sad day for harriers

having been busy for weeks it seems like I managed a trip to one of my Marsh Harrier spots this morning; from soon after sunrise it was clear that something was not right; no males hunting just one bird dropping bits of nest material into random places in the reedbed and a new female who seemed to be just wandering around; no sign of the other pair or the original female; after 3 hours I checked another site close by -  again no sign of any harriers then a chilling sight of grey and rufous feathers in  hawthorn; a dead male from a breeding pair and no sign of the female -- what is going on? does it come down to the usual local grumblings of too many Marsh Harriers eating all my birds? -- at another site locally another male has disappeared of late and a female Peregrine has been picked up dead; it becomes almost a dread task checking other nest areas but at one area I know there is very little harrier activity compared to recent years --- or is it just the spring weather we have had?? the dead bird is going off for analysis