In 2001 management of red and fallow deer in the Deelerwoud was stopped by Natuurmonumenten. Management of roe deer had already been stopped earlier. This experiment served the purpose of developing an ecosystem that was as complete and natural as possible and in which held opportunities for the development of a natural life style of these animals. Also, the experiment aimed to improve visibility of these animals to the public visiting the reserve. In order tot evaluate this experiment, INBO was asked to analyse a large number of different available data sources on the different deer populations in the Deelerwoud. However, a number of these data were not sufficiently robust to allow conclusions. The analyses of these data have been carried out as part of this research and are discussed in the report. Since no reliable conclusions could be drawn, none of these analyses were included in this summary. Changes in numbers and proportions in the populations of large ungulates. The data show a strong increase in the population size of red deer in the Deelerwoud since the start of the experiment, followed by a stabilisation in the last few years. The observed growth rate was more pronounced than for red deer outside the Deelerwoud and sex ratio stronlgy shifted towards a population that was almost exclusively female. The number of calves per deer doe fell slightly while the general condition of the calves remained stable. The population of fallow deer also increased strongly, but in this case, growth rate was comparable to that of fallow deer populations outside the Deelerwoud and without any stabilisation up to this point. In fallow deer the proportion of females also increased strongly, but less than in red deer and starting from a situation that already held a higher proportion of females. The number of calves per fallow doe decreased strongly over the entire period. The data available on roe deer only allowed to determine that the population has very strongly decrease to extremely low values in het last few years. ...