Effects of structural and functional habitat gaps on breeding woodland birds: working harder for less

The effects of habitat gaps on breeding success and parental daily energy expenditure (DEE) were investigated in great tits (Parus major) and blue tits (Cyanistes caeruleus) in urban parkland (Cardiff, UK) compared with birds in deciduous woodland (eastern England, UK). Tree canopy height, the percentage of gap in the canopy and the percentage of oak (in the wood only) within a 30 m radius of nest boxes were obtained from airborne remote-sensed data. Breeding success was monitored and parental DEE (great tits: both habitats; blue tits: park only) was measured using doubly labelled water in birds feeding young. In the park, mean (± SD) tree height (7.5 ± 4.7 m) was less than in the wood (10.6 ± 4.5 m), but the incidence of gaps (32.7 ± 22.6%) was greater (9.2 ± 14.7%). Great tits and blue tits both reared fewer young in the park and chick body mass was also reduced in park-reared great tits. Park great tits had a higher DEE (86.3 ± 12.3 kJ day-1) than those in the wood (78.0 ± 11.7 kJ day-1) and, because of smaller brood sizes, worked about 64% harder for each chick reared. Tits in the park with more than about 35% gap around their boxes had higher DEEs than the average for the habitat. In the wood, great tits with less oak around their boxes worked harder than average. Thus structural gaps, and functional gaps generated by variation in the quality of foraging habitat, increased the costs of rearing young

A miscellany of traditional management techniques of woody field margins on the Po Plain, Italy: implications for biodiversity conservation

Here we summarise the findings of a study investigating the environmental, management, and land use factors that influence patterns of biodiversity in field margins in the Po Plain, Italy, and evaluate these habitats for their cultural and biodiversity value. We highlight four traditional management techniques of woody vegetation in field margins on the Po Plain, Italy, and make recommendations for further study to investigate the ecosystem services and cultural significance of these feature

A functional classification of herbaceous hedgerow vegetation for setting restoration objectives

Hedgerows are valuable habitats for biodiversity in farmed landscapes. The herbaceous vegetation at the hedge base is an important component of this habitat but its condition in Britain has deteriorated due to a combination of nutrient and pesticide contamination, and inappropriate management or neglect. The condition of herbaceous hedgerow vegetation is included in policy targets for biodiversity conservation, so a strategy is required for its restoration. This vegetation can be highly variable, so a classification of the main types is required to set realistic objectives. Vegetation classifications based on species’ functional characteristics can have more general application that those based on species identity. Using existing datasets from a countrywide survey, a functional classification of herbaceous vegetation from hedgerows in Britain was developed. Cluster analysis of vegetation plots, based on attributes of the species present, produced thirteen vegetation types in six broad groups. These were differentiated by the association of the component species with woodland, grassland or arable habitats and by gradients of soil nutrient status and pH, light availability, disturbance and grazing tolerance. By using species’ ecological characteristics as a basis for the classification, the condition of vegetation can be established and the prevailing environment predicted. From this information, a realistic strategy for restoration can then be determined

The effect of eroded ecological networks on the movement of harvest mice (Micromys minutus)

Habitat fragmentation and degradation of ecological networks have been identified as an influencing factor of M. minutus population viability, although, this has yet to be fully quantified. Within a specially designed release enclosure located in semi-improved grassland, various sized gaps were created in cross sections of ‘hard’ (artificial road surface 4.8m) and ‘soft’ (mown, with low vegetative cover 1m, 2m and 4.8m). Movements of a reintroduced population of M. minutus (Soft ♂N=5, ♀N=9; Hard ♂N=8, ♀ N=13) over these gaps were recorded. Whilst both genders crossed narrower fragments that have ground vegetation, as gap width increased willingness to cross decreased significantly (P < 0.001). The implications here suggest that gaps over just 2m will impede movement and dispersal of both sexes, with potential genetic implications on M. minutus populations

Detection dogs for conservation monitoring

Humans have historically benefited from the close affiliation of the dog (Canis familiaris), the symbiotic relationship between the species has persisted and evolved and these days has more of an emotional benefit to the human rather than a functional one. However, working dogs have different and ever expanding roles as detection dogs, where they are relied upon to alert the presence of target scents. Their role as detectors dates back as far as 12,000 years, where hunting dogs would have been detecting the scent of prey and locating it with ease. The more formal role of detection dog is comparatively more recent, with reports of dogs used for conservation purposes over 100 years ago. There are many examples of the uses of detection dogs in conservation, the effectiveness of dogs at detecting small and elusive species has been key in formulating the idea of a harvest mouse (Micromys minutus) detection dog and training of the dog is in its final stages. The harvest mouse study aims to establish if it is possible to accurately determine presence through scent alone and whether the using olfactory indicators is more effective than visual clues at determining presence of harvest mice

Altitudinal and habitat selection of capercaillie Tetrao urogallus: an assessment of change after ten years in the Scanuppia reserve (Central Alps, Northern Italy)

Capercaillie (Tetrao urogallus L.), a territorial galliform, favours intermediate canopy cover forest, formed by old and open stands and with a high presence of ericaceous species (in particular Vaccinium myrtillus L.). Although Capercaillie is not thought to be at risk, it has undergone a decline over much of its range. This study was undertaken in the Scanuppia reserve (546 ha) in the Trento Province in spruce (Picea abies (L.) Karsten) dominated forest with some areas of silver-fir (Abies alba Miller), larch (Larix decidua Miller), beech (Fagus sylvatica L.), and mixed stands, as well as open areas of pasture. The aim of this study was to determine change in summer Capercaillie habitat between 2001 and 2011. A systematic sampling design was used in which 10-m radius circular plots were sampled along contour lines between ca. 1500 and 1800 m asl in which stand structural and vegetation characteristics were quantified and the presence/absence of Capercaillie was determined by droppings. Whilst the overall population count appeared to remain unchanged, the 2011 results showed that there had been an upward altitudinal shift in distribution whereas the 2001 results emphasised the effects of habitat variables at a lower altitude. The selection of habitat towards the upper limit of forests may be linked to increased summer temperatures, to anthropogenic disturbance or to a combination of both. This study underlines the need for further research to disentangle potential factors explaining the observed changes in Capercaillie habitat selection in relation to management