Intrinsic and extrinsic factors influencing coyote predation of small mammals in Yellowstone National Park

1996 ◽  
Vol 74 (5) ◽  
pp. 784-797 ◽  
Author(s):  
Eric M. Gese ◽  
Robert L. Ruff ◽  
Robert L. Crabtree
Keyword(s):  
Small Mammals ◽  
Yellowstone National Park ◽  
Snow Depth ◽  
National Park ◽  
Habitat Type ◽  
Prey Detection ◽  
Extrinsic Factors ◽  
Detection Rates ◽  
Factors Influencing ◽  
Capture Rates

We examined the intrinsic (age, sex, and social status) and extrinsic factors (snow depth and hardness, temperature, cloud cover, wind speed, and habitat) influencing coyote (Canis latrans) predation of small mammals in Yellowstone National Park, Wyoming. We observed 54 coyotes (49 residents from 5 packs, plus 5 transients) for 2507 h from January 1991 to June 1993. We observed 6433 prey detections by coyotes during which coyotes made 4439 attempts to capture prey, resulting in 1545 successful prey captures. The age of the coyote influenced prey-detection rates, predation attempts, and capture rates, plus the proportions of prey attacked after being detected and capture success. Pups had higher prey-detection rates and higher attempt rates than alphas and betas, but capture rates were similar. Snow depth and hardness and habitat type were factors influencing detection rates, predation attempt rates and capture rates. Coyotes hunted mainly in mesic meadows and shrub–meadows, where prey-detection rates, predation attempt rates, and capture rates were highest. Snow depth influenced coyote predation on small mammals, prey-detection rates, predation attempt rates, and capture rates being highest in low snow cover and lower in deeper snow. Our findings indicated that young, inexperienced coyotes detected and attacked small mammals at a higher rate than older coyotes. Yearlings and adults were more selective, and thus detected and attempted to capture prey at a lower rate than pups. Overall, however, pups and older coyotes captured similar numbers of prey per hour.

Foraging ecology of coyotes (Canis latrans): the influence of extrinsic factors and a dominance hierarchy

1996 ◽  
Vol 74 (5) ◽  
pp. 769-783 ◽  
Author(s):  
Eric M. Gese ◽  
Robert L. Ruff ◽  
Robert L. Crabtree
Keyword(s):  
Social Status ◽  
Small Mammals ◽  
Yellowstone National Park ◽  
Snow Depth ◽  
National Park ◽  
Canis Latrans ◽  
Habitat Type ◽  
Activity Budgets ◽  
Extrinsic Factors ◽  
Time Activity

We examined the influence of intrinsic (age, sex, and social status) and extrinsic (snow depth, snowpack hardness, temperature, available ungulate carcass biomass) factors in relation to time–activity budgets of coyotes (Canis latrans) in Yellowstone National Park, Wyoming. We observed 54 coyotes (49 residents from 5 packs, plus 5 transients) for 2507 h from January 1991 to June 1993. Snow depth, ungulate carcass biomass, and habitat type influenced the amount of time coyotes rested, travelled, hunted small mammals, and fed on carcasses. Coyotes decreased travelling and hunting and increased resting and feeding on carcasses as snow depth and available carcass biomass increased. Age and social status of the coyote influenced activity budgets. During times of deep snow and high carcass biomass, pups fed less on carcasses and hunted small mammals more than alpha and beta coyotes. Pups apparently were restricted by older pack members from feeding on a carcass. Thus, pups adopted a different foraging strategy by spending more time hunting small mammals. Coyotes spent most of their time hunting small mammals in mesic meadows and shrub–meadows, where prey densities were highest. Prey-detection rates and prey-capture rates explained 78 and 84%, respectively, of the variation in the amount of time coyotes spent hunting small mammals in each habitat in each winter. Our findings strongly suggested that resource partitioning, as mediated by defense by older coyotes, occurred among coyote pack members in Yellowstone National Park.

scholarly journals Effects of 1988 Fires on Ecology of Coyotes in Yellowstone National Park: Baseline Preceding Possible Wolf Recovery

1993 ◽  
Vol 17 ◽  
pp. 109-116
Author(s):  
Robert Crabtree
Keyword(s):  
Data Collection ◽  
Small Mammals ◽  
Yellowstone National Park ◽  
National Park ◽  
Initial Density ◽  
Mortality Data ◽  
Late Winter ◽  
Scat Analysis ◽  
Field Season ◽  
Ungulate Mortality

Sixty healthy adult coyote Canis latrans and 53, 8-12 week old pups captured at dens were radio­ tagged in the Lamar Valley and Blacktail Plateau areas of the northern range of Yellowstone National Park. Adults range in age from 1 to 12 years and average nearly 3.3 years old. Territorial packs in both study areas are adjacent, non-overlapping, contiguous, and average 15 km2. Based on information from the last four winters and data collected from 1946 to 1949, territorial areas are traditional and have changed little in the last 45 years. We estimate that 85 to 90% of coyotes on the northern range belong to packs. A territorial group or pack during the winter consists of 2 alpha individuals, 2 or 3 beta adults, and 2 or 3 adult-sized pups (average pack size = 7). Fifteen marked coyotes have died since November of 1992. Initial density estimates are 1.4 coyotes per square mile. Preliminary scat analysis suggests that small mammals, especially voles, dominate the diet with ungulate remains becoming important in May through July (presumably elk calves) and late winter (mostly scavenging). Two graduate students have finished their data collection and another student is currently working on his last field season. More than 2500 hours of foraging observations were conducted from January 1991 through June 1993 resulting in data collection on more than 4400 predation attempts on small mammals. Eight hundred and fifty hours of den observations were completed during 1992 and 1993. Beta pack members were observed to bring food to pups and protect den sites from intruders. Coyote behavior and ungulate mortality data were collected on sixty-one carcasses found during the 1992-1993 winter. Five successful and 4 unsuccessful predations by coyotes on ungulates have been seen. Coyotes appear to impact ungulate numbers in 3 ways: predation on calves and fawns shortly after birth (up to 8 weeks), predation on short-yearlings and adults during winter, and indirect impact from harassment of other predators at ungulate-kills. Coyotes may be the major ungulate predator on the northern range due to their cooperative social and foraging behavior, ability to take advantage of vulnerable ungulates, and high population levels. Wolf extirpation has probably resulted in high coyote population densities and coyotes have, at least partially, slid into this vacant niche.

scholarly journals Small Mammal Communities After Two Recent Natural Fires in Yellowstone National Park

1979 ◽  
Vol 3 ◽  
pp. 128-132
Author(s):  
R. Moore ◽  
M. Wood
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Yellowstone National Park ◽  
National Park ◽  
Management Practices ◽  
Fire Policy ◽  
Natural Fires ◽  
Wilderness Areas ◽  
Small Mammal Communities ◽  
Mammal Communities

As part of the National Park Service's goal of maintaining an area in as natural condition as possible, Yellowstone National Park in 1972 developed a fire policy whereby natural fires were allowed to burn in wilderness areas of the park. Several investigators have studied the relationship between small mammals and fire due to timber management practices (Gashwiler, 1970 and Tevis, 1956) but few studies have investigated the changes in abundance and composition of species of small mammals after recent natural fires (Bendell 1974). The purpose of this ongoing study is to quantify the effects that recent natural fires have had upon small mammal communities. Two burn sites were studies, the Divide fire which burned in 1976 on the south arm of Yellowstone Lake, and the Trail Creek Fire which burned in 1974 on the southeast arm of the lake.

scholarly journals Effects of 1988 Fires on Ecology of Coyotes in Yellowstone National Park: Baseline Preceding Possible Wolf Recovery

1991 ◽  
Vol 15 ◽  
pp. 219-226
Author(s):  
Robert Crabtree
Keyword(s):  
Cervus Elaphus ◽  
Yellowstone National Park ◽  
National Park ◽  
Habitat Type ◽  
Late Winter ◽  
Density Estimates ◽  
Mountain Lion ◽  
Breeding Groups ◽  
Territorial Group ◽  
Annual Mortality

Fifty-four healthy coyotes (Canis latrans) and 32, 8-12 week old pups captured at dens were radio­tagged in the Lamar Valley and Blacktail Plateau areas of the northern range of Yellowstone National Park. Seven of the 40 captured in the fall were 6 month-old pups which suggest slow population productivity. Adults range in age from 1 to 12 years and averaged nearly 4 years old. Territorial packs in both study areas are adjacent, non-overlapping, contiguous, and averaged 15 km2/ We estimate that 85 to 90% of coyotes on the northern range belong to packs. A territorial group or pack during the winter consists of 2 alpha individuals, 2 or 3 beta adults, and 2 or 3 adult-sized pups (average pack size = 7). Nine adults were killed (2 mountain lion [Felis concolar], 2 road-kill, 2 shot, and 3 unknown) which equates to a 15% annual mortality rate. Eleven of 36 pups have died between the ages of 3 and 9 months old. Population productivity ranges from 2.0 to 2. 7 pups recruited per territory. The reproductive failure rate among breeding groups averaged 15% during 1990 and 1991. Initial coyote density estimates are 0.09 per km2. Intensive foraging observations were conducted from January through June 1991. In 353 hours of focal observations 427 capture attempts were made on small mammal prey with 162 (38%) successful. Habitat type played a key role in the success rate. Mesic meadows had the highest capture rates followed by willow/meadow habitats and sage habitat. Small mammals, especially voles (Microtus spp.), dominate the diet with ungulate remains becoming important in May through July, presumably elk (Cervus elaphus) calves and late winter, mostly scavenging. We have observed numerous successful and unsuccessful predation attempts on ungulates in our study areas. Coyotes appear to impact ungulate numbers in 3 ways: predation on calves and fawns shortly after birth (up to 8 weeks), predation on short-yearlings and adults during winter, and indirect impact from harassment of other predators at ungulate-kills. Coyotes may be the major ungulate predator on the northern range due to cooperative social and foraging behavior, their ability to take advantage of vulnerable ungulates, and their high population levels. Wolf (Canis lupus) extirpation has probably resulted in high coyote population densities.

Factors affecting gray wolf (Canis lupus) encounter rate with elk (Cervus elaphus) in Yellowstone National Park

2018 ◽  
Vol 96 (9) ◽  
pp. 1032-1042 ◽  
Author(s):  
H.W. Martin ◽  
L.D. Mech ◽  
J. Fieberg ◽  
M.C. Metz ◽  
D.R. MacNulty ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Canis Lupus ◽  
Yellowstone National Park ◽  
Snow Depth ◽  
National Park ◽  
Encounter Rate ◽  
Encounter Rates ◽  
Hunting Success ◽  
Kill Rate ◽  
The Relationship

Despite encounter rates being a key component of kill rate, few studies of large carnivore predation have quantified encounter rates with prey, the factors that influence them, and the relationship between encounter rate and kill rate. The study’s primary motivation was to determine the relationship between prey density and encounter rate in understanding the mechanism behind the functional response. Elk (Cervus elaphus Linnaeus, 1758) population decline and variable weather in northern Yellowstone National Park provided an opportunity to examine how these factors influenced wolf (Canis lupus Linnaeus, 1758) encounter rates with elk. We explored how factors associated with wolf kill rate and encounter rate in other systems (season, elk density, elk group density, average elk group size, snow depth, wolf pack size, and territory size) influenced wolf–elk encounter rate in Yellowstone National Park. Elk density was the only factor significantly correlated with wolf–elk encounter rate, and we found a nonlinear density-dependent relationship that may be a mechanism for a functional response in this system. Encounter rate was correlated with number of elk killed during early winter but not late winter. Weak effects of snow depth and elk group size on encounter rate suggest that these factors influence kill rate via hunting success because kill rate is the product of hunting success and encounter rate.

scholarly journals Effects of 1988 Fires on Ecology of Coyotes in Yellowstone National Park: Baseline Preceding Possible Wolf Recovery

1992 ◽  
Vol 16 ◽  
pp. 179-183
Author(s):  
Robert Crabtree
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Initial Density ◽  
Substantial Reduction ◽  
Habitat Type ◽  
Late Winter ◽  
Density Estimates ◽  
Breeding Groups ◽  
Snow Conditions ◽  
Territorial Group

Sixty-five healthy coyote (Canis latrans) adults and 53, 8-12 week old pups captured at dens were radio-tagged in the Lamar Valley and Blacktail Plateau areas of the northern range of Yellowstone National Park. Adults range in age from 1 to 11 years and averaged nearly 3 years old. Territorial packs in both study areas are adjacent, non­overlapping, contiguous, and averaged 15 km2. Based on information the last three winters and data collected from 1946 to 1949, territorial areas are traditional and have changed little in the last 45 years. We estimate that 85 to 90% of coyotes on the northern range belong to packs. A territorial group or pack during the winter consists of 2 alpha individuals, 2 or 3 beta adults, and 2 or 3 adult-sized pups (average pack size = 7). Only one radioed adult coyote has died since May of 1992. Twenty­ four of 53 pups have died between the ages of 3 and 9 months old. Population productivity ranges from 1.8 to 2.5 pups recruited per territory. The reproductive failure rate among breeding groups averaged 15% during 1990 and 1991. Initial density estimates are 1.4 coyotes per square mile. Intensive foraging observations were conducted from January through June 1991 (353 hours) and from November 1991 through April 1992 (1100+hours). Focal observations collected from January-June 1991 resulted in 427 capture attempts on small mammal prey with 162 (38%) successful. Habitat type played a key role in the success rate. Preliminary analysis of the November 1991 to April1992 data indicated a substantial reduction in prey attempts and prey success. This reduction was mostly a function of harsh snow conditions in early winter and abundlint elk carrion in late winter. Over eighty ungulate carcass were located this winter in the 2 study areas. However, small mammals, especially voles, dominate the diet with ungulate remains becoming important in May through July (presumably elk calves) and late winter (mostly scavenging). We have documented numerous successful and unsuccessful predation attempts on ungulates in our study areas. Coyotes appear to impact ungulate numbers in 3 ways: predation on calves and fawns shortly after birth (up to 8 weeks), predation on short-yearlings and adults during winter, and indirect impact from harassment of other predators at ungulate-kills. Coyotes may be the major ungulate predator on the northern range due to cooperative social and foraging behavior, their ability to take advantage of vulnerable ungulates, and their high population levels. Wolf extirpation has probably resulted in high coyote population densities and coyotes have, at least, partially slid into this vacant niche.

The effect of habitat type and seasonal conditions on fauna in two areas of the Tanami Desert

2001 ◽  
Vol 28 (3) ◽  
pp. 247 ◽  
Author(s):  
Rachel Paltridge ◽  
Richard Southgate
Keyword(s):  
Species Richness ◽  
Small Mammals ◽  
Habitat Type ◽  
Relative Importance ◽  
Significant Difference ◽  
Central Australia ◽  
Species Richness And Abundance ◽  
Taxonomic Groups ◽  
Track Counts ◽  
Capture Rates

Australian deserts are characterised by highly patterned plant productivity and an extremely unpredictable climate. The Tanami Desert in central Australia is dominated by vast sandplains interspersed with more productive habitats such as palaeodrainage lines. During 1996 and 1997 fauna surveys were conducted in two areas of the Tanami Desert to investigate the relative importance of palaeodrainage habitat for fauna under different seasonal conditions. The two areas were at latitudes separated by approximately 400 km, and during the study period the northern study area (Tennant) received considerably more rainfall than the southern study area (Kintore). The species richness and abundance of a range of taxonomic groups were compared between the two study areas and between palaeodrainage habitat and adjacent sandplain habitat. The only significant difference between habitats was that small reptiles were more abundant in sandplain than palaeodrainage habitat. Overall, bilbies, bustards and macropods were significantly more abundant at Tennant than Kintore, but significantly more small mammals were captured at Kintore. In both habitats and areas, capture rates, track counts and species richness of reptiles varied significantly with season. The biomass of invertebrates captured also showed significant temporal fluctuations. Burrowing frogs were active only after rain, and birds showed significant fluctuations in abundance and species richness associated with rainfall. The abundance of small mammals did not vary significantly during this study. Overall, local seasonal conditions were generally more important determinants of the abundance of fauna in the spinifex grasslands of central Australia than was habitat type.

Interference competition between gray wolves and coyotes in Yellowstone National Park

2009 ◽  
Vol 87 (1) ◽  
pp. 56-63 ◽  
Author(s):  
J. A. Merkle ◽  
D. R. Stahler ◽  
D. W. Smith
Keyword(s):  
Canis Lupus ◽  
Yellowstone National Park ◽  
National Park ◽  
Interspecific Interactions ◽  
Interference Competition ◽  
Population Level ◽  
Physical Contact ◽  
Gray Wolves ◽  
Factors Influencing ◽  
Rare Opportunity

Factors influencing the outcome of interspecific interactions between sympatric carnivores, along with population-level consequences, are not clearly understood. The reintroduction of gray wolves ( Canis lupus L., 1758) to Yellowstone National Park provides a rare opportunity to study interactions with coyotes ( Canis latrans Say, 1823), which had lived in the absence of wolves for >60 years. We evaluated direct interactions between wolves and coyotes to identify factors influencing the outcomes of interspecific interactions and describe the context and degree of competition and coexistence. Using radio-collared wolves, we documented 337 wolf–coyote interactions from 1995 to 2007. The majority (75%) of interactions occurred at ungulate-carcass sites. Wolves initiated the majority of encounters (85%), generally outnumbered coyotes (39%), and dominated (91%) most interactions. Wolves typically (79%) chased coyotes without physical contact; however, 25 interactions (7%) resulted in a coyote death. Interactions decreased over time, suggesting coyote adaptation or a decline in coyote density. In the majority (80%) of fatal interactions, wolves outnumbered coyotes. However, wolves did not outnumber coyotes in interactions (n = 18) where coyotes chased or attacked/harassed wolves. Our results suggest that wolves are the dominant canid, group size may influence the outcome of interactions, and coyotes must benefit from the access to carrion at wolf-killed carcasses.

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