Long-term monitoring of pelicans in National Chambal Sanctuary, India

: Monitoring of Gharial Gavialis gangeticus in National Chambal Sanctuary (NCS) since 1983 has resulted in collection of data on other ecological associates, located between 25.8474–26.4389 0 N, 76.5645–79.2132 0 E. One such beneficiary of this long term monitoring program are the pelicans, locally called ‘Hawaseel’. Pelican species visiting Chambal from November to March include the Dalmatian Pelecanus crispus , Great White Pelecanus onocrotalus , and Spot-billed Pelecanus philippensis . Species-wise separation of pelicans at the sites of congregation is often difficult. The total number of pelicans counted during the annual census from 2003 to 2016 was 4,429. The study area extends over 435 km comprising 12 study zones, 99% counts were made in the study zones X, XI and XII. These zones stretch over 115 km that occur near the confluence of Chambal with river Yamuna. Here, the river is deep. Other large birds seen with the pelican squadrons are groups of Cormorant Phalacrocorax carbo , Painted Stork Mycteria leucocephala , Nakta or Comb Duck Sarkidiornis melanotos , and the Greylag Goose Anser anser . Other large birds seen on the riverbanks were the Common Crane Grus grus , Sarus Crane Grus antigon , Greater Flamingo Phoenicopterus species, and Demoiselle Crane Grus virgo . The study provides a baseline about the population of pelicans and the availability of large wetland birds in NCS. The biodiversity significance of NCS got highlighted because of the ongoing gharial conservation programme. The Chambal River Sanctuary is a composite unit of several un-notified ‘core areas’. The sanctuary fulfills six of the nine criteria for possible consideration as an international Ramsar Wetland.


INTRODUCTION
The erstwhile Central Crocodile Breeding and Management Training Institute (CCBMTI) of the Government of India established a Field Research Camp in the campus for gharial project of Madhya Pradesh at village Deori in Morena district. The purpose was to conduct studies on the population of Gharial that was assisted through conservation measures in National Chambal Sanctuary (NCS) since 1978 (Singh 1985(Singh , 1999Bustard 1999).
The camp operated in NCS during 1983-85, but the field work continued in the sanctuary till 2016 by the Madhya Pradesh Forest Department. These exercises helped in understanding the population status and trends of Gharial, Mugger Crocodile Crocodylus palustris, Gangetic Dolphin Platanista gangetica, river turtles, Indian Skimmer birds Rynchops albicollis, five species of storks and thirty species of raptors (Singh 1985;Rao & Singh 1987a,b,c;Sharma & Singh 1986, 2014, 2015Singh et al. 2022).
Three species of Pelicans, discussed in the present article, were also sighted and counted during annual surveys for gharial in NCS from 2003 to 2016. The species are the Great White Pelican (GWP), Dalmatian Pelican (DP), and the Spot-billed Pelican (SBP). The IUCN Red List status of DP and SBP is NT (Near Threatened) and GWP is LC (Least Concern) (Birdlife International 2021). This article intends to record the biodiversity significance of NCS in terms of temporal and spatial occurrence of pelicans, locally known as 'Hawaseel'.

STUDY AREA
River Chambal included under wetland types 11 (rivers, streams -slow-flowing, lower perennial) & 12 (rivers, streams -fast-flowing, upper perennial) (Scott 1989). It is in the semi-arid zone of northwestern India. It is a clear, perennial, and fast flowing river which origins in the Vindhyan range of Madhya Pradesh. The gharial population in Chambal was highlighted in 1974 when the national crocodile survey was conducted (FAO 1974

Survey years and data
Annual surveys of Chambal were made ever since 1983 (Supplementary Table A and Table 1). The surveys were conducted from mid-December to mid-February. In specific, the pelican counts were continuously recorded during the years 2003 to 2016, and have been used for understanding their spatial and temporal characteristics. Although three pelican species were visiting Chambal (Images 2-6), it was difficult to segregate them and make species wise separate counts. Therefore, the data was analysed for total pelican counts (Table 1).

Equipment
The survey facilities included an aluminium boat with outboard engines issued by the FAO component of the conservation scheme. These were available round the year with NCS, MP since 1983. One YAMAHA 20 HP engine was used for normal movement, and a 5 HP outboard remained standby. During the survey the motorboat speed was kept at the minimum, depending on the demands for observation and navigability of the river. The accelerator to the engine didn't have calibration expressing speed in terms of km/hour. Several stretches were also covered on foot by walking along the riverbank. To go beyond rapids or the Rahu water fall, the boat and other equipment were hand lifted from negotiable point. Pelicans were counted with the help of a pair of binoculars (Canon image stabilizer 10x30 IS). Occasionally, a spotting scope (Fujinon Japan super field scope 60-5) was used.

Survey hours
The team moved and made observations during the day. The actual survey hours per day was variable and usually after 0900 h in the morning when fog cleared, and there was good visibility from a distance. A survey day lasted till about an hour before sunset when camping arrangements had to be made before it was dark. Night camps were made on the river bank, or a village overlooking the river. As per a tentative itinerary agreed from the beginning, the research Land Rover or a four-wheel jeep of the state government was usually available in some close by village in Madhya Pradesh. The vehicle could come to the riverside village only at a few locations.

Data sheets
The 435 km stretch of the river from Pali up to Pachhnada, was divided into twelve study zones (I through XII), starting from Palighat in Rajasthan up to Pachhnada in UP. The zones are name-based and easily identifiable (Image 1, Table 1) by the staff and local people. From 2003 onwards, Garmin GPS sets were introduced in the field. Instead of the coordinate values, the authors have retained the use of the names of locations. Most of these names were identifiable over topographic sheets issued by the Survey of India.
For daily use during the survey, observation sheets were prepared on A4 paper using map copies of 5-km stretches from the toposheets. Data on pelican and other species were recorded directly on the observation sheets. It showed the exact locations where sightings were made. The protocol of the field survey was based on descriptions given in Singh (1985) for gharial, mugger, turtles, dolphin and all bird species. Birds were identified according to the procedure and description given in Ali (1979Ali ( , 2002, Grimmett et al (2011), and Gill et al (2021).

Pelicans in different study zones (Table 1)
In the last three study zones, i.e., zone X, XI and XII the count was the maximum, totalling 4,375 (99%) out of 4,429. The counts were 71 in the study zone-X (Ater-Barhi), 784 in zone-XI (Barhi-Chakarnagar) and 3,520 in zone-XII (Chakarnagar-Pachhnada). Other than these, in study zone-I (Pali-Rameshwar) 19 pelicans were counted during the study period. But there were no pelicans observed here during the past five years (Table 1).

Photo documentation of other wetland birds (Images 7-13)
In the course of our annual survey, we photo documented the pelican squadrons while they shared the habitat with groups of Great Cormorants, Painted Stork, Nakta or Comb Duck, Greylag Goose, Common Crane, Sarus Crane, and Greater Flamingos. The Demoiselle Crane were recorded in the beginning years of our observations (Sharma & Singh 1986). However, in the more recent years they were seen in Chambal only for a few days at the start of winter.

Spatial occupation
Pelicans appear to have preferred the study zones X, XI, and XII which is a stretch of 115 km from Ater to Pachhnada. Majority of the counts, i.e., 99% were recorded here. In this stretch, the water course is deep. In the region around the confluence of Chambal with Yamuna, nylon set netting for fishing exists in deep water, but killing of pelicans is not confirmed. In upper stretches of Chambal, the appearance of pelicans in study zones I (Pali-Rameshwar), III (Khirkhiri-Baroli), and V (Atar-Sarsani) appear to be due to the conditions created at the confluences of rivers Parbati, Banas, Seep and Kuno. Here, the water depth and food availability are better. It is possible that the pelicans have avoided the stretches where adult breeding Gharials are present. These aspects need to be further studied.

Migration of pelicans to Chambal
Of the roughly 1,220 regularly occurring species of birds in India, 280 are long distance migrants, 116 are migrants within the subcontinent, and the remaining species are residents, either sedentary or showing local movements (State of Indian Birds 2020). Out of 310 species of wetland birds in India 107 species are winter migrants (Kumar et al. 2005). The sighting of pelicans in river Chambal may be due their local migration.
The Spot-billed Pelican (SBP) is a resident and local migrant species breeding in Brahmaputra valley and a few other locations in southern India. Some of the locations in Andhra Pradesh are the deltas of Krishna and Godavari. A famous location in Tamil Nadu is the Pulicat which borders Andhra Pradesh (Subramanya 1996;Talukdar 1999;Kannan & Manakadan 2005). Pandav  (1987,1991) reported SBP in Karera Bustard Sanctuary, M.P. during 1986-87. Karera is in the direction closer to Pali (study zone-I).
GWP is a habitat specialist, largely depending on open water areas (Thirunaranan et al. 2017). The migration routes and stop over sites of GWP are poorly known (Izhaki et al. 2002). DP have been reported in Delhi by Ganguli (1975) and Urfi (2003). Rahmani et al (2021) in their work for the Madhya Pradesh Biodiversity Board, drew attention to the threatened birds of Madhya Pradesh. In this context they mentioned that the DP population in India is about 20,000-25,000 (Rahmani et al. 2021). A dedicated study on pelicans is expected to trace the status of migration and arrival

Ramsar-criteria fulfilment by NCS
A Ramsar site has to fulfil one of the nine criteria (Anonymous 2022). Besides, the responsible stakeholders are expected to remain committed for maintenance & sustenance of the ecological, hydrological, and socioeconomic characteristics of the site. NCS meets six of the nine criteria for the international Ramsar-tag.
River Chambal in NCS is recognised under the wetland types 11 and 12 (Scott 1989), with ecological continuity in the semi-arid biogeographic zone (Rodgers & Panwar 1988), which is also termed in the Khathiar-Gir Ecoregion in India (WWF 2021). The studies on spatial and temporal trend of several indicator species from NCS for more than thirty years, testify the significance of the sanctuary as a 'site of international importance for conserving biological diversity (Ramsar Group-A Criterion 1).
Out these species for maintaining the biological diversity in the semi-arid biogeographic zone (Criterion 3).
NCS satisfies the Ramsar Criterion 4 as the river supports or provides refuge to several migrating bird species at a critical stage in their life cycles Singh et al. 2022; and the present study). In fulfilling the Ramsar Criterion 9, the 572 km long river within NCS supports more than 1% of the individuals in population of wetland-dependent non-avian animal species namely the Gharial.
In the context of Ramsar Criterion-9, we refer here to the suggestion by Dubey & Mehra (1959) for more specific and long-term study on the fish fauna. The study continues to provide a general, yet landmark, ecological picture of the fish resource and fisheries in Chambal from the location of Gandhi Sagar dam up to River Yamuna. The fish fauna comprised sub-mountain and plain-land species. It is important because, of the 71 species they recorded, 46 are important for fisheries. The game-fish species include Tor tor, Barilius bola and Puntius thagunio. Hilsa is generally known as a longrange migratory species from estuaries of Bay of Bengal through Ganga and Yamuna. Such migration may not be entirely for breeding but also for feeding. During our work in 2000s, Tilapia and a Sting Ray was also reported by the fishermen. A series of dams and the Kota barrage have been constructed over Chambal but fish population do not seem to be severely affected as local consumption is extremely low. Big fishing enterprises were not existing and fishing practice was extremely low compared to that which existed in the Yamuna.