Population estimation of freshwater crocodiles (Crocodylus novaeguineae) and tree vegetation diversity at wildlife reserve of Mamberamo Foja, Papua, Indonesia

Suharno, Kadir A, Sembiring E, Masiki AD, Mubarak T, Lessil N, Ratnawati LD, Idris D, Imbenai JG. 2021. Population estimation of freshwater crocodiles (Crocodylus novaeguineae) and tree vegetation diversity at wildlife reserve of Mamberamo Foja, Papua, Indonesia. Biodiversitas 22: 2928-2936. The structure and composition of vegetation in the conservation area have a major influence on the existence of other flora and fauna, including freshwater crocodiles (C. novaeguineae). Wildlife Reserve of Mamberamo Foja (WRMF) is a conservation area in Papua that aims to protect the habitat and existence of freshwater crocodiles. The purpose of this study was to estimate the number of freshwater crocodile populations and tree species diversity in the WRMF, Papua. The method used was a field survey. The crocodile survey was carried out using the spotlight night count method. Tree species diversity was assessed using the line-transect plot method in 6 different locations representing the Upper, Central, and Lower Mamberamo. The results of the investigation showed that the freshwater crocodile population in the WRMF was around 0.3-19.7 individuals per kilometer. The population of this freshwater crocodile was very high, with an average of 4.5 individuals per 1-kilometer distance. The highest population numbers were found in the upstream Mamberamo River area 6.22 ind./km, followed by the central Mamberamo (2.21 ind./km) and downstream Mamberamo area (2.05 ind./km). Crocodiles were found in the Mamberamo River and other river systems, such as swamps and lakes. The tree vegetation in this area is still relatively good, and there are 112 species, dominated by the Moraceae, Burseraceae, Myrtaceae, Rubiaceae, Lauraceae, Dipterocarpaceae, and Euphorbiaceae families. The results of this study are important as a basis for determining the conservation policy for freshwater crocodiles that have limited distribution.

In search of Makara, an Extirpated Freshwater Crocodile Crocodylus siamensis (Schneider, 1801) of Java Island, Using Temple Reliefs, ᴪ AIC and Habitat Modeling

Ancient reliefs in temple can provide information of past ecosystem along with biodiversity including Makara relief representing crocodile figure. In here, this study aims to identify and model the population of freshwater Crocodylus siamensis as portrayed in reliefs in 6 temples. The result shows that the crocodile reliefs in temples were having similar pattern to the freshwater Crocodylus siamensis fossils in term of locality. The temples and the fossils were located in the inland and near the rivers. While the temple locality patterns were in contrast to the locations where extant saltwater Crocodylus porosus has occurred. These contradictions strengthen the possibility that the crocodile portrayed in reliefs was made based on the C. siamensis occurrences. Based on the analysis, it is estimated that the C. siamensis once has occupied river and wetland in Java and its presence has been recorded in the reliefs. This occurrence at least happened from 1280 to 700 BC. From assessments of habitats near the temples using ᴪ AIC, most surrounding habitats have high detection probability and occupancy for C. siamensis from ᴪ 0.500 (95%CI:0.058-0.941). to ᴪ 1.000 (95%CI:0.000-1.000).

Morphometric analysis of the Australian freshwater crocodile (Crocodylus johnstoni)

We conducted a morphometric analysis of 279 Crocodylus johnstoni, using specimens from the McKinlay River (n = 265) and Arnhem Land (n = 14), to meet the management need for predicting body size of C. johnstoni from isolated body parts. The results also allow reconstruction of C. johnstoni dimensions for comparison with other crocodilian species. We detected sexual dimorphism in some body measurements from the McKinlay River, and geographic variation in the morphology of McKinlay River and Arnhem Land populations, but differences were slight. There is pronounced allometric growth in C. johnstoni in the immediate post-hatching phase, largely due to elongation of the snout after exiting the confines of the egg. We compared the size, shape and relative growth of C. johnstoni with that of other crocodilian species for which equivalent data are available, but particularly the other Australian crocodile, Crocodylus porosus. C. porosus has a proportionately longer tail and a shorter but wider snout than C. johnstoni, and we discuss possible ecological correlates of these and other differences.

Hatchability Problem Of Exsitv Conservation Of The Freshwater Crocodile Crocodylus Palustris(Lesson 1831) At Dulahazra Safari Park, Cox’s Bazar, Bangladesh

In this research hatchability problems of freshwater crocodile in Dulahazra Safari Park have been discussed. The findings focused on meteorological factors, lack of suitable habitat in semi-captive enclosures and some physiological factors which are mainly responsible for non-hatchability of freshwater crocodile in the park environment. The research emphasized on finding rationale that interrupts breeding failure of this crocodile in this park. The hatchability problem was identified with some influential factors which are main barriers to escalate and proliferate the reintroduce program in Bangladesh. The findings showed that the influential factors including high stock density in a small space, low water deepness and narrow sandy bank of the enclosure with lack of nesting materials, high temperature and heavy rainfall are mainly responsible for the failure of freshwater crocodile breeding potentiality. Asiat. Soc. Bangladesh, Sci. 41(2): 155-161, December 2015