I thought it was high time we issued a quick update with our latest sightings from the reserve, as May is our peak month for visitors and with good reason- it is quite easy to see many of our star species, and the reserve is full of summer migrants now.

Bitterns have been showing pretty well recently, with quite a few visitors getting lucky each day with a sighting- two birds were seen from New Fen Viewpoint yesterday (23 May) but anywhere with reedbeds or dense sedge offers you a chance. Booming has more or less finished now, but you are more likely to see one than a month or two ago as male are now often pursuing females in courtship. Marsh harriers are in the throes of raising young and so can be quite visible as paired males bring in food to the nest. At this stage, most nests will either have eggs or young chicks, so females are likely to be remaining quite close and attentive to the nest, so they may fly up for mid-air food passes with the male. Later on, when the chicks are larger and able to regulate their own body temperature, Mum will leave them to hunt herself as well, so they have two parents working to satisfy their growing appetites.

  Photo credit: A food-pass between Marsh harriers, by Matt Walton. The more strongly-marked, but smaller bird on the right is the male.

Many visitors come here to see our Hobbies, and it would seem that we have passed peak numbers- a couple of weeks ago we were recording 40+ individuals, whereas now we seem to have perhaps 10-15 across the reserve. This movement of birds from us outwards to probably quite local breeding grounds seems to have happened a bit earlier than normal, but it is still possible to see several birds on a sunny day. We will keep perhaps 3-4 pairs all summer long anyway, as they breed here. Interestingly, Hobby chicks have an almost 100% survival rate to fledging because they can be fed on such a wide variety of food items- from small birds to insects or even small mammals like Field voles. However, their food of choice is large insects like dragonflies and Cockchafers, and this is what the adult birds are feeding up on now.

It is difficult to miss the sound and even sight of Cuckoo on fair weather days- at the moment they are calling across the reserve and can often be seen flying over the reedbeds, from one poplar plantation to another. The arena of New Fen reedbed, surrounded by East, West and Trial Woods on three sides, is a particularly good place to wait and watch for them. Listen out for the curious bubbling calls of the females if you have never heard this before- you can listen to recordings here: https://xeno-canto.org/species/Cuculus-canorus.

Our Common cranes are doing well- although we can't really report on specifics until after any chicks have fledged (as they are extremely vulnerable to disturbance) our pairs are doing well at present and we hope to bring good news to our visitors and followers by mid-summer. So far this year the Cranes haven't suffered much human disturbance (as monitored by our trail cameras) so we are thankful to everyone for adhering to signage they see and for respecting the Cranes' need for space and privacy. There will come a time when they are easier to see, when the families are more mobile, but we aren't there yet.

Smaller summer visitors like warblers are showing well too, with a Common whitethroat feeding some fledglings by the Dragonfly Platform yesterday (23 May) and no matter where you are, Blackcap, Cetti's warbler and Garden warbler are particularly vocal at the moment. Sedge and Reed warblers can be heard in reedbed areas in small numbers, as many of both species are paired up and raising young, so will be relatively quiet. Even when breeding, males will sing to maintain territory boundaries and failed breeders will sing more persistently to try to attract a new mate if needs be. Grasshopper warblers have been reliably heard from Joist Fen Viewpoint early or late in the day recently. We are hoping to pin down the locations of one or two more so if you hear one, do let us know where you heard it. They are often silent during the day, whereas early morning and early evening can be particularly good times to visit for them. Nightingale have also been popular here recently with two still singing on 23 May in the scrub next to the Visitor Centre, as you walk towards the hard track. Two more were recorded in a popular spot for them- in the scrub surrounding Nuttall's Tunnel. This tunnel is used for water movement by Anglian Water and is surrounded by green security fencing which has long become overgrown with scrub and brambles, and is bordered by a semi-circle of poplar trees. If you walk along the riverbank from Joist Fen, towards Botany Bay, you will reach it on your left after about half a mile. Listening on the riverbank here can be very productive for Nightingale as they love the dense scrub.

  Photo credit: Common whitethroat by Tushar Bala

On the bird feeders at the Visitor Centre we are seeing up to three Greenfinch most days, along with a male Great spotted woodpecker. With luck, we'll see some fledglings soon if he is part of a successful pair. There has been a seemingly very successful Robin nest near the Visitor Centre as multiple fledglings are dotted around the area, as well as lots of fledgling Blue tits and Great tits, and a few Pied wagtails who like to nest in the lid of our gas tank!

Butterflies and Dragonflies

Interestingly, we have seen a large number of migratory insects on the reserve in recent days- Silver Y and White point moths in the light trap, as well as a few Red admiral butterflies about and a couple of Painted ladies were recorded last Sunday (19 May) too. Other butterflies that are easy to see in good weather at the moment are Large, Small and Green-veined whites, Orange-tip and Small tortoiseshells. We are seeing the first Scarce chasers now and last week saw our first Banded demoiselles and Brown hawker on the wing. Wherever you go, you are often surrounded by Azure and Common blue damselflies resting on vegetation by paths, which lift up and float on the breeze as you go past. The Common mayfly is particularly obvious as you walk anywhere close to water at the moment, with males dancing up and down in the air column around you, or resting on Common reed stems. As well as being beautiful in their own right, they are a vital food supply for insectivorous birds nearby, including Reed and Sedge warblers, as well as the many Swifts, Swallows, House martins and Sand martins that can be seen hawking for insects over the Washland most days at the moment.

  Photo credit: Common mayfly by Heidi Jones

Hopefully this blog has provided you with a good picture of what you can see on the reserve at the moment, and over this coming Bank Holiday weekend. The Visitor Centre and the toilets will be open from 9am until 5pm every day, with access to the trails, viewpoints and Mere Hide provided at all hours thanks to our side-gate at the Visitor Centre. We hope to welcome you on the reserve soon!

With best wishes, Heidi Jones (Visitor Experience Officer, RSPB Lakenheath Fen).