Control of some Avian and Mammalian pests

Abstract

• Biology and control of rat and mice. Rodents are a serious threat to agriculture in Pakistan. Effective and ecologically sound programme should be developed to inhibit their depredations. This necessitated a study of those aspects of the life of these pests which were relevant to population management. The present study was focused on some of the reproductive and demographic parameters and predators, of Tatera indica, bandicoa bengalensis, Rattus meltada and Mus musculus, which happen to be the most common rodent pests of agriculture in the croplands of central Punjab. 1. No fertile male of T. indica was recorded in December, and of B. bengalensis and R. meltada in December- January. Fortile males of M. musculus were found round the year. The females of T. indica, B. bengalensis and R. meltada remained reproductively quiescent during December- January, whereas the females of M, musculus bred almost round the year. 2. The annual prevalence of pregnancy in T. indica and B. bengalensis varied widely. The average annual prevalence of pregnancy in T. indica, B. bengalensis, R. meltada and M. musculus was 33.60%, 47.36%, 54.12% and 51.06%, respectively. Pregnancy peaks were recorded in April-May for all the four species. A second pregnancy peak was perceptible in October-November of T. indica and M. musculus, and in August- September for R. meltada. 3. The embryonic liter size in T. indica was 6.76 ± .344 (39), and for B. bengalensis, R. meltada and M. musculus it was 7.40 ± .512 (27), 5.33 ± .249 (46), and 6.17± .287 (47), respectively. M. musculus tended to produce larger litters during December through May, whereas the other three species generally produced larger liters in February- May. The maternal body weight and the number of embryos were significantly related in T. indica, R. meltada and M. musculus. 4. The annual rate of production i.e., the number of young produced per female per year varied greatly in T. indica and B. bengalensis as compared to that of R. meltada and M. musculus. The average annual rate of production for T. indica, B. bengalensis, R. meltada and M. musculus was 47.32, 75.18, 65.78 and 76.63, respectively. 5. The average annual trap success in sugarcane crop was 11.2% The trap success showed two peaks, one in December- January and the other in August-September. In the combined annual samples, the order of dominance was: R. meltada, m. musculus, B. bengalensis, T. indica. The average trap success for the wheat crop was 9. 1%. Peak abundance was recorded in February-March. The order of dominance in the crop was B. bengalensis, T. indica, M. musculus and R. meltada. In fodder-I (Leguminosae) crops the average trap success was 8.4%. Trap success peak occurred in June-July. The order of dominance was R. meltada, B. bengalensis and M. musculus and T. indica was not recorded from these crops. In fodder-II (Gramineae) crops the average trap success was 12.3%. Highest abundance was recorded in June-July. The order of dominance was R. meltada, B. bengalensis, M. musculus and T. indica. In miscellaneous sub habitats (minor crops and alkaline waste) the average trap success was 6.3%. Peak abundance possibly occurred in August-September and the order of dominance was T. indica, M. musculus, B. bengalensis and R. meltada. The seasonal and sub habitat-wise variations in the trap success were not only related to the rates of recruitment to these rodent populations but also to the temporal changes in the area of various sub habitats. 6. Rat and mice infestation of the wheat crop indicated low rodent density in the wheat fields during sowing and early tillering stages. During the late tillering and bootings stages their populations increased by several folds. But density peak was not recorded earlier than the flowering stage. Past this peak, the populations declined rapidly and by the harvesting season rodent density was very low. During the sowing and tillering stages only T. indica and M. musculus were present; during the bootings, flowering and early maturation periods all the four species including R. meltada and B. bengalensis were present; and during late maturation and pre- harvesting period only B. bengalensis were present. Apart from providing sample shade and space, the wheat fields have a surfeit of nutritious food. The rodent exploits these resources intensively and channelize to acquired energy for attaining accelerated rates of reproduction. They must, therefore, be denied these resources and must be annihilated before they get a chance to establish themselves in the wheatlands. For this they must be intercepted in the crops/ sub habitats from where they emigrate. 7. Sugarcane plays an important role in providing proper microenvironment and shelter to rodents in late fall and early winters. The rodent populations of the cane crop had a density peak in October. Past October, their populations began decling and T. indica was not recorded after/ this month. By march two more species, namely R. meltada and M. musculus also vanished; B. bengalensis being the only species left in the cane field. The rodent damaged the cane crop mainly during and before October. Sustained baiting of the cane crop from October through March had no favorable effect on the canes of the treatment fields. This indicated that to inhibit rodent depredations on the cane crop, plant protection measures should be taken earlier than October. 8. Sustained baiting of the wheat crop failed to provide sufficient protection against rodent depredations. But sustained baiting of sugarcane fields for three weeks in December, leguminous fodder crops for six weeks in January-February, and the wheat crop for eleven weeks in February-April in conjunction with intermittent treatment of the rat borrows with zinc phosphide bait provided complete protection to the wheat crop from rodent attacks. Inhibition of rodent populations through sustained baiting is a promising strategy for small farmlands provided he protection measures are not confined to a single crop. 9. Studies on reproduction, infestation and damage patterns of the rodent pests, response of these pest populations to poison baiting and ecological niche of the pests in the agro-ecosystem lead to the development of a strategy for inhibiting their populations in the central Punjab. The salient features of this strategy are a) For sustained baiting chronic poisons such as fumarin, recumin etc. should be used. The various crop should be treated with this poison according to this schedule: sugarcane from September to November, leguminous fodder crops (lucern, shaftal and berseem) and minor crops (pulses, vegetables etc.) in April and May. b) For baiting the rodent burrows zinc phosphide may be used. Rodent burrows of nearby alkaline and sandy tracts should be treated in October of the cane fields soon after the crop is harvested, and of the wheat fields once during the tillering-bootings stage and again during the flowering stage. c) Control measures should cover large areas. Larger the protected area more permanent shall be the effect of control efforts. Preferably, the area to be protected should be bounded by such physical barriers as irrigation canals, highways, railroads, alkaline tracts etc. • Biology and control of house sparrow: 1. The house sparrow (Passer domesticus) spends the night in communal roosts which are mostly located in trees and shrubs with dense and thorny crowns. The sparrows can easily be killed in these nocturnal assemblages. The sparrows began entering the roost 35 to 85 minutes before sunset. The rate of arrival at the roosts generally peaked 5 to 40 minutes before sunset and terminated 1 to 18 minutes before sunset. The number of sparrows in the roosts varied in space and time; the range being 106 to 8278. The duration of arrivals to the roosts was generally longer during breeding season, the pattern of arrival in different seasons was depicted by means of curves. The sparrows began leaving the roosts a few minutes before sunrise except during the winter season when they departed from the roosts a couple of minutes after sunrise. The process of departure was completed in 15 to 50 minutes time. Peak departure was recorded within 10 to 15 minutes of the first departure. During the colder months of the winter at least some of the roosts were entirely abandoned. The roost size was the largest in July. 2. An average village house had 7.22 and an average room had 1.54 sparrows nests in them, while per house and per room nest density in urban situations was respectively 3.23 and 0.37. Thatched and beamed roofs tended to harbour large number of sparrows nests, only 10% of these nests were located outside buildings roofs. The bird nested in outdoor situation only after available nesting niches indoor situation had been filled. 3. Eggs and nestling were recorded from March through September. The average clutch size was 3.0 and the average brood size was 2.80. the fledgling began to be recruited to the popular by April. 4. For the nestlings, both plants and animals’ food were consumed with almost equal frequency. Insects among the animal food and wheat among plant food were the staple of the diet of the nestlings. As compared to the nestlings, the older sparrows dependent for their nutriment mainly on plant seeds in which wheat grains, seeds of fodder and weed plants were prominent. 5. The rhythm of the foraging activities of the House sparrow in the cultivations was studied. During the ripening season of the rice crop, the sparrows attacked the crop with the greatest intensity between 7:30 a.m. and 10 a.m., and 4 p.m. and 6.05 p.m. The sparrows also foraged in large numbers in the recently harvested wheat fields, on and around the piles of harvested plants, and in leguminous fodder crops. 6. Besides the house sparrow (Passer domesticus indicus) two more species of sparrows were present in the study area. These were Passer Pyrrhonotus and Passer Hispaniolensis. The former joined the house sparrows feeding flocks in the vicinity of riverine and marshy habitats, whereas the individuals of the latter species were found mixed in house sparrow flocks in April and September. 7. Making the findings of the present studies on the biology and behavior of the house sparrows a basis, a number of control procedure have been suggested and assessed. • Ecology and control of the rose-ringed parakeet. 1. A study aimed at knowing the roosting habits, nestling niche, breeding habits, foods, and general behavior of the Rose-ringe Parakeet (Psittacula Krameri) in the cultivations of the central Punjab was carried out to know its ecological niche and weak links in its life so that the same could be exploited to inhibit its population The parakeets spent the night in groves of tall trees found in civil lines and cantonment areas, along irrigation canals, and in forest plantations. The parakeets started leaving the roosts a little before sunrise for foraging and feeding in flocks of various size. The rate of departure generally peaked at sunrise or a little earlier. After two or three hours the departure rate was minimal. Parakeets begin to return to the roost shortly after the morning departures and arrivals peaks were recorded late in the afternoon and a second arrival peak 15 to 50 minutes before the sunset. The size of the departing flocks ranges from 1 to 17 with a mean of 2.325. the departing flocks in January and October tended to be larger than those of the other months. The arriving flocks comprised of 1 to 40 birds and the mean flock size was 2.075. The flock size being the largest in January and October. 2. A variety of sub habitat sin the cultivations were surveyed to know the density of parkeet pest in them. The survey revealed that .40, 17.32, 18.95, 15.48, 5.90 and 0.72 parakeets nest cavities were present in each acre of the cropland, road side plantation, canal side plantation, city road avenues, city gardens and parks and village trees and groves, respectively. The older trees tend to offer more nesting sited than the younger ones. Acacia Arabic, Albizzia, Tamarix, Terminalia, Salmalia, and Erythrina were carried larger number of nest cavities than other trees. 3. The parakeets showed interest in nest cavities as in December. A lot of agonistic behavior was elicited by the breeding pairs for the occupation and defense of the nest cavities. The female played a leading role in the selection, occupation, and defence of the nest. A number of cavity nesting birds and the palm squirrel competed with the parakeet for the nesting cavities. The parakeets copulated and laid eggs in march. Hatch was observed in April. Fledglings were recorded in late April and May. The females were the chief actors in defending the nest during the incubation and brooding periods. The males were busy in procuring food for brooding females and the nestlings. They fed the female through regurgitation. The females fed the young in turn. The males also participated in defending the nest against intruders, if they happened to be around. 4. The parakeets utilized a large variety of plant food. But they heavily depended on maize, guava, sunflower during the fall, maize, Brassica, guava, Ziziphus and albizzia during the spring and maize, guava, and sunflower during the summer season. Of the various sub-habitats, the croplands offered the greatest variety and abundance the parakeet food. The proximity of the canal-side and road-side plantations to the croplands and the presence of trees in the croplands helped the parakeet in exploiting the rich food resources of the croplands. During the spring season the parakeet ate fruits and seeds of plants which were of no economic value to man. During other seasons, however, they heavily depended on cultivated crops and orchards fruits. 5. The parakeets attacked maize and sunflower crops severely. Crops of the plants located near their nocturnal roosts, received severe damage. 6. From the above studies it was concluded that scarcity of the proper nesting cavities and plays an important role in keeping the parakeet population below the carrying capacity of the cultivations. The parakeet population could be managed by manipulating the nesting sites. Some other methods of inhibiting the parakeet populations were also discussed.