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prove breeding, as individual single males may simply be passing through a site. In order to understand this enigmatic species a little better, in the 1990s, the RSPB led a major initiative into finding out exactly how many Bitterns were breeding, and their specific needs. Novel sound analysis techniques were used to record the calls of the males and prove how many individuals were present, and whether the same male was staying for the whole season. Intensive research into the success of the nests revealed that the chicks were often starving, because the reedbeds did not support enough fish. Radio tracking of adults showed that these birds need Bitterns are making a dramatic comeback in the UK, thanks to research and habitat management. It is still very hard to see one this well, though... The BTO runs volunteer surveys to monitor and explain changes in bird populations. To find out more about the Waterways Breeding Bird Survey visit a matrix of open water and reeds for foraging, as they prefer to hunt at the water’s edge. This research informed a huge programme of work by the RSPB to create appropriate habitats in a last-ditch attempt to bring breeding Bitterns back from the brink. This work has been a success; numbers of booming males have climbed to more than 100. The 2007–11 Bird Atlas shows that their breeding sites are clustered around wetland landscapes in Kent, East Anglia, Somerset and Yorkshire, including those that owe their presence to substantial habitat creation schemes. In winter, when we are joined by migrants from the Nordic and Baltic countries, Bitterns are much more widespread, as they do not need the large areas of reedbed required to support a nest of chicks, and they can be found at much smaller sites, even along river banks. They are vulnerable to cold weather, and during freezing conditions they are forced to move in search of open, unfrozen water, making them more likely to be seen. During the harsh winter of 2009/10 there were estimated to be at least 600 Bitterns present at nearly 400 UK sites. While the recovery of breeding Bitterns in the UK over the past 20 years has been a conservation success story, their reedbed habitats remain under constant threat from drying out, development and sea level rise. Awareness, monitoring, and appreciation of this flagship species will be key to the long-term success of these birds.
Kate Risely is the British Trust for Ornithology’s Garden Birdwatch Organiser 6.11 6.23 6.57 6.90 6.92 7.22 7.43 7.57 7.62 7.53 7.53 6.95 6.59 6.28 6.10 6.08 6.20 6.40 6.46 6.66 6.82 6.93 6.99 7.00 6.95 6.85 6.71 6.56 23:02 6.54 14:09 7.33 14:54 7.33 16:22 7.02 18:41 6.12 19:42 5.91 20:54 5.84 22:06 5.96 12:29 6.57 13:08 6.68 13:42 6.76 14:48 6.86 15:22 6.82 16:33 6.56 17:55 6.27 6.421 8:48 6.31 6.36 20:23 5.89 21:51 12:30 13:21 15:39 16:22 17:51 23:11 14:15 15:57 17:12 19:58 21:21 6.13 7.14 7.27 7.23 7.02 6.41 6.20 6.83 6.71 6.41 6.15 6.10 6.24