A 160 m firn and ice core was recovered from Eclipse Icefield (60.510 N, 139.470 W, 3017 m elevation) in the summer of 1996. Visible stratigraphy (location and thickness of ice layers) and density measurements were made in the field, and then the core was shipped frozen to the University of New Hampshire.

In ungulates, rank order is determined by differences in weight, body size, weapon size and age. In the Caprini tribe (Bovidae: Caprinae), adult male Himalayan tahr are unique to show different coat colours, but no sexual dimorphism in weapons. A highly significant correlation between hair colour and rank order was found during the rut: males with a lighter coloured ruff dominated over darker ruffed ones, in both aggressive interactions and access to oestrus females. We studied colour-based dominance in relation to weight, age and testosterone levels, which establish the social rank in most ungulates. No differences in weight and testosterone concentrations were found between adult male colour classes, but males with paler ruffs were significantly younger than darker adult males. The distribution of physical traumas from fights confirmed that younger, lighter-coloured males had a higher rank than older, darker males, a pattern which is unusual amongst ungulates. Coat colour seems to work as a signal of rank in male-male aggressive interactions and it changes according to age, whereas the relevant physiological determinants deserve further research. Intrasexual male competition has not changed weapon size or shape in the Himalayan tahr, but ruff colours are apparently used to signal rank and dominance. Colour patterns of adult males may then be homologous to ritualised weapons, apparently being a unique feature of male tahr amongst mammals.

A 160 m ice core was recovered in June 1996 from Eclipse Icefield (60.51 degrees N, 139.47 degrees W, 3017 m elevation). Visible stratigraphy (location and thickness of ice layers) and density measurements were made in the field, and then the core was shipped frozen to the University of New Hampshire. The core was continuously sampled in 10 cm segments, corresponding to a minimum of 12 samples per year. Above the firn-ice transition which occurs at 45 m depth, core was scraped on an acrylic lathe system under a laminar flow bench using a titanium scraper so that all surface and sub-surface contamination from the drilling process was removed. Below the firn-ice transition, samples were cut into 3 x 3 cm pieces 10 cm long and the middle of the samples melted out using a custom made melter also used to sample the GISP2 ice core. Samples were analyzed for major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-) using a Dionex model 2010 ion chromatograph in a dedicated laboratory at the University of New Hampshire. The cation system used a CS12A column with CSRS-ultra suppressor in auto suppression recycle mode with 20 mM MSA eluent. The anion system used an AS11 column with an ASRS-ultra suppressor in auto suppression recycle mode with 6 mM NaOH eluent. Analytical precision was monitored by analyzing 10% of the samples in duplicate and found to be 11% for K+, 10% for NH4+, 7% for Na+, and less than 5% for all other species. Aliquots of the same samples were also analyzed for oxygen isotopes (delta 18O) at the Stable Isotope Laboratory in Copenhagen, Denmark (precision ± 0.05‰). Chronology of the Eclipse ice core is based on multi-parameter annual layer counting of seasonal oscillations in the stable isotope and major ion records (especially Na+ and NH4+). Age control on the chronology established via annual layer counting is provided by the 1963 and 1961 beta activity reference horizons and volcanic reference horizons identified by statistical analysis of the sulfate record and verified by tephrochronology. The resulting time scale indicates that the Eclipse 1996 ice core covers the period 1894 to 1996, with dating error in the core estimated to be +1 year based on the number of independently dated horizons. The chemical data presented here are at sub-annual resolution, and annually averaged. Data for the years 1894, 1995, and 1996 are incomplete and not included in the annual averages.

The Tibetan Plateau is a vast, elevated plateau in Central Asia with an average elevation of over 4,500 m and contains the world’s third largest store of ice. It occupies a climatic transition zone between the Asian monsoons and westerly airflow. As a result of this location, the region is sensitive to changes in climate on timescales of decades to millennia and longer. Long-term data are needed to evaluate climatic changes and their impact on ecosystems, but in areas as remote as the Tibetan Plateau, long-term instrumental records of environmental change are geographically sparse and monitoring has only been undertaken in recent times. Paleolimnological approach might be then one of the few means by which environmental variability can be ascertained at scales that allow comparison with contemporary monitoring data and future model projections. Therefore, a paleolimnological study was undertaken in eight different lakes sampled along a North–South transect across the Tibetan Plateau analysing geochemistry and algal pigment in order to assess longer term variability in the trophic condition of these systems and their potential to reconstruct changes in relation to recent climate evolution and possible human impacts. Chronologies for the last century were based on radiometric techniques (210Pb, 241Am and 137Cs). Results show that inorganic sediment dominates the composition of the cores used in this study. Organic carbon constitutes less than 5% d.w. in all the lake cores, except for Kemen Co core where concentrations up to 14% d.w., are observed. Corg:N ratios are generally in the order of 5–10, indicating that autochthonous algal production is the principal biological source of organic matter. Pigment preservation is generally good throughout the cores from all lakes as shown by the 430:410 nm ratio that is generally around 1.0 or higher. Six out of eight lakes show an increase in primary production in recent times. High pre-1800 AD pigment concentrations were detected only in Qinghai Lake. Since most of the lakes show a similar behaviour in the most recent section of the core, we interpret this as a response to climate and land-use changes that have increased autochthonous production throughout the Tibetan Plateau.

Twenty-five years ago, the snow leopard Uncia uncia, an endangered large cat, was eliminated from what is now Sagarmatha National Park (SNP). Heavy hunting pressure depleted that area of most medium–large mammals, before it became a park. After three decades of protection, the cessation of hunting and the recovery of wild ungulate populations, snow leopards have recently returned (four individuals). We have documented the effects of the return of the snow leopard on the population of its main wild prey, the Himalayan tahr Hemitragus jemlahicus, a ‘near-threatened’ caprin. Signs of snow leopard presence were recorded and scats were collected along a fixed trail (130 km) to assess the presence and food habits of the snow leopard in the Park, from 2004 to 2006. Himalayan tahr, the staple of the diet, had a relative occurrence of 48% in summer and 37% in autumn, compared with the next most frequent prey, musk deer Moschus chrysogaster (summer: 20%; autumn: 15%) and cattle (summer: 15%; autumn: 27%). In early summer, the birth rate of tahr (young-to-female ratio: 0.8–0.9) was high. The decrease of this ratio to 0.1–0.2 in autumn implied that summer predation concentrated on young tahr, eventually altering the population by removing the kid cohort. Small populations of wild Caprinae, for example the Himalayan tahr population in SNP, are sensitive to stochastic predation events and may be led to almost local extinction. If predation on livestock keeps growing, together with the decrease of Himalayan tahr, retaliatory killing of snow leopards by local people may be expected, and the snow leopard could again be at risk of local extinction. Restoration of biodiversity through the return of a large predator has to be monitored carefully, especially in areas affected by humans, where the lack of important environmental components, for example key prey species, may make the return of a predator a challenging event.

In ungulates, rank order is determined by differences in weight, body size, weapon size and age. In the Caprini tribe (Bovidae: Caprinae), adult male Himalayan tahr are unique to show different coat colours, but no sexual dimorphism in weapons. A highly significant correlation between hair colour and rank order was found during the rut: males with a lighter coloured ruff dominated over darker ruffed ones, in both aggressive interactions and access to oestrus females. We studied colour-based dominance in relation to weight, age and testosterone levels, which establish the social rank in most ungulates. No differences in weight and testosterone concentrations were found between adult male colour classes, but males with paler ruffs were significantly younger than darker adult males. The distribution of physical traumas from fights confirmed that younger, lighter-coloured males had a higher rank than older, darker males, a pattern which is unusual amongst ungulates. Coat colour seems to work as a signal of rank in male-male aggressive interactions and it changes according to age, whereas the relevant physiological determinants deserve further research. Intrasexual male competition has not changed weapon size or shape in the Himalayan tahr, but ruff colours are apparently used to signal rank and dominance. Colour patterns of adult males may then be homologous to ritualised weapons, apparently being a unique feature of male tahr amongst mammals.

Icecore 345 m was recovered in 2002, core was sampled continuously at high resolution for major ions and stable isotopes to establish a detailed chronology for the core. Sample resolution ranged from 6 to 15 cm for major ions and 2 to 15 cm for stable isotopes. Stringent core processing techniques were used to ensure samples were contamination-free at the ng/g level.