As well as the practical conservation work that the reserve team and volunteers carry out at Lakenheath, bird surveying also takes place and has been well underway here for a while now, involving early morning starts for some species and late nights for others. As well as bird territory surveys of the poplar woods, we also carried out surveys for specific species such as nightingale and spotted crake. While the spotted crake proved elusive/absent, nightingales were recorded in both Brandon Fen in the east and Botany Bay to the west.
Bittern surveying is ongoing and involves a number of staff and volunteers being strategically placed around the reserve at locations with good vantage points - some of you may have encountered us along the riverbank and at the view points. The earlier stage of the surveying involved noting down estimated locations of ‘booming’ male bitterns along with the time of the booms - this helps to avoid duplicate recording of the same bittern by more than one recorder (those booms can carry a long way!) The results suggested we had six booming males, including one in Botany Bay for the first time, although the overall figure is one less than in 2011. An interesting note about male bitterns is they each have their own ‘voice’ and their boom should be distinguishable from that of another, this has proved easier to notice with some than with others!
We are now surveying the bitterns in terms of potential nests, recording flights to and from similar locations for the purpose of feeding their young. Three flights within a four hour survey indicates a probable nest while a fourth confirms it. Sitting still and remaining highly observant for such a long period of time is more difficult than it might seem – there are plenty of distractions to be found, such as watching juvenile marsh harriers and discovering many invertebrates amongst the vegetation (see picture below, hard evidence of distraction!) It’s all too easy to miss that short bittern flight and they can be particularly sneaky too, taking off and landing in a number of different places then walking to their nest so as not to give away the exact location. So far two nests have been confirmed, which is less than last year and we are keeping fingers crossed for some late developments.
Photo credit: Ali Blaney - Longhorn beetle (Leptura quadrifasciata)
Last but not least, surveying of marsh harriers is also ongoing. Much airborne action has already been witnessed, firstly of adults carrying nesting material and passing food and now juveniles are popping up all over the reedbeds! Hopefully when numbers are tallied we’ll have had another bumper year for nests and fledged chicks.
I’d like to finish off with a big thank you to the volunteers who help us with the surveying – the bittern watch especially requires stamina, patience and enthusiasm, particularly when the four hour period can sometimes end without a single recording of a bittern!