Margaret Mosse, Grace Kibue, Wilfred Odadi
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Crocodylus niloticus, human disturbance, human-dominated landscapes, land conversion, land cover.
The Nile crocodile (Crocodylus niloticus, Laurenti, 1768) supports important ecological and socio-economic functions; however, its survival in most of its ranges in Africa continues to be threatened by anthropogenic activities. Here, we compared selected attributes of Nile crocodile nests (abundance, clutch size, distance from water, and presence or absence of eggs, tending and predation) across three human disturbance regimes (low, intermediate and high), indexed by coverage of cropland and settlement, along lower River Tana, Kenya. We conducted a crocodile nest survey in January 2019 and overlaid the resultant data on the most recent land cover map of a 1-km wide strip on both sides of the river, segmented into the different disturbance regimes using remote sensing and geographical information system techniques. The low, intermediate and high disturbance regimes comprised combined cropland and settlement coverage of 2%, 9% and 15%, respectively, and covered 28%, 27% and 47% of the surveyed river segment. We counted a total of 99 nests, with 45, 34 and 20 nests located in low, intermediate and high disturbance regimes, respectively. Nests were 56% less frequent than expected under high disturbance, whereas they were 69% more frequent than expected under low disturbance and showed expected frequency under intermediate disturbance. In addition, nests were 56% and 41% less frequent under high disturbance compared to low and intermediate disturbance, respectively. However, nest abundance was statistically similar between the latter two regimes. No significant differences were observed in other assessed attributes across disturbance regimes. Our study underscores the importance of minimizing land conversion in such human-dominated landscapes for enhanced sustainable utilization and conservation of crocodiles.
Cite this paper: Mosse, M., Kibue, G., Odadi, W. (2023). NILE CROCODILE NESTING ECOLOGY UNDER VARYING HUMAN DISTURBANCE INTENSITIES ALONG LOWER RIVER TANA, KENYA. Current Trends in Natural Sciences, 12(24), 110-126. https://doi.org/10.47068/ctns.2023.v12i24.012
