Diversity, Abundance, and Distribution of Avifauna in District Jhang, Pakistan

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Introduction
Deserts are low average annual rainfall areas usually containing 100 millimeters (less than 4 inches) or less rain per year.A desert is considered to be one of the most susceptible ecosystems in the world to climate change.Increasing temperature, declining rainfall, and a high level of atmospheric CO 2 are expected to highly affect the structure and function of desert ecosystems intensively disturbing desert-inhabiting birds [1].The present research investigated diversity, abundance, and distribution of avian fauna in terrestrial and semiaquatic types of habitats including the Thal desert and Trimmu barrage of district Jhang.
Birds are valuable components of the world desert and aquatic habitats; i.e., they play a key role in maintaining the stability and inherent functions of dwelling ecosystems.On top of that, birds amuse humans with their behaviour, beautiful colors, and songs [2].Insectivorous birds eliminate vectors of various diseases, and scavenger birds such as Corvus albus (pied crow) as well as vultures serve as decomposers [3].Birds are one of the most significant contributors to seed dispersion and pollination along with disease control [4].
Small rodents which cause incalculable damage to crops are controlled by birds such as the kestrel and barn owl [5].Desert birds (desert wheatear, common quail, and Indian golden oriole), have behavioural adaptations such as the tendency to survive in unfavourable conditions.This behaviour allows these birds to move from less productive sites to more productive sites.Some birds such as the burrowing owl use the burrows of rodents during the mid-hot day to avoid very high temperatures.The majority of desert birds frequently feed on ants, very rarely seen by other temperate-region birds.Most birds such as the Asian koel, striated babbler, common myna, bank myna, and baya weaver show a seasonal feeding behaviour according to the availability of food [6].Since Pakistan is the 5 th largest populous country in the world, this overpopulation imposes some detrimental threats ranging from loss of habitat to extinction to avian diversity due to deforestation, agricultural expansion, urbanization, industrialization, change in desert ecosystems (human settlement, plantations, and agricultural practices), and habitat loss [7].
Deserts are the result of erratic climatic changes.Deserts contain scarcity of surface water which directly affects species richness because just like other organisms, water is the basic requirement for the survival of birds [8].The total number of bird species across the globe is 9042 while 2700 avian species have been reported from Asia [9].Pakistan harbours a diverse avian fauna due to its geographical structure that encompasses diversity of habitat, i.e., forest habitat, desert habitat, and aquatic habitat, and is home to more than 750 species of birds including 105 water bird species [10].Previous reports show that wetlands and riverine systems are some of the best sites for wintering and migratory birds [11].Wetlands are transitional areas between aquatic and terrestrial ecosystems.Pakistan has one of the largest irrigation systems in the world representing 225 wetland sites.Pakistan contains 43% endemic bird species, 30% of species are long-distance migrant, and 27% of species are winter visitors [12].The Thal desert area and Trimmu barrage support a huge number of residents as well as migratory birds such as the houbara bustard, cuckoos, and quails.Some of these birds travel from central Asia during the winter season to avoid harsh climatic conditions [13].The study area Trimmu barrage is an important wetland site for migratory and endemic species of birds.The barrage area is a complex of aquatic and terrestrial ecosystems and provides an ideal habitat for a vast variety of migratory and endemic avian fauna [14].The Thal desert is spread across the districts of Jhang, Layyan, Bhakkar, Khushab, and Mianwali.The most prominent feature of this desert is the dunes [15].The Thal desert area of district Jhang is approximately 120 km.Athara Hazari is the most dominant tehsil of district Jhang contributing to 80 percent (100 km) of the desert area.On one side, the district contains an open desert ecosystem while, on the other side, it contains flowing water in the form of the river Chenab and river Jhelum.The union of both these rivers contains a huge reserve of water in the form of the Trimmu barrage.Both rivers merge at Athara Hazari and then originate from Trimmu barrage as a single Chenab river.Despite this fact, the study area (Jhang) is one of the dominant avian regions of Pakistan due to two very distinct types of habitat.Three major threats have been observed in the study area.The natural desert ecosystem is being converted by irrigation systems; hunting on a large scale which has been adopted as a profession, even though the Thal area has been declared as a game reserve by the government of Punjab (Pakistan); and disturbance by visitors especially at Trimmu barrage.Regional study for the determination of avian diversity in these areas is highly warranted and pivotal for the conservation of the bird species [16].However, urbanization resulting in commercial farming [17] has been a permanent factor endangering the wildlife.Abouelela et al. [18] has reported the transformation in anatomical and histological features of cats.Different types of bacterial, protozoal, and parasitic infections emerging in food animals, mainly chicken, pork, sheep, and goat [19], and companion animals, i.e., dog and cats, ultimately pose a very high risk on the wild bird population, which may get infected through exposure to them [20].
The present study was conducted in the Thal desert area and Trimmu barrage of district Jhang to determine the diversity, abundance, and distribution of avian fauna in one of the richest biodiversity regions of Pakistan.The current survey is the second and recent research in the Thal desert area of district Jhang, as the first study was conducted in 2009.The combined research of both habitats (Thal desert and Trimmu barrage) is the first ever attempted.2.2.Field Survey.This survey was conducted throughout the year from March 2021 to February 2022 to find out the diversity and abundance of migratory and local birds.This was done on a monthly basis from sunrise to sunset (full day) to explore every possible opportunity.Thus, the study hours were limited not only to dawn and dusk.During each month for the two sampling sites (Trimmu barrage and Thal desert), each site was visited consecutively on a separate day.Two visits were done each month, while the area was visited 24 times during the whole study period.The point count method was used to determine the bird diversity and abundance in Trimmu barrage.The survey points include river banks, island, and surroundings fields.Ten point counts were established randomly in each survey point.The total number of point counts was 30 over the strip of 5 kilometers.The minimum distance between two point counts was a 250meter radius [13].The head pond area was visited by using a wooden boat while the marginal bunds were visited by foot to observe the avian fauna.Both direct and indirect methods were used for the collection of data.The direct method included field area observation by experienced observers while, indirectly, the information was gained from local people and hunters.Birds were enumerated by using a pair of binoculars and a spotted scope while a camera was used to photograph the birds for later identification.For identification of avian fauna, various practical guides were consulted [21,22].

Materials and Methods
By following Mola et al. [11], the line transect method was used for observing the birds of the wetland area of the Thal desert.Since the Thal desert contains a uniform type of habitat due to very little vegetation, birds are easily visible.Two transect lines were arranged, and the length of each transect line was 20 km.Keeping in mind the topography of the study area, the transect lines were isolated from each other at a distance of 200 to 250 meters.

Data Analysis.
For statistical analysis, the Minitab software was used.The Shannon-Weiner index was calculated to find out the diversity of birds in the sampling area.The Shannon-Wiener diversity index (H) was calculated to point out both species richness (the number of species in a given area) and their abundances.Its values normally ranges between 1.5 and 3.5.The level of significance was 0.05.The following formula was used for the Shannon-Wiener index.H = −∑ p i * log p i , where H is the Shannon wiener index, p i is the proportion of individuals of the i-th species in a whole community, and log is the natural logarithm.
Relative abundance = ni/N × 100, where ni is the number of individuals of a single species and N is the total number of individuals of all the species.
One-way ANOVA and t test were used to compare the month-wise diversity and abundance of birds at both sampling sites.

Avian Fauna of District
Jhang.During the study, 67 bird species were identified from the two different sampling sites (Trimmu barrage and Thal desert) of district Jhang.The number of individual birds at Trimmu barrage was 18,791 while 12,905 individual birds were identified at the Thal desert.The most dominant order was Passeriformes representing 24 species of birds belonging to 13 families.The most common families were Accipitridae, Ardeidae, and Anatidae each representing 5 species.Fifty-eight species were observed at Trimmu barrage while 45 species were observed from the Thal desert area of district Jhang.Out of the 67 bird species, 36 species were common at both types of habitat.A total of 31,696 individual birds were observed at both sampling sites.Figure 1 represents the difference in the abundance of birds at both sites.Highly significant differences (X 2 = 14979 7, df = 11, and P < 0 01) were observed in the diversity and abundance of birds overall between the Trimmu barrage and Thal desert area on a monthly basis (Table 1).The most prominent feature of the present study is the identification of Xenus cinereus (Terek sandpiper) and Ammomanes phoenicura (rufoustailed lark) in district Jhang as both species have no previous record in the study area.

Distribution Status of Avian Fauna in District Jhang.
As for the distribution of avian fauna, 39 species were resident, 18 species were winter visitors, 9 species were summer breeders, and a single species (Terek sandpiper) was a passage migrant.2(a)).
The least number of species was observed during September and October when only 35 species were identified.During this part of the year, the summer breeders move back and winter visitors are yet to arrive.So bird diversity and Key: NS: nonsignificant (P > 0 05); * significant (P < 0 05); * * highly significant (P < 0 01).), highly significant differences (P < 0 01) were detected in the diversity of birds.Significant variations (P < 0 05) were recorded in abundance as well as diversity during September (t = 1 98) and November (t = 2 06).Statistically nonsignificant differences (P > 0 05) were noted during January (t = 0 00), March (t = 1 28), and October (t = 1 07; Table 3).According to the distribution of avian fauna in the Thal desert area, 33 species were residents, 6 species were winter visitors, and six species were summer breeders.During the month of January, bird abundance was at the peak level as 1447 individuals were observed followed by December (1231), March (1210), August (1195), May (1134), November (1075), June (1034), February (993), July (990), April (980), October (865), and September (750).Table 5 concisely elaborates the diversity and abundance of birds at the Thal desert of district Jhang.

Journal of Zoological Systematics and Evolutionary Research
Bird diversity was also at the top level during January when 38 species were observed followed by November and August (37 species each); December, February, March, and June (35 species each); and April, May, and July (34 species each).The least bird diversity level was recorded during September and October when only 32 species and 31 species were observed, respectively.The highest Shannon-Weiner diversity index (3.292)was noted for January while the lowest was for October (2.704; Table 3).Concerning the abundance of birds between the Thal desert and Trimmu barrage, significant difference (P < 0 05) was observed for the months of April (t = 2 01), May (t = 1 99), July (t = 2 21), and August (t = 2 22).During the months of January, February, March, June, September, October, November, and December, no significant differences (P > 0 05) were seen (Table 6 and Figure 1).

Discussion
The current study was conducted on monthly bases in district Jhang to find out the diversity, abundance, and distribution of avian fauna.During the study, 67 species of birds were identified and 31,696 individual birds were observed  7 Journal of Zoological Systematics and Evolutionary Research from the two sampling areas (Trimmu barrage and Thal desert) of the district Jhang.From the Trimmu barrage, 18,791 individuals and 58 bird species were identified while 45 species and 12,905 individuals were observed from the Thal desert area.Among the 67 species, 39 species were residents and are found throughout the year, 18 species were winter visitors, 9 species were summer breeders, and a single species was a passage migrant.The most dominant order was Passeriformes.
Mahboob and Zaib-un-Nisa [14] conducted a 9-month survey at the same site (Trimmu barrage) during 2004-2005 and recorded 89 species of birds having 9699 individuals.Resident species were 52, winter visitors 29, summer breeders 4, and ordinary migrants were also 4. Comparison of both studies reveals that bird diversity has decreased while the number of individuals rose up.Our findings are similar to a previous study with respect to the distribution of birds as both studies share that December and January (winter season) were the most favourable time for the diversity and abundance of avian fauna.During the previous study, the green bee-eater was observed from December to August continuously, while during the current study, it was found from February to August only.No individual was observed during the winter months of December and January.
In the present study, 58 bird species and 18,791 individuals were observed from the Trimmu barrage.The most dominant species were the common pochard (2332 individuals) followed by the little grebe (2327 individuals), common coot (1776 individuals), cattle egret (1281 individuals), gadwall (1270 individuals), little egret (956 individuals), red-wattled lapwing (488 individuals), and common teal (475 individuals).Sixteen species of birds of the current study were similar to those of another previous survey.Khan et al. [13] did a field survey during 2018 at the Trimmu barrage and reported 11,556 individual birds belonging to 26 species.Both the studies have 16 common species.The common coot (7240 individuals) was the most common species of the 2018 survey followed by the common pochard (1102), northern shover (630), little grebe (495), common teal (311), black-winged stilt (258), and gadwall (193).The current survey identified these same species except for the northern shover but contradict with the diversity and abundance of avian fauna.
The present study confirmed that out of 58 bird species observed in the Trimmu barrage of district Jhang, 39 bird species were common at the Trimmu barrage and Taunsa barrage.Bibi et al. [23] conducted a study during 2008 at Taunsa barrage located in the Muzaffargarh district of Pakistan and recorded 171 species of birds.The most notable thing was the presence of various vulture species such as Gyps bengalensis and Gyps africanus.However, no vulture species was observed in present study.Secondly, in the Taunsa barrage survey, the population of the black drongo and gadwal was in a decreasing trend, but in the current study, the population of both species was increasing.
The current research evaluated that 30 species of the Trimmu barrage were similar to those of the Chashma barrage (Mianwali, Pakistan).Akbar et al. [24] investigated the diversity and abundance of the Chashma barrage (Mianwali, Pakistan) and recorded 533,965 individuals of 46 species.The most dominant species of the present study were also recorded from the study of the Chashma barrage, but their number of individuals was very high.
According to the present finding, the common fauna of the Trimmu barrage and Dhapchapak lake of Dera Ismail Khan (KPK, Pakistan) included the great egret and gadwal, Asian koel, Eurasian hoopoe, common kestrel, greater coucal, Indian roller, black drongo, purple sunbird, red collared dove, and Indian golden oriole.Najam-un-Nisa et al. [12] determined the bird diversity of the Dhapchapak lake of Dera Ismail Khan and observed 13,933 individuals belonging to 39 species of birds.The great egret and gadwal were the most abundant species.The least common species were the Asian koel, Eurasian hoopoe, common kestrel, greater coucal, Indian roller, black drongo, purple sunbird, red collared dove, and Indian golden oriole.We also recorded similar observation about the common kestrel, red collared dove, and Indian golden oriole as all the three species were fairly common while the rest of the species were common.
The current research determined that more diversity and abundance of birds was noted at the Trimmu barrage compared to the Keti Bunder wildlife sanctuary.However, the Trimmu barrage of district Jhang was less diverse than the Trimmu barrage overall.During the survey of birds at the Keti Bunder wildlife sanctuary (Thatta, Pakistan), 4280 individuals belonging to 49 bird species were identified [7].
The presently investigated 30 bird species of the Thal desert of district Jhang were also observed in the Australian desert.A study conducted in the Australian desert identified 28,000 individuals belonging to 91 bird species.It was pointed out that climatic changes and rainfall affect the diversity and abundance of avian fauna [8].Sixty-one species of both studies were different which may be due to very different climatic and geographical conditions.Where the distribution of birds is concerned, 65% of bird species of our survey were residents.A similar type of distribution pattern was also observed by another survey which was done in the desert of northern Saudi Arabia.The survey recorded 131 species of birds.Most (70%) were residents while 30% were migratory [25].In our research, the crested lark was among the least common bird species while the crested lark and hoopoe lark were the most abundant residential species in the desert of northern Saudi Arabia which may be due to different landscape types.
Twenty-five bird species of the Thal desert of district Jhang were also observed from the desert of Morocco.
Passeriformes was the most dominant order of our research with 31 bird species.A total of 130 species of birds were reported from the study of the Sahara desert (Morocco).Passeriformes with 68 bird species of 16 families was the most dominant order followed by Accipitriformes (13 species) and Charadriiformes with 6 species.Fringillidae with 280,520 individual birds was the most abundant family [16].Avian diversity of wetlands in the Bahir Dar, Ethiopia was determined during wet and dry seasons.The field survey identified 96 species of birds in which 40 species were observed in the wet season and 13 species in the dry season while 43 species were common at both seasons [11].
According to present findings, the most common species of birds of the Thal desert were the Indian roller, common quail, cattle egret, little egret, red-vented bulbul, common myna, Indian house crow, and Indian/pariah kite.Mahboob et al. [15] conducted a study from December 2008 to November 2009 at the Thal desert of district Jhang to find out the diversity of birds.During the year-round survey, 2,550,219 individuals from 55 species of birds were reported.Among these bird species, 36 species were residents, 13 species were winter visitors, 6 species were summer breeders, while a single species was an ordinary migrant.Passeriformes was the most dominant order with 26 species.The common myna and house sparrow were the most abundant species.Both studies have similar findings, as the midwinter season (December and January) was the most dominant time for the diversity of avian fauna.The most distinguishing feature between both studies is the abundance of avian fauna.Previously, a total of 2,550,219 individual birds were identified while, in the present study, only 12,905 individuals of 45 species were observed.By comparing with other studies, the current recent study demonstrates that the diversity and abundance of avian fauna have been declining in district Jhang.

Conclusion
District Jhang provides an ideal environment for birds due to a variety of habitats.The district contains a desert ecosystem, aquatic ecosystem, and agriculture land for the cultivation of a variety of crops which support the avian fauna.Only 12,905 individuals of 45 species were identified from the Thal desert, and 18,791 individuals of 58 species were observed from the Trimmu barrage.The current study results clearly indicate that the bird diversity has been dramatically decreased when we compared it with previous research conducted in this area.The reports from hunters and local villagers also support the results of the current study.The winter migratory birds are especially vulnerable due to extreme hunting pressure by Arab as well as local hunters.Hunting, contamination of the aquatic ecosystem, and disturbance of the natural habitat are some major threats in the study area.The authors suggest that strict and immediate action is required in this matter to prevent the decline in the diversity and abundance of avian fauna.Awareness programs would be highly valuable for the conservation of avian fauna.

Data Availability
Detailed data can be provided upon request.

Figure 1 :
Figure 1: Comparison in abundance of birds at Trimmu barrage and Thal desert on monthly bases.
This study was carried out in district Jhang, Punjab, Pakistan, located between 31.1929°N and 72.2364 °E and covers an area of 6162 km2.Two habitats, namely, Thal Desert and Trimmu barrage, were selected to determine the avian diversity, abundance, and distribution at different parts of the district.2.1.1.Trimmu Barrage.Trimmu barrage is located in tehsil Jhang, 21 km from Jhang city.It comprises both aquatic and terrestrial habitats.The dominant flora encompasses Acacia nilotica, Albizia lebbeck, Ficus religiosa, Eucalyptus camaldulensis, and Dalbergia sissoo.Ground vegetation comprised Chenopodium album, Malva parviflora, Medicago polymorpha, Alhagi maurorum, and Melilotus indica.Aquatic plants comprised Hydrilla verticillata, Vallisneria spiralis, Nymphaea lotus, and Saccharum bengalense, etc.The head pond area of Trimmu barrage is 3680.43acres.The peripheral region of the river Jhelum and river Chenab flowing through district Jhang contains very fertile land for the cultivation of wheat, rice, corn, and sugar cane.2.1.2.Athara Hazari Thal Desert.It is a barren area with harsh weather conditions that spreads across the districts of Jhang, Layyan, Bhakkar, Khushab, and Mianwali.It has been declared a game reserve since 1974 by the government of Punjab.Athara Hazari is the major Thal desert area which constitutes 80% (100/120 km) of the Thal desert in district Jhang.The current study on the Thal desert was conducted in Athara Hazari tehsil.About 85% of the area of this desert is nonirrigated.The only nonirrigated cultivated crop is chick pea (Cicer arietinum) which is grown in winter and fully depends on rain.It is one of the major sources of food and shelter for migratory and local birds.The noncultivated flora include Prosopis cineraria, Tamarix aphylla, Prosopis juliflora, Salvadora oleoides, Acacia jacquemontii, Capparis aphylla, and Calligonum polygonoides.

Table 1 :
Month-wise analysis of variance (ANOVA) between sampling sites.

Table 2 :
Distribution of avian fauna of district Jhang.

Table 4
briefly shows the diversity of birds at the Trimmu barrage of district Jhang.

Table 3 :
Comparison in diversity between Thal desert and Trimmu barrage in different months by t test and Shannon diversity index.

Table 4 :
Diversity of birds at Trimmu barrage of district Jhang (March 2021-Feb 2022 survey on month bases).

Table 5 :
Diversity of birds at Thal desert of district Jhang (March 2021-Feb 2022 survey on monthly bases).

Table 6 :
Comparison in abundance of birds between Thal desert and Trimmu barrage in different months by t test.