India is said to be copiously rich in avian wealth (about 1200-over 3000 species, Ali & Futehally 1967, Negi, 1993), many of them being ornamental, recreational, environmental, medicinal, food and agri-insect-pests controlling value. A great variety of climate in country enriches India with seasonal avi-fauna from other parts of world to tender service of reduction of entomeload in agriculture.

In light of consecutive strongly felt need to reduce indiscriminate chemo-pesticides use in agriculture causing alarming health and environmental hazards, identification and study of bio-control agents other than micro-fauna (bacteria, spider, flies etc.) such as avian predator is also matter of particular significance and urgency (Ali & Futehally, 1997). Frequent call and even inaction of legislation for reducing pesticides use e.g. Scandinavian countries enacted legislation, Denmark's call for 50% cut by 1997, Sweden targeted 50% reduction within 5 years and these leads being already followed by other countries and further weightage to such activity.

An attempt to identity avi-wealth and to assess its status as predators of mainly underground pests of potato was made during September, 1996 to March, 1997. A host of battle, weevils, worms, grubs, termites, ants, aphids, hoppers, bugs, flies, caterpillars, borers, moth, loopers, crickets, thrips, snails and slugs etc., belonging to different generous, species and numbering about 80 out of over 100 potato pests reported to damage this crop in India by goggling up both under and above ground parts or as vectors of diseases. For this purpose, a farm of about 300 hectares at Macchri under district Meerut mostly and largely monocultured with potato over about 20 years, thus creating congenial home for regional potato pests was selected. Birds visiting farm during period from field preparation to harvesting operations were closely watched and identified with the help of descriptive cum pictorial book namely, `Common Birds' written by Salim Ali & F. Laeeq (1967) published from NBT, India, A-5, Green Park, New Delhi 110 016.

Attempt made resulted in identification of 17 avi-predators useful in reduction of regional potato pests (Table 1). They were noticed to pick-up insects during all field operations even from standing crops but particularly during irrigation and soil disturbance at mechanical harvesting, interculture and field preparation operations. They were seen picking up grubs, caterpillars, worms, beetles and other insects. Most active avi-predators were Myna Acridotheres tristris, Housecrow Corvus splendens, Black Drongro Dicrurus adsimilis, Redwattled lapwing Vanellus indicus large pied wagtail Motacilla caspica & maderaspatensis, Cattle Egret Bulbulcus ibis and Pied Myna Sturnus contra. Most close followers of plough to capture insects were seen to be cattle egret followed by common myna redwettled lapwing, house crow and sometimes black drongo. In absence of cattle egret, common Myna turned to be prime follower of plough. Most close air followers of plough were common myna followed by house crow and rarely cattle egret. Number of common myna was seen also to exceed over all avi-visitors followed by house crow, black drongo and cattle egret. Most active ones were seen to assembling large flocks during morning hours (7-8 A.M.) at ploughing, harvesting and intercultural operations. Number reduced after 11-12 p.m. first by cattle egret and then by house crow. Common myna, large pied wagtail, black drongo, redwattled lapwing and some other small birds (plover etc.) continued to tender service of insect-capturing till day light of different months of the period.

House crow, black dronge, sometimes common myna were seen to be in habit of snatching insect picked by other avi-fauna and chasing away them for the same. Black drongo, and sometimes common myna when in large flockes dared to chase away even house (row. Black drongo was seen sitting on large soil clodes or other perches and then hurriedly flying to spot of insect available. This mode of insect collection was too seen in small blue king fisher and chers Gyps bengalensis & indicus or Saras cranes Grus antigone gliding down sometimes to field from nearby tall trees or sky blue jay were observed to be great scarer of all birds seen. Although these birds were noticed to be present but it appeared that they did not feel small insects sufficient for them. They hence used to fly away after small half in the field. Small birds like large pied wagtail and some plovers etc., were seen short, long flying or running all over field to capture insects.

Table 1. Avian predator of potato pests.

[Reference Book: Ali, S and Fatehally, L. 1967. Common Birds, NBT India, A-5 Green Park, New Delhi 1100016]

* Most active avian predators of pests.

Common myna, cattle egret, redwettled lapwing, tree pipit, large pied wagtails, common sandpiper, some rare visitors like herons, saras cranes and other egrets were noted to be most active water wandering insect catchers while remaining to be outside watchers and entered water of irrigated field when felt necessary. Some of them like Indian roller & black drongo etc., were recorded to pick up insects from standing water without entering on their feet. Barring redwattled lapwing and cattle egret, all birds under study were also recorded to capture insects from piles of potato haulms and other garbages on farm.

None of the birds under watch was found to eat any part of potato plant although several of them reported to be herbi-cum-insectivorous or herbi-cum-carnivorous. Exception was house crow that was noticed flying away with cut or rotten potato sometimes, attempting to eat recultantly but leaving half eaten. Recorded birds appeared to be completely safe predators of regional above and especially underground pests in potato without any damage from them to the crop, possibly in other root, rhizomatous, tuber crops and sugarcane.

Strictly insectivorous of them in all horticultural and agronomical crops while herbi-cum-insectivorous ones strictly up to field operations, but not after sowing, are also safe avian reducer of entomo-load. Several birds like vulcher, owel, etc., are reported to be alive reducer of rodents.

Only harms excepted from avi-insectivorous are spread of diseases especially viral ones and death of some useful lives like earthworm etc., and predators of insects (some spider & dragon flies etc.). The exact value of avi-insectivorous in reducing under ground pests under field conditions is always difficult to determine due to one or other reasons. But a difference in presence of kind/number of pests between a square disturbed and non-disturbed plot exposed to bird visit may generate some idea. Not already existing sporadic shallow study in Indian agri-literatures but a comprehensive scientific investigation led by a team of agri-entomologists (insect identification etc.), ornithologist (bird identification etc.) and botanist (vegetation identification etc.) may lead to efficient workable avian based technology of reducing entomo-strains, protection against damage done by herbi-cum-insectivorous birds and even exploitation of herbi-cum-insectivorous birds without their damage in agriculture.

Suggestions: Read as below harvesting efficient services of reducing agri-entomo-strains on agricultural farm by avi-fauna.

• Permanent water source.
• Boundary plantation of vegetation of non-food value to man but of food, resting nesting value to avi-insect-predator on mixed farm of root, tuber including potato, rhizomatous, bulbous selected plantation crops (coconut, rubber, tea etc), cut flowers and sugarcane crops. Need research to identify such vegetation.
• Boundary plantation of vegetation of non-human-food value but of nesting and resting value to strictly insects and carnivorous birds on farm crops susceptible to bird damage. Research needs to identify such vegetation.
• Cultivation of bird amaze free crops like coconut, most cut flower crops, bel and colosassia etc., to force birds to feed upon insects.
• Frequent deep required soil disturbance, irrigation and exposure of field of avi-insect-predators for acting upon.
• Identification of regional/climate/crop specific avi-insect-predators in addition to general types coming to all crops, Reason being, not all birds visit same crop, region climate and season.
• Restricted use of chemo-insecticides lethal or repelling avian insectivorous from visiting field itself.
• Development of non-toxic spray enabling plants to repel avi-cum herbivorous but attracting insectivorous birds.
• Minusing genes responsible for herbivoracity from insect cum herbivorous birds (House crow, poultry birds, ducks etc) and induction of genes liable for easy to tame, strong identification of residence to return same, response to human inviting call from white pigeon into them, or incorporation of genes responsible for strong insectivoracity from strictly insectivorous birds into white pigeon through advanced bio-techniques may lead to development of bird stocks of enhanced insect controlling or multipurpose value. Attempts to breed out or breed in desirable or undesirable characters will be more useful in birds with capacity to escape from predator or capacity by immediate flying away. Capacity to escape from catching lacks in weak fliers (poultry bird or ducks etc.). Idea appears to be funny, But in light of recent advancement of bio-technology does not seem to be so funny. Synthesized birds for this purpose should be strong insectivorous nature, free from herbivoracity, able to identify residence to return same, able to respond human inviting call and escaping from catching, able to forage within restricted area, need not to be caged always. These all qualities do exist in white pigeon which has also good value in Tripura and tamed for the same but lacks strongly in insectivoracity. Needless to mention that wide variability in these characters does axise among birds belonging to same species, genera, family, class for this purpose. 

Birds name changes - a brief information