Bird Diversity in Asam Kumbang Crocodile Breeding Area Medan Selayang District Medan City

. Asam Kumbang Crocodile Breeding is a breedig ground for crocodiles that contain several birds. Species diversity is indicated by differences in the types of organisms. One of the most diverse organisms of its kind is birds. Birds in this region are able to setle down and coexist with crocodiles. Crocodiles are one of the predators of bird. It aims to identify the diversity of birds and status of protected birds at the research site. The method used in this study were point count method, thus resulted in 12 species of birds belonging to 5 ordo, 6 family, and 11 genus. The most common birds species found on the 3rd observation with as many as 9 species of birds, while the least species of birds found on the 4th observationas many as 5 species of birds. Diversity index value (H’) of bird in location classified into category of “moderate category” with the results of analysis 1,171 and the indeks equitabilitas value of 0,47. According to the Ministry of Environment and Forestry Regulation 2018, there are 2 types of birds found in the study area of birds found in the study site.


Introduction
Diversity is an abundance related to the number, type, shape, appearance and nature of various levels of living things. The diversity of living things is also known as biodiversity which consists of three levels, namely: gene diversity, species diversity and ecosystem diversity. Gene diversity can be influenced by the carrier factors in the chromosomes. Species diversity is influenced by morphological and anatomical factors of living things that differ between species or species. Ecosystem diversity is influenced by abiotic factors that can cause differences in the types of living things between ecosystems [1].
Species diversity in living things can be identified and measured according to research needs, one of the species of living things whose species diversity can be measured is birds. Birds are wild animals that can be found in various types of habitats such as coastal forest, lowland forest, hill forest and mountain forest [2]. Several types of birds are also able to live in several different types of habitats because they have the ability to adapt to the environment they live in. The adaptability of birds to different environments can be found in the Acid Beetle Crocodile Captive in Medan City, North Sumatra. This area is one of the bird habitats which is a type of wetland, because there is a pool of water in the form of a crocodile pond. Wetlands are ecosystems that are flooded by water with long periods of time for the development of vegetation and other specially adapted organisms [3].
Habitats that can support the existence of birds are places that are able to provide a source of food, a place for nesting and reproduction and far from predators. Habitat is generally used by birds as a place to rest, nest, breed and shelter from predators [4].
Birds in the Asam Kumbang Crocodile Captivity are able to live permanently and side by side with crocodiles. Crocodiles are one of the predators for birds. Birds do not feel threatened by the presence of crocodiles in the same area. There is a reciprocal relationship between birds and crocodiles. Birds place nests on trees so they cannot be reached by crocodiles and feel protected from other predators (humans), while crocodiles get food in the form of eggs and chicks that fall from the tree [5].Studies and information on the diversity of bird species found in the Asam Kumbang Crocodile Captivity have not been known until now. In accordance with the description above, a study entitled "Diversity of Bird Species in the Acid Beetle Crocodile Breeding Area was conducted, Medan Selayang District, Medan City".

Time and Location of Research
The research was carried out from December 2018 to January 2019 at the Asam Kumbang Crocodile Breeding, Medan Selayang District, Medan City. Identification of bird species found and data analysis was carried out in January 2019 at the Animal Systematics Laboratory, Department of Biology, Faculty of Mathematics and Natural Sciences, University of North Sumatra, Medan.

Area Description
The research location is located on Jalan Bunga Raya II, Asam Kumbang, Medan Selayang District, Medan City, North Sumatra Province (Figure 1). This area is a crocodile breeding place with an area of 2 hectares and in it there is a 1 hectare pond, and there is vegetation in the form of Chinese petai trees which are used by birds as nesting and perching places.

Data Collection
The collection of data on the diversity of bird species was carried out using two methods, namely observation and interviews. Observations were made for 5 days of data collection using the Point Count method [6]. The point count method is carried out by walking slowly, quietly and observing birds using binoculars and taking photos of birds using a digital camera at a certain point, then recording the number and types of birds encountered using counters and stationery. The points used as observation points are 5 counting points, the distance between the points is 15 meters, and the viewing distance is 25 meters with an observation time of 20 minutes at each point ( Figure 2).
Observations were made in the morning at 06.00-10.00 WIB and in the afternoon at 14.00-18.00 WIB.

Identification of Bird Species
Identification of bird species is carried out directly in the field and continued in the Animal Systematics Laboratory by looking at photos of bird species that have been taken using the bird species identification book [7].

Figure 2 Forms of Observation Points using the Point Count Method
International Journal of Ecophysiology Vol. 03, No. 02, 2021 |190-205 Bird data obtained in the field during observations were then processed and counted, including: diversity index (H') and evenness index (E). [8,9].:

Diversity of Bird Species in the Acid Crocodile Breeding Area Beetle, Medan Selayang District, Medan City
The results of research that have been carried out in the Asam Kumbang Crocodile Breeding Area, Medan Selayang sub-district, Medan city, there are as many as 12 bird species belonging to 5 orders, 6 families, 11 genera, as shown in Table 1 below. Information : : Found -: Not found Table 1 describes the number of bird species found in the Asam Kumbang Crocodile Captive starting from the 1st data collection to the 5th data collection sequentially as many as 8 species, 7 species, 9 species, 5 species and 7 types of birds. Bird data are grouped by family and order.
The most dominating order is the order Pelecaniformes which consists of one family, namely the Ardeidae family of 5 bird species. Ardeidae have an almost even distribution throughout Indonesia, such as Sumatra, Java, Kalimantan and Bali [2] .
The number of bird species found in the Asam Kumbang Crocodile Captivity is relatively small compared to the results of research by [10] using the same method. Research by [10] in the Telaga Warna area, Cisarua, Bogor, there were 60 species of birds. The results of this study are different from the results obtained in the Asam Kumbang Crocodile Captivity, which is as many as 12 species of birds. This is influenced by several factors. The first factor is that there are rice fields not far from the research location. Birds have the ability to move, so at the time of observation it is possible for birds to find food in rice fields which is one of the places for birds to find food. Birds usually forage in rice fields [11].
According to [12], birds are a type of animal that has a high ability to move so that its distribution is very wide in the world. Nesting locations and foraging locations for birds are different, different types of birds will fly to look for food and return to the nest at certain times [13]. This is because the research location is a habitat that does not provide food for several bird species, in terms of vegetation type, food availability and environmental factors.
The Acid Bumblebee Crocodile Captive contains a pond as an aquatic habitat that can support the life of water birds. Waterbirds can be interpreted as bird species that depend on wetlands [14]. Waterbirds are one of the groups and classes of birds that forage in the waters [15].
International Journal of Ecophysiology Vol. 03, No. 02, 2021 |190-205 This is why at the time of observation, water bird species were found to be more common than terrestrial bird species. Water bird species also tend to be more visible because they have a larger body size and open land is a place for foraging for water birds. [16] stated that the identified water bird families include Phalacrocoridae, Ardeidae, Anatidae, Rallidae and Alcedinidae. The second factor is the structure of the vegetation that is open and little so that it affects the number of bird species encountered when observing at the research site. [17] suggested that canopy cover, the height of the canopy on the tree determines the diversity of bird species in a place.
According to [18], each type of animal can depend on certain groups of plant species to live. [19] added that the more tree species, the more possibilities of bird species that can live together. According to [20], habitats that have diverse vegetation variations and provide abundant food sources will increase the diversity of bird species.

Figure 3 Types of Trees Used as Nesting Places
The tree that is favored and used as a place for nesting, perching and foraging by birds in the Asam Kumbang Crocodile Farm is the Chinese petai tree (Leucaena leucocephala). According to [21], there are 3 types of plants visited by birds, namely green ki (Albizia saman), banyan (Ficus benjamina) and Chinese petai (L. leucocephala). This plant can provide many food sources for birds such as nectar in flowers, insects, seeds and fruit. Birds are also easy to adapt to the Chinese petai tree (L. leucocephala) because it has a transparent canopy structure so that birds are easier to catch insects as prey. Furthermore, by [22] stated that the Chinese petai tree (L. leucocephala) is used by birds because it has seeds in the pods which can be used as a food source by seedeating birds. Chinese petai (L. leucocephala) also has strong and elastic stems that birds can use to make nests and are used by birds as perches. This is what causes some species of birds choose the Asam Kumbang Crocodile Breeding as a nesting habitat and some as a place to find food.
The Asam Kumbang Crocodile Farm is a crocodile breeding place in which there are crocodiles.
Crocodiles are one of the predators for birds, but in this area birds can still live and coexist with crocodiles. This is because birds and crocodiles do not feel disturbed and threatened. Birds place their nests on trees so that crocodiles cannot reach them. With crocodiles, birds feel protected from other predators such as monitor lizards, snakes and human disturbance. This is in line with [5] research which revealed that birds are more attracted to crocodile areas, because where there are crocodiles, no raccoons or possums (predators that threaten bird nests) are present. In this case there is a reciprocal relationship between birds and crocodiles.
The third factor is that the time of data collection used for research has not been efficient so that the number of bird species encountered is small. Data collection was carried out for only 1 month and in that month there was no rainy season. During 1 month of observation, the types of birds found were constant (neither increasing nor decreasing). According to [7] ,  species that were most frequently found was 9 bird species in the 3rd data collection, this was presumably due to the environmental conditions when the data collection process supported the presence of birds, while the least number of bird species found was in the 4th data collection as many as 5 species of birds, due to the hot weather during the data collection process ( Table 2).
The number of bird species in the 1st data collection was 8 bird species, 2nd and 3rd each were 7 bird species. The number of bird species found during observations in crocodile breeding areas was slightly compared to the number of bird species in [10] in Cisarua, Bogor, presumably due to the influence of physical factors from the environment, such as temperature, humidity and duration of sunlight. According to [23], the presence of a bird species in an area can be influenced by several factors, including temperature, humidity, availability of food sources, distribution of vegetation and preferred tree species as nesting and resting places. [24] added that the factors that affect the vertical stratification of bird species communities in a place are the availability of food, vegetation structure and physical factors. Physical environmental factors at the time of observation at the Acid Beetle Crocodile Cap are as follows (Table 2).  candela, there were more bird species found, because the data was collected in a more shady environment, so there were many birds perched on trees. While the least number of birds was found in the 4th data collection with a temperature of 35.1°C, air humidity of 59% and light intensity of 602 candela, due to hotter environmental conditions causing birds to move to find a more shady place. According to [9], the behavioral response of endothermic animals, including birds, is to remove or reduce body heat by moving to a humid environment or entering underground holes in the summer and basking in the hot sun in winter.
Data on environmental physical factors at the time of observation affect the number of bird species encountered during observations. This is in line with the research of [25] who stated that at a temperature of 30°C with 70% humidity, the highest number of birds perched on trees, while at a temperature of 35.5°C with a humidity of 63% and at a temperature of 33°C with 66% humidity, no perching birds were found. This matter This is due to the open vegetation structure in the area so that direct sunlight occurs. Added [26], several environmental factors that dominantly affect animal life, one of which is temperature. Temperature variations in the natural environment and their impacts have a potential role in determining life processes, distribution and abundance of animal populations.

Species Diversity Index (H') and Equitability Index (E)
The

This is presumably due to several factors, including environmental conditions in the Asam
Kumbang Crocodile Breeding area that have not been able to support the survival of several bird species and the unavailability of adequate food sources for birds. The diversity index is a value that indicates the high and low diversity of a community. The higher the diversity value indicates that the habitat conditions are good in supporting natural bird life. According to [27], The existence of birds is supported by the suitability of the habitat and the ability of birds to adapt to environmental conditions. [28] argues that birds are one of the wildlife that are found almost everywhere, but for their life it requires certain conditions such as the existence of suitable, good, and safe habitat conditions from all kinds of disturbances. According to [29], habitat is an area that consists of various components, both physically and biotically, which is a unit that is used as a place to live and breed. Added by [30], habitat is a place that is used as a place for nesting and resting that is protected from various threats from predators. A good habitat should be able to provide food, water, shelter, The second factor is because during the data collection process there is no access or road to approach the bird, because at the observation location there are crocodile pond that must be passed to be able to approach the birds. Another factor encountered was human disturbance in the form of activities of visitors to the crocodile farm and workers when cleaning the crocodile pond so that the birds felt disturbed and the number of bird species found was less. According to [31], the presence of human disturbance (tourist and worker activity) at the observation site. The index value of bird species diversity found during 5 times of data collection at the observation location fluctuated. The index value was influenced by the number of species and the number of individuals encountered from day 1 to day 5 (Table 3). The value of diversity obtained from the results of data analysis starting from the 1st data collection to the 5th data collection is not stable, as well as the number of species and the number of individuals obtained. The results of observations in the field for five observations found several patterns of fluctuations in the composition of bird species, namely: 1) the number of species and the number of individual birds and the diversity index obtained varied, 2) the number of species could affect the diversity index value on each day of observation, 3) the diversity index The highest diversity index was obtained on the 3rd day, namely 1.69, 4) the lowest diversity index was obtained on the 4th day, namely 0.58, 5) the most visible species experiencing daily fluctuations was B. ibis, 6) the species that did not have a pattern , found only once under observation, namely Halcyon pileata and Prinia flaviventris. This is related to environmental factors such as temperature, light intensity and humidity on the day of observation. According to [32], the distribution of bird species in a habitat can be influenced by several factors include past habits, geographic barriers, climate (especially temperature, wind, altitude and humidity), behavior and mobility of birds. [33] suggest that the presence of birds in a habitat is closely related to physical factors such as soil, water, temperature, sunlight and biological factors including vegetation and other animals.

Grouping of Birds by Type of Feed
The availability of natural food at the location affects the number of species and the number of bird species. The Asam Kumbang Crocodile Farm is a location with a low vegetation level.
Vegetation can affect feed availability. [11] stated that the distribution of birds is closely related to the availability of food. Furthermore, [34], the diversity of animal species, including birds, is strongly influenced by the level of feed availability.
Birds need food for their survival. Birds have a preference for certain types of feed, so to meet their food needs, birds look for habitats that can provide the appropriate type of feed. According to [35], birds have a preference for a food, if one place does not meet their needs, birds will choose another place that has abundant food sources.
The grouping of birds based on the same pattern of resource use (guild) in the feed category has a relationship with tree species and the availability of food sources. According to [36], each community in different locations can show different patterns in plant species composition, guild structure and bird density. [37] suggests that environmental aspects that can affect bird distribution patterns include the presence and availability of food resources which are influenced by vegetation composition. Data on bird species grouping based on the type of feed guild category can be seen in Table 4.  Gleaning Insectivore (LGI) insectivorous feeding on litter or forest floor. Insect-eating groups are very common. This is because insects dominate the terrestrial ecosystem. According to [38], most birds are insectivorous or use insects as an alternative food. According to [14].

Conclusion
The conclusions of this study are: a. Diversity of bird species found as many as 12 bird species, namely Streptopelia chinensis