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Gulls. Professor John C. Coulson
Читать онлайн.Название Gulls
Год выпуска 0
isbn 9780008201449
Автор произведения Professor John C. Coulson
Жанр Биология
Серия Collins New Naturalist Library
Издательство HarperCollins
Once colonies have started to decline, the impact and pressure from the same numbers of Foxes or American Mink produce a vicious spiral that has an increasing impact on the remaining birds. Another predator at Ravenglass was the Hedgehog (Erinaceus europaeus), which had developed the habit of consuming the flesh of live gull chicks that had not reached fledging age. Several of the colonies referred to in the past as sites where eggs were collected have now ceased to exist, and some authors have attributed these to uncontrolled egg collecting extending throughout the entire breeding season. It is ironic, therefore, that it was only after egg collecting had stopped at Ravenglass that the colony declined and then disappeared, presumably owing to the lack of efficient predator control.
When a colony disappears in a matter of a few years, it is unlikely that the adults have died, but rather that they have moved to other sites and colonies. The decline at Sunbiggin Tarn following predation resulted in some adults moving to Killington Reservoir alongside the M6 motorway in Lancashire, a move confirmed by a few ringing recoveries of adults previously marked at Sunbiggin Tarn. However, this colony contains nowhere near the numbers of birds recorded breeding at Sunbiggin Tarn, which implies that many adults from Sunbiggin probably moved considerable distances and to several different sites, as no other single large colony was established within 80 km of it at the time of its decline. This is also true of many small, ephemeral colonies on upland moorland in northern England and Scotland. A consequence of this is that mobile groups of Black-headed Gulls are often overlooked, and new colonies can grow rapidly through immigration in only a few years – as has happened at Saltholme (Fig. 24).
Exploitation of eggs and young
In the past, both the eggs and young of Black-headed Gulls were extensively exploited in Britain by humans. Michael Shrubb gives a detailed account of this in his 2013 book, Feasting, Fowling and Feathers, from which I have extracted some of the information given below.
Through the combination of Black-headed Gull numbers, their extensive inland breeding often close to human populations, and the relatively easy access to many nests compared to those of gull species that nest on coastal islands and sea cliffs, the eggs of this species have been exploited more extensively than those of other gulls in Britain and Ireland for the past 500 years and probably longer. In some places in the sixteenth century, nearly fledged young were collected by driving them into nets, and they were then housed and fed until required for human consumption. Some were purchased by the wealthy for 4–5d each, (equivalent to about £7 at today’s prices) or given as gifts, just as we now give flowers. Oxford college records at the time also list Black-headed Gull eggs being bought for a fraction of a penny each.
In the seventeenth century, one landowner is said to have made a profit of £60 in one year (equivalent to about £7,000 today) by collecting and selling gulls’ eggs. Exploitation of young birds probably decreased over time, but they continued to be sent to London markets nonetheless, and egg collecting became more frequent and extensive. Exploitation continued into the eighteenth century, and there are more records at this time of eggs being collected throughout England and Scotland. There are also records of gull colonies disappearing, the causes of which were attributed at the time to excessive egg collecting.
In the nineteenth century, egg collecting for human consumption throughout Britain and Ireland was extensive. In some areas it was organised by the landowners, but elsewhere it appears to have been uncontrolled. Well-established markets existed in London, and eggs collected in bulk in Norfolk and Hampshire were sent there for sale. That the Black-headed Gull was widely distributed as a breeding bird in southern England is evident from records of the large numbers of their eggs being collected and sold in the London markets. For example, in 1800 some 8,000–9,000 eggs were collected at Scoulton Mere in Norfolk, while in 1864 and later, 2,000 eggs a year were collected. From 1858, 700 eggs were taken each year at Hoveton in Norfolk, and in 1864 alone, 2,000 eggs were collected. According to The Spectator (17 April 1897), in 1834 at Stanford in Norfolk, a ‘tumbrel-load’ of eggs was collected in a day and sold for 3d a dozen.
It is probable that landowners enforced a degree of protection to the gull colonies in the nineteenth and early twentieth centuries owing to the value of the egg trade. In some cases, collecting was limited to taking eggs only from nests that held one or, occasionally, two eggs, to ensure that those collected had not been incubated, and at some but not all sites, collecting ceased on 15 June. As a result, clutches of three eggs were often left untouched, while cessation of collecting in June permitted some gulls to re-lay and breed successfully from late, repeat clutches.
An account of annual egg collecting in Ayrshire, Scotland, in the first 40 years of the twentieth century is given by Ruth Tittensor in a 2012 edition of Ayrshire Notes. The eggs were collected for local bakeries and domestic use, and even for egg fights between youths. Interestingly, the article includes a personal account of egg collecting by a person who later became a senior member of the Nature Conservancy! Elsewhere, the sale of eggs also continued into the twentieth century. In the 1930s, for example, more than 200,000 gull eggs were sold annually at Leadenhall Market in London. Egg collecting increased extensively during the two world wars, with large numbers collected to supplement rationing. An archived Pathé News ciné film shows several Land Girls based at Muncaster Estate during the Second World War collecting baskets of eggs at the large Ravenglass colony and boxing them up in crates ready for dispatch to London. Hugh Cott describes eggs being on sale in Cambridge in 1951 at 9d each. A London market for Black-headed Gull eggs existed for the whole of the twentieth century, with some being sold as ‘plovers’ eggs’.
Today, despite current bird protection Acts, systematic collecting of Black-headed Gulls’ eggs is still permitted in England by licence holders, although there is little general knowledge of the numbers of licences and eggs collected. The licences are issued annually by Natural England for collecting eggs for food consumption. As a result of a request for information, Natural England responded in 2016 by stating that ‘Licences are only issued where evidence of hereditary/ancestral/traditional family rights to collect eggs can be given’. The public body also stated that it seeks ‘to ensure that collection of eggs is sustainable in relation to numbers collected and colony size’. However, I still await a response as to how this is achieved and where the records are deposited, since they do not appear in the Seabird Colony Register or local county bird reports. An accurate census of a colony where many eggs are collected is often difficult to carry out because of the greater spread of laying and repeat clutches.
A freedom of information request granted by Natural England in 2016 revealed that it had issued licences recently for egg collection at six sites in England: the North Solent nature reserve in Hampshire; Lymington, Pylewell and Keyhaven marshes, also in Hampshire; Barden Moor in North Yorkshire; and the Upper Teesdale National Nature Reserve in County Durham. Currently, up to 40,000 eggs are collected annually and sent to London. These details are not publicised and I found no information in the published literature. A further freedom of information request to Natural England revealed that in 2015 it issued 24 licences to collect Black-headed Gull eggs in England (22 in Hampshire, one in Yorkshire and one in County Durham). Table 10 shows that the numbers of eggs collected in Hampshire remained at about the same level over the period 2009–15. Those taken in North Yorkshire increased 17-fold between 2011 and 2012, and since then the numbers collected have continued to increase, with more than 32,000 eggs taken in 2015.
No mention of these annual egg collections appear in recent county ornithological reports, while Natural England made the surprising statement that information prior to 2008 ‘has not been retained’. This public body should not destroy historical information on colony sizes and the numbers of eggs collected, and such data should be archived. Natural England also refused to identify the colonies from which eggs were collected, or to whom licences were issued, thereby preventing further research on these activities. How this quango carries out the annual monitoring of the colonies