There is growing evidence that harnesses may not be an effective technique to attach radio-transmitters on geese. The use of neck collars is an alternative, but studies on the effect of collars with or without radios on geese have reached divergent conclusions. As our objective was to determine if radio neck collars affect behaviour, pair bonds and breeding success of greater snow geese Anser caerulescens atlanticus, we fitted 230 females with radio neck collars during the 1995–1998 moulting periods on Bylot Island, Nunavut. Data were subsequently obtained for 159 birds on the staging and breeding grounds. Radios represented 2.5 ± 0.1 % (± SE) of the birds' body mass. Unmarked geese and those fitted with conventional plastic collars served as controls. The behaviour of radiocollared geese was affected during the first fall after marking, but negative effects disappeared thereafter. Geese with conventional collars had similar behaviour as unmarked birds. Divorce rates were low for birds with conventional collars (0–4%), but were as great as 30% for radio-collared geese. We suggest that the modified behaviour of the radio-collared females promoted separation from the male. Apparent breeding propensity, nest initiation date, clutch size and nesting success of radio-marked birds were also negatively affected. Until better alternatives are developed, we recommend minimizing the mass of radio collars to < 2.5% of the birds' body mass and reducing the antenna length. This implies a trade-off between effects on birds and performance of the transmitters in terms of battery mass (longevity) and antenna length (range).

In some parts of Britain, pheasants Phasianus colchicus are infested by Ixodes ricinus ticks in the spring and summer. The effects of experimental reduction of tick infestation levels on the breeding success and survival of reared female pheasants were studied on two estates in southern England during 1995–1997. Females were radio-tagged and half of the birds, selected at random, were fitted with a slow-release acaricide, which substantially reduced their tick burdens. Clutch survival was significantly higher for treated females throughout the three-year study period, and hence more chicks were hatched by treated females (3.30 ± 0.86) than by control females (0.70 ± 0.36), even though treated and control birds produced the same numbers of clutches and eggs. During April-July, the female survival rate was significantly higher for acaricide-treated birds, showing an improvement of 10–15% over that of control birds each year. While these impacts will be of minor importance where annual pheasant releasing takes place to supplement autumn stocks for shooting, they might reduce the potential harvest on estates with wild pheasants or on those aiming to re-establish self-sustaining naturalised populations.

We investigated previously observed but unexplained differences in incubation success between wild and hand-reared common pheasants Phasianus colchicus. Hand-reared birds are widely released in late summer in Britain and elsewhere to supplement wild stocks for shooting purposes. We radio-tracked 53 wild and 35 previously released reared female pheasants occupying simultaneously the same areas on a game-keepered estate in eastern England between February and mid July 1999 and 2000. Predation of adult birds was comparatively low for both wild and reared birds, and overall survival did not differ between years or between groups. However, of 52 nests incubated by wild females 49% hatched, whereas of 30 nests incubated by reared pheasants only 22% hatched. Mayfield estimates of daily nest survival probability thus differed significantly between groups. However, predation of eggs was similar for both wild and reared birds. Instead the observed difference in hatch rates was due to nest abandonment, with more reared females (41%) deserting apparently unmolested nest sites than wild females (6%).

We evaluated distance sampling and dung plots as cost-effective methods of estimating the density of mountain hares Lepus timidus on moorland in the Scottish Highlands. We compared density estimates derived from these techniques to those derived from labour-intensive capture-recapture techniques. Distance sampling and capture-recapture techniques produced comparable density estimates at medium and low hare densities. Density estimates derived from distance sampling were higher than those derived from capture-recapture in high-density hare populations. Both distance sampling and capture-recapture techniques gave wide confidence intervals at high hare density. Histograms of perpendicular sighting distances showed that a large proportion of hares were seen on or close to the transect line and that there was a rapid fall off in detection rates with distance. This finding indicated that hare behaviour may lead to problematic survey design and may reduce the precision of density estimates. The collection of accurate distance sampling data was particularly problematic when hare density was high. In contrast, in low-density hare populations, considerable sampling effort was required to obtain sufficient sightings of hares to reliably estimate density. Dung plots provided a relative index of abundance that successfully ranked populations of mountain hares in order of increasing density as determined by distance sampling and capture-recapture techniques. With careful study design, distance sampling provides a good compromise between accuracy, precision and effort in estimating the density of mountain hares. The use of dung plots is a rapid alternative when only estimates of relative abundance are required.

We determined the validity of water content, rump fat thickness, a subjective fat index, a kidney fat index, and an index based on total body weight (TBW) and the hind foot length (HFL) in order to predict lipid content of arctic foxes Alopex lagopus. The total fat content was either determined by extracting lipid from minced carcasses (N = 75) or by dissecting all visible adipose tissue (N = 35). Water content and rump fat thickness proved to be the best predictors of fat content in arctic foxes. The ratio TBW/HFL was also a reliable index and should be a convenient and practicable way of estimating the condition of live foxes. A subjective fat index could be applied when divided into three categories, whereas the kidney fat index was not a reliable predictor of lipid content of arctic foxes.

Both ground and helicopter surveys are commonly used to collect sex and age composition data for ungulates. Little attention has been paid, however, to whether data collected by each technique are similar. We compared helicopter and ground composition data for both elk Cervus elaphus and mule deer Odocoileus hemionus across a variety of habitats in the state of Washington, USA. We found that ground and helicopter counts differed (P's < 0.002) consistently in male age structure estimates for elk, and that the two survey methods differed in estimates of adult sex ratios for mule deer (P = 0.023). Counts from helicopters provided larger sample sizes, tended to be more consistent annually in their results, and were corroborated by other demographic studies of the test populations. We conclude that helicopter and ground surveys differ for male age structure and perhaps male:female ratios, but are similar for young:female ratios. Managers should maintain a standardized technique using the same survey vehicle for trend analysis of composition data.

The radioactive fallout from the Chernobyl accident in 1986 contaminated parts of the boreal forest ecosystems in Sweden, and we report on the activity concentration of radiocaesium ¹³⁷Cs in the meat of moose Alces alces caught in the county of Västerbotten in north-Sweden during 1986–1996. Countywide, the geographic distribution patterns of ¹³⁷Cs activity in moose muscle were similar in 1986 and 1993. The underlying relationship between ¹³⁷Cs concentration in moose muscle and ground deposition remained significant for all years, but the proportion of variation explained by this relationship was variable and low in most years. The transfer rate of ¹³⁷Cs to moose underwent marked annual fluctuations that appear to be synchronous over large areas. The fluctuations in the uptake of ¹³⁷Cs by moose most probably result from variations in food selection or shifts in habitats. The transfer rate of ¹³⁷Cs to moose seems to be higher in coastal areas than in inland areas. The ¹³⁷Cs activity in moose was considerably higher in 1993 than should be expected from a simple decay model based on original deposition data and the ¹³⁷Cs levels in moose meat from 1986. The large temporal variations in transfer rate make future predictions of transfer to moose and man unreliable. We found that the annual hunting of moose is a major source of ¹³⁷Cs transfer to man in this region.

Native populations of mountain goats Oreamnos americanus are sensitive to harvest. To assess the potential effects of limited hunting on population dynamics, we analysed long-term data obtained from aerial counts of 12 native mountain goat herds in Alberta, Canada, during 1973–2001. Seven herds were hunted until 1987 and five were not hunted. Despite a decrease in the number of permits issued, mountain goat numbers declined in most hunted herds between 1980 and 1983. Hunting was closed in 1987. Only three of seven herds increased after hunting was closed. Unhunted herds also showed substantial among-herd differences in population trends. Our results suggest that factors other than sport hunting contributed to the population decline. Future harvests should target adult males, but the adult sex ratio of one intensively studied population was heavily biased in favour of females. A herd of 100 goats may only sustain the harvest of 1–2 adult males per year.

Age estimation is particularly crucial for the conservation of the saiga antelope Saiga tatarica, but modern laboratory methods for aging have not previously been applied to this species. There is an urgent need for evaluation of the techniques that could be used for age estimation in order that long-term ecological data sets can be correctly interpreted and conservation advice given. We evaluated the repeatability, practical feasibility and comparability of three techniques for age estimation of saiga antelopes; the tooth sectioning technique (TS), the tooth eruption and wear technique (TEW), and a visual aging technique routinely used in field studies. We found that TS and TEW gave repeatable results, and agreed well. The visual method underestimated the age of males compared to laboratory methods. It assigned animals consistently to the age class of at least one year old, but less consistently to the age class less than one year old. Although studies of known-age animals are needed to evaluate precision and accuracy of these methods, we suggest that either TS or TEW would be suitable for aging saiga antelopes, with the choice being determined by practicalities such as the availability of the necessary expertise and equipment.

Supplementary feeding of wild red-legged partridges Alectoris rufa with wheat is a widespread management practice in hunting areas in Spain. Many studies note that energetic diets affect the physiology of hand-reared galliforms. In order to assess if cereal supply might also affect wild birds, we studied the weight of the heart, spleen and liver, and the length of the small intestine and caecum of 129 wild red-legged partridges from three hunting estates where wheat is supplied, and compared it with 67 partridges from two non-supplied estates. Non-supplied partridges had heavier hearts (9%, both in juveniles and adults), and longer caeca (20% in juveniles and 14% in adults) than supplemented birds. An excessive intake of energy-rich items, such as the wheat supplied, instead of fibre-rich or proteic natural food, might explain the differences found. The management implications of these findings are discussed.

As part of a project to restore the fisher Martes pennanti in Pennsylvania, USA, we evaluated flumazenil (0.02 mg/kg) for partial reversal of tiletamine-zolazepam (10.0–11.0 mg/kg; i.e. antagonizing the effects of zolazepam) by monitoring immobilization intervals and physiologic responses of fishers (N = 4). Flumazenil reduced mean down time and alert time, but did not reduce mean recovery time. Trends in respiratory rate, body temperature, pulse rate and arterial oxygen saturation expressed by immobilized fishers were not altered by flumazenil within eight minutes post-injection. Flumazenil did not enhance practical utility of tiletamine-zolazepam at 10.0–11.0 mg/kg because fishers that received flumazenil exhibited residual tiletamine effects such as prolonged recovery and profound ataxia.