local patch – Enviro-Mentalist

The Tern Report

So, feeling bad about not checking on my terns, I’ve paid two visits this week. First, an evening trip after work on Monday. The majority of the noise and activity was from the tern rafts – other birds such as the swifts were not present in great numbers and the big gulls were still down at the far end of the water.

The birds seemed to be busy setting up territories with quite a bit of squabbling going on when an interloper tried to land – they could land on certain parts of the raft, but not others. Most parts of the raft had only one bird in place – mainly sitting, have a preen or shouting at the other terns. Sitting around the edge of the raft in general seemed to be tolerated, particularly on the larger, higher new raft. Landing, within the confines less so. I did see some digging around by a couple of birds – not sure what they were digging into or if it was some sort of bonding ritual, and I also saw the presentation of a newly caught fish from one tern to another – that seemed much clearer. I left feeling that all was well with my terns and looking forward to watching them next weekend.

However, the weather in between then and now has been terrible -strong winds, thunder, lightning and lots of rain. The results were fairly predictable. Returning today (Sunday) it was noticeable that a number of the older, shallower rafts were under water to some extent again. Whilst they were occupied I think it was just somewhere for the terns to sit and have a rest. I hope that none had laid their eggs in the last week – if they did, will they lay again? I have no idea. The other, more robust rafts, were still occupied although I’m not sure how many birds were there – I saw the tips of some wing feathers peeking over the top but couldn’t be certain that there were more than a couple of birds in residence.

I did get a good view of the terns fishing – they looked beautiful backlit by the sun, at times almost hovering, wings and tail spread, at other times they zoomed past so fast on the gusts of wind they appeared as just a white flash through my telescope. More wet weather is forecast for the coming week – I just hope that the birds sit tight and keep away from those old rafts.

The water is quite quiet apart from the terns at the moment, but I did notice a fairly sizeable chick with one of the great crested grebes – I guess they nested quite early this year. Note to self – find out when great crested grebes usually nest.

In amongst a flock of seagulls…

No, I don’t mean the 80s pop band (they were around in the 80s weren’t they), but the black headed gulls bobbing about on the water at Daventry Country Park.

In my last post I waffled about my discovery of a totally new species for me – the black tern. Well, that wasn’t the only new species that I spotted that day when out with my scope. As I mentioned the black terns seemed to be quicker than the common terns over the water, and I had a bit of trouble following them in my scope. This was made a little more difficult by the fact that I get easily distracted and, on this occasion it was probably a good thing. Bobbing about on the water, seemingly quite happy amongst the bigger gulls, was a black headed gull. Unlike the gulls named black headed gulls (BH gulls), this one did actually have a black head, rather than chocolate brown. I was sadly very excited. Not only because here was the second new species in a day, but because I actually noticed it and decided it was different. Notebook time again (it’s becoming a bit of a habit) and I really wish I could draw, but I can’t so I scribbled instead.

I noted that the bird was smaller, as I mentioned above, that it had a black head that came all the way down its neck (that is what I was trying to get at in the picture) and that it didn’t have a white ring around its eye – I somehow knew that this was important (probably due to the huge number of bird books I had read over the years). The bill also looked neater than that of the BH gulls all around it and it seemed to have a pinky tinge to its breast feathers.

I’ll not bore you with the details, but this was a Little Gull, larus minutus, unlike the BH gull, appropriately named as it is the smallest gull, and is described as more delicate than the BH gull with which it bears some similarities. So, one trip with a telescope to the country park and two new birds to add to my lifetime list (if I kept such a thing).

The appearance of a small, dark stranger.

It all started with a tweet on Easter Sunday. Apparently there were 24 arctic terns spotted at Daventry Country Park. I wasn’t convinced, but thought I should maybe pop over and see if I could tell the difference between an arctic and common tern. By the way, I’m not a twitcher, but if there is a chance to see a new bird at the local country park? Well, I’d be a fool not to, especially on a bank holiday weekend. Besides, this means that if nothing else, the common terns were back – if you’ve never seen a common tern close up, gracefully patrolling the shallower water, then you’ve missed out.

However, not willing to admit that I wanted to see if I could see arctic terns that possibly didn’t exist some subterfuge was in order and I suggested a walk but only a quick trip into the country park with my small binoculars to see if the terns had come back. This worked and we happily sat for ten minutes or so watching the aforementioned common terns wheeling about. There were other gulls there too, but I was only interested in the terns. However, something else caught my eye, some of the terns seemed darker, but it could just have been a trick of the light – after all, there was some sun despite it being a bank holiday, and I did only have my little 8 x 24 bins with me.

I thought about them during the rest of our walk, wondered if perhaps they were younger terns or if I was just seeing things. More information was needed, so I went back later in the afternoon (trying to reduce my exposure to the many families and their dogs off leads that were bound to be there) armed with my telescope and a notebook.

I was right, they were definitely darker, they moved a lot faster too and never stopped. There were no arctic terns there, but there were a couple of dozen common terns. These had the good grace to stop once in a while on the tern rafts so I could get a good look at them. (Arctic terns apparently look like common terns but have no black on their beaks in summer and have longer tail streamers). The dark strangers didn’t, so I had to resort to note taking, a habit that I need to get into. (As I read on a completely different subject, about fungi as it happens, you should describe something first, then try and identify it, rather than trying to do it the other way round and therefore potentially miss some important features.)

Anyway, this is what I noted down;

darker wings than the common tern, darker below than above.
seemed slightly smaller than the common tern
white rump and greyish tail
lightish under the wing and the grey wings had white edges in flight
seemed to be faster than a common tern

Once back home it was time to hit my myriad of books. There was only one conclusion, I had spotted some black terns, something I didn’t even know existed until Easter Monday.

According to the RSPB handbook of British Birds it is ‘smaller than the common tern’. The Collins Bird Guide gives this description: ‘typical marsh tern. In summer body black, under tail white; slate grey upper wing and tail, underwing entirely silver-grey; bill and legs dark red’ (although on this point the RSPB disagree and claim it has a black bill and it definitely looked black to me). It is a ‘light airy bird that flies with great agility’. This sounds exactly like the birds I had been watching. Unfortunately I don’t have a photo, but there are plenty on the web if you want to see this pretty bird.

It is apparently a common passage bird through the UK (which means that you might see it in spring and autumn on its way to somewhere else) and has made a few unsuccessful attempts at breeding in the UK. I was a little unsure as to whether I had really seen some of these until I noticed someone tweeting that there were some at Summer Leys nature reserve over the other side of Northamptonshire – I guess I was right after all and these were probably the same birds.