Distribution of the brown bear (Ursus arctos marsicanus) in the Central Apennines, Italy, 2005-2014

Despite its critical conservation status, no formal estimate of the Apennine brown bear (Ursus arctos marsicanus) distribution has ever been attempted, nor a coordinated effort to compile and verify all recent occurrences has ever been ensured. We used 48331 verified bear location data collected by qualified personnel from 20052014 in the central Apennines, Italy, to estimate the current distribution of Apennine brown bears. Data sources included telemetry relocations, scats and DNA-verified hair samples, sightings, indirect signs of presence, photos from camera traps, and damage to properties. Using a grid-based zonal analysis to transform raw data density, we applied ordinary kriging and estimated a 4923 km2 main bear distribution, encompassing the historical stronghold of the bear population, and including a smaller (1460 km2) area of stable occupancy of reproducing female bears. National and Regional Parks cover 38.8% of the main bear distribution, plus an additional 19.5% encompassed by the Natura 2000 network alone. Despite some methodological and sampling problems related to spatial and temporal variation in sampling effort at the landscape scale, our approach provides an approximation of the current bear distribution that is suited to frequently update the distribution map. Future monitoring of this bear population would benefit from estimating detectability across a range on environmental and sampling variables, and from intensifying the collection of bear presence data in the peripheral portions of the distribution

Assessment of point-frame method to quantify wolf diet by scat analysis.

Scat analysis is a widely used technique to assess food habits of wolves Canis lupus, but complete dissection and thorough hand separation of the undigested remains for their individual identification is laborious and time consuming. In addition, this technique is susceptible to inter-observer sources of error. Alternatively, the point-frame method allows systematic sampling of undigested remains of faecal samples and greatly reduces the processing time. Based on a sample of 200 wolf scats, we compared hand separation and point-frame methods using four widely used scat analysis quantification methods (frequency, volume and biomass models). Qualitative and quantitative estimates of the wolf diet showed close agreement between hand separation and point-frame procedures, but point-frame sampling allowed for an 85% reduction of the processing time. Given that the method is properly applied and its assumptions are met, we conclude that application of the point-frame method is reliable and more time effective than hand separation of wolf scat. The point-frame method could also provide a more rigorous sampling approach to reduce observer subjectivity as to what constitutes an accurate hand separation of undigested remains in scat

Efficiency of scat-analysis lab procedures for bear dietary studies: The case of the Apennine brown bear

Bear food habits are often quantified using scat analysis, mainly due to its non-invasiveness and because samples are relatively easy to collect. However, lab processing time can be daunting and may end up competing with other field activities. Sub-sampling a bear scat to analyze its contents may reduce the lab processing time, but the number of subsamples per scat is usually chosen arbitrarily. We investigated the effect of the number of subsamples per bear scat on the estimatation of the diet composition of the Apennine brown bear in the Abruzzo Lazio and Molise National Park. Based on a sample of 328 bear scats collected in 2006, and from 5 to 1 subsamples (10 ml) per scat, dietary analysis showed qualitative and quantitative stability at a decreasing number of subsamples, and only food items of negligible importance were occasionally missed using 1-2 subsamples per scat. We concluded that 2 subsamples can be used without significant loss in accuracy, corresponding to a 60% reduction in lab time, and to more than 50 days of lab work for one operator to process our entire bear scat sample. By assessing the effect of sub-sampling a bear scat for dietary analysis, we also present preliminary data on the seasonal food habits of the Apennine brown bear population

Counts of unique females with cubs in the Apennine brown bear population, 2006–2014

Brown bears in the Apennines, central Italy, survive in a precarious conservation status but the reproductive performance of the population has never been formally assessed. Each year, from 2006-2014, we conducted surveys of females with cubs (FWC) to estimate the minimum number of female bears that reproduced and annual productivity in this bear population. We discriminated unique family groups based on simultaneity of sightings, presence of individually recognizable bears, and ad hoc distance-based rules developed using GPS relocations from 11 adult female bears in our study population. To estimate the true number of FWC from unique counts, we applied two estimators (Chao2, Capwire) known to handle heterogeneity in sighting probabilities relatively well at small sample sizes. Annually, we estimated 1–6 (x ̅ = 3.9 ± 1.5 SD) unique FWC and tallied a minimum of 3–11 (x ̅ = 7.4 ± 3.0 SD) cubs in the population. No temporal trend in FWC was observed and the mean estimate of reproductive females corresponded well with an independent estimate of total population size obtained in 2011. Although we confirmed that the population is still reproductively functional, the low number of reproducing females and their year-to-year fluctuations dramatically underline the precarious status of Apennine bears. We concur with previous authors that counts of unique FWC are an effective means to assess reproductive output in small bear populations, although it is advisable that more in-depth demographic studies complement this technique

A case of autumn mating in the Apennine Brown Bear (Ursus arctos marsicanus)

Although the breeding season of brown bears generally occurs during early spring or summer, a few incidents of autumn mating have been recently documented in British Columbia and Japan. Considering the rarity, yet the relevance, of these events, we report a case of autumn courtship and mating in the Apennine brown hear observed as late as 3 November 2010 in the Abruzzo Lazio and Molise National Park, central Italy. Mating was preceded and followed by muzzle sniffing and play lighting, and involved an adult female associated with a cub. During the 20-min observation, the female did not display cub defence behaviour, nor the adult male acted aggressively toward the cub. We briefly discuss this observation on theoretical grounds, including the potential meaning of late breeding for this small bear population

Seasonal and annual variation in the food habits of Apennine brown bears, central Italy

Only scanty and outdated knowledge is available on the food habits of the Apennine brown bear (Ursus arctos marsicanus) population, despite its critical conservation status. Based on 2,359 scats, collected from June 2006 through December 2009, we documented seasonal and annual variation in the diet of this bear population within its 1,294 km2 core distribution in Abruzzo, Lazio and Molise National Park and its external buffer area in central Italy. Using correction factors to estimate digestible energy, we revealed substantial consumption of plant matter by bears, including herbaceous vegetation in spring (31.7 ± 25%) and early summer (19.0 ± 7%), a variety of naturally occurring berries in summer (56.5 ± 14%), and hard mast (66.9 ± 21%), largely supplemented by fleshy fruits (26.3 ± 18%), in the fall. Bears also consumed insects, mostly ants, in early summer (38.3 ± 7%), and wild ungulates in spring (10.2 ± 11%). Hard mast production strongly influenced year-to-year variation in the diet. High-quality foods, such as berries and other fleshy fruits, were increasingly consumed by bears in years of low to null hard mast productivity, suggesting that habitat productivity is currently high and diversified enough to allow bears to avoid the risk of nutritional stress during occasional hard mast failures. Nevertheless, as exemplified by a negative trend in late-summer consumption of buckthorn berries (Rhamnus spp.) by bears, our findings demonstrate the need to implement management strategies that will ensure long-term habitat productivity and provide optimal foraging opportunities for Apennine brown bears

Assessment of key reproductive traits in the Apennine brown bear population

Although knowledge of reproductive parameters is critical to project the chances of persistence of small populations, no data on basic reproductive traits have ever been estimated for the relict Apennine brown bear population (central Italy). From 2005-2014, as part of an ongoing ecological investigation, we compiled re-sight data on marked adult female bears (3 ≤ n ≤ 10 per year, 78 bear-years) and unmarked, distinct family groups (n = 18) to estimate litter size (1.9±0.7 SD cubs), weaning time (range: 7 May-6 June), interbirth interval (3.3-3.7 years), and reproductive rate (0.19±0.13 SD female cubs/adult female/year). We also applied multi-event models in a capturerecapture, robust design framework to our re-sight dataset of marked adult female bears to account for imperfect detectability of female bears with non-functioning radiocollars. Due to a high annual probability of re-sighting (0.77-0.82 for reproductive and non-reproductive females, respectively), and a negligible classification error (p = 0.003), multi-event models produced results similar to naïve estimates. Female bears had highest probability to reproduce 3-4 years after their last reproduction, and their average reproductive rate was 0.24 (95% CIs = 0.07-0.59). In addition, we produced a naïve estimate of apparent cub survival (0.49) as the proportion of cubs that was seen again the following spring before weaning, and a bias-corrected estimate of adult female bears survival (0.93, 95% CIs = 0.83-0.97), as a derived parameter of multievent models. Our findings tentatively place the Apennine bear population at the lower bound along the spectrum reported for other non-hunted brown bear populations. Coupled with high levels of human-caused mortality, a relatively limited reproductive performance could explain why Apennine bears failed to expand their range during the last decades. More in-depth demographic investigations are required to support our results and eventually assess whether they reflect density-dependent mechanisms or inbreeding depression