We are pleased to share these recent URSUS articles with you. The articles below are open access and can also be accessed through your IBA membership account link to BioOne.
Denning ecology of an at-risk American black bear population in a unique habitat on the Bruce Peninsula, Ontario, Canada
Melissa B. Coady, Martyn E. Obbard, Frank G. Burrows
Ursus 2024 (35e18), 1-17, (23 October 2024) https://doi.org/10.2192/URSUS-D-23-00017R1
KEYWORDS: American black bear, Bruce Peninsula, denning, den site characteristics, habitat selection, karst, Ontario, Ursus americanus
Open Access Article
The American black bear (Ursus americanus) population on the Bruce Peninsula in southern Ontario, Canada, is small (∼300 bears), genetically isolated from the closest bears in other parts of Ontario because of geography and urban development, and it is at risk because of habitat loss. The Bruce Peninsula is underlain by dolostone, and soils over much of the Peninsula are shallow. The bedrock is karstic with extensive networks of rock fissures and underground drainage systems created by solutional processes. During the nondenning season bears select dense mixed forest and dense deciduous forest stands. From May 1998 to February 2004, we documented the habitat requirements of denning black bears on the Bruce Peninsula and described the characteristics of winter dens in this unique substrate. Thirteen of 30 (43%) dens were located in dense mixed forests, 12 of 30 (40%) were located in dense coniferous forests, and 4 of 30 (13%) were located in dense deciduous forests. Eighty-one percent of dens (25 of 31) were within rock crevices often >2 m deep and ending in a subsurface chamber. Of the remaining dens, 3 were excavated, 2 were under brush piles, and 1 was under a large boulder on a steep talus slope. Twenty-one of 29 dens were located with potential sanctuary trees (>30 cm diameter at breast height) within 30 m of the den. Population viability analysis determined the most effective management action that would ensure persistence of black bears on the Peninsula to be conserving habitat outside of Bruce Peninsula National Park. The importance of dense mixed and dense coniferous stands for denning shown in this study emphasizes that point.
Andean bears below the Andes
Flynn B. Vickowski, Russell C. Van Horn
Ursus 2024 (35e19), 1-8, (22 October 2024) https://doi.org/10.2192/URSUS-D-23-00012.1
KEYWORDS: AMAZON, Andean bear, camera traps, distribution, Elevational gradient, Tremarctos ornatus, tropical Andes, visual detection
Open Access Article
We lack many quantitative data on the current distributions of several bear species, and hypotheses about the mechanisms underlying those distributions. We raise this point by discussing visual detections of Andean bears (Tremarctos ornatus) in sampling from 14 September 2016 to 24 August 2017 in the Haramba Queros Wachiperi Ecological Reserve Conservation Concession in southeastern Peru, at 811–920 m above sea level, lower in elevation than >90% of known locations for this species on the eastern slope of the Peruvian Andes.
No tenemos muchos datos cuantitativos sobre las distribuciones actuales de varias especies de osos, ni hipótesis sobre los mecanismos detrás de esas distribuciones. Ilustramos esto discutiendo unos registros visuales del oso andino (Tremarctos ornatus) durante foto trampeo del 14 septiembre 2016 al 24 agosto 2017 dentro de la Concesión para la Conservación Reserva Ecológica Haramba Queros Wachiperi, de elevaciones de 820–920 msnm, más bajos que 90% de los lugares conocidos para la especie en las laderas orientales de los Andes peruanos.