▁E gl w ys ▁N un y dd ▁covers ▁, ▁has ▁a ▁shore ▁line ▁two ▁third s ▁of ▁which ▁is ▁in ▁the ▁form ▁of ▁a ▁concrete ▁bow l . ▁and ▁is ▁around ▁ ▁deep . ▁ ▁Bird life ▁E gl w ys ▁N un y dd ▁has ▁shall ow , ▁al kal ine ▁water ▁with ▁a ▁bed ▁that ▁compr ises ▁mainly ▁s ilt ▁and ▁c ob bles ▁where ▁the ▁fert ility ▁encourag es ▁we ed ▁growth ▁which ▁in ▁turn ▁prom otes ▁a ▁product ive ▁insect ▁population . ▁It ▁was ▁originally ▁designated ▁as ▁a ▁Site ▁of ▁Special ▁Scient ific ▁Interest ▁for ▁its ▁bird life ▁in ▁ 1 9 7 2 , ▁and ▁this ▁was ▁confirmed ▁in ▁ 1 9 8 2 . ▁The ▁site ▁is ▁notable ▁for ▁its ▁bre eding ▁birds ▁which ▁include ▁great ▁cr ested ▁gre be , ▁little ▁gre be , ▁m all ard , ▁g ad wall ▁and ▁E uras ian ▁co ot . ▁Other ▁species ▁normally ▁present ▁include ▁tu ft ed ▁du ck ▁and ▁common ▁po ch ard ▁and ▁among ▁the ▁local ▁bird watch ers ▁it ▁has ▁a ▁reputation ▁for ▁producing ▁locally ▁rare ▁birds ▁such ▁as ▁go os ander , ▁sm ew , ▁long - ta iled ▁du ck , ▁greater ▁sc au p ▁and ▁great ▁northern ▁diver . ▁ ▁K iller ▁sh rim p ▁In ▁ 2 0 1 0 ▁it ▁ws ▁reported ▁that ▁the ▁invas ive ▁am ph ip od ▁D iker og am mar us ▁vill os us ▁had ▁been ▁found ▁in ▁the ▁res er voir .