Leigh---Some random thoughts about gulls:
I remember Whipsnade many years ago [when I first visited as a small child, about 1960], always had a few pinioned examples of the larger gulls walking about in the paddock. I think London Zoo also had them in the long pond at the botttom of the Mappin Terraces; now of course, Herring Gulls breed wild in the zoo, and they would not think of including them in the captive collection. Some time around the 1970s/1980s, London Zoo bred a lot of Silver Gulls, and rather fewer Grey Gulls. At least some of the former went into private aviculture. London Zoo bred Glaucouis Gulls in the later years of the 19th century. The only breeding gulls that I know of currently in UK aviculture, are the Grey Gulls at Paignton.
John Lewis Bonhote, writing in the Avicultural Magaziune in 1910, describes his experiences with six gull species, commenting that unpinioned birds in an aviary do better than the same species when pinioned, reflecting that no unpinioned gull of the larger species had EVER died in his possession. He warns that Greater Blackbacks will kill smaller waterfowl. Steinbacher's 'Cage & Garden Birds' gives basic instructions on the two species you mention. An author who goes into much more useful detail is Arthur Moody in 'Game Birds & Waterfowl in Captivity'.
My personal experience of captive gulls is small. I picked up a Black-headed about 1970, with a badly smashed wing, which had already more or less rotted off at the pinion joint. This bird lived happily in a friend's back garden for several years, coming into breeding plumage and defending a nest scrape in a flower bed from the family dog. It lived largely on brown bread and the occasional piece of cheese; every time it was given fish, this was vomited up. It was eventually killed by a cat.
A few years ago, I picked up an adult Lesser Blackback with a broken wing, clipped back the primaries to take the weight off the injured pinion joint, and turned it out with the waterfowl. Initally pampered with bread and tinned sardines, it soon took to eating grain and poultry pellets. The following year, having moulted out, it was gone one morning. This came as a surprise, as I thought the damaged joint had locked. I never saw the bird again, but heard many months later that it spent a ferw days on a nearby goldfish pond, thinning out the rightful inhabitants.
Re seriously keeping gulls, I would suggest two sources of supply. First, talk to any wildlife hospital about rehoming non-releasable wild casualties, which I'm sure are routinely euthanised. Secondly, it should not be difficult to get a licence to take eggs for hatching. I suggest you check the legal ramifications, as it may be that you cannot sell the young bred bred from wild injured stock; there was talk about this, some years ago.
Just a thought on pinioning, or even wing-clipping. Those long flight feathers must play a big part in keeping a bird warm. Put it another way, a bird that lacks them, is going to use more of its resources to keep warm. This may explain Bonhote's experience of full-winged birds being better doers.
I would be fascinated to hear more about your Herring Gulls. I think gulls are sadly neglected as avicultural subjects, and the larger species particularly appeal to me.
- There's a variety of bird species I didn't know could be kept that I'd like to get when I'm older