Food habits of a small Florida black bear population in an endangered ecosystem

Consequences of severe habitat fragmentation on density, genetics, and spatial capture-recapture analysis of a small bear population

“…Although black bears are habitat generalists that can be synanthropic in areas of low anthropogenic development along the wildland-urban interface (i.e., exurban areas [ 22 ]), that cities or large expanses of open ranchlands present in the study area could solely support or be preferentially selected by an entire bear population as suggested by the inhomogeneous D models is unlikely. Corn ( Zea mays ) dispensed at remote wildlife feeders by white-tailed deer ( Odocoileus virginianus ) hunters in areas of high quality natural cover was the dominant human-sourced food item in the diet of HGS bears across all seasons, whereas garbage comprised < 1% of consumed foods [ 45 ]. Furthermore, few radio-monitored HGS bears frequented urban developments [ 42 , 43 ], collectively indicating that most HGS bears are probably not residing in areas of low or no natural cover.…”

“…However, we only placed hair traps in sampling cells for which ≥ 20% of the cell’s area was comprised of natural cover (i.e., black bear habitat [ 15 ]); this resulted in a single, baited hair trap in each of 46 sampling cells (36.5% of cells; Fig 1 ). We did not construct traps within citrus groves, which are human-created monocultures that provide traversing cover for bears, but are not considered primary or secondary habitat and do not offer a primary food for bears [ 43 – 45 ]. We constructed all traps using 2 wires placed at 25 and 50 cm above the ground; both were wrapped around 3–5 trees to create an approximately 25-m 2 enclosure.…”

Metal(loid) exposure assessment and biomarker responses in captive and free-ranging European brown bear (Ursus arctos)

“…Other toxic metal(loid)s, like As and Hg were detected in 6-32% and 16-26% of brown bear samples (Table 2), respectively, and in an order of magnitude lower than reported for Florida black bears Florida black bears which are exclusively part of the terrestrial food web. Thus, the Hg difference between our bears and Florida black bears point to geographical differences, because the diet of these populations is very similar (Murphy et al 2017, Cicnjak et al 1987, Kusak and Huber 1998. All of the brown bears had blood Hg within normal range established for cattle, sheep (<106 µg/L, Puls 1994) and humans (<20 µg/L, Klaassen et al 2013).…”

Pleistocene–Holocene vicariance, not Anthropocene landscape change, explains the genetic structure of American black bear (Ursus americanus) populations in the American Southwest and northern Mexico

“…Anthropogenic activities, in particular, overharvest, urbanization, and transportation infrastructure such as highways with high traffic volume have also influenced the abundance, movement patterns, and genetic structure of black bears. In the western and eastern portions of their range, overhunting and persecution during European settlement severely reduced the abundance of black bears with some populations recovering and recolonizing portions of their former range (Evans et al, 2017; Malaney et al, 2018), while others have been rendered into small, isolated populations more susceptible to genetic drift, eroding genetic diversity (Hooker et al, 2015; Murphy et al, 2017; Murphy et al, 2018). In Florida, major roads have heightened mortality (McCown et al, 2009) and acted as semipermeable barriers, that when coupled with urbanization, fragmented bear habitat, decreased connectivity, and caused appreciable genetic structure among subpopulations (Dixon et al, 2007; Karelus et al, 2017).…”