As part of a program to recover the peregrine falcon Falco peregrinus in the southeastern U.S. we recorded perching behaviour with the objective of characterizing perches used in the reintroduction area. We used a site-attribute design and logistic regression to compare characteristics between used and non-used perches. Peregrines used pines Pinus spp. exclusively, while pines comprised 78% of available trees. Perches were larger than non-used trees (diameter at breast height in cm (in x¯ ± SD); 29.2 ± 15.7 and 23.9 ± 10.3), in more advanced stages of decay (2.5 ± 1.5 and 1.5 ± 1.1 (index)), and usually dominant in crown class (1.5 ± 0.6 and 1.7 ± 0.5 (index)). Perches were always on cliff plateaus and tended to be situated in sites with a less even canopy (0.5 ± 0.3 and 0.7 ± 0.2 (index)) and fewer deciduous stems (1.8 ± 3.4 and 2.3 ± 2.3 (stem density)) than non-used trees. These attributes depict selection of perches that provide unobstructed flight paths, good visibility, and a capacity to detect and respond rapidly to stimuli.

Rates of survival and reproductive success in black grouse Tetrao tetrix were assessed during a four-year study at Lake Vyrnwy in North Wales between 1999 and 2003. We used radio-tracking to assess survival rates of 33 individuals. The juvenile (September-February) survival rate was 0.18, compared with 0.66 over the same time interval for adults. Predation by raptors accounted for almost ⅔ of deaths. Broods were surveyed using pointer dogs in late August. Reproductive success was low, averaging 1.0 chicks/hen. Recruitment into the breeding population was insufficient to balance the observed mortality rates, resulting in a 67% decrease in breeding adults during the four-year study. This happened despite the likely immigration into the study area of dispersing juvenile females from adjacent areas with higher breeding success. An equivalent reduction in the abundance of red grouse Lagopus lagopus scoticus was observed, and this was also associated with years of low breeding success. Management methods that both reduce the impact of raptors on juvenile black grouse survival and improve breeding success are probably required to conserve black grouse in Wales.

We tested the impact of two types of radio transmitters on flight performance in racing pigeons Columba livia. Prior to each of two flights of known distance, 60 birds were randomly selected from three flocks and put into one of three groups: control, 5-g (i.e. 1.1% of body weight) tail-mounted radios or 8-g (i.e. 1.8% of body weight) sacral-mounted radios. The design of the sacral attachments changed between races as the initial harness caused lesions. Birds with sacral-mounted radios flew more slowly and lost more weight and condition than the other groups. Birds fitted with tail-mounted radios performed similarly to the control group. Loss of condition was correlated with a decrease in flight velocity. We conclude that small tail-mounted radios carry little cost, but sacral mounts may bias results and may be inappropriate for some ecological studies.

The historical ranges of the European brown hare Lepus europaeus and the Iberian hare L. granatensis meet in Aragón in northeastern Spain. We studied the relative abundances and the population trends of the two species in 60 localities (13 for the brown hare, 38 for the Iberian hare, and nine from the transition zone where both species are present) by spotlighting in winter during 1992-2002. We carried out a total of 1,407 counts covering 41,511 km. Both the Iberian (132.2 ± 33.2 hares/100 km; range: 52-192) and the brown hare (106.7 ± 26.8; range: 53-136) were more abundant in their respective zones than both species combined in the transition zone (90.9 ± 50.5, range: 37-157). The highest Iberian hare abundances were recorded in the northern Iberian Mountains, an area with well-preserved cereal-dominated ecosystems and a less extreme climate than in other parts of the study area. The Iberian hare had significant inter-annual differences both locally and generally, which was mainly due to a peak in 1998, and this species showed a general positive trend during the study period, suggesting that Iberian hare numbers are increasing. Contrary to the marked declines reported from other European regions, the brown hare abundance indices obtained in the Spanish Pyrenees during our study period remained stable.

We present morphological and ecological data on hares of the genus Lepus living on the Italian peninsula and Sicily. During 16 years, we analysed specimens shot by hunters with respect to their habitat choice and distribution. Our morphometric data confirmed the existence of two different but closely related species, i.e. Lepus europaeus present in central and northern Italy and Lepus corsicanus endemic to central and southern Italy and Sicily. The distribution of the two hare species overlaps in a wide area of central Italy, tentatively estimated to be > 200 km. In terms of altitude, L. europaeus and L. corsicanus do not differ significantly when they live in allopatry. However, when they coexist in sympatry, L. corsicanus occurs at altitudes significantly higher than L. europaeus. L. europaeus inhabits significantly higher altitudes when it lives in allopatry than when it lives in sympatry, and L. corsicanus inhabits significantly higher altitudes when it lives in sympatry than when it lives in allopatry.

Feeding habits and interspecific trophic niche overlap of two sympatric predators, the pine marten Martes martes and the red fox Vulpes vulpes, were studied in a deciduous forest habitat in Hungary with conditions of differing abundance and dominance in the rodent community. The main food source of the predators consisted of small mammals, mainly rodents. Consumption of small mammals was higher during bank vole Clethrionomys glareolus dominated years than in Apodemus mice dominated years. Both predators preferred bank voles as prey and consumed less Apodemus mice and shrews (Soricidae) than expected by availability. The two opportunistic predators utilised different, seasonally-dependent food resources. Martens consumed more plants, reptiles, amphibians and fish, whereas foxes consumed more small mammals and ungulate carcasses. In summer and autumn, percent biomass of bank voles in marten diet and Apodemus mice in fox diet was positively correlated with the number of rodents in the available food resources. In winter and spring, the density of rodents varied slightly; therefore, variations in the diets of these two predators were not related to prey density. The prey consumed was characteristically terrestrial and small sized (< 50 g). There was no difference in prey weight distribution between martens and foxes, but martens consumed more arboreal and foxes more terrestrial prey. The standardised food niche breadth did not differ significantly between the two species. Food niche overlap between the two predators was higher in winter and spring, but the difference between seasons was not significant (mean overlap  =  72%). In comparison with higher latitudes, we found a larger food niche overlap in our study.

We studied home ranges and habitat selection of 10 adult sloth bears Melursus ursinus inornatus at Wasgomuwa National Park, Sri Lanka during 2002-2003. Very little is known about the ecology and behaviour of M. u. inornatus, which is a subspecies found in Sri Lanka. Our study was undertaken to assess space and habitat requirements typical of a viable population of M. u. inornatus to facilitate future conservation efforts. We captured and radio-collared 10 adult sloth bears and used the telemetry data to assess home-range size and habitat use. Mean 95% fixed kernel home ranges were 2.2 km² (SE  =  0.61) and 3.8 km² (SE  =  1.01) for adult females and males, respectively. Although areas outside the national park were accessible to bears, home ranges were almost exclusively situated within the national park boundaries. Within the home ranges, high forests were used more and abandoned agricultural fields (chenas) were used less than expected based on availability. Our estimates of home-range size are among the smallest reported for any species of bear. Thus, despite its relatively small size, Wasgomuwa National Park may support a sizeable population of sloth bears. The restriction of human activity within protected areas may be necessary for long-term viability of sloth bear populations in Sri Lanka as is maintenance of forest or scrub cover in areas with existing sloth bear populations and along potential travel corridors.

Proper management of wildlife relies on metrics of population development. Typically, the best estimation techniques are too expensive for coarse-scale management. In marine fisheries, catch-per-unit effort is commonly used, but problems may arise due to changes in spatial harvest effort or in habitat use as density changes. Managers in Norway are in the early phases of implementing ′seen deer′ during harvesting and ′spring counts′ on farmland as a means of monitoring red deer Cervus elaphus populations. We provide a first evaluation of how suitable these methods are by comparing the results with population estimates obtained using cohort analysis, and by analysing the within-season variation in number of seen deer. ′Seen deer′ predicted annual increases in populations fairly well. Adjusting for harvesting effort provided less good estimates, due to a proportionally larger increase in effort relative to deer population size as population size increased. The number of seen deer per day decreased rapidly at the beginning of the season, and then levelled off or increased slightly during the rut, especially on farmland. The number of seen deer increased both with the number of harvesters and hours harvested, but at a diminishing rate. The current practice of ′spring counts′ was not successful in predicting population changes, probably due to a lack of replication. Indeed, date strongly affected the number of deer seen during spring counts. While ′seen deer′ seems to be a very promising tool for monitoring population size of red deer, there are some limitations to the practice as implemented for moose Alces alces in Scandinavia due to a more complex relationship with harvesting effort. Our study highlights that the large number of hours harvesters observe wildlife can provide a useful tool for population monitoring. However, the use of such indices may vary between species and according to harvest techniques and should thus be assessed with care before implementation.

In mountainous terrain, performance of VHF telemetry is often impaired by long distances between observer and animal, and by reflections of radio signals. GPS telemetry should be less affected by such constraints, but its performance has not been sufficiently tested in areas of rugged topography. We studied how current GPS telemetry deployed on red deer Cervus elaphus performs in the strong topographic relief of a rugged Alpine landscape. We examined the influence of topography, vegetation and red deer activity on GPS performance, assessed the accuracy of 2D positions of red deer and compared differences in GPS performance between collars in trials and collars fitted to deer. GPS performance was characterised by consistently high position acquisition rates (PAR), but a relatively low proportion of 3D positions compared to smoother terrain. The proportion of 3D positions was lower in forest than in open land but within forest different vegetation structures had only a weak influence. For collars fitted to red deer, we found that > 70% of the positions were either 3D positions or accurate 2D positions. The collars produced higher PAR and proportions of 3D positions in the trials than when they were fitted to red deer, probably reflecting an effect of red deer behaviour. We also observed better performance of collars on red deer during night than during daytime, because animals were more active at night where they more often occurred in open land. An effect of season on the proportion of 3D positions was found in collars fitted to red deer, but not in the trials, and may be interpreted as a secondary effect produced by seasonal differences in habitat selection by red deer. The fact that PAR was not affected more strongly by the rugged mountainous relief probably reflects the recent progress achieved in GPS technology, whereas the comparatively low proportion of 3D positions illustrates that the probability of four satellites being available at any one time is still constrained by topography.

In this pilot study, we estimate roe deer Capreolus capreolus density in a fragmented landscape, using radio-tracking and direct observation in a Petersen-Lincoln framework with the joint hypergeometric maximum likelihood estimator. We used radio-tracking to obtain a direct count of the number of marked animals potentially observable in a given sample area, thus avoiding edge effects. We then carried out a coordinated observation survey, including drive beating, to ascertain the proportion of marked roe deer in the population sampled and thus generate a population estimate. Surveys were repeated three times in four sample blocks within the fragmented landscape, and estimates were compared to a sample block of a central forest in the same area. In general, roe deer are difficult to observe and census, but our experimental set-up in the fragmented landscape enabled us to observe on average 75% of marked animals present in a given survey (compared to 21.5% in the central forest). The variability in capture probability between individuals was low as three quarters of all marked individuals were observed in all, or all but one, of the surveys. Density estimates were largely similar across the sample blocks of the fragmented landscape (4.0-7.9 deer/100 ha), but lower than in the central forest (34.3 deer/100 ha). The variability of daily population estimates was quite low and similar in the fragmented landscape (CV of 25.9%) and the central forest (CV of 25.3%). Taking availability of woodland into account, the density in the fragmented landscape was as high, or higher, than in the central forest, reaching an exceptional 145.3 deer/100 ha of woodland in one survey area.

Cervid densities have recently increased in many parts of North America and Europe. To design sustainable harvesting strategies, a good understanding of deer population dynamics and reliable estimates of population densities are required. This is especially true on Anticosti Island, Québec, Canada, where sport hunting is the main source of income, and where long-lasting impacts of white-tailed deer Odocoileus virginianus on the forest ecosystem have been reported due to high deer densities. We compared white-tailed deer densities estimated in 2001 on the basis of an extensive aerial survey of 512 plots, each 3.5 km long by 60 m wide, with indices based on hunting statistics in 24 hunting zones on the island. We found a positive correlation between the number of deer seen per hunter day and the density of deer estimated by the aerial survey, but this correlation was highly influenced by the four locations with the highest densities of deer. We detected no significant correlation between deer density estimated by the aerial survey within each hunting zone and the number of deer harvested per hunter day. Our results underline the need for comparative studies addressing the validity of density indices based on hunting statistics to monitor variations in cervid population numbers.

Many dabbling ducks Anas spp. are largely granivorous, consuming a variety of seeds chiefly from aquatic plants. To assess the relative value and carrying capacity of wetlands for dabbling ducks, species-specific information about seed mass is needed, but it is still largely missing or scattered in the literature. By combining weights of seeds collected in the field with a literature review, we provide a reference table for seed mass of 200 western European plant taxa frequently encountered by foraging dabbling ducks. Seeds collected in the field were sampled in microhabitats and at depths at which ducks were observed to forage, and study sites represent wintering, staging as well as breeding areas within a flyway in western Europe. When combined with calorimetric data, the present reference table will aid managers and scientists in assessing the importance of seed food resources at different sites and during different parts of the annual cycle.