Nature Diary

Seagull Survey (Part VII)

In the latest instalment of her survey Roxanne describes the progress made by her protégés, and then considers the seagulls’ dietary habits and lists some of the other birds which are eking out a living and raising their young on the arid little island of Perdiguera.

This is the seventh article in a series of ten. If you haven’t already read the others, start with the first article!

For the full story of Roxanne’s hand-reared gulls and her study of the yellow-legged seagull colony on Isla Perdiguera, buy her book, Two Gulls and a Girl.

It is now the first week of June, and Romulina has become very good at flying. She has learnt how to land and take off from the boat in all sorts of different wind conditions. It is easier to take off when there is not much wind, because when it is windy the birds sometimes get carried backwards and tangle themselves in the rigging. But it is easier to fly when it is windy, because then they don’t have to flap so hard, and they can swoop and flit all over the place. Romulina flits about almost as cleverly as an adult gull. Remus still lands in the middle of the deck, which, to be fair, is more than any other juvenile could do, but his sister has three favourite perches. One is the barrel of chain on the foredeck (soon to become our new, super-beefy anchor chain… when the skipper finds time to change the gipsy. JDS). One is a huge great can of paint on the poop deck to starboard, and the other is the outboard motor fastened to the rail on the port side of the poop deck. (Romulina has made several attempts to start the outboard but, thus far, has had no more success than the Ship’s Engineer.)

These perches are higher than anything else on the deck, so she likes to sit on them and look around. She even sleeps on top of her perches, during the day time, always keeping one eye half open for danger. The perches are all taller than the guardrail, so she can take off from them easily, with nothing in her way, and she flies from one to the other, around the boat practising landing. She always lands upwind – even Remus knows, instinctively, that you have to take off and land upwind – and her favourite trick is to come sweeping round the stern, dive towards the water, and then swoop up onto the paint can.

Always, as she lands, she makes her little warning call. I think it started because she always used to find Mummy standing in the way with her camera. (“Get out of the way, you ruddy fool!”) And whenever she lands she gets a little piece of cheese as a tasty treat. She loves cheese, and sometimes she flies from one perch to another just so that she can demand another piece of cheese. Often, when she was just learning to swoop up onto her perch, she was being pursued by a big mean looking adult, and the adults were always very cross and scolded loudly when they saw that this little chick was sitting where they couldn’t get her and eating something! Once I gave Romulina a piece of asparagus, for fun, and she flew with it all around the boat and then back to her perch!

Romulina also likes to practice picking things up from the water. Remus plays this game with her, but in his case it is because he is hoping that the thing that they are playing with might be something he can fit in his mouth. The first time they played the game it was with a feather, and Romulina came back proudly holding it. Next time it was a cork, which was a bit alarming. If it had been Remus who found it he would have swallowed it. (Roxanne is certain that when she grows up she will never be so worried by her children as she is by these youngsters. “At least babies don’t go off by themselves and get lost, or find dangerous things to put in their mouths.” JDS)

By now you are probably wondering what all these gulls on Isla Perdiguera find to eat. Gulls do not eat other gulls, even if they find them dead, but they seem to think of every other bird or animal as food. I suppose people are a bit like that too, unless they are vegetarians. For gulls, humans are a source of food, although I don’t suppose they realise that it is humans who put those mountains of food at the dump, near Cartagena. Gulls also eat fish, and we sometimes find small dead fish which have been dropped by the birds as we approach. We also find lots of dead rabbits, but we don’t know whether a gull could catch and kill a rabbit. I think they could only kill a sick rabbit or a baby. Once we found two dead newborn rabbits lying beside N1 (the nearest nest to the one which was Romulina’s birth place). We don’t know who got the rabbit kittens out of their burrow. Surely a gull couldn’t go down a burrow? And a snake would eat them underground where he found them. Ten minutes later, when we walked back along the same path, one of the dead rabbits was gone. It was much too big to feed to a chick – all of the chicks were very tiny at the time – so it must have been eaten by a parent.

We find rabbit bones littered all over the island, together with chicken bones, and the bones from joints of meat. Once we found one back leg from a huge lizard. This was very surprising as we have only ever seen small, stripey lizards on Isla Perdiguera. Would a seagull carry a lizard, or a lizard’s leg, all the way across the water from the mainland? The lizard’s leg was a beautiful shimmering bluish green. We took a photo but we haven’t had it identified yet. (The leg was about 3 inches (7.5 cm) from the tip of the longest toe to the severed hip)

Another thing that we sometimes find is the wings from small birds, and once I found a tiny skull with a red beak. We can’t find a bird like this in the bird book, so perhaps it was a cage bird. (A zebra finch, perhaps?)

Because the gulls are so dangerous not many other birds nest on Perdiguera. Any who do must nest in a very thick bush or else keep a very good guard. At least one pair of blackbirds nests on the island. They escape the gulls because their nest is in a thorn bush. (But we haven’t seen any young, and when I think of the fledgling blackbirds which used to bumble about on Mum’s lawn, back home in England, I can’t imagine anything so innocent managing to survive in the company of several hundred voracious gulls. JDS) The stone curlews, with their huge yellow-rimmed eyes and their long legs, also nest here – or at least, we are fairly certain that they do. We hear their beautiful calling at night – Mummy says it is the most beautiful sound in all the world – and after a lot of patient watching we finally saw where they kept flying from and, from a distance, watched one run along cautiously and rush into the bushes. We will never find that nest, or the babies, and nor will the gulls. They are no better than us at scrambling through thorn bushes.

There are also lots of pairs of Sardinian warblers on the island, and we always hear their shrill scolding when we go ashore. We knew where one pair were nesting and we once had a very close encounter with one of the fledglings, which flapped across the path right under our feet. It was so tiny! I picked it up, before any of the gulls could, and put it back in the bush with its brother. Later we searched the bush to find the empty nest for my museum, but we can’t find it, it is so well hidden.

There is also at least one pair of shelduck which we often see at Barbecue Beach. The gulls don’t seem to mind them. They don’t drive them off, they just ignore them and the ducks ignore the gulls. Mummy doesn’t think they have a nest, because we almost always see both of them together, but I think they have a nest hidden in the bushes. (It may be that the shelducks will nest later in the season, after the gulls have finished their business. JDS)

In the winter we see lots of crested larks on the island, and we still see a few now. We recently saw one with food in its beak, but we don’t know where it is nesting. There are also common terns and little terns, but we think that we would certainly have spotted their nests when we row round the island. I suppose they are nesting at the salterns, which are not very far away as the tern flies. We also see a pair of turnstones and some little ringed plovers and quite a few kentish plovers. Once we saw a kentish plover pretending to have a broken wing, so we know that its nest must have been nearby, but we didn’t find it.

Four egrets also visit the island or live here. We often see them wading along the shore near Barbecue Beach, and we once saw them clumsily perched amongst the thorn bushes on the hillside. The gulls don’t go amongst the bushes, but we don’t really think that there is a nest here.

We did find one nest which was a bit different from the gulls’ nests. It was just a scrape in the ground, with no lining of grass and feathers. There were three eggs and they were not quite like the yellow-legged gulls’ eggs. They were a tiny bit smaller, and they were not so pointed. They were also a bit darker. We never saw what kind of bird was sitting on these eggs. One possibility is that they were the eggs of an Audouin’s gull. We didn’t tell anybody about them, because if they really did turn out to be Audouins’ eggs the biologistas would probably come along and kill every yellow-legged gull on this part of the island. We wanted to watch from the boat, to see what kind of bird was sitting on the eggs, but the weather was never right for us to anchor there, and no bird of any sort scolded us while we visited the nest. One day when we checked on this nest one of the eggs was hatching. Yellow-legs eggs always hatch in the same way, with the chick pecking a hole in the blunt end and then breaking out at that end, but this egg had a hole in one side. Later that same day there was no change – the hole hadn’t got any bigger – and that evening we had to sail back to the port for some boring reason. The next time we visited the island, a few days later, all three of the eggs had gone. There were no chicks. Whoever hatched from those eggs had either run away or been eaten by the gulls.

All the chicks at Perdiguera have slightly different shapes, colours or speckles. All of them look very like Romulina – alert, quick, always glancing about, and with a very graceful shape, a light coloured neck and head, and a dark brown back. They swim with their heads held upright. Their beaks are different lengths – the long one for the males and the short one for the females, I believe. Romulina usually leads a group of gulls about, but sometimes she is led. She is one of the best flyers, although all of her crowd are very good now. Unlike the novice flyers they are seldom mobbed, and when she is mobbed Romulina does all the tricks and gliding and swinging off to one side that the adults use. If an adult swims too close for her liking she sees it off. If someone tries to bomb her she is no longer pushed down onto the water, which is what the adults seem to want. Instead she flies swiftly to the boat and swoops up onto her perch at the stern.

Remus is different. He is huge – bigger than any other juvenile in the group. In fact he is as big as an adult, and even bigger than some adults. He has darker feathers than any other chick. He doesn’t have a graceful rounded head, his head is big and square. Although he has a neck like the other birds he doesn’t use it. He sits very low in the water, like the unfledged chicks, and he doesn’t look around. He just swims along squeaking. (He still squeaks most of the time.) Remus never leads the other chicks around, but they don’t seem to think any worse of him for being so different. It seems that he is wrongly formed, and perhaps that’s why he couldn’t get out of the egg without our help. Perhaps it wasn’t anything to do with getting too dry. And certainly getting too dry couldn’t have spoiled his whole body shape. We always assumed that his mad character was because he never saw his real mother, but it might be because he is wrongly formed. If we had picked a different egg and treated it in exactly the same way we might have ended up with a sane, clever chick like Romulina.

On the 29th of May Romulus and Remus spent all day on the water with their friends, off Barbecue Beach, rushing back for a plate of fish or a snack of cheese every now and then. They lost track of time and stayed with their friends until it was dusk. The other chicks started getting closer and closer to the shore, because the parents were rounding them up and leading them home. At last Romulus and Remus realised what was happening and took off to fly home to the boat, but by now it was quite dark, and they had never landed in the dark before. After trying and failing several times they went and landed on the water a few boats’ lengths away. Daddy and I went to get them with the dinghy. I took a large net, and Daddy rowed the boat while I tried to pick up the birds. They don’t like being picked up, and as we came near I could see that they were going to take off, so I reached out for the nearest one, who happened to be Romulina. It would have been better to get Remus, who was the least likely to be able to land in the dark.

As I picked up Romulina the rest of the gulls went up in a panic, including Remus. I calmed Romulina, who hates being held, and I gave her some cheese, for a special treat, and put her in the cage with a big plate of fish. She ate the fish and then paced up and down, worrying about Remus. I was worrying about him too. He had disappeared into the darkness and now he was lost. We all stood on deck calling him. We even searched with the night-vision scope, but there were no chicks on the water. Then, after a long while, I thought I heard Remus cheeping: “Cheep, cheep, cheep.” Nobody else could hear it. I was sure it was Remus because no one else cheeps like that, continuously – but then the noise stopped and I thought, “Maybe the cheeping was coming from the island. Maybe it was just a baby.” But then the cheeping started again, and it began to move from one side of the boat to the other. Then it went away. Then it started again, much louder, and suddenly Remus appeared out of the dark and landed, in his usual place, on the coach roof.

Remus was a long time getting to sleep that night, and in the morning he was scared to go flying. He was like a child who has fallen off a bicycle and is afraid to get back on!

On the 2nd of June we had to move to a different anchorage, to buy some food. We moved the boat at night, so that it would be less disruptive to the birds, and so that we wouldn’t have to put them in their cage during the day, but at first, when we let them out of their cage in the morning, they didn’t realise we had moved. They took off and flew once round the boat, in their usual way, and then they happily set off in the direction of the island! The island is visible from the port, but the birds can’t have recognised it. They had a perfect sense of direction. (Having now studied their behaviour as we move from place to place I believe that they have some sort of internal compass. Although we had moved four miles, the island just happened to be on the same bearing as it had been for the previous few days.) They carried on flying until they were just little dots! We couldn’t stop them! Fortunately a whole crowd of sub-adults followed them like a pack of wolves, and started mobbing them. When they had gone about 600 yards Remus panicked and turned back. Romulina would never abandon her brother, and so she turned back too, to look after him. They eventually dropped down onto the water about 500 yards from the boat and they sat there for almost an hour. They must have been very confused. After lots of calling and coaxing they were finally persuaded to come home. For the rest of the day they stuck very close to the boat.

That afternoon the birds had settled down, and they had a lovely time playing with all sorts of things on the water. They picked them up and flew round the boat, dropped them, swooped down on them, and played tug of war over them. I was afraid that Remus would eat the things, but he didn’t. Then Mummy threw in a small piece of bread, and they knew the difference. Even though we have never given them bread to eat they knew that this was food, and they had a proper tug of war over that! Their playing is good practice for when they have to fish for their supper. Sometimes I throw their whitebait into the water, one at a time, and they have to catch them before they sink.

The next day we had to sail across to the other side of the Mar Menor, and although I put Remus in his cage, to keep him safe, I decided that Romulina was sensible enough to stay with the boat – and she did. On the next day we wanted to move back to Perdiguera, where the birds really belong. They had both spent all day flying around, dodging the attacks of the sub-adults, and so we said to ourselves, “They are great big birds now, not babies, and they are probably sensible enough to stay aboard. We don’t need to put them into their cage.”
We hoisted the sails. This caused some confusion and consternation. Then we started to wind in the anchor, which on a steel boat is a very noisy business. Romulus and Remus paced up and down nervously, and then they took off and landed on the water nearby.
“Never mind,” we said. “They can fly along behind the boat.”
We got the anchor aboard and we sailed away.

Romulus and Remus waited until we had gone about 200 yards and then they took off from the water and flew to us. They flew round the boat, calling, and they tried to land but everything was different. Seagulls always land into wind, and when the boat is at anchor it always lies head to wind, but now that we were sailing the wind was across the boat. To land into the wind on her usual perch Romulina had to approach the boat from the side, and that confused her. I think the gulls may also have been afraid of the sails, and Caesar said the sails were disturbing the air flow. They eventually flew off to where we had been anchored and landed there, on the water.

So in the end we had to anchor again, and furl the genoa, and wait for the birds to join us. After about five minutes they both flew to the boat, and then we had to put them in their cage, which Romulina doesn’t like any more. They were not happy birds that night, sailing along – but in the morning to their delight they found that they were back at Isla Perdiguera.

In the next instalment of Roxanne’s survey things take on a more sombre tone, as we discover a psychopath lurking amongst the inhabitants of Perdiguera.

For the full story of Roxanne’s hand-reared gulls and her study of the yellow-legged seagull colony on Isla Perdiguera, buy her book, Two Gulls and a Girl.

3 Comments

  1. hello Roxanna

  2. Hi Roxanne & family
    It’s so fascinating reading all your studies of the seagull colonies. I’m guilty of previously thinking of seagulls as a nuisance, just a marine version of London’s pigeons!
    I’d never considered the complexities of learning to eat (fish = good, pencils = bad), fly (and possibly more importantly, land!), ‘speak’, etc.
    Would be great to see your map of the island, with all the nests marked: any chance of a photo of it on your next instalment?
    Keep up all the good work
    Katy

    1. Jill SPAIN  (Mollymawk crew) 

      Thanks for your comments, Katy. Yes, I keep meaning to put Roxanne’s map on line. I’ll have to photograph it, because it’s too big to scan.

      While I’m here – a quick update on the status of Isla Perdiguera. It seems that I am behind the times with my information: the island was sold to a private individual, but when he found that he couldn’t get permission to build a hotel here he kicked up a fuss. The more so since (according to the rumours) he had been under the impression that he was buying the whole island, including the man-made beach and the part which, according to the government / vendors is actually a separate isle. As a result, he has now been granted lands elsewhere and the entire island has now reverted to government ownership.

      Rumour also tells me that the place is to be made into a Nature Reserve, with a warden. I can’t see this happening – unless the Audouins take up residence – and I don’t honestly think that it would be a good thing. At the moment this is a very special, completely unique place. People come here and enjoy themselves in a completely unrestricted, unregulated manner – they swim, and camp, and fish, and light fires on the beach, all without anybody’s permission – and most of them take home their litter and do no harm. The world needs places like this for people like Roxanne to explore. People who don’t get the chance to handle nature cannot be expected to understand and respect it.

      Jill

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