Energy requirements of eastern coyotes

1990 ◽  
Vol 68 (4) ◽  
pp. 656-659 ◽  
Author(s):  
Peter J. Pekins ◽  
William W. Mautz
Keyword(s):  
Prey Species ◽  
Energy Requirements ◽  
Late Winter ◽  
Critical Temperatures ◽  
Energy Needs ◽  
Snowshoe Hares ◽  
Daily Energy ◽  
Seasonal Metabolism ◽  
Snow Conditions ◽  
Free Ranging

We used indirect respiration calorimetry to measure seasonal metabolism and lower critical temperatures (TLC) of eastern coyotes (Canis latrans var.). The yearly mean basal metabolic rate was 10.6 L O2∙kg−1∙d−1. No difference was found among seasonal BMRs. The TLC values were 10, 0, and 5 °C during summer, autumn, and spring, respectively. Metabolism increased linearly below the TLC values. Normal temperatures in New Hampshire were well within the seasonal thermoneutral zones of eastern coyotes. The average daily energy requirements of free-ranging eastern coyotes during winter were estimated as 163.5 kcal∙kg−1 (3 × BMR). A 15-kg coyote required three snowshoe hares (Lepus americanus) every 2 days to satisfy these energy needs. In northern forested habitats, where hare and white-tailed deer (Odocoileus virginianus) may represent the primary prey species, interrelationships of the energy requirements of eastern coyotes with coyote breeding activity, sociality, and snow conditions may favor predation of white-tailed deer during late winter, particularly if hare availability is low.

Differential sex-related winter energetics in free-ranging snowshoe hares (Lepus americanus)

2016 ◽  
Vol 94 (2) ◽  
pp. 115-121 ◽  
Author(s):  
E. Ellsworth ◽  
M.R. Boudreau ◽  
K. Nagy ◽  
J.L. Rachlow ◽  
D.L. Murray
Keyword(s):  
Energy Expenditure ◽  
Food Availability ◽  
Lepus Americanus ◽  
Energetic Cost ◽  
Food Supplementation ◽  
Natural Food ◽  
Daily Energy Expenditure ◽  
Snowshoe Hares ◽  
Daily Energy ◽  
Free Ranging

Animals spend considerable time and energy acquiring food to meet their metabolic requirements, but if energetic or fitness costs are substantive, such as during winter, then some individuals may limit daily energy expenditure by reducing foraging duration. To date, the prevalence and magnitude of such compensatory foraging responses are poorly known. We examined energy balance compensation in free-ranging snowshoe hares (Lepus americanus Erxleben, 1777) via a food supplementation experiment to determine whether individuals reduced their daily energy expenditure (DEE) and activity periods in response to increased food availability. Overall, food supplementation had no effect on diel activity patterns, although males had higher DEE compared with females. During early and mid-winter, hares did not alter their activity periods in response to food supplementation, but during late winter, when natural food availability declined, food-supplemented females (but not males) were ∼11% less active compared with controls. Natural food likely was sufficient and could have been acquired at relatively low energetic cost, but because males likely have higher DEE due to mating behavior whereas females may limit their activity (and thus DEE) to reduce predation risk, we conclude that gender-specific life-history demands can over-ride predicted responses to supplemental food when baseline food abundance is adequate.

scholarly journals Sized-related changes in winter condition of male calves in reindeer

Rangifer ◽  
1987 ◽  
Vol 7 (1) ◽  
pp. 2 ◽  
Author(s):  
T. Helle ◽  
E. Pulliainen ◽  
J. Aspi
Keyword(s):  
Body Size ◽  
Food Competition ◽  
The Body ◽  
Carcass Weight ◽  
Length Ratio ◽  
Late Winter ◽  
Winter Condition ◽  
Selection For ◽  
Snow Conditions ◽  
Free Ranging

<p>Size-related changes in body condition of free-ranging male calves of semi-domesticated reindeer were studied in northern Finland from October 1983 to February 1984. In October-November, back fat depth or muscle fat percent correlated positively with the body size (=back length). In January, the highest means especially for muscle fat percent were found among medium-sized calves. Carcass weight and weight/back length ratio correlated positively with size, excluding February sample, where correlation for carcass weight was non-significant and for weight/back length ratio negative. Weight in the autumn correlated negatively with weight in February. Therefore, normalizing selection for body size (working against small and large phenotypes) is expected to occur in late winter. Small calves may be at greater mortality risk because of lower initial body reserves. Large calves commonly disperse during the rutting season and they may suffer most from increased food competition later in winter. Using of medium-sized calves for breeding might be the safest policy on ranges characterized by short food supply and difficult snow conditions.</p><p>Koon vaikutus poron urosvasojen talviseen kuntoon.</p><p>Abstract in Finnish / Tiivistelm&auml;: Koon vaikutusta vapaana laiduntavien poron urosvasojen kuntoon tutkittiin Pohjois-Suomessa loka-helmikuussa talvella 1983-84. Loka-marraskuussa selk&auml;rasvan paksuus tai lihaksen rasvaprosentti riippui vasan koosta ( = sel&auml;n pituus). Tammikuussa sen sijaan lihaksen rasvaprosentti oli korkein keskikokoisilla vasoilla. Ruhopaino sek&auml; ruhopaino/sel&auml;n pituus oli yleensa riippuvainen koosta. Helmikuussa ruhopainon riippuvuus koosta ei ollut en&auml;&auml; tilastollisesti merkitsev&auml;, ja koon ja ruhopainon/sel&auml;npituuden v&auml;linen korrelaatio oli negatiivinen. Eniten painoa menettiv&auml;t (%) loka-helmikuun v&auml;lill&auml; suurikokoisimmat vasat. Havainnot viittaavat siihen, ett&auml; talvella esiintyv&auml; kuolleisuus on normalisoivaa koon suhteen (karsii pieni&auml; ja suuria fenotyyppej&auml;). Pienten vasojen kuolleisuusriski on suuri alunperinkin v&auml;h&auml;isen varastoravinnon vuoksi. Suuret vasat puolestaan erkaantuvat usein emist&auml;&auml;n jo rykim&auml;aikana, ja joutuvat k&auml;rsim&auml;&auml;n eniten talven mittaan kiristyv&auml;st&auml; ravintokilpailusta. Niukoilla laitumilla siitokseen on turvallisinta s&auml;&auml;st&auml;&auml; keskikokoisia vasoja.</p><p>Sammenhengen mellom st&oslash;rrelse og vinterkondisjon hos hankalver av reinsdyr.</p><p>Abstract in Norwegian / Sammendrag: St&oslash;rrelses-relaterte forandringer i kroppskondisjon hos fritt beitende han-kalver av semidomestiserte rein er studert i Nord-Finland fra oktober 1983 til februar 1984. I oktober - november korrelerte tykkelsen av ryggfettet eller muskelfett-prosenten positivt med kroppsst&oslash;rrelsen (= rygglengden). I januar ble de h&oslash;yeste middelverdier, s&aelig;rlig for muskelfett-prosenten, funnet hos kalver av middels st&oslash;rrelse. Skrott-vekter og vekt/rygglengde-forholdet korrelerte positivt med kroppsst&oslash;rrelse bortsett fra februar-pr&oslash;vene, der korrellasjonen for skrott-vekt var ikke-signifikant og for vekt/rygglengde-forholdet var negativt. Vekt om h&oslash;sten korrelerte negativt med vekt i februar. Derfor ventes et normaliserende utvalg for kroppsvekt (som arbeider mot sm&aring; og store fenotyper) &aring; skje p&aring; senvinteren. Sm&aring; kalver er utsatt for st&oslash;rre d&oslash;dsrisiko p&aring; grunn av lavere kroppsreserver. Store kalver streifer vanligvis under brunsttiden og kan komme til &aring; lide under &oslash;kt n&aelig;ringskonkurranse p&aring; senvinteren. Bruk av middels store kalver i avlen kan v&aelig;re den sikreste metode p&aring; beiter som karakteriseres av d&aring;rlige n&aelig;ringstilgang og vanskelige sn&oslash;forhold.</p>

Estimating energy intake of free-ranging moose cows and calves through collection of feces

1994 ◽  
Vol 72 (8) ◽  
pp. 1409-1415 ◽  
Author(s):  
Olav Hjeljord ◽  
Bernt-Erik Sæther ◽  
Reidar Andersen
Keyword(s):  
Energy Intake ◽  
Energy Content ◽  
Average Energy ◽  
Late Winter ◽  
Daily Energy Intake ◽  
Energy Deficiency ◽  
The Poor ◽  
Daily Energy ◽  
Medium Quality ◽  
Free Ranging

We calculated the daily energy intake of wintering cow and calf moose from a series of 24-h feces collections and from estimates of the digestibility and energy content of forages from four different habitats in Norway during a 3-year period (1984–1986). Habitats varied in condition from good to poor. In early winter, the estimated energy intake of cows ranged from 803 kJ∙kg−0.75∙day−1 in the good- and average-quality habitats to 573 kJ∙kg−0.75∙day−1 in the poor habitat. Estimated energy intake decreased by 15–30% from early to late winter. The estimated energy intake of calves ranged from 920 kJ∙kg−0.75∙day−1 in the good habitat to 414 kJ∙kg−0.75∙day−1 in the poor habitat; a significant decrease over winter was not evident. The estimates of daily energy intake correspond to a browse wet mass of 8–17 kg for cows and 4–10 kg for calves. In the good- and medium-quality habitats the average energy deficiency of adult cows over winter was estimated at 25–30%.

scholarly journals Protein content of diets dictates the daily energy intake of a free-ranging primate

2009 ◽  
Vol 20 (4) ◽  
pp. 685-690 ◽  
Author(s):  
Annika M. Felton ◽  
Adam Felton ◽  
David Raubenheimer ◽  
Stephen J. Simpson ◽  
William J. Foley ◽  
...  
Keyword(s):  
Protein Content ◽  
Energy Intake ◽  
Daily Energy Intake ◽  
Daily Energy ◽  
Free Ranging

NITROGEN UTILIZATION IN CALORIC INSUFFICIENCY

PEDIATRICS ◽  
1953 ◽  
Vol 11 (5) ◽  
pp. 435-448
Author(s):  
WARREN M. COX ◽  
RUDOLPH C. ELLINGSON ◽  
A. J. MUELLER
Keyword(s):  
Protein Hydrolysate ◽  
Caloric Intake ◽  
Tissue Growth ◽  
Nitrogen Utilization ◽  
Energy Requirements ◽  
Protein Loss ◽  
Dietary Nitrogen ◽  
Energy Needs ◽  
New Protein ◽  
Normal Stock

To determine whether a portion of ingested protein can be used for tissue growth when insufficient calories were fed, isocaloric and suboptimal amounts of calories in the form of dextrose or as dextrose and protein hydrolysate (amigen®) were fed to protein-depleted, partially starved, scalded and normal stock rats together with adequate vitamins and minerals. It is concluded that: 1. The greater the need for protein, the greater is the utilization of ingested nitrogen for new protein synthesis under conditions of caloric limitation. Protein-depleted rats are able to build new protein tissue even when basal energy requirements are not completely supplied. 2. Protein depleted, partially starved, scalded and stock animals retain or gain more weight when fed adequate or suboptimal quantities of the hydrolysate-dextrose diet than when fed isocaloric quantities of the dextrose diet. 3. Stock animals with no pre-existing protein loss, and in good nutritive condition, do not utilize dietary nitrogen for tissue building when the caloric intake is suboptimal. 4. When the caloric intake is less than that required to meet the estimated basal energy needs, a diet supplying approximately 20% of the calories as protein supported better growth than those supplying more or less than this amount.

Snowshoe hare feeding behavior responds to coyote and moose cues at diverse vegetation densities

2020 ◽  
Vol 101 (3) ◽  
pp. 710-717
Author(s):  
Zachary K Lankist ◽  
Christine R Maher
Keyword(s):  
Chemical Cues ◽  
Prey Species ◽  
Vegetation Density ◽  
Vegetative Cover ◽  
Feeding Sites ◽  
Risk Of Death ◽  
Lack Of Information ◽  
Snowshoe Hares ◽  
Number Of Visits ◽  
Indirect Cues

Abstract Heterospecific competitors can use chemical cues left by dominant species to avoid aggressive interactions. Similarly, prey avoid chemical cues from predators at feeding sites, presumably because risk of death outweighs the benefit of food. This study addressed the lack of information regarding mammals’ avoidance of direct cues from competitors and also examined how indirect cues, i.e., vegetative cover, affect foraging behavior. To test if chemical cues and vegetative cover alter the number of visits by prey species and time spent at feeding plots, we observed snowshoe hares (Lepus americanus) in plots containing coyote (Canis latrans; predator) and moose (Alces alces; competitor) urine across a spectrum of vegetation densities. Snowshoe hares significantly reduced number of visits to plots that contained coyote or moose urine. In plots treated with coyote urine, number of visits decreased significantly as plots became more densely vegetated. Neither chemical cues nor vegetation density affected time spent in plots. These results suggest that competition between snowshoe hares and moose has selected for an avoidance response. This study also reinforces the idea that an increase in vegetation density could prove disadvantageous to prey, perhaps because some predators use dense vegetation to their advantage.

Daily energy requirements in heart failure patients

Metabolism ◽  
1997 ◽  
Vol 46 (11) ◽  
pp. 1294-1298 ◽  
Author(s):  
Michael J. Toth ◽  
Stephen S. Gottlieb ◽  
Michael L. Fisher ◽  
Eric T. Poehlaman
Keyword(s):  
Heart Failure ◽  
Energy Requirements ◽  
Heart Failure Patients ◽  
Daily Energy

The cold shoulder: free-ranging snowshoe hares maintain a low cost of living in cold climates

2009 ◽  
Vol 87 (10) ◽  
pp. 956-964 ◽  
Author(s):  
Michael J. Sheriff ◽  
J. R. Speakman ◽  
L. Kuchel ◽  
S. Boutin ◽  
M. M. Humphries
Keyword(s):  
Metabolic Rate ◽  
High Latitude ◽  
Low Cost ◽  
Resting Metabolic Rate ◽  
Mean Field ◽  
Resource Scarcity ◽  
Doubly Labelled Water ◽  
Snowshoe Hares ◽  
Free Ranging ◽  
The Relationship

The hypothesis that cold air temperatures (Ta) constrain the metabolic diversity of high-latitude endotherms is based on the observation among birds and mammals that mean field metabolic rate (FMR) increases, whereas the variability of FMR decreases, from the warm tropics to the cold poles. However, there is a paucity of FMR measurements from above 60° latitude and below 0 °C. We measured the daily energy expenditure of a high-latitude population of free-ranging snowshoe hares ( Lepus americanus Erxleben, 1777) in Yukon, Canada, in winter (Ta-mean = –16.4 °C) and in autumn (Ta-mean = 0.5 °C). Doubly labelled water measures of FMR were approximately 20% lower in winter than in autumn, and were a similar, low multiple of resting metabolic rate in both seasons (2.04 and 1.94, respectively). The mass-corrected FMR of snowshoe hares in winter was only half the value predicted by extrapolating the relationship between FMR and Ta > 0 to –16.4 °C. These results contribute to an emerging pattern of a reversal in the relationship between FMR and Ta in free-ranging mammals from negative above 0 °C to positive below 0 °C. We refer to the positive, low Ta portion of this relationship as the cold shoulder, and suggest that it may reflect the general necessity for free-ranging mammals to use behavioural and (or) physiological means to conserve energy during long winters when cold conditions coincide with resource scarcity.

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