This morning at a local park, I noticed a young Herring Gull picking an object, flying off and being chased by another. Then the gull landed on the water and dropped the object and pretended to dive to pick it up repeatedly, as in a lazy drop-catch game. When I saw the object at a better angle I realised it was an empty freshwater mussel shell, which happened to float. Funnily enough, a couple of hours later when I walked past either another or the same young Herring Gull was still playing with it.
The young gull flies off with the freshwater mussel shell.
Later on, with cloudy weather, two gulls handling the shell.
Carrion Crows have a complex social structure. Territory-owning Carrion Crows remain paired year round, often flying and feeding together or not far from one another. They remain near their nest during the breeding season, although they may range wider outside this period. Birds that don't hold a territory form part of a loose flock that roosts communally, usually in large trees. Both male and female of a pair participate in territory defence, keeping other crows (or potential predators) away from the nest. Males have a more prominent role: if a male loses his mate he is able to defend the territory until he remates, but a female losing his mate will also lose her territory, as she would rapidly be evicted by other pair.
In one of my local parks there is a very high density of Crows. There are several territories, but the park is also the main ranging area of the non-breeding flock (where there is also a winter roost). There are a lot of interactions going on, but without ringed birds, it is hard to make sense of what is actually happening. Yesterday, I observed several interesting interactions. First, a Black-headed gull appeared most annoyed with a Carrion Crow and mobbed it repeatedly, dive-bombing on it when the crow tried to stop on an aerial. The crow did not vocalise and deftly avoided the gull attacks. Later, I heard the rattling call of a crow and watched a chase between two crows, one of them calling with the call I usually associate to mobbing a raptor. Crows, it appears, can use this vocalisation to fend off conspecifics.
Finally, I watched a Crow it an amazing display: its head feathers raised, bill pointing down, looking really at its best. After taking a few photos, I realised it's partner was walking nearby using the same posture. Today I learned about this display in 'The Crows' by Franklin Coombs. It is called the 'Bristle head' display. It is a territory-owner display, used in territory boundaries to signal their occupancy, and also aimed at intruders within the territory. Both members of the pair display while they walk about. There is no vocalisation. Territory intrusions mostly occur during the spring, but there is also a peak in October-November.
I can only presume that this pair of crows are a pair ot territory owning breeders. They do look in great shape!
This is a still from a video, which shows both members of the pair with their 'bristle heads'.
A side view of the displaying crow.
This photo is a bit overexposed, but it shows the details and metallic iridescence of the crow really well.
I've been wanting to take a photo of a Blackbird in this posture for a long time. Blackbirds do often cock their tails. When they alight they do that tail-cocking so as to keep their balance - in a similar way to Woodpigeons - they often do a jerky tail-cocking action when they do one of their various alarm calls 'chok, chok, chok' at the same time than they flap their wings. On Sunday, a windy day, this Blackbird perched on the side of a drinking trough, the wind made it lose its balance a bit and it stayed, tail cocked, for that second longer for me to press the shutter. Got you!