ROE-DEER CENSUS AND POPULATION ANALYSIS 8i 



J. Andersen : Obviously a number similar to the excess of production 

 must disappear each year. They leave the estate: hunters in the neighbour- 

 hood, who return our marking collars, probably take a good deal of the 

 balance. In past years since 1954 we have not ourselves shot deer on the 

 estate, but this year we killed eighty as an experiment. 



I. A. McLaren: Have you any idea what would happen if you fenced 

 the estate? 



J. Andersen: The estate is fenced, but public roads cross the perimeter 

 and the animals certainly use these as routes to pass in and out. On a nearby 

 enclosed estate which had been completely fenced for fifty years the total 

 stock (161) was destroyed in 1954 as it was a poor one. The number of fawns 

 was low. Only • 9 fawns were present per doe as opposed to i • 8 at Kalo. 



E. B. Worthington: Is predation a factor of any significance? 



J. Andersen: No. Foxes may take new-born fawns but on the whole 

 the influence of predation must be very slight. 



T. B. Reynoldson: Is there any evidence that the deer on the enclosed 

 estate you mentioned were affected by starvation? 



J. Andersen: There was perhaps some slight indication, because dead 

 animals were picked up each winter, but no definite evidence. There was 

 however one interesting result of a study made on the ovaries of the deer 

 from that enclosed estate. In Kalo does have on average 2-0 corpora lutea 

 per ovary: on this estate the figure was i -6. This suggests that the population- 

 limiting effect was being felt in the enclosed wood even at the very begin- 

 ning of the reproductive cycle. An age difference was also perhaps involved. 

 The mean age was 2-0 in Kalo as compared to 3 years in the enclosed area. 



D. Hancock: Do adults and fawns take different food? Could your 

 difference in proportions of fawns and adults trapped from year to year be 

 due to a variation in the relative amounts of young and adult food — thus 

 affecting the readiness with which they came to your bait. Would not this 

 also affect relative mortalities? 



J. Andersen: The fawns often suckle their dams until Christmas time. 

 There is no real evidence of what other food they take, or of any diet 

 differences between foraging fawns and adults. 



J. A. Eygenraam : In Holland roe-deer are increasing rapidly. What do 

 you consider to be the cause of their increase in Denmark ? 



J. Andersen : Afforestation, chiefly with spruce, is going on over a large 

 area in Denmark, which is one factor aiding the increase. Farming is also 

 becoming more intensive, and deer, like hares and pheasants increase accord- 

 ing to rises in farming productivity. 



