​Avian Diversity in Agricultural Mosaics in District Ludhiana, Punjab, India

Being an agrarian state of India, Punjab has an area of 50,362 sq. kms and composed of 23 districts. After thorough scrutiny of literature, it has been observed that most of the works on avian documentation are from various wetlands especially the Ramsar sites and Shivalik foothills in the state. However, not much work has been done on avian diversity of agricultural mosaics including agricultural/rural/urban zone and village ponds and forest habitats of an area as such. Birds play a crucial role in many food webs of aquatic ecosystem and the birds are known as good ‘bio-indicators’ as they are very sensitive to minor environmental changes (Debnath et al., 2018). It needs to be mention here that the bird species dwelling in the state are mainly dependent on the agricultural profile of an area and have direct interaction with the agricultural crops and human habitations. Hence, an attempt has been made to explore the avian diversity of agricultural, aquatic and forest habitats of district Ludhiana. This district of Malwa region is centrally located district of Punjab and lies between latitude 30°55’N and longitude 75°54’E. It shares its boundaries with other districts including Jalandhar, SBS Nagar, Rupnagar, Moga, Ferozepur, Barnala, Sangrur and Fatehgarh Sahib. The cropping pattern, scattered patches of natural vegetation, water bodies and rural/urban areas presents a unique ecological system for exploring the associated avian diversity. The scattered works on the bird species of the study area are of Whistler (1919), Dhindsa et al., (1988), Kler (2006), Kler (2009), Kler and Kumar (2015a), Kler and Kumar(2015b), Arora et al., (2016), Pannu and Kler (2018) and Sidhu et al. (2021).

The monthly and opportunistic surveys were conducted in the study area from May 2016 to April 2019. For this purpose, the study area was categorized into three habitats namely agricultural habitat (Type 1), aquatic habitat (Type 2) and forest habitat and roadside vegetation (Type 3). All the birds seen, heard or in flight were recorded along with species name, number of individuals and habitat type. To avoid disturbance to the birds, Olympus 10X50 DPS binoculars were used to count the birds from some distance. A DSLR camera Canon 60d was used for the purpose of field photography. For documenting the bird species, Line transect method (Buckland et al., 2001) for agricultural and forest habitats and Point count method (Sutherland, 1996) for aquatic habitats was used. For identification of bird species, various field guides viz., Ali and Ripley (1987), Ali (2002), Grimmett and Inskipp (2010) and Grimmett et al. (2011) were used. Bird species were also assigned resident and migratory status as per Grimmett and Inskipp (2010) and IUCN Red list status 2020. The following parameters were also calculated:

(i) Relative diversity of bird families (RDi) (Torre-Cuadros et al., 2007).

(ii)    Sorenson’s similarity coefficient (Sorenson, 1948).

Where;

C= The number of species common at both sites.

A and B= The total number of species at site A and site B respectively.

A total of 173 species of birds referable to 17 orders and 56 families have been recorded during the present study (Table 1). The order Passeriformes is found to be most dominant order (42.8% species) followed by Charadriiformes (10.4% species), Anseriformes (9.83% species), Pelecaniformes (5.78% species), Accipitriformes (4.6% species), Columbiformes and Coraciformes (4.05% species each), Gruiformes and Piciformes (2.89% species each), Sulliformes and Cuculiformes (2.31% species each), Galliformes, Psittaciformes and Strigiformes (1.73% species each), Ciconiformes and Bucerotiformes (1.16% species each) and Podicipediformes (0.58% species) (Fig 1). The family Anatidae has been observed as the most diverse family with 17 species (RDi=9.83) followed by families Muscicapidae and Scolopacidae with 10 species (RDi=5.78) and 9 species (RDi=5.2) respectively Table 2. The common species found in the study region mainly belongs to families such as Ardeidae, Anatidae, Accipitridae, Phasianidae, Rallidae, Recurvirostridae, Charadriidae, Columbidae, Psittacidae, Pycnonotidae, Nectariniidae, Sturnidae, Dicruridae and Corvidae.

Table 1: List of avian species recorded from different habitats of the study area.

Fig 1: Percentage of order-wise representation of species recorded from the study area.

Table 2: Relative diversity (RDi) of recorded avian families from the study area.

As per Grimmett and Inskipp (2010), out of total 173 species, 103 species (59.5%) have been recorded as resident species, 57 species (32.9%) as winter migrants (WM), 7 species (4.05%) as summer migrants (SM) and 6 species (3.47%) as passage migrants (PM) (Fig 2). A considerable number of winter migrants (n=57) recorded from the study area may be attributed to geographic position of Punjab which occupies a strategic position in the migratory flyway of the birds (Toor et al., 1982). As per IUCN Red list 2020, the recorded species have also been categorized i.e., 1 species as “Vulnerable (VU)”, 1 species as “Endangered (EN)” and 5 species as “Near Threatened (NT)”. The remaining 166 species have been identified as “Least Concern (LC)”.

Fig 2: Percentage proportion of species with their resident or migrant status in the study area.

The number of avian species recorded during the present study is more than the records in earlier reports. Whistler (1919) recorded 169 species of birds from Ludhiana whereas Dhindsa et al., (1988) recorded 66 species from cultivated areas of the district. Kler along with her co-workers (2006-2015) compiled work on avian fauna of the district including 29 species (Kler, 2006), 97 species (Kler, 2009), 104 species (Kler and Kumar, 2015a) from different habitats of district Ludhiana. Kler and Kumar (2015b) recorded Tawny Eagle, Pallied Harrier, Paddyfield Warbler, Red-rumped Swallow and Rufous-bellied Babbler from Ludhiana which are not documented during present study. However, some other species such as Greylag Goose, Yellow-wattled Lapwing, White-tailed Lapwing, Jack Snipe, Yellow-eyed Babbler, Rufous-fronted Prinia, Yellow-bellied Prinia and Bar-tailed Treecreeper are the additional ones reported in the present study.

During present study, the maximum number of species is recorded from habitat Type 1 (n=118), followed by Type 2 (n=114) and Type 3 (n=71), however some species are found common in all the three habitats. Sorenson’s similarity indicated that these habitats show some level of similarity in diversity (Table 3). The highest similarity has been found among agricultural and aquatic habitats (62.07%) followed by agricultural and forest habitats (58.20%) and lowest among aquatic and forest habitats (18.92%). It has been observed that the habitats with more similar structure and vegetation possess more common species e.g., in study area, the village ponds are mostly surrounded with agricultural fields and residential areas, hence, as many as 72 bird species are found common with agricultural habitats. Similarly, forest and aquatic habitats differs in structure and vegetation types, hence, only 28 common species are recorded among these habitats.

Table 3: Sorenson’s similarity index (Q/S) to compare community structure of different habitats in the study area.

The conversion of forest lands or woody patches into agricultural areas is observed as one of the major consequences of green revolution which ultimately affected the avian species which prefer forest or undisturbed woody areas. This deforestation and conversion of forested lands is still under progress, due to which biodiversity of the state including avian diversity are under great impact. It has also been revealed during present study that the agricultural habitats exhibit more number of species than forest habitats in the study area. The study area also possesses more area under agriculture than forests as in other parts of the State which resulted in similar distribution pattern in the study area. While exploring the avian diversity, number of threats causing loss of various bird species in the study area has also been observed. These threats include mainly anthropogenic activities such as deforestation, extensive agriculture, excessive use of pesticides, urbanization etc. The anthropogenic activities at water bodies affect the distribution, foraging success, breeding success and ultimately the species richness. Beale and Monaghan (2004), Rees et al., (2005), Palacio-Nunez et al., (2007) and Thiollay (2007) also concluded similar results. In the study area, it has been observed that the water bodies such as village ponds and canals etc. are facing problems due to sewage disposal, garbage dumping and construction of cemented walls which ultimately cause disturbance to the birds inhabiting these water bodies. The encroachment of village ponds by some plant species such as Water Hyacinth Eichhornia crassipes also affects the presence of various bird species such as waders and herons etc. However, more individuals of Purple Moorhen and Black-winged Stilt are also recorded from such sites.