Loafing gulls

 Gulls spend a good portion of their days doing what is known as 'loafing', in open areas of good visibility: playing fields, beaches, but also on water and on ice in frozen lakes, the same sites are chosen year on year. These loafing areas are different from night roosting sites. At loafing sites gulls appear relaxed: some sleep - head under wing - others sit or stand watching around, others preen. Immatures may play with objects such as sticks or leaves. Loafing areas are common areas, and tend to be quiet, with little or no squabbling or aggressive behaviour, often with several species mixing in the same area. Individuals come and go, commuting to their feeding areas, unless a disturbance provokes a sudden communal flight. On the coast, the number of individuals in a loafing area follows a tidal cycle - as low tides expose food resources the gulls move away the loafing area to feed- and also time of the year. Tidal influence in sleeping is highly prevalent in wading birds, which strongly depend on exposed shores for feeding. A study in Herring Gulls suggest that they have a dual sleeping pattern, with the proportion of sleeping gulls peaking at midnight and at midday. This may be a common pattern with urban gulls or away from the coast, where food is less related to tidal fluctuations.

A mixed flock of Black-headed gulls, Common Gulls and Herring gulls loafing on a rise on a local park.

Loafing gulls allow good opportunities to check individuals for plastic rings, as shown by this preening Common Gull.

A group of Common Gulls loafing on ice on a frozen pond of (16/1/2013)

More information
Shandelle M. Henson, James L. Hayward, Christina M. Burden, Clara J. Logan and Joseph G. Galusha. 2004. Predicting Dynamics of Aggregate Loafing Behavior in Glaucous-Winged Gulls (Larus glaucescens) at a Washington Colony. Auk 121, 380–390.

Cooke, F. and Ross, R. K. 1972. Diurnal and Seasonal Activities of a Post-Breeding Population of Gulls in Southeastern Ontario. Wilson Bull. 84, 164–172.

Galusha, J. G., JR and Amlaner, C. J., JR. 2008. The effects of diurnal and tidal periodicities in the numbers and activities of Herring Gulls, Larus argentatus, in a colony. Ibis 120, 322–328.

The first singing chaffinch

The first chaffinch sung in the park today. They often start tentatively, but this one sung three or four times before starting foraging on the tree. Spring must be in the air!

Ringed Common Gull

The Common Gulls at the local park have been back for a few weeks, slowly building up in numbers to about a hundred today. I searched for ringed ones and found JV47, which I first saw on its first winter in January 2015. It is a fully adult gull now and trusting enough to allow me to take a close up.

Another shot from today.

JV47 as a 1st winter immature in typical chick 'hunchback' posture (23/1/2015). He was ringed  the previous October at Bergen, Norway.

Click here to find out about other ringed common gulls at Pearson Park. If you find a ringed gull and you can read the ring, you can report it to Euring, the European Ringing scheme.

Encounters of the Sparrowhawk kind

I treasure encounters with Sparrowhawks as they are quite secretive and alert birds which don't like being seen. Today I managed some sightings of a pair in my local park. First I heard a call 'kikikikiki!' and I saw a female landing on a tree. The view was quite obstructed and unfortunately, she flew off as I tried to get a better view. 

Then, a while later, in the same area I spotted the male. Not sure how, possibly a blue tit alarm call alerted me. He had some prey, what looked like a small bird, and was plucking it.

 He flew off, carrying the prey in his talons, and I wandered after him towards some big trees where he had disappeared. Then I saw the pair together, high up the crown of one of the largest trees in the park, a poplar (top shot). Fortunately the beautiful light made up for the distance to take some photos. The male started preening. I couldn't see if the female had the prey now. Male Sparrowhawks hunt for the female while she incubates.

The male at the top, smaller and with reddish tones in his plumage. The female at the bottom, all alert. Soon tree foliage will completely obscure views of these birds from the ground.

 On my way back from work I looked longingly at the poplar. No Sparrowhawks to be seen there. But then, beyond the tree, high in the sky, the pair was circling together, playfully chasing and soaring.

Social play in gulls?

Yesterday, the pond at my local park was almost completely iced over. While the ducks and geese kept to a small ice-free patch, the gulls seem to like walking on ice. A few young Common Gulls were about. One of them, a second winter bird, was carrying and handling (or should I say 'billing'?) a piece of moss. She would drop it, pick it up, shake it. She was being followed at close range by another two younger first winter common gulls. The first one eventually dropped the moss and one of the younger gulls swiftly picked it up and carried it for a while, in a repetition of the sequence. Then this gull found a short stick and she pecked it and picked it up repeatedly. I was pleased to get this sequence in video.


I have anecdotally documented play in gulls since Ralph Hancock drew my attention to this behaviour in his blog. Play has been described in gulls before, but only solitary play. But, was the behaviour I watched social object play?  According to Judy Diamond and Alan Bond, in a review on social play in birds (where gulls are not mentioned) state:

'Social object play occurs when two or more individuals engage in repeated interaction with one or more inanimate objects in the environment without subsequent consummatory behavior. The best evidence of social object play is provided by contests over items that cannot be otherwise turned to useful purposes. Role reversals are common in social object play, and the interaction often ends with the contested item simply being discarded.'

I believe that the sequence I watched fits this description quite well. The gulls respond to one another in which the 'carrier' changes direction to avoid the 'chaser' and the chaser follows the carrier paying attention to what it does and is quick to retrieve the object when dropped. The interaction ends when the item is discarded. The interest in the moss by the second individual is affected by the carriers interest in it, like the object is given a new meaning as a 'toy'. Much evidence on social play in birds is anecdotal, which a few exceptions, notably in Keas and Ravens. However, given how social gulls are, and how opportunistic, with much adult behaviour involving stealing food items from each other, it appears surprising social play hasn't described in gulls. Possibly casual watchers of distant gulls assume food objects being the centre of attention instead of inedible 'toys'. The park's wintering flock is well used to people and allow close approximation, so it is easy to check what the gulls are handling. I should definitely pay more attention in the future to potential play sequences.

For more posts at The Rattling Crow on play in birds click here.

More information

Diamond, J., & Bond, A. B. (2003). A comparative analysis of social play in birds. Behaviour, 140(8), 1091-1115.

Play in gulls

I usually check for ringed Common Gulls in my local park. Yesterday the flock, about a hundred strong, converged around someone providing food. While I was checking, a boy run towards the gulls flushing them. A few settled on a puddle nearby, and a second winter one was ringed! I approached and took some photos to try and see the code. No luck, the light was wrong and the gull too active. I decided a video could work as I might be able to get a sharp screen-grab. The gull found a pink object (visible on the left side on the photo above) and started to pick it up and drop it repeatedly, the object bobbed up on the water every time and the gull seemed quite interested, until, after a while, it walked away. I had ended up recording a session of gull play behaviour! I walked away and then thought I wanted to check the object, just in case it was some food item, but no, it was a spongy piece of plastic, probably torn from a soft ball. You can watch the clip here:

 I had never thought gulls played until I started following Ralph Hancock's wonderful blog on the birds on his daily walk around Hyde Park and Kensington Gardens. He describes and documents gulls (Herring, Common and Black-headed) playing drop-catch with various objects: sticks, leaves, plane tree seed heads, rubbish, and stones, and his observations made me pay more attention. He also pointed to this photo sequence of a young gull playing drop-catch.
 How can we know that a particular behaviour is play? Usually play is invoked when a behaviour appears to serve no adaptive purpose. Jennifer Gamble and Daniel Cristol, from the College of William and Mary, Virginia, studied drop-catch behaviour in Herring gulls to discount alternative hypothesis to play. Their Herring Gull population often dropped clams they find on the mud flats at low tide over hard substrates - a tarmac road nearby - to break the shells and eat them. Could drop-catch serve be a practical behaviour? They tested two alternative explanations: the 'kleptoparasite hypothesis' where drop-catch behaviour could allow a gull to asses the chances that other gulls that might be nearby, be ready to steal the clam as it hit the ground, or the 'reposition hypothesis' where the gull might drop the clam and then catch it to reposition it before a proper drop. In contrast, if drop-catch is a play behaviour they expected:
1) It would be carried out more frequently by juveniles.
2) Objects other than clams would be used.
3) It would be performed over soft substrates.
Their results rejected the alternative hypothesis and fitted the predictions of the play hypothesis: younger gulls engaged in more drop-catching than older gulls, that drop-catching was more commonly done over soft surfaces (the mud flats, as opposed to the road and gulls were less likely to drop-catch a clam (9%) than a non-clam object (62%). The conditions at which drop-catch happened were also more favourable to play behaviour: Drop-catch happened more often at warmer temperatures (when the gulls are less cold-stressed) and when wind was stronger (and flight is less costly).
 Play has been much less studied in birds than in mammals, and most of the research in birds has been done with corvids. Gulls are quite opportunistic, long-lived species and play could potentially have long-term beneficial consequences: perfecting the development of the coordinated flight behaviour required to succeed in kleptoparasitic attacks (gull often chase other gulls carrying food and if the attacked gull drops the food, individuals able to catch the dropped object in the air might have a higher chance of success of catching it first) or possibly practice the clam dropping behaviour.
 I have kept the bit of pink plastic, but I haven't yet managed to read the code on the ring, it starts by JP...

More information
Gamble, J. R. & Cristol, D. A. Drop-catch behaviour is play in Herring gulls, Larus argentatus. Animal Behaviour 63, 339–345 (2002). Here.

The female Sparrowhawk and the 'missile' thrushes

There is a breeding pair of Mistle Thrushes in the park. Last week, one was busy finding earthworms on the lawn and carrying them neatly folded in its bill. This means they must be feeding young.  Today I heard the rattling call of annoyed Mistle thrushes. They use this call when they guard their berry trees in the winter, against Blackbirds and even much smaller birds like Chaffinches. The pair of them called and called from a tree. I tried to spot them and saw that a female Sparrowhawk was sitting on a branch. The Mistle Thrushes rattled and swooped over the hawk, the hawk ducked every time they dive-bombed her, although they didn't actually touch her.
 The female Sparrowhawk is an impressive raptor compared to the almost cute, much smaller, male. She is as large as a Woodpigeon, with broad chest and piercing yellow eyes. She can actually bring down Woodpigeons. Although the thrushes appeared fearless, they always stayed over the hawk, not underneath. The hawk moved onto an ash tree nearby, and although higher up, there were fewer leaves in the way, and after some trying I found a clear line of view and managed to take some photos and a video of the 'missile' thrushes dive bombing her. This behaviour, known as 'mobbing' involves potential prey individuals harassing or sometimes actually attacking predators when they are encountered. Mobbing is at its most intense during the breeding season. It is a behaviour that is not completely understood. One explanation, the 'move-along' hypothesis, is that mobbing diverts the predator attention from places where there are nests or young. When the Sparrowhawk's young hatches, they will be fed almost exclusively on fledglings, so harassing the predators might encourage them to move on, and hunt somewhere else.

Mistle thrush with worms in bill (14/4/2015)

The 'missile thrush' was my photo management software autocorrection, but I think it is actually quite fitting! This is an initially very shaky clip (no tree nearby to hold on). Watch out at 11 seconds.

New moorhen chicks

This morning, a moorhen was on the island with three very young chicks. They were tiny and a bit clumsy, and had some trouble following the adult about. There was only one adult with them, so I wonder if its partner is still incubating, or brooding other chicks on their tree nest. These tiny chicks either jumped from their nest, or climbed down the tree unharmed. They peeped and flapped their tiny wings comically, stretching out to their parent, who will occasionally give them tiny morsels of food, one at a time.
 After a while the parent brooded them on the ground, a bit restless trying to get itself comfortable. The following time I saw them, the adult was trying to arrange some nesting material on a branch by the water, maybe not happy with brooding the chicks on the ground? There were a number of large gulls about, and with just one parent around, I wonder what the future of these chicks holds.

Parent finding food.

Chick begging

Brooding time

Coots settling in the park

I wrote about the visiting coot a few posts ago, but there has been new developments in the local park, a few days ago two coots were present and today I counted three coots. They were quite dispersed in and around the pond, but from a particular location all were visible. If they are just coming in or they have been here all along since I saw the first one, I do not know. They are relatively vocal, appearing to keep in touch with each other. This afternoon, two of them seemed quite content, preening close to each other, while surrounded by playing children and lots of people in the park, they most likely dispersed from another park, where they have grown accustomed to people. Male and female Coots have similar appearance, although males are larger and heavier, so possibly the individual in the foreground on the shot above, much larger, is a male. Male and female, however, have very distinct calls. I hope that at least a pair stays in the park as they will provide opportunities to get to watch them closely and learn more about their behaviour.

One of the coots being chased away by the resident Moorhen (with its nest in the island tree).

Coot about to dive

This is the third coot, note its very large frontal shield, protruding from the top of the head and stained pink. The two individuals at the top of the post have much smaller shields.

The Viking gulls

A flock of about 100 common gulls winters in the park, they arrive at the end of September/October and are around most of the time until the end of March. They are very excitable and their squeals provide the background noise of the park in winter, especially when visitors empty their bags of bread by the side of the pond. A cacophony of calls and chases ensues while the gulls pick the bounty fast, before the ducks and geese have the chance to react.
 Is not only bread though for the park gulls, there are very quiet times, especially during the middle of the week, and the gulls will move onto the grass, looking for worms and other invertebrates, watching the ground intently as they walk.

 In wet days they can be seen 'dancing' (foot-paddling) to entice the worm to the surface of the soil. Like so.

Then they spend some time just flying in circles over the park, in a flock, I am not sure if in preparation to roost, although I am not sure where they spend the night.

A quiet moment in the flock, with preening, snoozing and yawning by the pond.

This is an adult one on winter plumage. Note the yellow bill with faint dark ring near the tip and the yellow legs, and spotty head.

on the 3rd of February this adult looked very nice on the snow, still in winter plumage.

On the 20th of February this adult had an almost white head and a thin red eye ring.

A close up of an adult's head showing mainly yellow bill, red ring. Note the scruffy back of the head, showing the ongoing moult towards a completely white head plumage.

I find them endlessly fascinating and can't stop myself from photographing them, and they are often co-operative, as they are so used to people. When I noted that the flock disappeared each year, one day in March or April I wondered where they would go in the summer, to breed. I need wonder no longer, these gulls come from Bergen, in Norway.
While watching them one day in January I found a couple of Common Gulls with plastic colour rings. I spent some time looking at the legs of many gulls since that day, but I didn't spot any other ringed ones. I managed to get photos where I could read the code and submitted the samples to Euring. I got an e-mail the same day from Morten Helberg with details of their ringing and recoveries. Since then, I have seen the ringed gulls a few times, and managed to get their portraits.

This is J2EX, sex unknown ringed its first autumn (1st calendar year in 2013) which means now should be in its 3rd calendar year (almost adult), although the bill and legs are still grey/bluish and doesn't have a red eye ring or prominent wing 'mirrors'. This is its ringing/recovery history:

15.09 2013 Byparken, Bergen, Hordaland, Norway
17.09 2013 Tveitevannet, Bergen, Hordaland, Norway
20.09 2013 Tveitevannet, Bergen, Hordaland, Norway
21.09 2013 Byparken, Bergen, Hordaland, Norway
14.06 2014 Kilnsea, Humberside, Great Britain
14.01 2015 Pearson park Hull, Humberside, Great Britain (the photo above is from yesterday, also observed 22/01/2015)

This is JV47, Sex male age, 1 cy when ringed last October, so it's in his first winter. He still called like a gull chick when feeding, and adopted this hunched chick posture. Legs and bill base pinkish.

This is it's ringing/recovering history:
05.10 2014 Tveitevannet, Bergen, Hordaland, Norway
(in the month after it was ringed the flock came back to Pearson Park)
14.01 2015 Pearson park Hull, Humberside, Great Britain 

Looking at photos yesterday, I found another ringed common gull, from the 20th of February. It looks like a first winter bird. The code reads JR20. I will update the post when I hear back from Euring.

It is very nice to know where these gulls spend the summer, but something equally rewarding is to know them as individuals. The rings have allowed me to recognised them in my visits to the park. I will look forward to them coming back in years to come, as gulls can be long lived. A typical Common Gull lives for 10 years (the record is 27).

Into the eye of the winter herring gull

 The resident pair of Herring gulls are back at the park. One of the individuals (above) has its full winter attire with a streaked grey head, which gives it a particularly stern look. The other one, which seems smaller (maybe the female?) still has a very white head. A young of the year is also about.

Broken Wing

This has been an unusual year for Canada Goose in the park. Usually, a flock visits during the winter, roosting elsewhere and returning every morning to enjoy the bread and food given by people. Some time during last winter, one of the geese got injured, its right wing hanging a bit loose on the side (I first noticed it the 16th of January, the photo above is from the 16th of March). The injury, at the base of the wing, prevented it from flying, and it must have happened in the park, maybe due to a collision with a tree branch or a fight with a dog. The bird seemed content, fed well and recovered enough for the injury to be almost unnoticeable. But when the flock decided it was time to depart for the breeding grounds, at mid February, the lame goose stayed behind. All through the summer it has been alone in the park, joining the mallards during feeding time, and probably roosting on the little island at night. I felt for him as geese are such sociable birds.

Part of the Canada Flock returning from the roost in the morning

 The flock of Canada Geese returned last week. I searched for the lame one in the pond, but failed to spot him, it must have mingled with the rest of the geese. I wished I had been there to watch his reaction to, first, the distant honks of the approaching flock, and then to the geese themselves once they landed. Then a couple of days ago, early in the morning, I spotted him with two others, just before most of the flock returned. Again, today, the goose was with a female before the main flock returned. They followed each other closely, like a pair of geese would do. Could it be that this was/is his partner? Geese form strong partnerships and bond through the year, and for many years if not for life. They also recognise many individuals in their flock, including their past offspring. The female goose is actually staying to roost with the lame goose at night, instead of following the flock. Maybe when the migratory urge kicks in spring she will leave with the flock, but maybe not.

The lame goose in the background, with a partner on the 30th of September

My peak count per visit graph for Canada Goose in Pearson Park. If you try you can see a tiny green bar between week 8 and week 39, corresponding to the lame goose. Created with BirdTrack.

A flock of Lesser Black-backed gulls

It is unusual to have more than a pair of Lesser Black-backed gulls in my local park. Today, I counted six circling over the pond in the morning to feed on scraps. They shared the pond with a few young of last year and and adult Herring gulls and a single common gull. After eating some bread, two individuals went to the water to drink.
 These are really beautiful gulls, with the most stern looks due to their deeply seated yellow eyes circled by a red eye ring. The individual at the top was particularly stunning, its red spot was really bright and extended extending to the top side of the bill, like some badly applied lipstick.
 Here, Lesser Black-backed gulls are summer birds, from March to August, and presumably breed atop buildings locally.

Four of the Lesser black-backed gulls

Lesser Black back gull on the water

A pair by the water. Note the darkish ring on the top of the bill, indicating these have recently adquired their adult plumage (about 5 yr old). Note also the different tone of the yellow legs.

Lesser Black Backed gull

Three different gull individuals, a Herring Gull, a Lesser Black Back, and a Common Gull arrived at the park and flew in circles around the pond, their keen eyes looking for food. Several people come early in the morning and leave bread and scraps on the side. After finally landing, before coming to the food, this Lesser Black Backed gull had a good look around, a bit nervous. Once the other two gulls landed, they all went in with the feral pigeons to eat.