A few records of predation on blue racers by other reptiles on the Reservation and Rockefeller Tract were obtained.
Predation on birds is relatively uncommon, and in most instances it involves the eggs or nestlings, or fledglings still slow and clumsy and incapable of sustained flight, or, occasionally, injured adults.
Because of their virulent dermal secretions, bufonid toads are avoided by many kinds of snakes and predation on them by the racer probably is unusual.
The general trend may be explained by the fact that in May most small mammal populations have a high proportion of young of the year, and these young are especially vulnerable to predation by the snakes.
Stickel kindly made available at my request records of predation on racers from the food habits files of the U.
Perhaps certain mammalian predators are even more important natural enemies than are raptorial birds, but records of predation on racers by mammals are few.
Further records of predation on racers by raptors were obtained from the U.
Loomis helped me in various ways with the field work, and made available his personal field notes with records of predationon Eumeces by various snakes.
Several authors have recordedpredation on Eumeces fasciatus by snakes of various kinds in captivity.
I have been able to find only a few specific references to predation on it.
For some of the many prey species the effect is certainly negligible, but for others its predation may be a major ecological factor.
With such added impetus to its reproduction the species might be able to withstand greatly increased predation pressure, or other mortality factors.
Skinks may have tended to wander away to more favorable situations or may have been more subject to predation than those elsewhere, since the incidence of recaptures was relatively low.
Various early records and statements pertaining to predation on small vertebrates by five-lined skinks probably pertain in most cases to E.
The effects of predation upon animal populations are complex, and predation is often a by-product of population rather than a controlling factor.
Predation upon grasshoppers, especially in summer and early autumn, benefits the farmer by helping to stabilize populations of grasshoppers.
More investigation is required to determine the significance of crow predation upon insect larvae in this area.
However, this is not harmful predation because as the root grows, a bark develops around the hyphae.
With the decline of organic matter, new problems with plant and animal health gradually developed while insect predation worsened and profits dropped because soils declining in humus need ever larger amounts of fertilizer to maintain yields.
Further verification ofpredation on mammals, reptiles and amphibians by this species is needed.
Most published references to the food habits mention predation on small vertebrates, especially lizards, but including also snakes, toads, rodents, and even rabbits.
Predation on vertebrates must be rare, and perhaps requires further verification in view of the rather vague character of the records so far published.
Absence of eggshells in the vicinity suggests predation by snakes.
Owl predationin Pennsylvania, with notes on the small mammals of Delaware County.
As in the case of channel catfish, I suspect that disturbance of a flathead in the early stages of guarding the nest results in destruction of the nest either by the guardian fish or by predation resulting from its absence.
In addition, predation on young channel catfish is increased in clear water (Marzolf; Davis, loc.
Bryan of Erie indicated that channel catfish, when disturbed in the early stages of guarding the eggs, either eat the eggs and abandon the nest or leave the nest exposed to predation by other animals.
Predation by owls in the Sierran foothills of California.
Young in the nest would seem to be especially susceptible to predation by the pilot black snake.
Few actual records of predation on woodrats were obtained because of their scarcity during most of the period covered by our study.
First litters of young, born in early March, are already well grown, and past the age of greatest susceptibility to predation before the snakes emerge from hibernation in late April or early May.
The female woodrat's habit of dragging the young attached to her teats as she flees from the house at any alarm must save many litters from predation by the pilot black snake.
The newly metamorphosed young often are forced to remain at a pond's edge for many days, or even for weeks, by drought and they must be subject to especially heavy predation by ranid frogs.
Freedom from the pressure of predationprobably exerts a direct influence on formation of species.
As mentioned previously, nonadaptive modifications may be perpetuated where the "weeding-out" process by predation is not an influence.
The few records of mammal and bird eating hawks in Micronesia indicate that predation on insular vertebrate populations from this source is at a minimum.
Thus, before the advent of man the factor of predation may not have been of great consequence.
The absence of the pressure of predation should remove a certain amount of control on the population turn-over.
A local study of predation upon hares and grouse during the cyclic decimation.
Turtles moving about sporadically in late autumn may be quickly chilled by a sudden drop in temperature and therefore be more susceptible to predation than at other times of the year.
Although small box turtles may occasionally be caught and killed by adults in nature, this seems not to constitute a major source of predation on the young.
Capacity to recover after serious injury is great but there is increased chance for secondary injury, infection, and predation in the period of recovery.
The incidence of predation on eggs and small juveniles is far greater than on older juveniles and adults.
Young are more vulnerable to predation and injury because of their small size, soft shells, and immovable plastra.
I have found little direct evidence of predation in the course of this study.
The selective effect of predation on prey populations is of significance in studies of evolution and population dynamics.
Relative rates of predation on deer of various ages, based on comparisons of the ages of wolf-killed deer with those of a theoretical population (dashed line) and those of the hunter-killed population.
Thus it is not surprising to learn that deer which succumb to wolf predation are generally weaker, older, or abnormal compared with the total deer population (Pimlott et al.
Selective predation can be an important agent in the process of natural selection, and it influences the extent to which predators limit the numbers of their prey.
However, only recently has it been shown that this generalization may extend to predation on the smallest hoofed prey of the wolf in North America, the white-tailed deer (Odocoileus virginianus).
The Effect of Snow Conditions on the Vulnerability of White-Tailed Deer to Wolf Predation L.
It is concluded that wolf predation on white-tailed deer in the study area during winter generally is selective in that it tends to remove members of the prey population that are old, debilitated, or abnormal.
This was evidenced by kills that were left partly or completely uneaten, and by a higher rate ofpredation by radiotagged wolves and their associates.
Although this might also reflect the influence of wolf predation on female fawns, it probably is more a result of the greater movement of bucks during the hunting season, which overlaps with the rutting season.
Wolf movements, activities and predation impact on a wintering deer population in East-Central Ontario.
The transition from peace to predation therefore depends on the growth of technical knowledge and the use of tools.
The conventions of the business world have grown up under the selective surveillance of this principle of predation or parasitism.
Jehl (1972) attributed the extinction of the Guadalupe petrel to predation by cats, in combination with the destruction of vegetation by goats.
Increases in many seabird populations over the last 75 years have been generally associated with relief from predation by humans such as the fowlers, eggers, and plume hunters of the 19th century.
Most authors have assumed that all such fluctuations reflect human disturbance of the natural system, because of the obvious effects of human predation during the last 200 years.
The distribution of horned puffins may not have been altered significantly, since they are relatively free from fox predation in their rock crevices.
In our discussion, we mainly consider predation by birds on commercial fish and competition between birds and commercial fish for food.
Imber (1974), however, provided data concerning the magnitude of rat predation on diving petrels and storm-petrels on some New Zealand islands.
In two instances, it is known that the occurrence of marine birds and the early life history stages of fish coincide so as to result in both potential predation on the fish by the birds and competition for food between the fish and the birds.
In their juvenile stages, many demersal fish frequent the near-surface waters (Table 3), where they become vulnerable topredation by piscivorous marine birds.
Although herring are particularly vulnerable to predation in spring and summer, they are available to marine birds during most of their life.
The effect of scoter duckpredation on a clam population in Dabob Bay, Washington.
Temporarily abandoned chicks and eggs are susceptible to predation by gulls or jaegers.
Food Habits and Predation The translocated wolves apparently scavenged more in Michigan than in Minnesota, at least shortly after their release.
Additional records cited in the section on intraspecies predation (p.
Of two species, the one producing the more young probably would be subjected to more parasitism andpredation than the species producing fewer young.
Although predation by carnivores would be expected to be higher on P.
Predation by the long-eared owl was especially heavy; remains of voles were identified in 72 per cent of its pellets examined.
The population of voles in that area was probably reduced somewhat as a result of predation by owls.
Shrew predation and vole populations on a limited area.
There is reason to believe that young voles, unable to leave the nest, are subject to predation by cotton rats.
An analysis of mink predation upon muskrat in north central United States.
The shape and size of some of the excavations suggested predation on skink nests.
On other occasions raccoons were caught in the steel traps, and their raids were characterized by systematic and dextrous opening of the mouse traps and, frequently, by predation on the small mammals inside them.
The horned owl is perhaps the most important natural enemy of the opossum on the Reservation, and instances of owl predation on opossums were noted.
White excreta of a large bird beside the carcass indicated predation by a raptor, probably a horned owl.
Numerous instances of horned owl predation on opossums have been recorded in the literature.
Adult cottontails seem to be secure from opossum predation under ordinary circumstances.
Softshells are principally carnivorous; the food consists mostly of crawfish and insects; there is evidence of cannibalism involving predation on first- and second-year-old turtles.
They are more sluggish at this time and more vulnerable to predation than later in the season when temperatures are optimal.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "predation" in a variety of sentences. We hope that you will now be able to make sentences using this word.
