Bear feeding activity at alpine insect aggregation sites in the Yellowstone ecosystem

1991 ◽  
Vol 69 (9) ◽  
pp. 2430-2435 ◽  
Author(s):  
David J. Mattson ◽  
Colin M. Gillin ◽  
Scott A. Benson ◽  
Richard R. Knight

Bears (Ursidae) were observed from fixed-wing aircraft on or near alpine talus in the Shoshone National Forest between 15 June and 15 September in 1981–1989. Bears fed on insect aggregations at 6 known and 12 suspected alpine talus sites, disproportionately more at elevations > 3350 m, on slopes > 30°, and on south- and west-facing aspects. While at these sites, bears almost exclusively ate invertebrates, typically army cutworm moths (Euxoa auxiliaris). Subadult grizzly bears (Ursus arctos horribilis) appeared to be underrepresented at the sites, and proportionate representation of adult females with young appeared to decrease between 15 June and 15 September. Overall, observations of bears at these sites increased between 1981 and 1989. We suggest that alpine insect aggregations are an important food source for bears in the Shoshone National Forest, especially in the absence of high-quality foraging alternatives in July and August of most years.

1998 ◽  
Vol 76 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Don White, Jr. ◽  
Katherine C Kendall ◽  
Harold D Picton

Grizzly bears (Ursus arctos horribilis) consume army cutworm moths (Euxoa auxiliaris) from late June through mid-September at alpine moth aggregation sites in Glacier National Park, Montana. To better understand the importance of army cutworm moths to grizzly bears, we determined the sex and age classes and minimum numbers of grizzly bears foraging at known alpine moth aggregation sites, and documented the timing and use patterns of grizzly bears foraging in these areas. A minimum of 36 grizzly bears were observed 106 times feeding at 6 of 9 known moth aggregation sites from late June through mid-September in 1992-1995; no bears were observed on moth sites in 1993. Bears fed on moth aggregations disproportionately more at elevations >2561 m, on slopes between 31° and 45°, and on southwest-facing aspects. Lone adult grizzly bears appeared to be underrepresented and subadults overrepresented at moth sites. Moths are highly digestible; all parts are digested except for the exoskeleton. We propose that army cutworm moths are an important, high-quality, preferred summer and early-fall food for grizzly bears in Glacier National Park. We do not present any data that demonstrate an increase in the importance of moths when other foods fail.


2001 ◽  
Vol 79 (5) ◽  
pp. 779-793 ◽  
Author(s):  
David J Mattson

I used data collected during a study of radio-marked grizzly bears (Ursus arctos horribilis) in the Yellowstone region from 1977 to 1992 to investigate myrmecophagy by this population. Although generally not an important source of energy for the bears (averaging <5% of fecal volume at peak consumption), ants may have been an important source of protein during midsummer and were heavily consumed during some years. Myrmecophagy was most common annually when known high-quality foods were scarce, as well as during the warmest months of the study, when regional average temperatures exceeded 12–15°C. Bears tended to select large ants (>8 mm long) nested in logs over small ants ([Formula: see text]6 mm long) nested under stones. Optimal conditions for consumption of ants occurred on the warmest sites with ample substrate suitable for ant nests. For ants in mounds, this occurred at low elevations at non-forested sites. For ants in logs, this occurred at low elevations or on southerly aspects where there was abundant, large-diameter, well-decomposed woody debris under an open forest canopy. Grizzly bears selected moderately decomposed logs 4–5 dm in diameter at midpoint. Ants will likely become a more important food for Yellowstone's grizzly bears as currently important foods decline, owing to disease and warming of the regional climate.


1976 ◽  
Vol 13 (2) ◽  
pp. 341-347 ◽  
Author(s):  
Charles S. Churcher ◽  
Alan V. Morgan

The distal end of the left humerus of a grizzly bear, Ursus arctos, has been recovered from above the Early Wisconsin Sunnybrook Till at Woodbridge, Ontario, from the same horizon that previously has yielded remains of the woolly mammoth, Mammuthus primigenius. The age of these specimens is estimated at 40 000–50 000 years BP, within the mid-Wisconsin, Port Talbot Interstadial. The only other recognized Canadian record of a grizzly bear east of Manitoba is from a gravel sequence at Barrie, near Lake Simcoe, Ontario, dated from a bone fragment to 11 700 ± 250 years BP. A specimen recovered in Toronto in 1913 from an Early Wisconsin horizon is also considered to represent the grizzly. Bears of the grizzly type, Ursus arctos-horribilis were present in Ontario before and after the Early and Late Wisconsin ice advances.


1986 ◽  
Vol 23 (2) ◽  
pp. 103-145 ◽  
Author(s):  
D. K. Salunkhe ◽  
J. K. Chavan ◽  
S. S. Kadam ◽  
N. R. Reddy

2021 ◽  
Author(s):  
Heiko T. Jansen ◽  
Brandon Evans Hutzenbiler ◽  
Hannah R. Hapner ◽  
Madeline L. McPhee ◽  
Anthony M. Carnahan ◽  
...  

ABSTRACTHibernation is characterized by suppression of many physiological processes. To determine if this state is reversible in a non-food caching species, we fed hibernating grizzly bears (Ursus arctos horribilis) glucose for 10 days to replace 53% or 100% of the estimated minimum daily energetic cost of hibernation. Feeding caused serum concentrations of glycerol and ketones (ß-hydroxybutyrate) to return to active season levels irrespective of the amount of glucose fed. By contrast, free-fatty acids and indices of metabolic rate, such as general activity, heart rate, and strength of the daily heart rate rhythm and insulin sensitivity were restored to roughly 50% of active season levels. Body temperature was unaffected by feeding. To determine the contribution of adipose to these metabolic effects of glucose feeding we cultured bear adipocytes collected at the beginning and end of the feeding and performed metabolic flux analysis. We found a roughly 33% increase in energy metabolism after feeding. Moreover, basal metabolism before feeding was 40% lower in hibernation cells compared to fed cells or active cells cultured at 37°C, thereby confirming the temperature independence of metabolic rate. The partial suppression of circulating FFA with feeding likely explains the incomplete restoration of insulin sensitivity and other metabolic parameters in hibernating bears. Further suppression of metabolic function is likely an active process. Together, the results provide a highly controlled model to examine the relationship between nutrient availability and metabolism on the hibernation phenotype in bears.


2011 ◽  
Vol 25 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Marta Eglaé Camargo Asinelli ◽  
Maria Conceição de Souza ◽  
Káthia Socorro Mathias Mourão

Garcinia gardneriana (Clusiaceae) is a small to medium-sized tree that usually occurs on the floodplains of the Paraná River and it is an important food source for the local inhabitants. The fruit itself is consumed in natura, and juices and sweets are made from it. The purpose of this study was to describe morphological and structural aspects of fruits and seeds of this species in order to classify the fruit type and the pulpy layer which involves the seeds. The material analyzed consisted of ovary and fruits in different stages of development, collected from five plants from Aurélio Island, Baía River (MS, BR) and the description was done according to standard procedures in anatomy. The fruit is a yellowish-orange spherical berry ("bacóide" type). The smooth, coriaceous skin consists of the lignified exocarp. The endocarp cell layers are derived from the activity of an adaxial meristem that undergoes radial elongation. The edible sweet white pulp is formed by the endocarp, as well as the spongy mesocarp, in which the secretory ducts lose their function. The unitegmic anatropous ovules develop into anatropous exalbuminous seeds with a collapsed and undifferentiated testa. The embryo is hypocotylar. The features here described generally occur in Clusioideae-Garcinieae and Symphonieae.


2006 ◽  
Vol 110 (11) ◽  
pp. 1333-1339 ◽  
Author(s):  
James M. Trappe ◽  
A.O. Nicholls ◽  
Andrew W. Claridge ◽  
Steven J. Cork

2013 ◽  
Vol 93 (8) ◽  
pp. 2257-2264 ◽  
Author(s):  
Houda Chaouch ◽  
Olfa Ben Abdallah-Ben Hadj Hamida ◽  
Mohamed Ghorbel ◽  
Othman Jarboui

The diet and feeding habits of the sharpsnout seabream, Diplodus puntazzo, from the Gulf of Gabès were investigated using stomach contents of 490 specimens ranging from 12.6 cm to 26.1 cm total length in size and from 29.95 g to 230.83 g in weight collected from commercial catches between April 2008 and March 2009. Of the total number of examined stomachs, 279 were empty (%VI = 56.94). This percentage varied significantly with months, attaining a maximum in spring (74.88%) and a minimum in autumn (37.38%). Eight major taxa were identified (Plantae, Spongia, Tunicata, Echinodermata, Crustacea, Annelida, Mollusca and Teleostei) in stomach contents of D. puntazzo. Plants were the most important food source, constituting 89.88% of the total Index of relative importance. The other groups, such as teleosts, molluscs, crustaceans and annelids represented accessory food. Significant differences in diet were observed in relation to season. Plants were the most important food source item in all seasons, especially during the autumn. The estimation of trophic level gave an average of 2.57 ± 0.2 for the whole population of D. puntazzo in the Gulf of Gabès. Based on the composition of its diet, this species may be considered as an omnivorous fish with a preference for vegetable material, and showing specialist feeding strategy.


Sign in / Sign up

Export Citation Format

Share Document