SOME VERTEBRATE PEST PROBLEMS IN JAPAN

The wildlife in Japan does more damage in outbreaks in forestry than in agriculture. Hares annually damage in excess of 250 thousand acres. Voles annually damage 50 to 100 thousand acres; in some areas great damage may occur suddenly. The giant flying squirrel damages areas of replanted trees in southern areas of Japan. The Himalayan black bear strips the bark on tree trunks. In agriculture, the sparrow and the duck do an excessive amount of damage in rice fields, and the boar does conspicuous harm in the plowed fields of mountain villages. In Okinawa, sugar cane is attacked by Rattus rattus, and in some years the loss is severe. Of even greater concern is the damage done by introduced vertebrates. The gem-faced civet was imported from Taiwan. Similarly introduced from Taiwan, the tree squirrel increased on Izu-Oshima. The nutria was introduced in 1940; they escaped from cages in Southern Honshu and have increased.

THE EFFECT OF INTENSE LIGHT ON BIRD BEHAVIOR AND PHYSIOLOGY

It has been known for centuries that light (photoperiod) is possibly the major environmental stimuli affecting bird behavior and physiology. The length of the light period stimulates the breeding cycle, migration, fat deposition, and molt in most species of birds. Therefore, it is only natural that one would think of using light as a means of bird control. In fact, light has already been used as a bird control; flood-light traps have been used to trap blackbirds (Meanley 1971); Meanley states that 2000-W search lights have been used to alleviate depredation by ducks in rice fields. Pulsing light is already used on aircraft, aircraft hangers and high towers as a means of detourinq birds (Schaefer, 1968). With some positive results already obtained with light as a bird control, the next step is to see if a better light source (the laser) might not have a greater effect. The laser is basically an intense and coherent light with extreme directivity and, thus, might have greater influence on a bird’s behavioral and physiological responses.

AN OVERVIEW OF DEPREDATING BIRD DAMAGE CONTROL IN CALIFORNIA

To many people, California is synonomous with Disneyland, freeways, Los Angeles smog, Yosemite, the California missions, or for you bird aficionados, the California Condor. But do you think about California when you eat strawberry shortcake? You should -- California leads the nation in strawberry production. How about artichokes? California produces over 98% of the artichokes raised in the United States. Dates? California produces over 99% of the dates in the United States. Yes, California is all of these, and it is much more. California may well be the most diverse state in the United States. Within its 100.2 million acres, California has the lowest place in the U.S. in Death Valley and one of the highest mountains with Mt. Whitney. Because California is such a diverse state and has a wide variety of micro- climates, it supports a uniquely diverse agriculture. Agriculture uses only about 36 million acres of its total 100.2 million acres, and most of the cash return from crops is produced on 8,6 million acres that are irrigated. California produces about 250 crops and livestock commodities (excluding nursery crops) and provides the U.S. with about 25% of its table foods. California leads the nation in the production of 46 commercial crops and livestock commodities; its farmers and ranchers marketed $8.6 billion of crop and livestock products in 1975, and the state’s harvested farm production in 1975 set a new record at 51.1 million tons. HISTORY OF BIRD PROBLEMS Records such as this are not achieved without some risk. Crops growing in Cali- fornia have always had competition from many types of vertebrate pests. The wide variety of crops grown in California and the varied climates and situations in which they are grown has resulted in many different species of birds damaging crops. Birds have compet- ed with man for his crops since the dawn of agriculture. McAtee (1932) cited examples of bird damage that occurred in a wide variety of crops in California during the early 1900s. During the 1920s, many requests for Information and relief from damage caused by a wide variety of birds, culminated in the assignment, in May 1929, of two biologists, S. E. Piper and Johnson Neff, of the former U.S. Bio- logical Survey, to initiate field studies in California. In cooperation with the Cali- fornia Department of Food and Agriculture and County Agricultural Commissioners, the study was to determine the problems and devise control procedures relative to bird depredations. Piper and Neff found such damage as Horned Larks pulling sprouting crops, House Finches disbudding deciduous fruit trees and devouring mature fruit. Blackbirds were a problem in the rice crop. Early controls were varied and, for the most part, lacked effectiveness. Flagging of fields was common to deter Horned Larks. Windmill devices were tried to frighten birds. Shooting to kill birds was common; scarecrows were.used. The six-year study brought forth the basis of most of the depredating bird control techniques still in use in California. At the end of the study, these two biologists compiled a book called “Procedure and Methods in Controlling Birds Injurious to Crops in California.” This was and still is the “Bible” for bird damage control techniques used in California. The thorough investigations conducted by these biologists resulted in techniques that have remained valid in California for over 40 years.