Gulls. Professor John C. Coulson

the gulls that frequently followed commercial ships entering the busy river were the reincarnations of past pilots, and were keeping a supportive eye on the steering of current pilots. An individual gull the pilots recognised because it called frequently was said to be the reincarnation of pilot ‘Clagger’ Purvis, who apparently had had as much to say for himself in life. Even at that age I found this story hard to believe, but the pilot was right about the frequency of gulls following both large and small vessels into the river.

      My interest in birds, and particularly in gulls, developed during my school days. As a member of a small group mentored by Fred Grey, a master at South Shields High School for Boys and a person with a lifelong passion for birds, I learned much about the identification of birds during mid-morning breaks and on field trips. Through his guidance, my questioning eventually expanded from ‘What is it?’ to ‘What is it doing?’ I was also very much influenced by the Reverend Edward Armstrong’s book Bird Display and Behaviour (1942), David Lack’s The Life of the Robin (1943) and, in particular, Sir Arthur Landsborough Thomson’s Bird Migration (1936), which highlighted some of the information that could be gained by ringing birds.

      While still in the sixth form at school, I wrote to Elsie Leach, who ran the national bird-ringing scheme in an honorary capacity for the British Trust for Ornithology (BTO) from a small office and a cupboard in the Natural History Museum in London, asking her how to become a ringer. I received a prompt response requesting a letter of support from an acknowledged ornithologist that I could identify birds. I obtained this from a local doctor; he had an excellent knowledge of the birds of northern Norway and I had previously been able to draw his attention to uncommon birds visiting the vicinity, which he would stop off to see while making slight detours en route to his house calls.

      Having sent the recommendation to Miss Leach, I received a reply within a few days simply asking what numbers and sizes of rings I wanted. At that time, 1948, there was no training whatsoever for potential ringers, nor an age limit. Every ring used had to be recorded on a thin cardboard sheet, which took only six ring entries and was guillotined into separate strips if the ringed bird was recovered. Ringing was on a very much smaller scale in those days! I remained an active ringer for 62 years, and have seen many changes to the British ringing scheme, including the intensive training now required for those who wish to ring. I also received one of the first mist nests in the country, and had to work out for myself how to use it – all I was told was to hang it between two poles!

      One day in early June 1950, Edward White (a school and university friend) and I walked along the coast to where Black-legged Kittiwakes (Rissa tridactyla, here referred to simply as Kittiwakes) were nesting on a stack called Marsden Rock and on the nearby mainland cliffs. As we walked on the beach below the colonies, we noticed that about a third of the nests on the stack contained chicks, while only one out of a hundred nests on the mainland cliffs had chicks. Two weeks later, we excluded predation as the cause of this difference, as almost all nests now contained chicks, even though those in nests on the mainland cliff tended to be smaller than those on the stack.

      This brief observation started a chain of interest and speculation. Why was there this difference, which was obviously not due to predation? Our attention was drawn to Frank Fraser Darling’s book Bird Flocks and the Breeding Cycle (1938). The local public library managed to borrow a copy from another library and we were able to read about the ecologist’s idea of social stimulation, which he believed affected the timing and success of breeding in colonial birds. Some authors suggested that the differences Fraser Darling had observed in small colonies of large gulls were due to young birds breeding later than old individuals, and that more young birds were breeding in some colonies than in others. However, we failed to find any information on the effect of age on the breeding biology of gulls and very little on birds of any species.

      Edward and I were both undergraduates at Durham University, and we planned to make twice-weekly visits the following year to the Kittiwake colonies at Marsden to count the numbers of nests containing chicks (counting when eggs were laid was not possible, as most nests could not be viewed from above). The difference we had observed the previous year was repeated, and we presented our first results at one of the delightfully informal annual student bird conferences held at St Hugh’s College in Oxford each January, organised by David Lack. This resulted in the opportunity to meet and engage with many knowledgeable researchers, including Niko Tinbergen, Charles Elton, Arthur Cain, Mike and Esther Cullen, ‘Mick’ Southern, Reg Moreau, David Snow, Lance Richdale and, of course, David Lack and his students.

      The problem of whether the differences we found between colonies were an effect of age or social conditions required knowledge of the breeding biology of Kittiwakes of different ages and, in turn, this needed marked individuals whose ages were known. The nests on the limestone cliffs at Marsden were inaccessible, but by chance, while crossing the river Tyne on a ferry two years previously, I had noticed a few pairs of Kittiwakes nesting on the window ledges of a riverside warehouse at North Shields. At Durham University, the head of zoology, Professor J. B. Cragg, was kind enough to take an interest in our study and in 1953 he obtained access for us to the building from the owners, Smith’s Dock Co. The company actively protected the Kittiwakes and the birds were the delight of the two employees working there. We were able to reach the nests from inside the warehouse, allowing us to capture and individually mark the breeding adults and chicks. Fate was very kind to us, because the windows on the ledges used by the Kittiwakes opened inwards, and we were able to snare adults without pushing off or even disturbing the nests and their contents. Our main tool was a 60 cm length of wire, which had been used to bind a crate of oranges. We shaped one end into a crook that could be passed out of a narrow gap when the window was ajar and slipped around the leg of the adult. The Kittiwakes were not alarmed by the wire, and indeed were often curious and pecked at it. Pairs on neighbouring windowsills did not react when an individual suddenly disappeared into the ‘cliff’ to be colour-ringed. Within a few years we were able to measure the timing of laying in individuals of different ages.

      The study eventually spanned more than 35 years, although there was never any guarantee that we would be able to continue it beyond a year or two at a time. At that time, long-term studies on birds were virtually unknown, the exception being that undertaken by Huijbert Kluijver on Great Tits (Parus major) in the Netherlands (which began in 1912), and it was many years before the research councils in the UK appreciated their considerable value and supported some of them.

      The opportunity arose for both Edward and me to study for a PhD, but independently we came to the same opinion that a doctorate in ornithology was unlikely to lead to employment. There were only three people at that time professionally employed as ornithologists in Britain, and one of these held a post of reader in entomology! Only two universities employed ornithologists (Oxford and Aberdeen), and there was one ornithologist who worked for the Ministry of Agriculture and Fisheries. An eminent Scottish professor of zoology at that time openly stated that the study of birds and butterflies was not part of zoology, and ecology was only just starting to develop in Oxford, under the influence of Charles Elton, David Lack and Alister Hardy.

      This situation was in marked contrast to the present day, when many of the now much more numerous universities have one or usually more staff researching in ornithology and ecology, while currently Natural England, the BTO, the Game and Wildlife Conservation Trust, Scottish Natural Heritage and the Royal Society for the Protection of Birds (RSPB) all employ professional ornithologists. Because of the situation in 1953, Edward and I both decided to work on entomological topics for our higher degrees, and studying Kittiwakes remained a happy hobby.

      Our cooperative studies of Kittiwakes had to cease after we both completed our PhD studies. Edward went to work at a college in Freetown, Sierra Leone, and then moved to New Zealand. I went into school teaching but continued the Kittiwake studies in my spare time. Eventually, I obtained a post-doctoral fellowship from the Royal Commission for the Exhibition of 1851, and this allowed me to develop a full-time research programme of my own choice – the study of both Kittiwakes and moorland insects.

      Two years later, I was offered a lectureship in zoology at Durham University, and in the following years I supervised a series of students working on seabirds and also on moorland invertebrates. Those studying seabirds included Jeff Brazendale, Brian Springett, Dick Potts, Andy Hodges, Ron Wooler, Jean Horobin,