Nature Diary

Seagull Survey (Part VI)

The continuing saga of the seagulls of Isla Perdiguera, researched and related by Roxanne, the Ship’s Naturalist.

This is the sixth 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 time I told you about the shape of Isla Perdiguera. The island is made of four hills. Three are joined together, forming a long curved mound with summits which we call Grasshopper Hill, Mount Yellow Foot, and Lily Peak. They make a fat sort of banana shape. Mount Yellow Foot is the biggest of the hills and is in the middle of the three, so of course we named it after the rulers of the island. But in July the island will be covered in grasshoppers – there are already some tiny ones around – and that is how the second hill got its name. The smaller hill is called after some plants which I think are lilies but which only grow here in the winter, when it is damp. It is not really a peak, but a sort of blunt knob, with lots of tall caves in it. After Lily Peak the land comes down into a point and ends in a little piece of shingly beach where we once found a pen shell – so we call it Pen Shell Point. On the north side of these hills, between Yellow Foot and Grasshopper, there is a valley which we call Palmito Valley, after the dwarf fan palm trees which grow there amongst the thorn bushes. At the bottom of the valley lies Barbecue Beach – also called Cormorant beach, because the cormorants go there in the winter. On the other side of the island there is a bay with a long curving sandy beach, and most of the people who visit Perdiguera don’t go further than the beach. The beach becomes a long sand strip which joins the biggest part of the island to the fourth hill, which I call Dragonfly Hill. This is technically a different island, but they were joined together when the long, thin beach was put here about seventy years ago. The two islands make another littler bay, on the opposite side of the island, which we call Caleta Medusa (Jellyfish beach). We often anchor here, depending on the wind, but most people anchor in the big bay on the other side of the island.

1st photo : Looking north-west, along the man-made causeway, from Dragonfly Hill. Lily Peak is on the left and Mount Yellow Foot on the right. The buildings are ruins dating from various eras. This photo was taken in the February, when the island was green and most of the birds were elsewhere.

2nd photo : Dragonfly Hill and the beach, as viewed from the saddle between Grasshopper Hill and Mount Yellow Foot. The principle anchorage is to the west, on the right hand side of the photo. The bay between Dragonfly and the main island is referred to in the text as Caleta Medusa. Again, the photo was taken in the winter.

When we went back to Isla Perdiguera on the 22nd of May we anchored first in Caleta Medusa and then, after a few days we moved to Barbecue Beach. This is not always a very good place to be anchored, but it is the best place for the birds. In the morning when we got up and let the birds out from under their net there were already lots of juveniles sitting on the water. Mostly they were in pairs. Romulus and Remus flew around the boat a few times and then they flew to the other chicks and settled on the water quite nearby. It was like children meeting for the first time. We are pretty certain that two of the other chicks must be the ones from N7 – Romulina’s nest. She spent ages sitting with the other chicks on the water and sometimes trying to get them to fly, like she does Remus, by hovering just above their heads. She loves flying, but most juveniles are lazy. Or perhaps it is that they are afraid of being mobbed. Romulina seldom gets mobbed now, she flies so well. After a while she came back to the boat and practised landing on the barrel of chain on the foredeck and on a huge paint can on the aft deck. None of the other juveniles would have been clever enough to do this. They had not practised landings at all, anywhere. When they wanted to go home they all swam ashore.

We are growing to know the birds on the island, their language and their signs. When we walk along our usual route the gulls seem to know us and they are more relaxed than they used to be. If we go right next to a nest or pick up a chick we usually get bombed, but otherwise we just get mildly scolded. The gulls land again as soon as we have passed.
“Those two come almost every day,” they say to each other. “Don’t worry about them. They’re a nuisance but they’re harmless.”
However, if we go somewhere different from usual there is a terrible fuss, all the birds go up in a big noisy panic, and the chicks start running around instead of just sitting tight in the bushes. It’s a bit upsetting.

We have noticed that the gulls have many different ways of talking. When a parent comes back to the nest territory after flying around the two birds greet each other by pointing their heads to the sky and screaming, “Kaaa, ka ka ka ka ka kaa!”. (I think this might perhaps be loosely translated as, “It’s me, yer ever lovin’ husband. Only me, Sweetheart! Don’t drive me off!” JDS)
Usually the one returning speaks first, and if he has only been away for a short while the other one sometimes doesn’t bother answering. But if it has been a long trip to the rubbish dump to get lunch, the second one answers and then they both yell at the sky at the same time.
(Second Gull: “What time d’you call this, you waste of feathers, you. Don’t you know the kids are starvin’?”
First Gull: “Blimey you’re such a nag! ‘Ere’s me, slavin’ all mornin’ while you sit about…”)

When a chick meets a parent who is returning to the family territory it bows up and down squeaking. When they are begging for food (which they usually are) they open and shut their mouths while they bob and squeak. Remus still does this almost every time I go on deck.
(Both gulls go into raptures of delighted bobbing when Roxanne laughs – which she does quite a lot. Her laugh has exactly the same rhythm as the adult gulls greeting noise.)

When we let Romulina and Remus out of their cage every morning, a single adult gull will alert the whole colony by calling. I suppose he is a sentry. He calls, “Kaa. Kaa. Kaa.” The words are slower and longer than the greeting call. A small group of gulls will come flying over to see what the fuss is about, and if they go away again without making any noise then the whole colony will ignore the alert as a false alarm. But if they join in and make the same call, all together, circling over the boat, then within a few seconds the sky above us will be black with birds. I think that at times like this the parents take it in turns to stay on their nest sites, to guard the chicks, because for several minutes there is a constant stream of birds coming and going until everybody has had a look.
(I think that this sort of thing is the highlight of a seagull’s day. They seem to love a bit of drama. I’d like to think that they were also discussing what they see – “Well, would you believe it, Amarilla? Two chicks stuck out there on one of those floating islands! Never in all my days did I see such a thing!” – but this is pure Richard Adams style fantasy; neither rabbits nor gulls really possess the ability to natter and gossip. JDS)

The adult gulls also make a chattering noise, which is their way of scolding or warning, and they make a howl as they dive bomb us. Sometimes they make a shriek. Romulina does this everytime before she lands on the boat (“I’m home, Mum!”) but sometimes a gull makes this shriek for no particular reason while it is flying round the boat, and all of the juveniles make the same shriek when they are being mobbed by an adult. (“Mummy! Mummy! Help!”)

Sometimes two gulls fly around together taking it in turns to call. One calls on a fairly high note and the other one quickly answers on a lower note, and they carry on for quite a while going, high low, high low, high low. We haven’t worked out what this means. Very occasionally a gull miaows, and we don’t know what that means either. We never hear any miaowing at the island, but the other day we heard some while we were in the port and it really sounded like a cat that was stuck somewhere. Mummy thought at first that it was Truco!

(Gull communication is impressively complex, and I believe that we have overlooked some of its subtleties. For example, this morning two gulls held a conversation which went something like this:
1st Gull, on the water astern of us : Mow (to rhyme with ow; much shorter than the miaow call) followed by an abbreviated version of the greeting call.
2nd Gull, flying around us : ku-ku-ku (a mild version of the scold), followed by one half of the high-low call, repeated four times.
1st Gull then repeated his previous remark, and 2nd Gull again said, “ku-ku-ku”.
After this, the gull on the water flew up and mobbed Remus, who was fooling about nearby and looking rather lke an oversized bath toy. Then he flew off with 2nd Gull.
Did the gull in the air, who could see Remus more clearly, instruct his chum to come and bully our boy? It looked that way; indeed, it looked as if he passed a message which said, “Juvenile to be mobbed. After which we’ll go flying together.” (Hence, the use of one half of the flying call.)
Meanwhile, our two youngsters presumably have the capacity to make the full range of seagull calls but, being mere toddlers, haven’t yet learnt the lingo. Romulina makes valiant attempts to communicate with Remus, but not by audible means. When she wants him to fly she will dive bomb his head gently, or hover over him. Sometimes she also pulls his tail, presumably in the hopes that he will be sufficiently annoyed to get up off the water. These efforts are not always successful – but largely, we think, because Remus is not very bright. JDS)

On the 29th of May we went ashore on Barbecue Beach and instead of going up through the valley or south along the coast we walked north. There were 11 juveniles sitting together in a little gang off Barbecue Beach, and our two were amongst them. The adult gulls sat separately in a very much bigger flock. As we walked along the coast we spotted a total of 23 juveniles which, disturbed by our approach, flew down onto the sea. On the opposite side of the island we counted 21 unfledged birds which were sitting in a tight group some distance from the beach. Of course there were lots of other big chicks, which live too far from the seaside to go swimming. They were running around in amongst the bushes, trying to keep out of sight. We saw very few little fluffy chicks.

Later that same day we walked further along the north coast of the island, towards the tunnel which cuts through Lily Peak. Before long we came across a juvenile gull lying dead beside the path. It had a fishing line coming from its mouth and the other end of the line was tangled around its feet and caught in the bushes. We have seen very few dead chicks. We had expected to see lots, because we had been told that many of them die of hunger because the adults can’t get enough food for them. This does not seem to be true. The adult gulls spend most of the day sitting about doing nothing. They aren’t desperately hunting for food. There is always plenty of food at the dump. In total we have seen about seven small fluffy chicks which were dead. One seemed to have drowned after he got stuck in a hole in the heavy rain a month ago. One appeared to have died of heat exhaustion. One was minus his head and one had been stabbed in the back, perhaps by an adult gull. The others we weren’t sure about. We have also found two dead juveniles – feathered chicks not quite ready to fly. In both cases there was a dead adult nearby, so presumably the chicks died of hunger when the parent died.

This juvenile that we found beside the path had obviously swallowed a fishing hook. Further along we found another chick, slightly younger, which was lying dead on the rocks below the path, and then we found another quite near it. Then we came to a clearing in the bushes with three dead juveniles, feathered but not quite ready to fly, lying strewn on the ground. One had its tail torn off, one had its back bitten and its head bitten, and one had its wings both torn off.

To have six dead chicks within a hundred yards something must have done it. A dog, it seems, killed five of them. Then we remembered that three nights before some fishermen had been here in the night, with their rods. I suppose they must have had a dog with them. If a dog was running loose on the island it might easily have killed five times as many chicks as we found. We only walked on the path, and quite probably there were other dead chicks in the bushes. Chicks are well camoflagued, but a dog would be able to smell them, and in the night they would panic and run. They can’t run very fast, and when they try to run they usually end up falling over or getting stuck in bushes.

The fishermen might even have deliberately cast to the fledgling chick, I suppose. Usually a line has a weight as well as a hook, and a seagull can’t dive after the bait. It can only eat things which are near the surface. The same fishermen leave their rubbish scattered all over the place – beer cans and crisp packets and empty boxes that come from the bait machine. I don’t understand why people do this sort of thing. Mummy says that some of them are wrong in the head and ought to be locked up, but that most of them just aren’t very intelligent and haven’t been properly educated.

(Perhaps, rather than merely regarding the yellow-legged gulls as vermin, and surplus to our requirements, the “biologistas” could use them to teach people about gulls, and about nature in general. Most seabird breeding sites are strictly protected and no one is allowed to visit them. Here is one which is currently open to the public (although most of it is actually privately owned) with occupants who are not remotely endangered and could thus be used as the front line troops in the war against ignorance. People are much more inclined to respect things when they understand them. As it stands, many people manage to spend a whole weekend in the anchorage and on the beach without even realising that the gulls cursing and carousing above their heads are breeding here! We often see parties of school kids arriving by ferry and being marched along the beach or up to the summit of Dragonfly (which is the only part of the island not privately owned). I very much doubt if they are being told about the nesting habits of the gulls. A few information boards wouldn’t come amiss. JDS)

Almost all of the eggs on the island have hatched now, and most of the chicks can fly or nearly fly. But at the beginning of May we started finding new nests. The first new nest that we found was so near to N52 that we thought it was a new nest built on top of the old one. We wondered if a bird which had lost her first brood would try again. But the N52 chicks were alive and well, so that didn’t make sense. Then we realised that it was a new nest, one bush along from N52. It is N100 on my map. All of the new nests, with one exception, have only two eggs in them. I still think that they are probably the nests of birds who lost their first brood, but it could be that the chicks who were born late are only just four years old now, and only just old enough to mate and breed. If they are first time parents this might explain why they are not especially good at it. Two of the nests were in rather silly places, too near to the beach (N99) and actually on the beach (N101), and none of the nests are very well guarded. We don’t get bombed or even scolded when we visit them. It is very odd that there should be eggs still not hatched while most of the other birds are learning to fly!

N52 is one of our favourite nests. It is right on the edge of Caleta Medusa, on the side of Grasshopper Hill. It is only just above the water. It had three eggs, and we watched one of them hatch. (A photograph of the newborn chick and his elder brother accompanies Part III of the Seagull Survey.) Something happened to one of the chicks. When we left the nest that day there were two chicks and an egg which was cracking, and when we came back a few days later there were only two chicks. It is possible that the other chick fell in the sea, but I don’t think that is very likely. The day after we left the island was the day when the naturalists came and took twenty five chicks for the new zoo in Murcia, and I think that the younger of the N52 brothers probably now lives there. I expect he gets lots of fish to eat and is very happy, but I hope there is a pond at the zoo because if he is anything like his siblings he will need one. They spend all day in the water, paddling around close to the shore or swimming so far away that they are just dots. After they got their full set of feathers they didn’t want to come out of the water at all, and their mother used to come down onto the shore to be with them. I suppose she even fed them there. These two chicks are two weeks younger than Romulus and Remus and when we were anchored here they tried to make friends, but one or other pair would always swim away before they came very close, like shy children. We don’t see the N52 chicks anymore, so I think they must have swum round the corner and come to live in the little bay off Barbecue Beach. Probably they are part of Romulina’s little gang.

It is very interesting to see the difference between Romulina and Remus. They are not only different in appearance but in character too. Remus is like the pigeon that Gerald Durrell had. This pigeon was reared from a chick and it always thought that it was a human. It refused to fly. Remus would be the same if Romulina was not here to try to show him how he ought to behave. Romulina is always alert, but Remus never watches the other birds or keeps watch for danger. He even used to walk up to the dog doing his feed me act! Luckily, Poppy has been brought up with a hamster and then a kitten, so she knows she must leave small animals alone. She walked away from Remus. “Stupid squeaky toy,” she seemed to be thinking.
Romulina, on the other hand, drives the dog away by spreading her wings at him.
Nowadays Remus doesn’t beg from Poppy but if her back is turned he runs up and pecks her hard. As a result she gives the seagulls a wide berth! (And no doubt she wishes she had finished them off when they were of a more manageable size… JDS)

Remus still tries to fit everything he finds into his huge mouth. He attacked Mummy’s flip-flop, and the other day she turned around and found him drinking her tea. (But I forgave him, because afterwards I found him trying to clean up his mess with the deck brush. JDS) Romulina is very clever and very alert, and she seems to have decided that Remus is just a silly baby who needs looking after – which is not far wrong. She swims beside him as he plays and flaps, and she even drives off any adult gulls who come and land too near for her liking. The other juveniles do not do this – when there is a crowd of juveniles sitting together on the water it is always Romulina who drives off any interfering sub-adults while the other juveniles just try to swim away from them – but we have noticed that juvenile gulls on the island do help their parents to guard the territory. They lunge towards any adult that lands on their territory. I have also seen a gull scare a rabbit off his territory.

Although all adult gulls look more or less the same to us, we have noticed that the juveniles can always recognise their parents even when they do not make the greeting call. Sometimes when an adult lands beside the group of juveniles on the water one of them will paddle quickly towards it and sit close to it. Romulina is usually at the head of the gang of chicks off Barbecue Beach. She and Remus seem to have adopted one particular friend, a pretty dark-headed juvenile about the same age as them, and they spend a lot of time leading him about. Once Remus swam right up to the bow of our boat with this friend. The friend was ducking his head in the water, like a sparrow in a bird bath, which is a thing that the gulls do when they are nervous.
“Remus!” I could almost hear him say, “What are we doing here? If my Mum catches us, I’m for it!”
An adult gull who had been following the chicks did not think it was a good idea at all to get so close, and she watched nervously until both of them were past Mollymawk and swimming away the other side. Then she flew over and joined them.

Romulina and Remus have learnt that if ever they are being harassed they need only to fly back to the boat to be safe again. Their mummy can’t fly after them and shoo away the other birds, the way some mother gulls do, but so long as one of us is on deck no adult will ever come to the boat! I think that the other gulls are rather impressed by the way Romulina and Remus are not afraid to land here.

Tune in next week for more news of Romulus and Remus and their pals on Isla 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.

2 Comments

  1. I have enjoyed reading the Seagull Survey and very well written it is too! I must admit I have in my time been the big bad biologist and punctured the eggs of Great Black-backed Gulls! At the time I was on my first research project and studying Puffins etc. The GBBGs would sit on the top of burrows and await the appearance of any adult Puffin and in one aweful movement split the Puffin down the middle, eat the offal and then leave the rest!! After watching these antics for a week or so I became all the things that a biologist shouldn’t be and interfered, visiting the nearby islet I proceeded to puncture all the GBBG eggs and smuggly watched for weeks as they brooded the long brood! I am ashamed of myself these days, but very hard not to interfere sometimes, still I learnt a guilty lesson and never interfered again, honestly!!

    Peter

    1. Roxanne  (article author) 

      Hello Peter,

      I suppose it would be rather tempting to interfere after watching the gulls do that! The yellow footed gulls are supposed to hurt the audouins gulls, but while we are watching the audouins have been very aggressive birds. When we throw bread in the water they scare off the yellows and take the bread for themselves. But the yellow feet are supposed to kill the audouins chicks, and I suppose that might be true. The audouins are smaller than the yellow feet.

      Roxanne.

Leave a Comment