harvest on our hunting areas
It must be said that we hunters generally make very great efforts to shoot as correct as possible in the roe deer population, but there are also many examples of small hunting areas, where a multiple shooting takes place, in relation to the number of animals that naturally ‘belong’ to the hunting area.
There are also examples of larger hunting areas where written permitted cull corresponds to the entire autumn population (and even more) on this area. – That so often in reality are not shot the promised numbers that you pay for, is another matter, because a little extra diligence or a few “pressure hunts” can easily change this. Regarding “pressure hunts” later in the season, the animals are in leaps/heards, which is why you must be aware that one are regulating on the populations of other hunting areas.
Unfortunately, the undocumented and population-damaging shooting policies for bucks are also used, e.g. ‘We only shoot from the top’, ‘We do not shoot prickets’, and ‘Two- pointers are not shot’.
The cull and cull distribution on the individual hunting areas is greatly affected by the many articles on roe deer management on the cull side in the media, and many hunters read and comply with the contents of these, but since there are so many and very different, the cull on the hunting areas will be very different and wrong, which is certainly not to the advantage of the roe deer population and the hunters. The hunting landlords, who often set a ceiling/limit/quotas for hunting yields, are an important part of this.
Nor should one overlook the importance of our hunting of roe deer becoming significantly more efficient than in the past. Good hunting books have been written and read, rifles have improved, binoculars have improved significantly, rangefinders have been added, camouflage is now almost unbelievable, game cameras tell a lot and can also be misused, infrared aids have appeared, decoys are good, hunting towers and ladders can bought for almost no money, consortium hunting enables widespread planting of deer as well as feeding – and now you can also get clothes that dampen the release of aviation, and thermal binoculars – soon the drones will be deployed (- if not already done).
The distribution of the cull
According to Game Information 2014 (hunting season 2012/2013), the distribution of shot roe deer was 54% bucks, 27% does and 17% fawn – but these figures were based on a small basis, namely 32,000 shot animals out of the annual outtake of 127,400. – DMU in Denmark conducted a small questionnaire survey (1200 hunters) in 1993-94, where the distribution was 48% bucks, 19% does and 33% fawn. – This shows very big differences, and both foundations were too small, but still the beginning of something good.
According to registered voluntary game yield information 2018/2019, where these accounted for 48,857 out of a total of 91,163 shot animals (53%), approx. 53% bucks, 25% does and 22% fawn. – In estimated numbers, distributed shoots bucks by approx. 79% bucks over 2 years and 21% in 1 year – does were distributed with approx. 74% over 2 years and 26% at 1 year – and of the fawn, 40% were buck fawn. – But this basis is still too small to be predictable, as this is calculated on the basis of only 53% of all shot animals, and because the hunters (for some reason) did not register age and sex for 38% of the 48,857 reported animals. – The registered 79% bucks over 2 years is also an excessive proportion.
As far as I understand, it is now recommended: ‘That one buck should be shot on an area where, since the laying of the last buck, one doe and at least one fawn has been shot’. – The wording is probably a bit difficult, and: ‘at least one fawn’ may well be 10 fawn, but I assume that there is ment a cull distribution close to: 25% bucks, 25% does and 50% fawn. – Is this tested in a simulated population analysis with a population size of 319,000, with a sex distribution of 1: 4, with a fawnshare of 45% and at a annual cull of 91,000 divided into 22,750 bucks, 22,750 does and 45,500 fawn, and where 84% of the bucks are shot in the summer – the result is after 6 years: A population decline of 153,000, sex ratio improves from 3,993 to 2,139, the population composition improves 71%, the average age of the males improves from 2,124 to 3,364 = 58% and the animals’ mating situation improves 75%. – Short result: We can only shoot 22,750 bucks against 48,316 in 2018/2019, and the population falls 153,000 in 6 years, and unrealistically good ratios arise which override and distort the animals’ natural biology, way of life (regime) and interaction – which will always go wrong.
If one thought instead of a cull distribution (above): 28% bucks, 28% does and 44% fawn, the result after 6 years would be: A population decline of 186,000, sex ratio improved from 3,993 to 2,810, population composition improved 25%, average age of males improved from 2,124 to 3,520 = 65% and the mating situation of the animals improves 59%. – Short result: We can only shoot 25,480 bucks against 48,316 in 2018/2019, and the population drops 186,000 in 6 years, and unrealistically good ratios arise which override and distort the animals’ natural biology, way of life (regime) and interaction – which will always go wrong.
To be a little ahead (upfront) of the cause and the solution to seen declines in the roe deer populations in 2009-2020, it can already be said that in 2013/2014 and in 2018/2019, relatively far too many does (27% and 25%) were shot, and that this is one of the main reasons for seen population declines – well helped by the fact that also the cull distribution in bucks and fawn was / is very wrong.
– Let us immediately and as soon as possible change the cull rate for does to 19-20%.
Appropriate Wild Game Yield Statistics are important
Before 2014, only 60-70% of hunters reported shot roe deer, after 2014, reporting became mandatory and approx. 95% are reporting now. In 2012, voluntary detailed game yield information (also for roe deer) was introduced, but in 2018/2019, only voluntary detailed game yield information (sex, age and weight) was reported for 53% of 91,163 shot roe deer in total.
Also because the hunters have not registered age (and gender) for approx. 38% in the voluntary reports, it would have been better and more accurate to also register prickets, two- pointers, six- pointers and return bucks (even though there are few six- pointers in 1 year and slightly more two- pointers in 3-4 years). – This would give a much better picture of the buck population, instead of alone: age 1 year and 2+.
Before 2014, we could not count on anything, after 2014 and until now we can count on the number of shot animals in total, but not (far from) be sure of the cull distribution. The voluntary detailed game yield information is missing before 2012. The voluntary reports now cover only 38% of the number of voluntary reports of shot animals, and 53% of the total annual hunting yield.
– and all this is certainly not sufficient and appropriate – and especially not in the case of prolonged population declines, where one tries to counteract this by tracing back in what probably went wrong – and the current level is also not sufficient for future cull planning.
– Therefore, it should be made mandatory to report gender, age, the 4 types of antler, healthy / sick and weight.
The cause of the roe deer disease – the cull or something else?
In the debates, some point out that incorrect cull can lead to dissatisfaction among the roe deer – and this must be completely correct, but whether dissatisfaction can lead to, or has led to, the roe deer disease is very unclear and difficult to detect. – The well-being of a roe deer population can be assessed as follows: the population is pleasant when: Large and strong bucks are seen in the buck population, when: there are enough bucks to cover the required number of does when when: disease not see
I do not make myself wice on this, if the roe deer disease is due to the early spring’s very protein-rich food, explosion in the number of ticks and deer lice that can really cause many insidious and ‘hidden’ diseases and impair the animals’ general well-being, parasites (also seen in many bird species), pharyngeal brakes, heartworm, heavy metals, altered pesticides, changes in crop genetics, over-fertilization in forests, climate change or something else – but I very much doubt that the roe deer disease is related to the shooting, and it would probably also be the first time such a thing is seen.
Self-regulation due to density-dependent factors in connection with the roe deer disease is probably hardly in play either, as the population has fallen by 135,000 to 180,000 animals – and is not seen improved by this, just as places with very dense populations are seen almost completely without the roe deer disease.
– Thus, I definitely believe that seen population declines are due to incorrect cull distribution (visibly demonstrated in a simulated population analysis), and that the population decline is exacerbated by ‘external’ disease. – But still, the cull must adapt to disease (and everything else).
Is found dead roe deer a good measure of the health of the population?
It has often been heard: “We do not see much fall game”. – But one must probably be very careful in assessing something based on the found dead game. Studies have shown that a dead animal, e.g. a fall game, will only lie on the spot on average approx. 8-10 days, before being eaten or dragged away, most often by foxes. It is probably only the fewest of us who actually go and look for fall game – just as it is the fewest of us who every 8-10. day has been looking for fall game in all the nooks and crannies of the terrain – and before we have done these things, we can not comment on the extent of fall game.
In addition, animals often hide quite well when they sense that ‘the time has come’. Also think about how difficult it can be to find an animal you just shot at for only 15 min. ago, and as you saw leaving an exact place and run into a dense spruce thicket, and where it often ends with a schweiss- dog.
One must also not forget that in addition to fall game as a result of the roe deer disease, approx. 74,000 animals dies annually (at a population size of about 356,000) for all sorts of other reasons, and if an animal has been dead for 8-10 days, it is often impossible to guess the cause of death. I myself have seen only 4 live animals with roe deer disease in the last 3 years, and I have found 4 pieces of fallow deer (3 roe deer and one sika deer), and where I have not been able to assess the cause of death due to condition. – When assessing roe deer disease, it is probably best to look at the live animals.
– So found fallen game is not a good measure of the health of the population.
The many perceived perceptions and recommendations are confusing and devastating
A lot has been written over the years about population management of roe deer, and a lot of different and opposing recommendations and instructions on shooting in the roe deer population have been seen. If this overview of these topics, all of which are important, is to make any sense, this must be described in detail and therefore fills something.
Just to name a few different instructions and recommendations for shooting distribution: DMU: 30% bucks, 20% doe and 50% fawn – From a Danish Hunter magazine: 50-20-30 – The Danish: ‘3-2-3’: 37.5 –25–37,5 – The Danish: ‘8-5-20’: 24,25-15,15-60,60 – The Swedish: ‘Max. Meat value ‘: 12.75-2.25-85 – The Swedish:’ Most trophy bucks’: 41-34-25. – The very big differences are seen.
Several cull models for shooting in the buck population often appear in articles and in the hunting consortia, for example: ‘We only shoot from the top’, ‘We do not shoot prickets’, or ‘Two- pointers are not shot’. – Some will always claim that (at least and if all else fails) these cull models will shoot fewer bucks – but this is contradicted vertically by the yield statistics, which do not show a relative decrease in number of shot bucks (aside natural population fluctuations).
Now that such recommendations, instructions and cull models are being made, what are these then based on and what is the basis? – Are there calculations on this, which show the probability that these are correct and do not harm the roe deer population and thus also the hunters and others?
– To these questions can be answered: No it apparently does not.
The very many and very opposite seen recommendations can not all be right (at the same time), and many of the seen would lead to collapse of the roe deer population if they were complied with by the roe deer hunters at national level or in larger areas. – This can be calculated, and is done.
It can also easely be calculated and documented that the ‘home-knitted’ cull policies: ‘We only shoot from the top’, ‘We do not shoot prickets’, or ‘Two- pointers are not shot’, ALL are extremely harmful to the roe deer population, and thus also to the hunters. – If you shoot unilaterally in any population, the negative effects of this will never be absent – but these can be so long along on the way, that at the time of discovery will require major efforts (and offers) to turn the development in a better and more correct direction. – Shoot as scattered in the population of adult males and adult females as possible in a ‘normal’ population, many forest- people have said. Today, however, with the repeated decline in the population over 11 years, we do not have a ‘normal’ roe deer population, but a skewed one – and that is precisely why the focus must be on e.g. to find the probable correct cull distribution of bucks / doe / fawn, but also the cull distribution within bucks – which corrects this.
You also see ready-made headlines such as: ‘Shoot more doe and fawn’ – but how many more of each and for how long, and what about the bucks? – and again, where is the documentation for this? – Every time you shoot a 1-year-old doe, after 12 years you have actually shot approx. 69 does and 72 bucks, when the differentiated mortality and hunting are taken into account. One thing can be said with great certainty in this connection, and is probably documented: that shot does should amount to approx. 19-20% of the total cull (- which we should ensure is implemented immediately and as soon as possible).
It was also once read that in the early autumn about 10,000 does were shot, leaving about 20,000 fawn motherless. If this is calculated on a probable correct basis, the probable correct number of motherless fawn will be approx. 1,700, of which approx. 400-450 will die as a result of them becoming motherless – and this is not good, but still a very small number compared to e.g. traffic death, or other general mortality. And for as long as I can remember, all the hunts I have taken part in have been very attentive, careful, strict and considerate on this very point: ‘fawn before doe’ – just as in many places you wait for doe hunting to enter. – and in many areas hunters are waiting to hunt does until November.
There have been figures in the media about 50,000 deer killed in traffic – and in apparently more valid studies, 25-30,000 animals are pointed out, as a possible but unconfirmed number. The reported 50,000 run-down animals can be completely excluded by a population of e.g. 356,000 individuals, where for comparison there will be a total general mortality of a total of approx. 74,000 animals that die from illness, accident, traffic, harvesting machines, consequences of birth complications, foxes’ cuts in the fawn, etc. – My calculations of the number of traffic-killed roe deer a few years ago were approx. 15,000 annually. This number must then be added to the number of fawn that will die, as a result of mother animals being shot during that period the fawn will not be able to fend for themselves. This number of fawn can be calculated at approx. 2,500 – which will give a total of approx. 17,500 animals annually, which die due to traffic, and this amounts to approx. 23% of total mortality, and approx. 5% of estimated autumn population.
One also sees and hears the claim that: ‘When more than 50 per cent. of the annual cull is bucks, then it gives a distortion in the population which means that the population rises explosively, and then is hit by density-dependent mortality: the roe deer disease’. – This claim (which, incidentally, is somewhat conditioned by what is then shot by does and fawn) is completely wrong according to my calculations in a simulated analysis. But if shot does is 20% and fawn 30%, at a population of e.g. 399,000, with a sex ratio of 1: 4, with a fawn share of 45%, at an annual cull of 115,476 divided into 57,738 bucks, 23,095 does and 34,643 fawn, and where 84% of the bucks are shot in the summer – the result will be: The population could in principle increase 11% over 6 years, but this does not happen because there will be too few 2-10 year old bucks compared to 2-13 year old does, which leads to insufficient recruitment (number of fawn set), rewarding population decline. This is if 50% of the hunting yield is bucks (which may in reality even be 53%).
– There will thus be (at 50% shot bucks) a lack of older breeding bucks in relation to the number of fertile females, and this will also deteriorate both sex and population composition, so that every 2-10 year old buck in the 6th simulation year will have impossible ca. 2.3-2.6 days per. required mating on average. Gender ratio deteriorates from 1: 4 to 1: 5.4, the population composition deteriorates 18% and the average age of the goats decreases 28% from 2,142 to 1,528 over 6 years. Males of 2-10 years in% of females of 2-13 years (ie the group of the productive animals) decrease 28%, which gives a 27% deterioration of the animals’ already strained mating situation over the considered 6 simulation years.
– In addition, with 50% shot bucks, the quality of the entire population will also decrease (to an unknown extent), because a relatively larger number of 1-year-old bucks (in the absence of 2-10 year old bucks) will participate in the mating, and quite a few of these will not have optimal nuisances / plants. – 50% bucks are therefore excluded.
– All this also agrees well with what we have experienced since 2009, when we shot 132,000, and where we now in 2020 shot approx. 87,000, at the same time as we have not generally seen an enormous amount of fallen game compared to before the wild game disease.
As can probably be seen above, no one can, in the head arithmetic or on the basis of sensations, overlook a particular cull policy, as a cull policy is basically about promotion. Each animal takes one step up the age ladder each year, or has died before, and who can oversee this promotion process for does in 13 age stages and for bucks in 10 age stages, and when all the other factors, variables and conditions that affect must be included at the same time in a roe deer population? The fact that many things work exponentially in a roe deer population makes both mental arithmetic, sensations and guesses even more impossible and unacceptable.
The many different recommendations for the cull the roe deer population, as well as the catchy headlines and the dubious allegations can neither have, nor have had any positive effect and or correctness, as we see a large population decline now over 11 years – so they have certainly confused more than they benefit. However, how should the hunters or hunting landlords also be able to choose the least incorrect recommendation between the many different publicly put forward?
– It can thus be stated, that it has gone wrong and has failed (or has not helped), to have so many different opinions, perceptions and recommendations in play – even if they are interesting to read about, and even if there there must be room for these.
Are we shooting too many bucks?
An important theme in population management on the shooting side is: What percentage of the shot adult animals should be bucks? – Again we are back to the very important distribution of the cull.
The way this can be determined very simply, if you want as many bucks as roe in the population, is simply to expect that approximately the same number of bucks fawn and doe fawn are shot, and then shoot adult bucks and does in the same ratio as they are born bucks fawn and doe fawn. Finally, it can be compensated for the fact that there may be 2.5 times as many does as bucks – as this is the roe deer’s own biological balance point, which one should approach as far as possible (but probably will never be able to achieve in a hunted population).
This means that if 51% of all set fawn are buck fawn, bucks and roe must be shot in the ratio 51/49 – ie 51% of shot adult animals should be bucks, and 49% should be does – so simple is this, and this is exactly how you maintain a gender distribution among adult animals of 1: 1. – Ie. that shooting of adult animals should be close to following the sex quotient, if the sex distribution is already 1: 1, and this and the population size are to be preserved.
Fortunately, however, in a roe deer population you do not have to have a sex ratio of 1: 1 (nor is this found anywhere in a huntable population on the free game range), but instead ‘only’ a gender ratio of 1: 2 (when young buck population) or 1: 2.5 (when older buck population) – which then means that you can shoot approx. 2 times as many bucks as does (reaches a young buck population). – This corresponds to approx. 66% of shot adult animals can be bucks, but this is noticeable in a population with a ‘normal’ population composition as seen in a non-hunted population.
According to Wildlife Information 2014 (approximately in the middle of our registered population decline) it could be read, that exactly 66% of shot adult animals were bucks. This indicates that in 2014 we shot in the buck population, as if we had a roe deer population with the same sex ratio (1: 2) as in a non-hunted population. – But we do not have this in our hunted population, where we must assume that the ratio buck / doe is approx. 1: 4-5 and in some places is 1: 7-9, and where we can certainly count on a completely different composition (age structure) in especially the buck population.
An older buck will probably mate 3 times more does than a younger one, and since most hunters will probably shoot an older buck, we must especially keep an eye on their number. We must also keep an eye on the number of younger bucks – for i.a. to be able to save appropriately on the number of the older bucks and ensure a sufficient promotion in the younger bucks. – On Kalø, a distribution of animals was seen: approx. 22% bucks, 45% does and 33% fawn, and that approx. 43% of the bucks were 3-10 years old – today the same approximate values are probably: 11% bucks, 43% does and 46% fawn, and 25% of the bucks are from 3-10 years old. – The differences thus show the effect of the shooting / hunting.
The differences in Kalø’s distribution of animals look very different from our assumed distribution today, which is why it must be emphasized that, despite this, there must not be unacceptably much change in the current cull and assumed distribution of this cull, to correct this sufficiently.
– So yes, we shoot too many bucks (and especially too many older bucks), giving a strained mating situation and even in some cases a challenged ‘effective population size’ – and here we have one of the main reasons for seen population declines from 2009 to 2020. The other main reason is that we have shot and shoot way too many does relatively and also incorrectly in the fawn population. – That it has not gone more wrong than seen, is due to the deer’s self-regulating ability, in the form of greater fawn share when the population is hunted, and our almost innate fidelity to ‘save the old doe’, as well as our mild winters, evergreen fields and hunters’ game management (referrals, game catchers, etc.).
Do we know the population size and population composition?
There are probably many who believe that the correct cull cannot be determined without knowing the population size and population composition. This is in principle completely true, and there is a serious snag here – but also a solution.
We can by no means or methods get to know the population size and population composition of our total roe deer population, and we can only estimate this by calculation based on the knowledge we have from an not- hunted roe deer population (eg the Kalø surveys in the period 1.1. 1966 – 15.5.1968), at the same time keeping a watchful eye on the yield size and yield distribution of the hunting statistics. Studies such as the Kalø studies could of course be repeated, but the natural biology, population composition and interaction of roe deer will probably not have changed significantly.
We then have an additional useful opportunity to assess the buck population in particular, by studying heards.
Such a basis will be fully sufficient to calculate an accumulated effect of any cull in a given population, over a longer simulation period of e.g. 6 years. – In a correctly performed simulated population analysis, you see both the start status of a selected population and you see the status and development over the years and you see the selected population situation in the final status – and right at that moment we have exactly what we need (namely development directions- and speeds on the analysis areas at certain choices), to find out exactly where things are going wrong – and to instead find the best cull, which is equal to the best population situation through years, which in turn is equal to sustainable hunting in the future. – We never achieve 100% correct numbers, percentages and key figures, but we can gain insight into the right speed-specific development directions and ‘pointers’ in all the key figures at different selected loads (eg hunting yield, cull distribution and mortality) – and this is fully adequate.
Several times we have heard of and seen estimates with a sex distribution in roe deer of 50/50. Such a gender distribution does not exist at any time in any huntable roe deer population on the free game range – so it is really dangerous to start determining harvest from this. By the way, let us all pray that we will never achieve a roe deer population with a sex ratio of 1: 1 – since we in such a population, with a population size of e.g. ca. 399,000 and by e.g. Game information 13´s recommended cull distribution of 25-25-50 used for 6 simulation years, could only shoot: 17% of the autumn population, corresponding to a total of approx. 68,000 animals in total, of which 17,000 are bucks – if we want to maintain the population size and have the prospect of that kind of reduced sustainable hunting in the future, and where we simultaneously override and distort the animals’ natural biology, way of life (regime) and interaction, which will always go wrong on a point in time.
One has also seen 1-year estimates that look exactly right, but if the values are put into a simulated population analysis, big surprises emerge.
The population composition is extremely important for the mating situation of the roe deer, which is crucial, and this is only affected in terms of the cull distribution between bucks, does and fawn, and this is not affected as such by the harvest rate (annual hunting yield in% of the presumed autumn population). – Population composition is gender ratio and age structure of the sexes.
The cardinal point of a hunted roe deer population is, and will be the sex ratio and population composition of the roe deer population – as this is crucial for the mating situation (whether it is impossible or possible). – Here you must also remember that the bucks must mate significantly more does (approx. 35% more) than necessary for next year’s number of fawn, because (pregnant) does die and are shot from the mating period July / August to approx. 02.06. the year after which fawn are set.
In Kaløs’ non-hunted population, a gender distribution between bucks and does was seen at 1 buck per 2-2.5 doe, which must then be considered close to the roe deer’s natural sex distribution – which you can probably never achieve in a shelled normal roe deer population. The average in our roe deer population is probably approx. 1: 4-5 pr. at the end of July, but in some areas 1 buck per 7-9 does. – If you study roe deer during the period of heards, the ratio between older bucks and all does is often 1: 10-15, and this ratio means that many roe deer are being mated by 1-2 year old bucks, which not all have proven their good genes and predisposition, which predisposes to less both resilience, vitality and pleasantness in the overall population.
– If we then put ourselves further completely illogical and harmful obstacles in the way, such as: ‘We do not shoot prickets’, then we deprive ourselves, among other things. the possibility of take away bucks, which we can all see will not turn into anything desirable, and at the same time we damage the population, when these transmit minor nuisances / plants. Professional shooters do a lot of shooting young bucks with expected poor facilities, in order to improve the general quality of the roe deer population – which also gives more, older and stronger bucks, and which improves the animals’ mating situation.
Can we assess population density and terrain carrying capacity?
You often hear: “Well, we see animals in all irrigations and scrub” – and yes, it seems really overwhelming when you see animals in the fields jumping out of several irrigations and depots. – But when you see e.g. 2 animals jump out of an irrigation or a depot in a field – so look around and judge the size of the field. The size of the field is perhaps 109 acres – and this only gives a population density of: 1 animal per. 54 acres, which is not impressive. – If there are no animals on the neighbor’s 190 acre field, the population density in the area is down to 150 acres per. animals – where the net population density on average in Denmark is approx. 23 acres pr. animals at a population size of approx. 356,000 animals. – Net population density is gross area less cities, road networks, trains, lakes, mountains and other areas where roe deer cannot be expected.
– We hunters can see if an area is a good roe deer terrain, but we can probably not assess the terrain’s maximum bearing capacity or maximum spatial bearing capacity, and we can therefore not assess whether the population density is at e.g. 60% of maximum resource carrying capacity, which one reads is the best level.
Fawn share and fawn per. doe
This relates to recruitment to the population, which also has an important set of key figures.
Hunters are often heard saying: “That all does put fawn” – but not in one of all animal species, all females produce offspring, just as this is also impossible to register.
The fawn share is a key figure that the animals themselves regulate. For example. studies of an non- hunted roe deer population on Kalø showed, that one year there was a juvenile share of 18%, another year 41%, and 35% a 3rd year. – It is these large fluctuations that make it impossible to count on an annual cull being a good index for the current population size. – Since it can be assumed that these different proportion of fawn were not due to such sharp declines in the population of adult animals, it is the number of born cubs that fluctuates from year to year, creating the natural population fluctuations and therefore also the differences in annual hunting yields. The proportion of fawn in a hunted roe deer population will be greater than in a not. hunted one, and is now probably around 45% per. end of July. – It must be said, however, that the proportion of fawn is an unknown and important factor in the assessment of our population, as unpleasantness, disease, level of disturbance, etc. other quite naturally affects fertility.
My calculations show: Number of fawn per. doe (incl. 1- year old does): 1,069 – Number of fawn per doe aged to give birth: 1,524. – Number of fawn per. dow that actually gives birth: 1,657. – This calculated per. at the end of July, when the fawn’ highest mortality (calculated at 40%) from the average date of birth on 02.06. to the end of July, is about to be over.
The connection between the known key figures and the population, as well as new key figures
There is a connection between the known key figures such as harvest rate, population composition, cull distribution, departure and influx, mortality, number of fawn per doe and fawn share – and the well-being and development of the population. – These key figures are therefore very important to find, monitor and be able to estimate ahead, but the connection is very complex and is obscured by the roe deer’s self-regulating ability and natural population fluctuations. Therefore, theoretical analysis, as in all other areas of the real world, is necessary to use as the only real possibility. – Countries and kingdoms would come to a standstill, without theoretical analyzes.
It is also possible to extract some new key figures, such as ‘Number of days per. necessary mating ‘regarding. the mating situation of the animals, and regarding. ‘The resulting recruitment’ and ‘The resulting promotions for significant age groups in the sexes’, which reveals whether the promotion conditions for / during the mating period are satisfactory.
It is about being able to monitor the roe deer population on an ongoing basis, to be able to see the expected development at this and the speed of development, and especially to be able to document that probable sustainable hunting is taking place – and it certainly seems that there is a need for groundbreaking innovations within this.
SOLUTION – so what are the recommendations, instructions and actions we are missing?
There is simply a lack of practical and concrete recommendations that hunters can relate to and deal with in practice, and which without the use of guesswork and sensations can be easily and quickly updated according to a publicly accessible, demonstrable and well-documented need.
For example. these recommendations, prioritized according to importance, should always be present and up to date:
* In Denmark – aim to:
1. the cull distribution between bucks, does and fawn is xx% – xx% – xx% (fawn about half of each sex).
2. shot prickets make up xx% of all shot bucks, two- pointers xx% and six- pointers xx%
3. number of shot adult males in% of number of all shot adult animals: xx-xx%.
4. each time 1 pcs. of 2-10 year old buck is shot – should be shot approx. x pcs. 1-year-old bucks “.
5. each time 1 pcs. of 2-13 year old doe is shot, approx. x.xx pcs. 1- year old doe should be shot.
6. always shoot away clearly sick and weak animals, as well as 1-2 year old bucks with clearly poor potential – as these will impair the overall quality and well-being of the population.
7. as well as possible ensure a harvest rate of approx. xx% (annual hunting yield in% of estimated autumn population at national level).
8. If you want to optimize the population of bucks (without it affecting the rest of the population badly), the cull distribution is used: xx% prickets, xx% two- pointers and xx% six- pointers, while shooting x% fewer bucks. – (NB: The major changes are not required to optimize – see in the Wild Game Analysis).
– All the x´s in the 8 important recommendations above can be found, and kept up to date, in a simulating population analysis model, where one finds the probable correct cull and the actually even more important probable best distribution of the cull, which will give a demonstrably appropriate population development at national level and on district plan for a number of years – and thereby sustainable hunting. – It can be demonstrated by simulating population analysis what the exact probable cause is for the observed population declines in both roe deer and moose in several countries around us – namely, an incorrect cull and more importent an incorrect distribution of the cull.
It is the cull down on the individual hunting areas that accumulates up to the total cull, which determines the population situation and the population development of the huntable game species – this both at district level, at national level and down on the individual hunting areas.
It is thus down to the individual hunting areas that the fate of the population, and also the fate of hunters and hunting landlords, is decided – and that is where action must be taken, and probably as quickly and broadly as possible.
– Therefore, it would be optimal if you had some practical and simple Cull Tools available, where you find the probable number of animals on your own hunting area, and where you find the best hunting yield and the best distribution og the cull on this hunting area.
This is underway by me, and on its way, as a socially beneficial initiative, and to avoid imposed restrictions that go beyond what is necessary – but let’s get the cull rate for doe down to 19-20% as soon as possible.
* Another action that is missing:
Game yield statistics should be expanded / optimized to promote better understanding and monitoring of the relationship between hunting yields (including cull distribution), and estimated population size, population composition, population dynamics and direction of development (and its rate/speed), and extent of disease.
Therefore, it should be made mandatory to immediately report gender, age (1 year and 2+), the 4 types of antlers (prickets, two- pointers, six- pointers and return bucks), healthy / sick and weight.
Ongoing actions: Cull Tools and Wild Game Analysis:
Cull Tools is out very soon.
Wild Game Analysis is coming out soon.
Now it has finally succeeded in developing Cull- Tools that hunters and hunting landlords and other population managers in all countries can use to ensure sustainable hunting – at national level, in the districts and all the way down to the individual hunting areas. – These will be published very soon. Wild Game Analysis is coming out soon.
The Cull- Tools have been developed as a socially useful and fast, safe tool for use in population management on the shooting/cull side – and are aimed at hunters, hunting landlords and others.
In Cull- Tools, which are international in Danish and English, you have 15 cull tools, where the tools for roe deer and moose are based on the results of an underlying large and extremely strong Wild Game Analysis, which simulates a given selected population situation for 6 years.
You will find both the number of animals and the best cull for roe deer in 8 countries in Europe, in the districts of these countries – and in your own hunting area.
You will find both the number of animals and the best cull for roe deer in 42 other countries with roe deer, in the districts of these countries – and on your own hunting area.
Here you will find both the number of animals and the best cull for moose in Sweden, Norway and Finland, in the districts of these countries – and on your own hunting area.
You will find both the number of animals and the best cull for moose in 17 other countries with moose, in the districts of these countries – and on your own hunting area.
There is also a rough cull tool for all other huntable animal species, with a biology and longevity much like roe deer and moose – all over the world.
Although at some point there may be restrictions on roe deer hunting, just as there are now quotas for moose hunting, as well as permissible number of shot animals on many larger hunting areas – there is nothing legal that can prevent the hunters and hunting landlords from (within the quota and the permissible) using the right cull and the correct cull distribution in the huntable game populations – and thereby preserve the game populations, the hunting experiences and incomes.
Wild Game Analysis:
Later, the Wild Game Analysis itself, which is behind these Cull Tools, will be published. In the Wild Game Analysis, you can analyze the population of any freely chosen roe deer population, moose population and many other similar animal species in any country. – In its Version Complete you can change all (pre) selected variables yourself.
The Wild Game Analysis is timeless, quality-assured, self-controlling and tested, and views population analysis in a very different way – and with unprecedented key figures. The Wild Game Analysis is simulating over 6 years.
In The Wild Game Analysis, which is international in Danish and English, you will find e.g. number of animal – sex and age-divided and the best cull in the countries, in the countries’ districts and all the way down to your own defined hunting area. – You can also optimize the population of trophy-bearing males, test yourself, see if you shoot more and better animals than others, see if your hunting area / your hunting trip in 8 countries is worth the effort and maybe learn a lot about roe deer, population dynamics etc.
Preserve the roe deer hunt and moose hunt: Use these Cull Tools – or the Wild Game Analysis.