HARES: THE EAST WEST DIVIDE

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HARES: THE EAST WEST DIVIDE STEPHEN HARRIS Today I am meant to be arguing the case to conserve hares.

First of all I want to look at whether or not we should conserve brown hares (Lepus europaeus). It can’t be denied that they are attractive and charismatic animals, I personally love to see them. They were included in the first tranche of species to get a Biodiversity action plan. The aim of which was to double the spring hare population by 2010 (this goal does not look achievable). They are such an interesting species that they are also included in many small local action plans as well, they are a focus of many areas and they are of course a feature of Suffolk. I would like to ask the audience how many of you are in favour of conserving brown hares? – A hundred percent of you!

Well what about grey squirrels then? – only one or two of you raised your hands in favour. Most of you will remember back to the sixties, before the grey squirrel, when the red squirrel was the dominant species in Suffolk, they were smaller, prettier and nicer. Grey squirrels in comparison are seen as American invaders –oversexed, oversized and over here! I recently put forward an argument in BBC Wildlife suggesting that we treat grey squirrels a bit better and asked for a vote on this argument which I lost two to one. In fact some people were so incensed that we should stop killing grey squirrels that they wrote to the Director of the BBC to complain about such an offensive article. Perhaps those people would be interested to read my article in this month’s magazine in which I suggest that we should maybe treat rats a bit better also! The point of this discussion is that nice as brown hares are, they are no more worthy of conservation than grey squirrels or rats.

Historically brown hares have always been hunted. It is believed that the Romans introduced hares to Britain for coursing. And hare hunting is a worldwide practice. In Japan the Japanese Emperors are depicted in art hunting hares with bows and arrows. Today in New Zealand, Australia and North America there are still many packs of hounds used for hunting hares.

Like the rat, the hare has migrated with human populations around the world which makes it hard to identify its native range. The species evolved on the open grassy steppes of Asia and has naturally spread westwards as land has been cleared for agriculture, it is now spreading northwards with climatic change. The Romans introduced the hare into Britain and the British in turn introduced the hare into New Zealand, Australia, South American, the Falkland Islands and Eastern North America. The peak of hare populations in Britain occurred around 1900 when there was an abundance of open landscapes and since then it has been in decline. From 1960 until 1990 this decline was more rapid but since 1990 hare numbers have been more or less constant (Figs 1 & 2). Today in Britain there are about three quarters of a million brown hares in the spring compared with about 4 million in 1900. This is not unique to Britain, Denmark and most of Europe shows very similar patterns in decline through time whereas since the end of the war roe deer population have gone up rapidly.

Trans. Suffolk Nat. Soc. 44 (2008)

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Figure 1 Hare population changes in Britain: Game bag records from 12 estates in East Anglia and the south-east.

Figure 2. Recent hare population changes in Britain It has been argued that one of the reasons for the decline of hare populations in Britain has resulted from over predation by red foxes. However, this is not the case, the brown hare is a food source worldwide and has different predators in different countries – lynx, cougars, cheetahs etc.

Furthermore, red fox numbers in Britain during the 1960s when hare populations were declining rapidly were relatively low, while now that red fox numbers have increased, hare numbers have remained fairly consistent. In

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Figure 3. Size is important - for brown hares, larger females have more offspring.

Europe the argument for red foxes causing the decline of hare populations is further disproved as fox numbers crashed after the Second World War, due to rabies, while hare populations declined rapidly also.

Today in Britain when we are looking at hare conservation we must talk about the East/West divide as we are dealing with very different habitats.

Generally speaking the West of Britain is predominantly pastoral while the East is predominantly arable and this has resulted in a divide in hare populations with the greatest declines in the west. Hare populations in the 1900s were fairly evenly distributed across Britain, but now in the East of Britain they are nearly twice as abundant. The average density is five hares per square km in the East as opposed to three in the west. Considering that hares evolved on the steppes of Eastern Europe and Asia it seems strange to think that they are declining in a pastoral habitat. Dietary analysis of East and West habitats show that they are of equal value so other factors must be having an effect. A closer look at the population in the West showed that they were generally smaller and lighter and that as a result they stopped lactating in winter and therefore had fewer young. Whereas those in the East tended to be over 3 kg the critical weight for breeding and had a longer breeding season (Fig. 3). Since the diets were of equal nutritional value the difference in weight was found to be due to climatic factors. It is relatively easy for the

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hares silky coat to become water logged and therefore in the wetter West hares have to expend more energy drying out and keeping warm.

Through radio tracking of hares it has become clearer that they need habitat heterogeneity to thrive. This can happen on a relatively small scale as long as the habitat is varied. Sward height is a critical factor with hares requiring both high sward for hiding and sheltering in, and low sward for feeding. Modern agriculture tends to produce a very uniform sward.

From a land management point of view farmers face a challenge for example the conservation needs of the brown hare which, as an alien species, don’t match those of the lapwing and other farmland birds. We need to give farmers clear messages about what the priorities are.

In February 1993, in the hare hunting season, six estates, three from Suffolk: Euston, Ixworth and Gazely and three from Norfolk: Holkham, Gayton and Raynham cooperated in a survey. We collected 100 hares from each estate for post-mortem. We also measured lots of habitat data on the estates and compared and drew graphs to illustrate the effect of habitat on hare populations.

One of the graphs showed the percentage of arable features (not including oilseed rape which hares do not like) to the size of the hare population and it was found that as one increased so did the other (Fig. 4).

Figure 4. Hare density is higher where more land area is covered in arable crops. 1 Euston, 2 Gayton, 3.Gazeley, 4 Holkham, 5 Ixworth, 6 Raynham.

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Figure 5. Leveret survival rates vary with month of birth.

Another thing we did was to age the hares. This is done very accurately by removing and weighing the hare’s eye lens. It was possible to then work out what month each hare had been born in and to see what percentage of hares each month had survived for a whole year. It was found that 30% of hares born in January survived, 25% in February, 10% in March, 5% in April and in May only 2 % this decline continued as summer approached with nearly all summer babies dying (Fig. 5). This is because hares need fresh, green grass and in Suffolk in summer the fields are full of tall, dry crops and the field boundaries are also fairly dry and inedible (Fig. 6). We analysed 77 reports from 12 other European countries and found that this pattern seems to be replicated across Europe (Fig. 7). This also explains the rapid decline in the 1960s when intensive crop farming was introduced, since then habitats and hare populations have been consistent. We can take some measures to improve conditions for hares but as hare population are now stable and these measures often conflict with measures need to conserve other species the question arises as to should we?

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Figure 6. Summer food quality limits leveret survival. 1 Euston, 2 Gayton, 3.Gazeley, 4 Holkham, 5 Ixworth, 6 Raynham.

One significant thing we could do which doesn’t conflict with other species is to have a closed hunting season for hares. It is the only game animal in Britain which doesn’t have a closed season and as a result it is targeted in its peak breeding months between January and March.

I believe that our standards in hare conservation are wrong. The brown hare is the grey squirrel of the hare world and that we should pay more attention to the mountain hare (Lepus timidus) which is restricted in England because brown hares do very well in lowlands, Mountain hares only survive at altitude. As temperatures increase with climatic change brown hares are now increasing their altitudinal range and this is having an effect on mountain hare populations.

In Ireland brown hare populations never really took off, probably because the climate is so wet and they do not thrive well in wet conditions. However, their native mountain hare population is thriving and is protected by a Biodiversity action plan.

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Figure 7. European perspective: Summarised 77 studies from 12 European countries. Results are very similar: habitat changes caused by agricultural intensification are the ultimate cause of hare population declines. Effects of changes of climate or predator numbers are magnified by loss of high-quality year-round forage and cover.

In conclusion, although the brown hare is a beautiful charismatic species and it is not my strategy to do anything to get rid of brown hares, it is not logical to spend money or effort conserving an alien species that is detrimental to a much rarer, much more vulnerable and much more important native species.

Prof. S. J. Harris School of Biological Sciences University of Bristol Woodland Road Bristol BS8 1UG

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