Service to Nature Performed by Birds

Nature when left to herself has balanced these forces evenly, so that the insects are kept by birds and other natural checks from becoming excessively numer­ous and destructive. But man has upset Nature's balance in many ways. First, new crops have been introduced; second, forests have been cleared and crops raised on larger areas, thus furnishing more food for insects and allowing them to increase; third, many insects have unwittingly been intro­duced into the United States from other countries; and fourth, most strange and unbelievable of all, man has wantonly destroyed the birds, Nature's check on the increase of injurious insects.

Service performed by the birds. The great service that birds and other insect-enemies are now render­ing to man is in destroying enough insects so that the remainder will not do excessive and uncontrollable damage. The birds can never utterly destroy any kind of insect, and this might prove undesirable even if possible, but they help to keep them in check to such an extent that man is able to cope with those that are left and thus raise his crops successfully.

If man were suddenly deprived of the services of the birds, this would allow insects to increase to such an extent that it would render it many times more difficult to raise crops; and some bird-students say that without the aid of birds it would not be possible to raise crops at all on account of the enor­mous number of insects that would prey upon them.

How serious the results would be if we were de­prived of the service of the birds, it is difficult to say exactly, but enough is known regarding the balance that Nature has established between birds and in­sects, so that we are sure that the birds are among man's greatest friends in his warfare on injurious insects. Amount of food eaten by birds.

One thing about birds that makes them such effective checks on in­sects is the enormous amount of food they require. The temperature of their blood is between 102 and 112 degrees, from 4 to 14 degrees higher than that in man, and large amounts of food must be eaten to maintain this high temperature.

The blood courses through the vessels with great rapidity, driven by the heart, which beats one hundred and twenty times a minute when the bird is at rest, and faster when the bird is in motion. And the digestive sys­tem is so constructed that it digests very rapidly the bird's food, which is then taken by the blood to the various parts of the body, where its oxidation main­tains the high temperature of the body.

Probably the whole process of digestion and assimilation of food may take place in an hour and a half, so that during the day the bird may eat enough food to fill its stomach ten or twelve times. The study of birds in the field and the examination of the contents of birds' stomachs show that a bird devours enormous quantities of food.

Records of field observations of birds are con­densed in the following table. These are taken from the reports of Edward H.

A few examples of the number of insects found in the stomach of a single bird are given below in the table. These figures are taken from the reports of the Bureau of Biological Survey: ­

Below are given some estimates that have been made of the number of insects destroyed by birds: ­Professor E. D. Sanderson estimates that the chickadees in the State of Michigan destroy annu­ally about 8,000,000,000 insects.

In the States of Virginia and North Carolina it is estimated that the bob-white alone eats 840 tons of insects from June 1 to August 1.

Mr. Chester A. Reed estimated that in the State of Massachusetts the birds devour !t1,000 bushels of insects each day during the summer season.

Mr. Bruner gives the following estimate of the number of insects destroyed in the State of Nebraska:­

Allowing 25 insects per day as an average diet for each individual bird, and estimating that we have about' one and one half birds to the acre, or in round numbers 75,000,000 birds in Nebraska, there would be required 1,875,000,000 insects for each day's rations. Another Nebraska naturalist has estimated that the birds of that State eat 170 carloads of insects per day.

It has been calculated that the birds of New York State destroy more than 8,000,000 bushels of noxious insects each season.

Value of nestling birds. Special attention may be called to the great service performed by birds when feeding their young. As explained in a previous chapter, nestlings require large amounts of food, being fed every few minutes from sunrise to sunset.

This destruction of insects comes at a most oppor­tune time, when the insects are present in great numbers and before the parasitic insects can be de­pended upon to reduce the pests. The chief food of the nestlings is insects. Even when the adults feed also on seeds, the young at first are fed largely on insects. The most common kinds of food of nestlings are caterpillars, grasshoppers, and spiders.

A sug­gestive estimate of the money value of nestlings has been made in a government publication, from which the following is taken:­

During the outbreak of Rocky Mountain locusts in Nebraska, in 1874--77, Professor Samuel Aughey saw a long-billed marsh wrencarry 30 locusts to her young in an hour. At this rate, for seven hours a day, a brood would consume 210 locusts per day, and the passerine birds of the eastern half of Nebraska, allowing only 20 broods to the square mile, would destroy daily 162,771,000 of the pests.

The average locust weighs about 15 grains, and is capable each day of consuming its own weight of standing forage crops, corn and wheat. The locusts eaten by the nestlings would therefore be able to destroy in one day

174.397 tons of crops, which at $10 per ton would be worth $1743.97. This case may serve as an illustration of the vast good that is done every year by the destruction of insect pests fed to nestling birds.

birds nature - Yahoo! News Search Results
birds nature - Yahoo! News Search Results

Birds could get used to mild weather
This winter, if you can call it that with the lack of snow we?ve experienced, has produced some interesting bird observations. Not only are the regular feeder species being seen, but so are a number of those birds usually referred to as summer residents.[...]
Rare birds spotted at nature reserve
RARE birds not seen in the South West for eight years have been spotted at a Portbury nature reserve.
Birds of a Feather: Genetic Classification Reveals Pigeons' Exceptional D...
Birds of a Feather: Genetic Classification Reveals Pigeons' Exceptional Diversity [Slide Show]
Video: Thousands of birds plague Kentucky suburb
European starlings cloud the sky every evening, polluting the town. Now some angry residents are fighting back. NBC?s Kerry Sanders reports. (Nightly News)
Birds? survival dependent on wetlands
The arboretum (tree garden) near the Ooty Lake was in focus on Thursday with the Public Awareness Association of Udhagamandalam choosing it as a venue for the observance of the World Wetlands Day.
For the birds
Nanaimo Museum exhibit opens Friday (Feb. 3).
Birds: entertaining backyard friends
With each change of season, it is so exciting to see what fine-feathered friends will come to my backyard. In the winter, there are the seed feeders, suet feeders, and berry-laden shrubs and trees...
Nature-Based Tourism Interview with Mark Pretti
What is nature-based tourism? What does it involve and how can it be preserved in Mexico and elsewhere? What are some of Mexico's nature-based hotspots? This article which spotlights an interview with naturalist and tour leader Mark Pretti addresses those questions and "naturally" much more.
Rescuing the Birds Many Love to Hate
At the core of New York City Pigeon Rescue Central are pigeon lovers, animal activists and eccentrics who dedicate themselves to the much-maligned birds? welfare.
Birds falling victim to Siberian chill
Just a few day of biting cold may already have cost Denmark 25 percent of its smallest birds, including species such as the goldcrest ( fuglekonge ), Eurasian wren ( gærdesmutte ) and European robin ( rødhals ), all of which are especially vulnerable to cold temperatures.