Chasing a Gropper 17th April 2025

Grasshopper Warblers (groppers in slang birding parlance) have proved, for some reason, a difficult bird for me to catch up with. Maybe it is my bad luck, as when others see them really well I am always for whatever reason somewhere else. Even hearing them without seeing them has proved frustrating as when I go to where they have been heard singing loud and clear I am met with silence. I can and have stood for over an hour at a known location but heard not a peep.

This year looked like it was going to be no different and the same frustrating state of affairs would be my lot yet again. On Sunday last I had a lunchtime social arrangement with Mrs U  and friends and what should happen but not one but two groppers were found at Pinkhill just outside the boundary of Farmoor Reservoir, one of which showed itself well and gave some great photo opportunities.

Pinkhill is ideal gropper habitat, being a largish neglected area of dead umbellifer and willow herb stems with the occasional hawthorn bush growing in their midst and with the River Thames running close by. Similar habitat exists on the other side of the river too and every year Grasshopper Warblers set up territories here.This year there are three possibly four males singing away in the stems

Fired with enthusiasm I resolved to head for Pinkhill early the next morning and of course there was neither sight nor sound of a gropper.

These Spring days with bird migration in full swing I am at Farmoor Reservoir virtually daily and on a dull overcast Tuesday I was wandering up the causeway when Dave, a fellow Farmoor regular sent me a text advising  a gropper was showing really well in a ditch full of dead umbellifer stems by the approach road to the northwestern end of the reservoir and Pinkhill. 

Fortunately I was at the right end of the causeway and made haste to the ditch and lo the gropper was reeling away loud and clear. Success! That was the easy bit but as any birder will tell you the harder part is to locate the bird, often perched low down in the depths of dense vegetation and not helped by the fact the warbler  imbues its voice with ventriloquial properties. The reeling song seems to be coming from one spot when in fact it is in another. They achieve this by turning their head one way and then another so the continuous  grasshopper like sound they make is projected in whatever direction their head is pointed.

Finally a movement, low in the thickest part of a maze of dead stems betrayed the bird, perching low down in the ditch. It was not there for long as it was promptly chased off by a territorial Sedge Warbler and fled further  along the ditch and disappeared under the rank grass at the bottom. Frustration and no little cursing on my part was directed at the Sedge Warbler.

Eventually the gropper was up again, reeling and again the process of locating it was a trial, but having been successful in locating it the first dog walker of the day arrived. Cue disappearing bird and much metaphorical gnashing of teeth. Mine not the dog. I should explain the approach road, accessible only to Thames Water vehicles and hardly used, conveniently links the nearby village houses with the Thames Path that winds its way alongside the river in  undeniably idyllic countryside so you can hardly blame people for walking their dogs here. It is also used by joggers and runners as a means of access to the perimeter track of the reservoir

The ditch frequented by the Grasshopper Warbler

Another twenty minutes passed in silence and then to my relief the gropper was back singing again and giving me a clear view. Great. I was just about to lock the camera onto it when a jogger came galumphing past, the warbler took fright and dropped like a stone into the rank grass in the ditch bottom

And so it went on as an intermittent procession of dog walkers, joggers and workmen came past at crucial moments.It seemed as if a curse had been put on me that every time I saw the bird well someone would arrive at the critical moment to scare the bird away. My frustration grew and grew until it got the better of me after a couple of hours and I departed in a huff.

Fast forward to Wednesday. A day of gale force, cold southwest wind that threatened to blow me off the reservoir causeway. I decided to try the ditch in the forlorn hope it might be more sheltered from the wind but it was only marginally so, although even  above the roar of the wind I could just about hear the gropper reeling but finding it in the swaying stems and gusting wind was a hopeless task and I left it at that.

Not willing to throw in the towel and  give up, I checked the weather forecast for the next day  I was encouraged to see the wind was predicted to die away to virtually nothing overnight.I formulated a plan to leave the house at 6am and get to the ditch by  6.30am before the dog walkers or anyone else appeared and hope the warbler would perform. 

There were a lot of if's and but's and uncertainty to my plan, however if it did work it could be rather good and gropper redemption would be mine to savour. Would lady luck and a bit of planning be on my side?

I parked in the road of houses that backs onto the reservoir and took the tarmac track that leads to the reservoir gate and Pinkhill Lock.

It was very cold and I was thankful I had put on warm clothes. A clear night had allowed a light frost to coat the grass but the rising sun was promising a lovely morning. The cold air reacting with the warmer water of the nearby river had formed a bank of low lying mist, that drifted like wood smoke from the river across the fields and rank vegetation, creating a faint fuzziness to the scene before me.I was not worried as the sun, newly risen, bright and golden, would soon burn away the mist and shadows. 

The stage was set  and now required the star performer to make an entrance and bring  some undoubted glamour and glitz to complement an atmospheric landscape that was far from quiet as a cacophony of birdsong filled the still air, seeming to come from every hawthorn and blackthorn bush. It was an urgency of warbler song, the numerous whitethroats and sedge warblers, newly arrived from Africa competing to be the loudest and most vociferous.The air fairly rang with their energetic outpourings as they sang at full throttle to attract a mate.

All well and good but from the gropper there was not a sound. For ten minutes I stood a little forlorn but defiantly optimistic and for once my hopes were realised as a familiar but faint metallic sounding, high speed, non stop trilling came from the ditch. Instantly energised I approached to where the sound issued, deep in the ditch.Not a dog walker in sight. I reckoned I had about twenty minutes before the first dog walker arrived, just me and the gropper and a host of its migrant warbler friends.

This time the bird was almost immediately visible, perching higher than it had at any time before on a dead stem. Its buff breast, illuminated almost to whiteness by the first rays of the sun reaching the ditch, betraying it amongst the dark stems. In typical fashion it moved its head from side to side. its bill wide open  to reveal a pale yellow gape as it poured forth its extraordinary insect like song.

I got my photos and the first dog walker duly arrived bang on time. I resolved to stick it out and see what would transpire.I had all day after all and it was only just gone 7.30am.The gropper seemed to hsve changed its behaviour since its first arrival and become much bolder and as the sun grew in strength and warmed the land during the morning, it would rise relatively high, well a few feet anyway, up a dead umbellifer stem to sing fully in  view.It seemed to no longer be troubled by the feisty Sedge Warbler and at times would sing close to it.Similarly it was more tolerant of all the birders come to admire it.

Gaining confidence over the next two hours I approached the gropper more closely and it would allow me to get within about eight metres without showing alarm but any closer and it dropped into the grass and threaded its hidden way underneath. I was close enough at times to note that its whole body, especially its tail, vibrated as it sang with a wide open bill, the mandibles held firm and non moving as the song emerged from its throat. Another feature observed from close range were its bright pink legs and feet, the elongated delicate toes no doubt adapted to aid its mouse like existence running across the ground and through grass.I have seen similar feet on a vagrant Pechora Pipit on Shetland, another haunter of rank grass and vegetation.

The song when heard close has a peculiar mechanical tone and is delivered at high speed creating an insect like reeling sound that is ventriloquial. Although it can sing throughout the day as this one did they sing most frequently at dawn and dusk.

It sang regularly but never for more than a minute in duration, often  much less. In between singing it would drop under the grass to emerge some minutes later a short distance away from where it had disappeared.Grasshopper Warblers rarely fly much except on migration, preferring to skulk on or just above the ground and run around like a mouse, for the most part remaining invisible. The males only make themselves visible when they sidle up stems or perch low in bushes and commence to sing to attract a mate

Grasshopper Warblers breed from Spain and France right across northern Europe to Scandinavia and western Russia.They migrate  to spend the winter in northern parts of tropical Africa south of the Sahara. Currently they are Red Listed under IUCN criteria and despite declining due to loss of habitat in both their winter and summer ranges, they still have an estimated population of 840,000-1.2 million breeding pairs and so are currently designated of Least Concern.

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