Robert Burns’ poem ‘My Heart's in the Highlands’ confirms that deer have been an important element of the Scottish Highlands for many years. But, what is distinctive about them? They can be separated from other vertebrates by an array of characteristic features including the absence of a gall-bladder, the doubling of the lachrymal orifice and the development of deciduous bony outgrowths of the frontal base of the skull—the antlers. In his paper, Lincoln discusses the shedding and regeneration of antlers with associated spring minimal, and autumn maximal, concentrations of testerone. He also describes how, in most young stags, antler formation will proceed unaided with successive annual developments being triggered by a healing response to the wound formed when the old antlers are cast. In other congenitally antler-less stags (hummels), it seems that antler formation can be induced in perpetuity by wounding antler pedicels, each of a pair needing to be damaged separately.

The evolutionary origins and relationships of deer are briefly reviewed, with special reference to the species currently living wild or feral in Britain. Two species (red and roe) are native to this country; a third (fallow) was previously native but has been re-introduced from continental Europe; and three taxa (sika, muntjac and Chinese water-deer) have been introduced from eastern Asia. The Pleistocene history of red, roe and fallow deer in Europe is traced in detail, with emphasis on changing patterns of distribution and the climatic and vegetational conditions associated with fossil occurrences. Comparison of Pleistocene habitats with those occupied at the present day helps in an understanding of the ecological flexibility and rangelimiting factors of each species. The taxonomic status and habitats of the Asian species in Britain, as compared to their countries of origin, are briefly reviewed, and the dates of introduction into Britain of the Asian species and of fallow deer are discussed.

Red deer are now being farmed for meal production on an intensive scale. They are manageable, adaptable and healthy animals, and. with care and good nutrition, they become far more productive than wild deer.

Their digestive efficiency resembles that of sheep. Productive activities caking and lactation, fattening and antler growth occur in summer when food is plentiful and depend on endocrine and metabolic cycles entrained by day length. Dietary energy needs of deer are similar to those of cattle but higher than those of sheep: however, because young deer store little fat, they produce lean meat as efficiently as sheep.

Deer produce rich milk: the growth of sucking calves reflects the supply of nutrients available to their dams. In winter, calves benefit from shelter: nonetheless, their growth and appetite decline, even when day length is experimentally lengthened. While good nutrition improves winter growth, this is costly: furthermore, improved winter growth is followed by somewhat poorer growth during the succeeding summer. Slaughter of calves at 6 months of age rather than 16 months may allow greater efficiency of meat production.

Deer carry 50%more muscle than sheep, much of it in their well-priced haunch. Cahes deposit little fat until half grown: adults lose their summer fat during the rut and winter. The lean character of venison well matches modern consumer requirements.

The mechanism involved in the control of antler growth was studied in three experiments using red deer living at Reedie Hill Deer Farm in Fife. Scotland. Observations were made on three congenitally polled stags (hummels) captured from the wild, one female red deer (hind) induced to grow antlers by treatment with testosterone, and four castrated stags (havicrs). The overall results support the view that in the stag it is the increase in secretion of testosterone by the testes at puberty which stimulates the initial development of the antler pedicles, and it is the subsequent seasonal cycle in the secretion of testosterone which dictates the seasonal casting and regeneration of the antlers. The high blood levels of testosterone in the autumn cause the calcification and death of the antler tissue, and also prevent the process of rejection of this tissue for the remainder of the breeding season. The dead antlers can thus act as an insensitive fighting weapon when rival stags compete for access to females during the rut. When the testes become fully regressed in spring, it is the withdrawal of testosterone which allows the old antlers to be cast off. and the wound on the surface of the antler pedicles triggers the regeneration of new antlers. In hummel stags which have failed to complete the initial growth of the antler pedicles, it is possible to trigger the development of antler tissue by wounding the rudimentary pedicle, and once this tisue has formed it is cast and regrown annually due to the seasonal evele in the activity of the testes.

Malignant catarrhal fever (MCF) is reviewed and recent findings described. It is defined as a fatal disease which affects many species of Bovidae and Cervidae, characterized by widespread necrosis and lymphoid cell proliferation and can be caused by at least two infectious agents. In Africa, a herpesvirus which infects its natural host, the wildebeest, without obvious symptoms causes substantial losses in cattle due to MCF. Elsewhere, the cause of MCF is unknown but circumstantial evidence implicates sheep as the source of infection. While cattle are infected only sporadically with this “sheep-associated” form ol disease, infection of farmed deer is common, representing the most serious disease threat to the industry.

It is considered that infection of sheep and wildebeest with their respective agents operates to their advantage, causing no disease in their natural host, while transmission to other ungulates has fatal consequences, eliminating these potentially competitive species.

Recent studies of the disease in deer and the transmission of MCF from deer to rabbits are described. The evidence suggests that the disease process involves a novel dysfunction of the immune system which results in a massive lymphoid proliferation and an atopic allergic response. It is considered that similar processes may also be involved as a component of other diseases of man and animals.

In the red deer population of the Isle of Rhum, the effects of increasing population density on reproduction and survival vary with the individual's sex, age. reproductive status, home-range quality, group size and social rank. Males are generally more strongly influenced than females. Within both sexes, individuals that are at an initial competitive disadvantage are generally most strongly influenced by rising density.

These differences are likeh to have far-reaching consequences. In particular, they may help to explain why dense deer populations commonly have female biased adult sex ratios: why calculations of maximum sustainable yield commonh overestimate the number of animals that can be culled; and why some populations that are not subiect to animal or human predation stabilize while others oscillate.

Documented studies of the ecology of red deer in Scotland refer principally to populations which occupy treeless moorlands. Commercial forests have become a major part of the Scottish landscape and little is known of the dynamics of the red deer populations which inhabit them.

Red deer which benefit from the enhanced shelter and nutrition of a woodland habitat often perform better than those occupying open-range. Birth rates of 60–70 calves 100 hinds are common, especially in forests in the south and west of Scotland. This potential may be reduced to a post-winter recruitment of 50 60 calves 100 hinds (cf. birth rates on open-range of 40 60 calves 100 hinds reducing to 30–35). A range of densities in forests of 5–15 deer km" is almost identical to the densities found on open-range.

Simulation models suggest that many woodland populations can support a sustained yield of about 20% of adults each year and focus attention on the practical difficulties of achieving culls in commercial forests. Simulations of changes in forest structure are used to demonstrate the related changes occurring in the ability of the habitat to support changing densities of deer through time.

In a study in Galloway, southern Scotland, evidence suggests that the red deer population has increased considerably during the expansion of commercial forestry between 1960–80.

The study began in 1978 at Glenbranter Forest, Argyll. Use of habitat by red and roe deer was measured from the accumulation of pellet groups and from observations. Approximately 2000 trees less than 9 years old and 6000 older ones were monitored for damage and response.

Habitats in areas dominated by heather in or close to the forest were the most occupied by both species and pole-stage crops the least. However, most dung was found on the extensive areas of recently planted ground. Roe deer were relatively more abundant than red deer in stands of 9 to 15 year-old trees.

In summer, red deer ate mainly grasses and roe mainly forbs. In winter, these preferences remained, but Calluna became more important to both.

Browsing on leaders was heaviest in winter and May–June. Approximately 50% of leaders on trees less than 6 years old were browsed annually. Most trees regained leaders within 12 months, many becoming multi-stemmed. Of the trees. 1% were bark-stripped per annum. In older stands the smaller trees were most damaged, in younger stands the larger trees.