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| Numbers of embryos per pregnancy (litter size) of hares culled in Scotland between 1960-73. Most females have two or three young per pregnancy3 A pregnancy lasts 43 days and most young are weaned after another 30 days. |
Hares can be prolific breeders and may become pregnant as early as February. A female can produce three or even four litters of three or more leverets a year until September. At birth the female leaves her young together in the open but over the following days they move apart so they are usually found singly4. After sunset the female returns to their birth place and suckles them for a few minutes. One visit per day is all the youngsters get from birth until they are fully weaned.
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| Trend in the numbers of brown hares shot from a sample of English estates during the 20th century. Data from The Game Conservancy Trust National Gamebag Census. |
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| Young leverets are very vulnerable to predation and they rely on cover to keep them out of sight. Grass cutting and grazing can often expose them to foxes and other predators. (Chris Knights). |
The hares’ breeding success is partially dependent on the summer weather. Warm dry springs and summers allow females to have successive pregnancies and leverets survive well. Under wet and cold conditions breeding success is poor and leverets succumb to cold and diseases such as Coccidiosis.
Old estate game books show that in Victorian and Edwardian times many more hares were being shot each year than has been the case in recent years5. This bag record directly reflects hare abundance and we can conclude that hares are now far less abundant than they were three generations ago.
There are at least two important factors that have caused this reduction. Firstly, many predators are now more abundant than they were a century ago and, secondly, modern agriculture is less suited to hares than was traditional farming.
The main predator of the brown hare is the fox. Although foxes perhaps only rarely surprise and kill adult hares, they can systematically prey on and kill leverets to such an extent that a fox family can eat the entire production of the local hare population6. However, modern farming could make hares more prone to fox predation than traditional ley farming did.
