A work‐for‐food enrichment program increases exploration and decreases stereotypies in four species of bears

Zoo‐housed bears are prone to exhibiting stereotypic behaviors, generally considered indicators of negative welfare. We explored the effects of a variable‐time feeding enrichment schedule on behavioral indicators of welfare in four bear species at Cleveland Metroparks Zoo. We distributed the diets of eight bears in one of five enrichment items, for two consecutive days each, and monitored behavior throughout the day. In Experiment 1, we compared variable‐time to fixed‐time presentation of enrichment over two, 10‐day periods. Overall, bears performed more exploratory behavior when enriched (p < 0.0001). Furthermore, variable‐time enrichment was associated with a greater increase in exploratory behavior than fixed‐time enrichment when compared to baseline (p < 0.001). Both fixed‐time (p_unadjusted <0.05, p_adjusted = 0.07) and variable‐schedule (p_unadjusted <0.05, p_adjusted = 0.09) enrichment were also associated with similar decreases in abnormal behavior compared to baseline. For Experiment 2, we tested habituation to enrichment over 30 days using multiple items and a semi‐variable presentation schedule. Again during the enrichment period, bears exhibited increased exploratory behavior (p < 0.0001) and decreased abnormal behaviors compared to baseline (p_unadjusted = 0.05, p_adjusted = 0.09). We observed no habituation during the 30‐day sustained enrichment period for these behaviors. Collectively, these results suggest that daily, variable‐schedule feeding enrichment, with intermittent presentation of unique enrichment items, increases behavioral indicators of positive welfare and decreases behavioral indicators of negative welfare.     

An Investigation of Factors Influencing Bear Spray Performance

Several studies have documented the effectiveness of bear spray in protecting users from aggressive bears. Bear spray failures, however, have also been reported along with speculation regarding the influences of temperature, wind, repeated canister use, and canister age on spray efficacy. We designed lab and field experiments to document the influence that temperature, wind, repeated discharges from the same canister, and canister age have on bear spray performance. To determine the influence of temperature on spray performance, we recorded canister head pressures at temperatures ranging from −23°C to 25°C and found a strong, positive linear relationship. Even at the lowest temperature tested (−23°C), bear spray had a range >4 m, though the plume was narrow and the spray was not well aerosolized. As canister temperature increased, head pressure, plume distance, and dispersion increased. We used computational fluid dynamics modeling and simulated the effect that headwinds, crosswinds, and tailwinds of varying speeds had on spray performance. Even under high headwind and crosswind scenarios (>10 m/sec), sprays reached targets that were approximately 2 m directly in front of the user. Crosswinds affected spray plume distance similar to headwinds, but the effect was not as pronounced. Tailwinds improved spray performance with respect to speed and distance. By weighing unused canisters ≤18 years old, brands tested lost weight ranging from 0.65 g/year to 1.92 g/year, presumably because of propellant that escaped canister seals. We also documented that bear spray head pressure declines in a logarithmic, not linear, fashion; over half of a new (7-sec spray time) canister's pressure was lost in the first 1 second of spray. We recommend not test-firing cans, keeping cans warm when in the cold, and retiring them when ≥4 years of age. Our results provide no compelling reason to not carry bear spray in all areas where bears occur, even if it is windy or cold. © 2020 The Wildlife Society.     

Using stage‐based system dynamics modeling for demographic management of captive populations

Management of captive populations relies on a complex synthesis of genetic and demographic analyses to guide populations toward sustainability. Demographic analyses of captive populations currently utilize age‐based matrix projections to predict a population's trajectory. An alternate approach is to use a stage‐based, system dynamics model for captive systems. Such models can more easily incorporate complex captive systems in which population dynamics are dependent on a combination of management and a species' biology. By linking these two areas, population managers can gain a more accurate understanding of how management decisions impact captive populations and which aspects of a species' demography should be of special concern in the future. We present a general stage‐based system dynamics model that has been developed for use with captive populations. The utility of the model is then illustrated by applying it to three captive bear populations: spectacled bears (Tremarctos ornatus), sloth bears (Melursus ursinus), and sun bears (Helarctos malayanus). Zoo Biol 22:45–64, 2003. © 2003 Wiley‐Liss, Inc.     

Fatal attacks by American black bear on people: 1900–2009

At least 63 people were killed in 59 incidents by non-captive black bear (Ursus americanus) during 1900–2009. Fatal black bear attacks occurred in Canada and Alaska (n = 49) and in the lower 48 states (n = 14). There were 3.5 times as many fatal attacks in Canada and Alaska but only 1.75 times as many black bears, and much less human contact for black bears in Canada and Alaska. There was a weak positive correlation (r_s = 0.56, P ≤ 0.000) between the estimated size of a bear population within a given jurisdiction and the number of fatal black bear attacks. Some jurisdictions had no fatal black bear attacks but had large estimated black bear populations. Of fatal attacks, 86% (54 of 63, 1.08/yr) occurred between 1960 and 2009. There was positive linear relationship between the number of fatal black bear attacks per decade and human population size in the United States and Canada per decade (r² = 0.92, β = 0.000, P ≤ 0.001). Of fatal attacks, 91% (49 of 54) occurred on parties of 1 or 2 persons. In 38% (15 of 40) of incidents, peoples' food or garbage probably influenced the bear being in the attack location. We judged that the bear involved acted as a predator in 88% (49 of 56) of fatal incidents. Adult (n = 23) or subadult (n = 10) male bears were involved in 92% (33 of 36) of fatal predatory incidents, reflecting biological and behavioral differences between male and female bears. That most fatal black bear attacks were predatory and were carried out by 1 bear shows that females with young are not the most dangerous black bears. As a result of our research agencies managing black bear can more accurately understand the risk of being killed by a black bear, and can communicate this to the public. With training, people can learn to recognize the behaviors of a bear considering them as prey and can act to deter predation. © 2011 The Wildlife Society.     

Natural-trap ursid mortality and the Kurtén Response

Ursid mortality data have long been used to evaluate associations between cave-bear remains (Ursus deningeri and U. spelaeus) and hominin (Homo sp.) remains. Typically, such ursid assemblages produce mortality patterns that indicate that juvenile and old bears died during hibernation, a pattern that is used to suggest that humans and bears occupied the same caves at different times. However, a different kind of mortality pattern can also be used to suggest human influence on cave bears, particularly under circumstances when bears and humans compete for habitat. In particular, data from Lawson Cave and Jerry Long Cave, Missouri indicate that young-adult North American black bears (Ursus americanus) are prone to capture in natural-trap caves. Similar faunal data from Sima de los Huesos in Spain, where cave-bear and hominin remains are found in the same deposit, might also suggest that the bears died from falling into a natural trap. It is concluded that mortality analysis of ursid remains from caves is a useful tool with which to evaluate accumulation histories of cave deposits and relations between humans, artifacts, and cave-bear remains. In particular, ursid mortality data are relevant to the Kurtén Response, a hypothesis reiterated in the recent literature that implicates human encroachment on ursid habitat (e.g., cave den sites) as a potential cause in cave-bear extinction.     

黑龙江省熊类资源现状及其保护对策

黑龙江省现分布有 2种熊 ,棕熊 (Ursusarctoslasiotus)和黑熊 (Selenarctosthibetanusussuricus)。棕熊广泛分布于全省各个林区 ;黑熊在大兴安岭无分布 ,仅分布于小兴安岭和东部山地的张广才岭、老爷岭和完达山林区 ,其分布北界为北纬 48～ 49°,东经 1 2 8～ 1 2 9°附近。 2种熊的总分布区虽无明显变化 ,但集中分布区明显向大兴安岭、小兴安岭、东部山地的腹地退缩。 1 996～ 2 0 0 0年全省棕熊的分布数量为 (63 1±1 43 )头 (n =463 9) ,种群密度为 (0 0 0 2 2± 0 0 0 0 5 )头 km2 ;黑熊的分布数量为 (1 1 1 0± 2 93 )头 (n =463 9) ,种群密度为 (0 0 0 65± 0 0 0 1 7)头 km2 。全省森工国有林区熊类分布数量 (1 1 71± 2 98)头 (n =61 2 ) ,与1 992年该林区熊类调查结果 (3 0 5 7± 73 0头 ;n =2 1 3 6)相比较 ,全林区 6年间熊类数量减少了 1 886头 ,减少率达 61 7% ,年递减率为 1 6%。熊类资源呈锐减趋势。其主要原因为 :(1 )森林长期超量采伐引起熊类栖息生境总体质量下降 ;(2 )人类活动导致熊类栖息地片断化日趋严重 ;(3 )人为捕杀是造成熊类数量减少的直接原因。最后 ,提出了今后全省熊类保护管理的 5点建议。     

Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears

Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we present an analysis of data from a large panel of polar bear and brown bear genomes that includes brown bears from the ABC islands, the Alaskan mainland and Europe. Our results provide clear evidence that gene flow between the two species had a geographically wide impact, with polar bear DNA found within the genomes of brown bears living both on the ABC islands and in the Alaskan mainland. Intriguingly, while brown bear genomes contain up to 8.8% polar bear ancestry, polar bear genomes appear to be devoid of brown bear ancestry, suggesting the presence of a barrier to gene flow in that direction.     

The story continues: recent advances on the life and death of the Pleistocene cave bear

ABSTRACT

In this issue, we cover an exceptional topic in Vertebrate Paleobiology that has been an enjoyable challenge for scientists and the popular media alike: the life and death of the Pleistocene cave bear (Ursus spelaeus). As an icon of the ice-age, the cave bear inhabited the glacial ecosystems of Eurasia, and it was the inspiration of a popular book written in 1976 by Björn Kurtén, entitled The cave bear story: life and death of a vanished animal. Although ‘The life and death’ was a summary of the knowledge acquired on cave bear biology at that time, four decades later, many aspects of its palaeoecology, extinction and evolution are still a matter of debate. With this volume, we aim to bring together the most recent research on cave bear biology in order to provide an update on the palaeoecology, biogeography, systematics, and phylogeny of this recently extinct ursine bear. We thus organised a symposium on the 1st of August 2017 as part of the three-day Annual Meeting of the European Association of Vertebrate Palaeontologists (EAVP) in Munich, Germany, that was an additional opportunity to announce the volume and to discuss this exciting subject face-to-face among specialists.     

Predicting spatial distribution of human–black bear interactions in urban areas

Human–wildlife interactions are often associated with a myriad of stakeholder groups, intense political scrutiny, and limited biological data, creating complex decision-making situations for wildlife management agencies. Limited research exists on the development and testing of tools (e.g., models to predict the spatial distribution of interactions) to reduce human–black bear (Ursus americanus) interactions (HBI). Available models predicting spatial distribution of HBI are usually developed at scales too large to predict across urban areas, are rarely tested against independent data sets, and usually do not incorporate both landscape and anthropogenic variables. Our objective was to develop a predictive modeling tool that could identify areas of high conflict potential across urban landscapes. We compared locations of HBI in Missoula, MT, recorded by Montana Fish, Wildlife & Parks from 2003 to 2008, to random locations using logistic regression. The final model discriminated the relative spatial probability of HBI within Missoula well, and a second study area moderately. The probability of HBI in Missoula increased when residents lived close to forested patches and major rivers and streams and in intermediate housing densities (approx. 6.59 houses/ha). Our results provide a wildlife management tool and a repeatable statistical framework that predicts spatial distribution of HBI using only a small set of variables. © 2011 The Wildlife Society.     

Gibbsiella dentisursi sp. nov., isolated from the bear oral cavity

A Gram-negative, rod-shaped, non-spore forming and non-motile bacterium, designated strain NUM 1720(T) , was isolated from the oral cavity of bears. Based on 16S rRNA gene sequence similarity, strain NUM 1720(T) was shown to be related to Gibbsiella quercinecans (99.4%). The gyrB and rpoB gene sequences of strain NUM 1720T showed 98.0% and 98.2% similarity with those of G. quercinecans. The DNA-DNA hybridization value of strain NUM 1720(T) with G. quercinecans was 63.8%. The G + C content of the genomic DNA of the isolates was 55.0 mol%. Fatty acid analysis data supported the affiliation of strain NUM 1720(T) to the genus Gibbsiella. The major menaquinone and ubiquinone were MK-8 and Q-8, respectively. Strain NUM 1720(T) can be differed from G. quercinecans by the reactions to acetoin, inositol and D-arabinose. Strain NUM 1720(T) therefore represents a novel species, for which the name Gibbsiella dentisursi sp. nov. is proposed, with type strain NUM 1720(T) (= JCM 17201(T) = DSM 23818(T)).     

Chronological and Isotopic data support a revision for the timing of cave bear extinction in Mediterranean Europe

Abstract

The Cave Bear, Ursus spelaeus (sensu lato), was one of many megafaunal species that became extinct during the Late Pleistocene in Europe. With new data we revisit the debate about the extinction and paleoecology of this species by presenting new chronometric, isotopic and taphonomic evidence from two Palaeolithic cave bear sites in northeastern Italy: Paina Cave and Trene Cave. Two direct radiocarbon dates on well-preserved collagen have yielded ages around 24,200–23,500 cal yr BP, which make them the latest known representatives of the species in Europe. The carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic values of bone collagen exhibit values similar to those of older cave bears from Swabian Jura and France, suggesting that the feedings preferences of cave bears remained unchanged until the disappearance of this species in Europe. Several bear remains preserved traces of human modification such as cut marks, which enables a reconstruction of the main steps of fur recovery and the butchering process. The broad range of plant types available and the favorable location of Berici Hills may have played an important role in the range expansion of cave bears and their interaction with the Paleolithic hunters settled the same area.     

马来熊在西藏吉隆县的分布新发现

<正>在开展全国第二次陆生野生动物资源调查——喜马拉雅南翼沟谷地理单元(No.176)调查期间,我们于2013年08月31日09:00,在西藏自治区吉隆县吉隆镇热索村(北纬28°16'59.8″,东经85°21'31.1″,海拔1 884 m)用佳能单反相机(Canon EOS 600D,EF 400 mm f/5.6 L USM)拍摄到单只熊科动物(图1),经过现场特征辨别,并与专家讨论,确认该个体为马来熊(Helarctos malayanus)。我们发现的马来熊个体,胸前斑块呈黄白     

Habitat preferences of the Andean bear (Tremarctos ornatus) in the Bolivian Andes

Habitat preferences of the Andean bear Tremarctos ornatus were studied within two adjacent protected areas in the north-western Bolivian Andes. Standard transects measuring habitat variables and bear sign frequency were used spanning seven different vegetation types. Andean bears were present at 28 of 33 sampled sites and actively preferred high-elevation elfin forest and upper montane humid forests, and used high-elevation humid 'páramo' grasslands and middle montane humid forests according to their availability. Bears were absent from dry montane and Andean foothill forests and relative abundance was low in lower montane humid forests. Elevation and basal area of food items were the variables most closely related to the relative abundance.     

Rejection of Schmidt et al.'s estimators for bear population size

Aerial distance sampling of bears to estimate population size has been used throughout many parts of Alaska. The distance sampling models are complex since they need to account for undetected bears and differences in detection probabilities. This will require covariates and mark‐recapture data. The models proposed by Schmidt et al. do not use covariates or mark‐recapture data and are inappropriate for these surveys.     

不同稀释液对圈养黑熊精液品质的影响

对23头圈养黑熊进行63次电刺激采精,并在对精液进行品质检查的基础上,通过对3种稀释液4℃保存精液结果的筛选比较试验,得出以下结果:圈养黑熊采精量平均为1.06±0.93ml,pH值为6.71±0.44,精子密度为(3.23±1.68)×108个/ml,精子畸形率为(23.48±7.95)%,顶体完整率为(88.58±3.86)%,精子活率和活力分别为(76.30±13.91)%和(63.91±18.53)%;Tris-柠-果-葡-卵稀释液保存圈养黑熊精液效果最好,可作为进一步研究优化的首选。     

Lead exposure in large carnivores in the greater Yellowstone ecosystem

Ingestion of lead rifle bullet fragments found in discarded hunter-harvested ungulate gut piles negatively affects avian wildlife. Some large carnivores, such as grizzly bears, are also known to target these gut piles as a food source and are therefore potentially at risk of lead exposure. We investigated whether large carnivores in the greater Yellowstone ecosystem were exposed to lead, and if so, if ammunition ingested from gut piles was an apparent source of exposure. Grizzly bears (Ursus arctos, n = 82) exhibited higher blood lead levels (median = 4.4 µg/dL, range 1.1–18.6 µg/dL) than black bears (Ursus americanus, n = 35, median = 1.6, range 0.5–6.9 µg/dL), but blood lead levels did not increase during the autumn hunting season when potentially lead-tainted gut piles are available. Wolves (Canis lupus, n = 21) and cougars (Puma concolor, n = 8) showed lead concentrations near or below the minimum level of detection in both blood and tissue samples. Unlike findings in previous studies on avian scavengers, we did not find lead ammunition fragments to be a widespread source of lead exposure in large carnivores. Grizzly bears do, however, exhibit blood lead levels that are higher than what is considered safe in humans, but the source of this exposure remains unknown. © 2011 The Wildlife Society.     

Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend

Identifying mechanisms of population change is fundamental for conserving small and declining populations and determining effective management strategies. Few studies, however, have measured the demographic components of population change for small populations of mammals (<50 individuals). We estimated vital rates and trends in two adjacent but genetically distinct, threatened brown bear (Ursus arctos) populations in British Columbia, Canada, following the cessation of hunting. One population had approximately 45 resident bears but had some genetic and geographic connectivity to neighboring populations, while the other population had <25 individuals and was isolated. We estimated population‐specific vital rates by monitoring survival and reproduction of telemetered female bears and their dependent offspring from 2005 to 2018. In the larger, connected population, independent female survival was 1.00 (95% CI: 0.96–1.00) and the survival of cubs in their first year was 0.85 (95% CI: 0.62–0.95). In the smaller, isolated population, independent female survival was 0.81 (95% CI: 0.64–0.93) and first‐year cub survival was 0.33 (95% CI: 0.11–0.67). Reproductive rates did not differ between populations. The large differences in age‐specific survival estimates resulted in a projected population increase in the larger population (λ = 1.09; 95% CI: 1.04–1.13) and population decrease in the smaller population (λ = 0.84; 95% CI: 0.72–0.95). Low female survival in the smaller population was the result of both continued human‐caused mortality and an unusually high rate of natural mortality. Low cub survival may have been due to inbreeding and the loss of genetic diversity common in small populations, or to limited resources. In a systematic literature review, we compared our population trend estimates with those reported for other small populations (<300 individuals) of brown bears. Results suggest that once brown bear populations become small and isolated, populations rarely increase and, even with intensive management, recovery remains challenging.     

Evidence of a phylogeographic break in the Romanian brown bear (Ursus arctos) population from the Carpathians

We analysed 33 brown bears from the Romanian Carpathians and the Italian Apennines at sequences of the mitochondrial control region and nine polymorphic microsatellite loci with regard to genetic variability and haplotype distribution. The Italian brown bears were monomorphic for mtDNA sequences. The Romanian bears yielded the highest variability found so far in this species. Haplotypes of both previously identified mtDNA lineages (western and eastern) were found in Romania. In the eastern part of the Carpathians western and eastern haplotypes occurred sympatrically, the bears from the western part of the mountain range only exhibited western-type sequences. This pattern provides evidence of a mitochondrial phylogeographic break in the distribution of the eastern lineage within the Romanian Carpathians. Conservation implications of this finding are discussed.     

Selectivity of tree species as activity target of brown bear in taiga

Data on trees with signs of activity of brown bears (Ursus arctos L.) were collected in Yar raion of Udmurtia, in the Pechora-Ilych State Reserve (Komi Republic), and the Sayan-Shusha State Reserve (Western Sayan, Krasnoyarsk krai). The forest stands in all studied areas consist of deciduous and coniferous species. The percentage of deciduous trees varies from 10 to 76%, averaging 35%; conifers are represented by four or five species. The author has analyzed papers that describe more than fifty bear trees. The original data on the species composition of bear trees and the fraction of bear trees in the local forest stands was analyzed with Student’s t-test. It has been deduced that bears definitely prefer coniferous species, especially fir and spruce. Bears can also mark deciduous trees, but if conifers are present, they choose coniferous rather than deciduous species.