Parasites and predators are not effective in controlling rising populations of the insect.
In the North two predators and nine parasites have been successfully established to help control the gypsy moth.
When larvae are dislodged by wind or feeding predators they fall or descend on a silken thread and continue feeding in the lower crown or on understory vegetation.
Poison is especially suitable for winter use against predators on some of the great stock ranges of the West, as it can then be employed with little or no danger to useful life.
Both hawks and owls probably prey upon Peromyscus in Mesa Verde, for they are well-known predators upon mice and small rodents in other areas.
One of the predators most commonly chosen for investigating the selective effect upon prey is the wolf (Canis lupus).
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.
Both of these aerial beauties must lay their eggs in water, and their larvae are fully aquatic predators that breathe with gills like fish.
Of course, the chief daily events of life in the desert are eating and being eaten, and predators that favor a certain diet make it their business to be out when their kind of dinner is around.
Few predatorscome away unscathed from a close encounter with those saw-edged blades.
Many predatorsinclude this big-eared, nimble-footed creature in their diets.
Apparently these colors warn predators that the lubber is distasteful.
The loud, continuous song of the male during nestbuilding alerts cowbirds and predators to the presence of a nest.
I am not fully convinced that song from the nest is simply a "foolish" habit, since snakes, the principal predators with which this species has to contend, are deaf.
By contrast, the young ofpredators indulge in wrestling games featuring use of teeth and claws, often beyond the point where fun ceases and anger begins.
Since most of the predators are active all winter, while many of the rodents are in hibernation, this can be a period of famine for carnivores.
Principal predators of the chipmunks are bobcats, hawks, foxes, and coyotes.
The very openness of their habitat prevents the larger predators from stealing up unseen.
It is of interest to note that in many places in the Southwest deer are on the increase, indicating the need for more predators to keep down their number.
The toll taken by all of these predators is high, yet the natural fecundity of the squirrel is so great that the population sometimes gets out of hand and disease has to eliminate the surplus.
This sometimes entails a trip of several miles, a hazardous undertaking for a small animal whose only escape from large predators is in an underground burrow.
It is said to be one of the few successful predators of the porcupine.
She usually is successful in driving away the smaller predators and sometimes intimidates even the largest with her bristling show of fury.
The predators hold a favored place in the esteem of most naturalists.
There they can count themselves safe from further pursuit by the larger predators and have a distinct advantage over those their own size or smaller.
The apparent ferocity with which some predators will kill, not only enough for a meal, but much more than they need, cannot as yet be explained.
The lion also has the dubious distinction of being one of the chief predators of the porcupine.
Perhaps the higher elevations at which they live keep them free from many of the predators to which their lowland cousins succumb, and thus they are able to maintain their numbers with smaller families.
This is a time of great danger, for the youngsters are easily caught by predators which would be eluded with little difficulty by a mature individual.
Eggs are laid by the mother butterflies in distinct places on leaves to avoid predators from feeding upon them.
Microarthropods are of two kinds-the detritivores that feed on the litter attacked by the microbes and fungi and the predators that feed on the detritivores.
Movements made by cottontails escaping from predatorsdiffer from movements made while foraging.
Paths or runways are used by cottontails escaping from predators in dense vegetation along fence lines, in thickets, or brush piles, or in snow that is eight or more inches deep.
In seeking protection from predators or from the weather, cottontails move farther in winter than in summer.
Such behavior suggests that digging predators may be important natural enemies.
Nest boxes are readily used by wood ducks, and their use may increase breeding populations, even if natural cavities are abundant, if predators are excluded.
Woodpeckers aspredators of the codling moth in Nova Scotia.
Woodpeckers are especially important predators of many species of tree-killing bark beetles (Massey and Wygant 1973).
Because of its choice of nesting habitat (very steep cliffs), this cormorant would not have been affected by predators except for the one that went into a very rapid population decline at a time that would fit--the Aleut.
Sea Ice Allows Terrestrial Predators Access to Breeding Sites The formation of ice between the mainland and offshore islands allows the arctic fox (Alopex lagopus) and otherpredators access to the islands used by breeding birds.
The nocturnal habit no doubt evolved because it was advantageous to concentrate on the breeding grounds only under the cover of darkness, when diurnal predators were at a great disadvantage.
At higher latitudes the small alcids have overcome this disadvantage by swamping predators through their sheer numbers.
Most of the breeding birds concentrate on islands where they are vulnerable to predators and to human disturbance.
Rats may be able to exploit a larger percentage of the seabird species on a given island than other introduced predators because they can enter crevices and burrows in search of the birds and their eggs and young.
Although this tern uses a wide variety of nesting sites, it tends to nest on flat sites where access by mammalian predators is easy.
Such habitats are not common in New Zealand because of the ubiquity of the introduced mammalian browsers, grazers, andpredators (Williams 1977).
The effects of introduced predators should be evaluated quantitatively, and if control measures are needed, effective, humane methods should be devised and implemented.
As an example, pursuit diving birds, such as murres and puffins, may be important predators on juvenile salmon in the eastern Bering Sea, but these same birds may compete for food with adult salmon.
The coyote is by far the most persistent of the predators of the western range country; and moreover, it is a further menace because it is a carrier of rabies, or hydrophobia.
Often the fresh tracks of shod horses along wolf and coyote runways are sufficient to cause the predators to leave the trail for some distance.
Tagging the pests with radioisotopes in order to identify the predators which consume them is much simpler because the most efficient predators contain the most activity.
Such experiments may lead to a deliberate increase of certain predators to control injurious insects.
Helpful parasites and predators must first be identified before they can be used.
Even if for some reason the predators died in areas other than within the fissures, thereby accounting for the absence of large bones, coprolites should appear in the deposits if, in fact, the fissures were feeding places.
The rats were more accessible to several predators than were smaller mammals such as meadow voles which were difficult to obtain because of the coating of ice over the fields.
Abandoned houses having one or more of the entrance holes enlarged, as by predators breaking through the side of the house to gain access to the nest, are especially well adapted for occupancy by the cottontail.
The snakes which were potential predators on the rats seemed to be merely utilizing the shelter in these instances, but they may have been lying in wait for prey there.
Deterioration of the habitat, as the developing forest shaded out undergrowth, and inroads of certain predators may have been important in preventing recovery of the population.
Repellant odor may have a protective value in young box turtles but it is unlikely that larger predators would be frightened away or even discouraged by odor alone.
By remaining hidden in a burrow or den therefore, box turtles are fairly well protected from predators but are at a thermal disadvantage.
Nest predators probably have greater effect on populations of T.
There is no evidence that soft-shelled turtles are activepredators on any kind of fish.
There is no evidence that softshells are active predators on any kind of fish, but their known food habits suggest that they compete with game fishes for food.
The Cooper's hawk and red-shouldered hawk also are probable predators as both are known to feed upon small reptiles.
Snakes, especially those of the genera Elaphe, Lampropeltis, Cemophora, Micrurus and Ancistrodon, may include some of the chief predators on the skink.
Of possible predatorsthat might have moved the rock and destroyed the nest, skunk and opossum seemed the most likely, but there was no definite clue as to the predator's identity.
The short-tailed shrew may be one of the major predators on the skink.
Nevertheless many kinds of predators probably utilize it as food, at least occasionally.
The striped skunk (Mephitis mephitis) is another of the predators which probably feeds upon the five-lined skink occasionally on this area.
But there was no great wave of predators immediately.
However, neither Luke Trull nor any extraordinary wave of natural predators had as yet attacked the muskrat colonies.
If this were true, the muskrats he had planted should have known by instinct that there would be predators about.
There had been no predators to keep them alert, whereas the swamp was filled with sudden death in many forms.
But trespass signs or not, there was going to be trouble in plenty if human predators started raiding his muskrats and trouble was always better avoided.
To buy more muskrats for predatorsto kill fell short of wise investment.
Predators could reach them there, but, above and beyond that danger, they'd be locked out of the slough when it froze.
Occasionally other predators visited the meadow in the afternoon, but the grouse came so quietly that these passers-by never knew of them.
He hadn't brought a gun because, though he'd known that predators might be raiding his muskrats, he hadn't expected to catch any in the act.
The number of humans destroyed by these predators annually is negligible but they do themselves destroy an enormous number of small creatures with which the humans compete for their food.
At least two nests on the Lavallette Marsh were destroyed by predators in the course of the breeding season of 1955.
Habitually cottontails escape predators in partly open terrain offering retreats such as low, thick brush, rock piles, and cactus patches; but on open ground beneath dense chaparral, cottontails may be vulnerable to predation.
The success of gray foxes as predatorsin the chaparral is probably due in large measure to their agility amid dense cover.
Coyotes, house cats and raccoons were identified aspredators on voles in the study areas.
Predation, as a general rule, does not significantly affect densities of populations, but large numbers of predators concentrating on small areas may rapidly reduce the numbers of prey animals.
The rattlesnakes probably were less important aspredators on voles than on other small mammals more common in the usual habitat of these snakes.
It was eaten frequently by almost all of the larger vertebrate predators on the Reservation and was, seemingly, the most important food item of the long-eared owl.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "predators" in a variety of sentences. We hope that you will now be able to make sentences using this word.
