Valutazione del foto-trappolamento per la conservazione e la gestione della fauna selvatica

Responsabili di progetto

Stefano Focardi, Peter Genov

Accordo

BULGARIA - BAS - Bulgarian Academy of Sciences

Bando

CNR/BAS 2013-2015

Dipartimento

Terra e Ambiente

Area tematica

Scienze del sistema Terra e tecnologie per l'ambiente

Stato del progetto

Nuovo

Proposta di ricerca

Introduction. Wildlife conservation is a major concern for many European countries since it impacts on conservation of biodiversity and hence on the service ecosystems provide to human society. It is used to distinguish between non-consumptive and consumptive uses of ecosystems. Among the former we include conservation of water supplies, tourism and atmospheric carbon uptake. Often non-consumptive use of  ecosystems do not provide local stakeholders with revenues since benefits are distributed to a larger scale. The only non-consumptive  ecosystem service which benefits local populations is tourism, but to be profitable the area has to be well connected to urban areas, airports and motorways, as well it is necessary the presence of attracting landscapes or monuments. Thus in many mountain areas in Europe, local populations have to rely on consumptive ecosystems services such as forestry and hunting.
For ecosystem conservation hunting is challenging because it is difficult to clearly establish game population size  to formulate sustainable hunting quotas. Several problems affect population assessment. The most relevant one is the low detectability of many wildlife species. Further some species use to migrate at long distance and because different species interact (e.g. because of competition, predation or facilitation), thus influencing reciprocally their population dynamics.
Wildlife managers in Bulgaria use artificial feeding points to monitor wildlife populations and exploit collected observations to manage large mammals (such as chamois, Rupicapra rupicapra balcanica, wild boars, Sus scrofa, red deer, Cervus elaphus, wolves, Canis lupus, and bears, Ursus arctos) ). The use of artificial feeding represents a relevant ecological disturbance for natural populations and its effects has to be evaluated but also an opportunity to study interactions among species and among sex and age classes (hereafter called community segments) within each particular species.
Observations at feeding sites can be made, by day and night, using photo-traps, i.e.  automatic recording devices which collect pictures or movies of the animals moving around the location of interest. This methods has been developed in the last years and now this method represents an interesting and cheap method to monitor wildlife populations. Low price and operation simplicity make possible the use of photo-traps by wildlife managers and rangers which use these devices for routine wildlife monitoring in remote areas.
Usually wildlife managers use photo-traps to identify areas of distribution of a given species and to have an idea of its abundance. However managers underexploit the amount of information collected by photo-trapping. In recent times in several hunting areas of Tuscany (Italy), protocols for the use of photo-traps in wildlife management have been developed. The aims of these studies were to (1) estimate population size (Morimando et al 2009) and (2) to get a structure of the population of interest. This work  represents a fundation for developing new approaches for the use of data collected by photo-traps. Indeed an yet unexplored line of research is that of studying behavioural interference among community segments on the feeding site. This analysis is relevant to different questions: (1) to understand bias in the representation of community segments. Whether a segment is subordinate, it will tend to avoid foraging sites and this effect  will results in an under-representation of these animals in photo samples and hence an underestimate of the size of this specific segment. Understanding animal behaviour in presence of potential predators/competitors is hence fundamental for a sounded monitoring of wildlife populations.
It is well-known that in natural communities competition is reduced by niche partitioning. Thus we expect that subordinate competitors should use feeding areas at different times with respect to dominant competitors and that that subordinates will exploit exhausted or poorer food resources that dominant competitors. This finally wold produce a reduction of population size in subordinate segments which could be severe under unfavourable climatic conditions (e.g. during snowy winter).
Study areas. In the years 2009-2011, Genov and co-workers of the Bulgarian Academy of Sciences have performed a  study for photo-trapping wildlife populations in the area of Kormisosh in the western Rhodope mountains on a surface area of  419 km2. The Bulgarian research team has used 10 photo-traps. The aim of the research was to document the presence of large mammals in the area. Population estimates are 750 red deer, 100 fallow deer (Dama dama), 1000 roe deer (Capreolus capreolus), 750 wild  boars, 400 chamois, 200 muflons (Ovis musimon) and 25 wolves. All this species can be hunted and need appropriate management. Further it exists a population of about 100 bears which are protected and has to be conserved.
Previous research has allowed the Bulgarian team with basic knowledge of the ecology of these species. Now it is necessary to develop a more sophisticated data analysis following the guidelines developed by the Italian team to improve knowledge available to wildlife managers. To do that it is necessary to develop a new campaign of data collection using photo-traps already available in situ and adopting a sampling design which maximizes accuracy and precision of population estimates and to develop an analysis of competitions among population segments, which is likely to be a main factor regulating populations. The research will develop into 3 steps. During the first year of project both teams would be involved in analyzing the data previously collected. This analysis  is propaedeutic to a new collection of data in the study area and to develop an innovative sampling design. Finally, during the second half of year 2 and in year 3 both new and older data shall be analyzed together to answer main scientific questions. 
 

Obiettivi della ricerca

Aims of the research. The  basic aim of the research it is to develop guidelines for a systematic use of photo-trapping in wildlife management to be delivered to management agencies in Italy and Bulgaria to improve wildlife monitoring at low costs. Specific targets  are:
1-      Experimental Implementation of methods for wild boar population assessment already used in Italy to study areas in Bulgaria;
2-      To evaluate efficacy in  quite different environmental conditions (hills in Italy, mountains in Bulgaria) to evaluate the portability of the method;
3-      To extend the method used for wild boar to other wildlife species, with particular reference to the bear, for which population monitoring is fundamental for conservation, and to red deer, a valuable game species which generates important revenues.
4-      To investigate interference among competing community segments to evaluate potential impacts on population dynamics and to evidence possible biases in population assessment.
5-      We believe that results can be published in international journals devoted to  management and conservation of wildlife populations. Dissemination is relevant for a better management of wildlife populations in both Italy and Bulgaria. Further the results of this research might be useful in all Balkans were human populations dwelling marginal areas get significant revenues exploiting wildlife, but where the lack of public funding do not allow for the use of sophisticated and expensive monitoring methodologies.
 

Ultimo aggiornamento: 08/06/2025