Eyes in the Sky: Using Drones to Monitor Deer

Over the next few weeks we will be carrying out our annual deer drone surveys in the Ashdown Forest and around Bayham near Lamberhurst.

Deer management is important in sensitive landscapes. Species such as the non-native fallow deer browse crops, woodlands and grasslands indiscriminately and are thought to be a major contributor to the decline in numbers of insects and birds such as nightingales. Without careful management and control, deer populations can increase by around 30% each year.

Why we use drones

The High Weald was the first National Landscape team to use drone technology to monitor deer.  Drone surveys use thermal imaging technology and high resolution aerial mapping to provide important information about deer populations, distribution patterns, species and sex ratios.

The surveys are non-intrusive, highly accurate and can cover large areas. The evidence collected allows landowners and deer managers to accurately calculate what levels of management are needed to either reduce or maintain deer numbers.  

In the High Weald, drones have been used since 2021 to monitor populations in the Ashdown Forest and around Bayham – an area of nearly 250 square kilometres. Currently, deer densities in the areas surveyed range from 25-60 deer per square kilometre, but for woodland conservation and regeneration purposes this needs to be much lower – ideally, fewer than 10 deer per square kilometre.

What the surveys show

The drone surveys are carried out annually. Last year’s survey in February identified around 3000 fallow deer in the Ashdown Forest and 1200 in the Bayham area. The survey indicated that the fallow deer population had remained static overall – an encouraging improvement on previous surveys, which showed populations increasing year on year.    

Supporting deer management

As deer are transient and do not stick to land boundaries, deer management is only effective if undertaken at a landscape level, which is why the High Weald National Landscape team manages these surveys on behalf of over 80 landowners.

The drone surveys are part of a wider drive to support deer management across the national landscape.  The High Weald team provides a range of support for landowners, farmers and deer stalkers, including practical advice, funding for equipment such as high seats and communal chillers, and training for deer stalkers and butchers to help get affordable venison from suppliers to consumers – see the deer management pages of our website for more information.

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