Animals are an important part of our ecosystem. Some of them are useful and some are harmful to agriculture. In this article some animals and birds are mentioned which are useful to agriculture. Along with these, the management methods to protect crops from some species of harmful birds and rodents are also described.
1. Useful Animals:
Both insectivorous and rodentivorous birds are included in useful animals. Ninety eight per cent of total bird species in India are useful to agriculture. Some of these are Drongo, Lapwing, Myna, Blue jay, Owl, Cattle Egret and Hoopoe.
A single pair of House Sparrow feeds insects to its young ones about 250 times a day. Predatory birds like owls, falcons, eagles, kites etc. eat a large number of rats and mice. Because of these reasons, these birds should not be killed or harmed. A single owl normally eats 4-5 rats a day.
Some of the useful birds are given below:
(i) Blue Jay:
It has rufous-brown breast and pale blue abdomen and is of Blue Rock Pigeon size. Insects form its main diet. It makes its nest in cavities of the trees.
(ii) Red-Wattled Lapwing:
Its colour is bronze brown from above and, white from below. The head, breast and neck is black in colour. Its food comprises mainly of insects and snails. It makes its nest on ground.
(iii) Cattle Egret:
The colour of this bird is white with yellow beak. It is often found following ploughing tractor and eating insects. This bird makes its nest in the form of colony on the trees.
(iv) Spotted Owlet:
This bird is of grayish brown colour with white spots. The colour of its eyes is yellow. Its food consists of insects, mice and lizards. It makes its nest in the cavities of the trees.
(v) Hoopoe:
This bird has black and white strips on wings, tail and upper part of the body. It has fan shaped crest and long gently curved bill. It makes its nest in the cavities of the trees. Insects form its main food.
Measures to protect birds in the surroundings are given below:
(a) Traditional trees like peepal, tahli, kikkar and toot should be planted to provide natural habitat.
(b) Breeding facilities to birds should be provided by installing wooden and earthen artificial nests on trees and other suitable places.
2. Harmful Animals:
Rats are the most important harmful animals. They cause heavy losses to the crops. These cause more damage at seedling and ripening stages of the crops. The average damage to sprouting and ripening wheat crop have been recorded to be 2.9% and 4.5 % respectively.
This damage is 1.1% at ripening stage of pea crop and 10.7% at the sprouting winter maize crop. The rodent damage to the maturing wheat crop fields adjoining to sugarcane fields, canals and roads may be up to 25 per cent. Some important species of rodents and their management methods are mentioned here.
I. Species of Rodents:
There are 8 important species of rodents and mice in Punjab. These are Indian mole rat, the soft furred field rat, the Indian bush rat, the Indian gerbil, the short-tailed mole rat, the house mouse, the field mouse, and the brown spiny mouse. Of these, the Indian mole rat is predominant in paddy-wheat and sugarcane growing areas. Bet areas have predominant populations of the Indian mole rat while the kandi region (district Hoshiarpur) has the Indian gerbil and Indian bush rat.
II. Methods of Rodent Control:
A. Mechanical Control:
(i) Killing:
During the irrigation of vacant harvested fields rats coming out of flooded burrows should be killed with sticks.
(ii) Trapping:
Use double chambered multi-catch trap which is developed by P. A.U. It has tunnel type entrance. With this type of trap many rats can be trapped at the same time. There are many types of traps available in the market. Before use wash the traps to remove any odour in them.
In crop fields, place 16 traps/acre covering runways, damage and activity sites of rodents. In houses, godowns, poultry farms etc., place traps (1 trap/4-8 square meter area) along with walls, in corners, behind the storage bins and boxes etc. For use in cold stores, cover the traps by wrapping paper around them.
(iii) Pre-Baiting:
To trap more rodents, pre baiting should be done in these traps. Place 10-15 gm pearl millet, sorghum or cracked wheat or their mixture smeared with 2% groundnut or sunflower oil and 2% powdered sugar for 2-3 days having open entry of traps.
(iv) Trapping of Rodents:
After pre-baiting close the traps by placing 10-15 gm of the plain bait on the piece of paper in the main chamber and a pinch of bait on the smaller piece of paper in the trap tunnel. Now kill the trapped rats by drowning in water. Traps can be used in the same location after an interval of minimum 30 days.
B. Chemical Control:
Method of Baiting:
Zinc phosphide and bromodiolone are being used for baiting for rodents.
(a) 2% Zinc Phosphide Bait:
Smear 1kg of bajra, or sorghum or cracked wheat or their mixture with 20 gm of sunflower or groundnut oil, 20 gm powdered sugar and mix it thoroughly with 25 gm of zinc phosphide. Never add water in this bait.
(b) 0.005% Bromadiolone Baits:
Mix 20 gm of bromadiolone powder, 20 gm of groundnut or sunflower oil and 20 gm of powdered sugar in 1kg of any cereal flour.
Bait Placement and Timings:
1. Baiting in May- June:
During this period, the rat burrows can easily be located in the fields. Close the burrows in the evening and on next day in new reopened burrows insert a paper containing 10 gm of zinc phosphide or bromadiolone bait about 6 inches deep in each burrow.
2. During Mid-February and Beginning of March:
It is most suitable time for killing of rodents. Due to cool weather before this time and due to milking stage of crops after this time, rats do not eat bait.
3. Pre-Baiting:
Pre-baiting is essential for the use of zinc phosphide bait. For this place 1 kg of sorghum or bajra or cracked wheat or their mixture smeared with 20 gm of oil at 40 bait points for 2-3 days. Bait of 1 kg is enough for two and half acres. After this in same manner baiting should be done with 10 gm of bait at 40 baiting points in one acre.
Precautions during Baiting Process:
1. Keep the rodenticides and poison baits away from the reach of children, domestic animals, pets and birds.
2. Mixing of rodenticides should be done with a stick, spade or wearing rubber gloves. Save the mouth, eyes or skin from the rodenticides touch.
3. Household utensils should never be used for preparation of poison bait.
4. Use polythene bags for storage and carrying the poison bait. Bury them after use.
5. Collect and burry the left over poison bait and dead rats from the fields.
6. Zinc phosphide is toxic and there is no antidote for it. In case of accidental ingestion induce vomiting by inserting fingers in the throat and then rush to the doctor. Vitamin K is the antidote for bromadiolone and can be given to the patient under medical supervision.
C. Environmental Control:
Weeds, grasses and bushes should be removed as these provide shelter and food to rodents. Highly infested bunds, water channels and field pavements should be periodically rebuilt to destroy permanent rat burrows.
D. Biological Control:
Owls, kites, hawks, falcons, eagles, snakes, cats, mongoose, jackals and monitor lizards are the natural predators of rats and mice. These should be protected.
E. Integrated Approach:
No single method is 100% effective in controlling rats. Therefore adopt an integrated approach by carrying out different methods at different stages of the crop. The left over surviving rats after zinc phosphide baiting should be tackled with bromadiolone. Zinc phosphide baiting should be carried out in the crop field after a gap of at least two months.
F. Village Level Campaign:
For better results in control of rats, village level anti- rat campaigns should be organized. The campaign should be carried out both in cultivated and uncultivated areas at the same time.
3. Harmful Birds:
Out of 300 species of birds of Punjab, only a few cause damage to crops, fruits, to grains in godowns, in shellers and in grain markets. Rose-ringed Parakeet is one such bird that is not beneficial to agriculture. It is the most harmful bird. It causes damage to almost all grain and fruit crops. It is exclusively harmful to sunflower crop. Doves, Pigeons and Weaver birds damage rice in godowns and shellers, for nearly two crore rupees.
Management Methods:
a. Mechanical Methods:
(i) False Gun Shots:
Make false gun shots at different intervals to scare the birds.
(ii) Use Scare Crow:
Fixing the scare crow i.e. a discarded earthen pot painted to look like human head supported with wooden sticks and clothed in human dress to give a human like appearance is one of the most effective traditional techniques to keep the birds away. Position, direction and the dress of the scare crow should be changed at least at ten day’s interval. The height of the scare crow should be one meter above from the crop height.
(iii) Hanging of Dummies of Crow:
Parakeet is the main pest bird of oilseed crops. Hanging of dummy crow on a stick in the crop damage area should be done. Crows and Mynas will leave that place even parakeets will also not visit that area. The height of stick should be at least one meter above from the crop height and its position should be changed after a gap of seven days.
(iv) Use of Automatic Bird Scarer Machine:
Use automatic bird scarers by shifting their position periodically and supplementing their noise with actual gun fires. The other simplest method is the use of rope crackers. It involves tying of sets of small fire crackers at the distance of 6-8 inches apart and igniting it from the lower end.
The explosions caused by the fire crackers on catching fire at different intervals scare the birds feeding on the sprouting. Fix up the rope crackers in the centre of the field during sprouting stage where as in maturing crops fix the rope on a stick in the periphery of the field.
b. Cultural Practices:
(i) The traditional practice of planting 2-3 border rows of less costly crops like millet, dhaincha equally preferred by birds will reduce the bird pressure to the inside sown cash crops particularly sunflower and maize etc. Moreover, planting of these crops also act as physical barriers/wind breakers and help in preventing lodging of crop during stormy/rainy days.
(ii) As far as possible, sowing of maize and sunflower crop should be avoided at sites most frequently visited by birds or where there are more resting sites like trees, electric wires, building etc.
(iii) To prevent parakeet damage in sunflower and maize crops sowing should be done in bigger area (at least 2-3 acres). Parakeets avoid feeding/venturing in the core of the field, so it helps in lessening bird damage pressure.