Giuseppe Bogliani

Occupancy of isolated woodlots by the red squirrel Sciurus vulgaris L. in Italy

Effects of habitat fragmentation on the pattern of occupancy by the red squirrel Sciurus vulgaris were investigated in 46 isolated oakwoods in the Po Plain and 34 in the Appennines, where habitat structure variables were also measured. Presence of the red squirrel was detected by the presence of dreys. Logistic regression analysis showed that only woodlot size in the Apennines and distance from the nearest ‘source-area’ in the Po Plain influenced the presence of the species. No habitat structure variable improved the models in the Apennines. Interdependent dynamics of patches and a ‘source-sink’ structure are suggested for the Apennine and the Po Plain study areas, respectively. In more isolated woodlots in the Po Plain short-term extinctions are likely to occur.

Woodpigeons nesting in association with hobby falcons: advantages and choice rules

Many bird species nest in close association with other bolder and more aggressive birds which provide protection against nest predators. The woodpigeons, Columba palumbus, that nest in poplar plantations in Northern Italy are found almost exclusively clumped around hobby, Falco subbuteo, nests. Woodpigeons settle in the area and build their nests after the hobby has started nesting. We carried out experiments with dummy nests and observations on woodpigeon nests. Dummy woodpigeon nests placed near a hobbys nest suffered less depredation by hooded crows, Corvus corone cornix, than those placed far from it. A logistic regression analysis showed that three variables, hobby nesting stage, distance from the hobbys nest and the hobbys aggressiveness, influenced the probability of nest predation. The degree of protection varied during the hobbys nesting period and was highest when chicks were in the nest. The hobbys aggressiveness against intruders varied both between and within individuals during different nesting phases. The predation rate of dummy nests associated with the falcon was negatively correlated with the aggressiveness score of the hobby during the 6 days of dummy nest exposure. Observations on real nests showed that woodpigeons selected hobbies that had a high fledging success, and a more vigorous defensive behaviour. Clues that would allow woodpigeons to choose the best protector may be early nesting by the hobby and its aggressiveness. Hobbies preyed on adult woodpigeons, but the risk incurred by the woodpigeons was low compared with the very high risk of nest predation in this area. Copyright 1999 The Association for the Study of Animal Behaviour.

Horn growth but not asymmetry heralds the onset of senescence in male Alpine ibex (Capra ibex)

Senescence can be defined as accelerating phenotypic deterioration with old age. For traits that grow throughout life, such as the horns of some ungulates, senescence may be expressed as a decrease in annual growth rates, or an increase in asymmetry, in the years preceding death. Age-specific yearly horn-growth segments of 378 male Alpine ibex Capra ibex L. that died from natural causes were analysed in the Gran Paradiso National Park (Italian Alps). Horn annuli displayed fluctuating asymmetry. The hypothesis that asymmetry and size of the annuli of the horns could predict annual survival probability was tested. It was found that between 5 and 11 years of age, male ibex that grew shorter annuli than the average for the population had a greater probability of mortality over the following years than those with greater rates of horn growth. Horn asymmetry and mortality rates were not significantly correlated. Annulus size, reflecting the onset of senescence, seemed to be a better indicator of individual quality than annulus asymmetry.

Foraging, feeding and time‐activity niches of eight species of breeding seabirds in the coastal wetlands of the Adriatic Sea

Abstract We studied the three main components of trophic niches in the richest assemblages of breeding gulls and terns in Italy (8 species) that typify the communities of the large deltas of Mediterranean Europe. Each species feeds mainly on fish, except for the gull‐billed tern that feeds essentially on terrestrial vertebrates. Other prey contributed slightly to the energy balance, although small invertebrates prevailed numerically in the diets of the Mediterranean and black‐headed gulls. The seabirds cumulatively consumed a variety of fish, in frequencies that closely reflected the latters abundance. Selection of fish species by each seabird were strongly determined by the birds foraging habitat, and not by any preference for particular prey. The size of the prey was related to the size of the seabird. The diurnal rhythms of feeding activity were uniform, and the time component did not contribute to niche segregation. Dietary patterns suggest that within the overall space of their niches, the seabirds...

Hobby nest-site selection and productivity in relation to intensive agriculture and forestry.

A hobby (Falco subbuteo) population of 12-18 breeding pairs was studied intensively for 6 years in the seasonal flood plain of the Po River in northern Italy. The 62-km 2 study area is managed as an intensive agroforestry system. We examined factors affecting hobby nest-site selection and productivity, and propose conservation guidelines integrating current agroforestry practices with the hobbys habitat requirements. Ninety-six percent of hobby nests were located within commercial poplar (Populus sp.) plantations. All nests used by hobbies had been originally built by hooded crows (Corvus corone cornix), Nests were on taller, more mature trees than randomly selected crow nests, were situated farther away from the nearest dirt road, and had a larger extent of mature poplar plantations within 800 m of the nest than randomly selected crow nests. Crow nests used by hobbies were further from each other than randomly selected crow nests. Clutch size was positively related to habitat diversity and the extent of fallow in the area surrounding the nest. The probability of successfully raising young was positively related to the area of cultivation around the nest, and negatively affected by proximity to the nearest dirt road. Our proposals to integrate hobby conservation within current agroforestry practices include the maintenance of mature plantations equally dispersed throughout the landscape, increasing the availability of mature woodland, fallow, and wetlands, and informing-educating foresters on methods to, and importance of, minimizing disturbance to wildlife, specifically nesting birds.

Breeding bird communities in fragmented wetlands

Abstract The breeding bird communities present in 33 isolated wetlands in the Po plain (northern Italy), ranging in size from 0.3 to 63 ha, were investigated in order to evaluate the effects of area, isolation and habitat diversity on community structure. In simple and multiple regressions, the effect of area was always preponderant (r2 = 64–83%). No other variables affected the number of species nesting exclusively within the wetlands while habitat structural diversity and isolation significantly increased the explained variance of the total number of species and of other community variables. The S.L.O.S.S. (Single Large or Several Small) debate is criticized where species level studies are not carried out.

One Health approach to use of veterinary pharmaceuticals

Weak environmental assessments undermine regulations An estimated 6051 tons of active substances went into the production of veterinary pharmaceuticals (VPs) for the treatment of food animals in the European Union (EU) in 2004, including 5393 tons of antibiotics and 194 tons of antiparasitics (1). With global meat production projected to increase (2) and the growing market for companion animal pharmaceuticals (3), the use of VPs will continue to increase. Although VPs may benefit the health and welfare of domestic animals and the efficiency of food animal production, they can contaminate the environment through manufacturing, treatment of animals, and disposal of carcasses, offal, urine, feces, and unused products (4) (see the chart). This contamination is a threat to nontarget species, including humans. With Spain having recently authorized marketing of a VP that was banned in South Asia in the past decade in light of environmental impacts, we recommend strengthening of current procedures and addition of a more proactive, holistic, One Health approach applicable to all VPs.

Eagle Owl Bubo bubo and power line interactions in the Italian Alps

We reviewed the importance of power lines as a cause of mortality for Eagle Owl in the Italian Alps. Power lines were the most important cause of unnatural mortality for this species, accounting for over 50% of recorded casualties. The number of reported dead owls tended to be higher in September–October, suggesting an influence on juvenile dispersal. Furthermore, the significance of power lines as a cause of mortality increased over time, being lower in the 1960–1980 period than in 1981–1999. Electrocution, which usually takes place at medium-voltage (15–30 kV) electricity poles, accounted for the vast majority of casualties. We suggest some protective measures that may be put into practice in the proximity of Eagle Owl breeding territories.

Nest Defense as Parental Care in the Northern Hobby (Falco subbuteo)

Abstract Intensity of nest defense against a human intruder was recorded for 42 male and 43 female Northern Hobbies (Falco subbuteo) from 1992 to 1994. Defense did not vary between repeatedly and rarely visited nests. Except during incubation, intensity of nest defense by females was higher than that by males. For both sexes, defense intensity increased from incubation to fledging, within the nestling stage, and from fledging to the first 10 days of the postfledging period. Intensity of nest defense was positively correlated with brood size in females, but not in males. Experiments with dummy nests showed that defense was effective in deterring nest predation, and that its effect was positively related to its intensity. Hobby nest defense was an individually varying “plastic” trait, probably tuned to the reproductive value of the offspring. Parents apparently trade off the costs and risks of the behavior against the increasing likelihood of offspring survival.

Birds and powerlines in Italy: an assessment

Summary Powerlines may pose severe threats to bird populations. We assessed the significance of powerlines as a source of avian mortality within the Italian electric transmission and distribution system. We reviewed data from 11 mortality censuses and compiled a list of species that were found among powerline victims in Italy, based on over 1,300 reported individual casualties. Overall, 95 species of birds were reported among powerline victims (19% of Italy’s total species). The number of recorded species was compared with the number of species in the Italian list, after grouping species based on morphology and ecology. Some groups (e.g. raptors, herons, storks and allies) were highly affected, while others (e.g. passerines and allies) appeared to be poorly represented among species involved in powerline accidents. Furthermore, we evaluated the validity of a published discriminant model for the classification of bird species as collision or electrocution victims according to body measurements. The application of the available model classified 54.7–73.5% of Italian species correctly (depending on the species included), compared with 88.6% of the original dataset. Two new discriminant models based on Italian powerline casualties classified 80.9–81.1% of species correctly. This approach can be a useful tool in assessing collision and electrocution risk for species in different geographical areas. While we recognize the need for a general preventive approach for reducing the bird–powerline conflict, our review highlights once more the importance of local situations, where powerlines may have a strong impact on avian communities.