High Incubation Attendance, Intense Male-Male Competition, and Nesting Site Constraints of the Sclater's Monal in an Alpine Environment in Southwestern China

Understanding avian reproduction ecology and their selection of suitable nesting sites is essential for their conservation. The Sclater’s monal (Lophophorus sclateri), a regionally threatened, typical alpine pheasant species, has a restricted distribution from the east Himalayas to the mountains of west Yunnan China. Due to its low population density and the difficulty of accessing its habitats, the breeding ecology of this species was understudied. Therefore, we aimed to understand the breeding behavior, the nesting site selection, and its life-history strategy to cope with the alpine environment. During our fieldwork from March to June 2015 and 2016 in the Gaoligong Mountains in western Yunnan, China, we found six nesting sites ranging from 3,535 m to 3,892 m. Three of the sites were active, with one being used in both years, and the remaining three were inactive but had been used in prior years. The clutch size was 2 or 3 (2.75 ± 0.5 eggs, n = 4 nests), and all 11 eggs were successfully hatched. The female solely performed incubation, spending a total of 97.2% of its time in incubating with an average duration of 25.69 ± 13.79 h (n=43) per on-bout, which indicates the female bird invested more time than other pheasants. The duration of the on-bout increased when the female monals experienced a lower minimum temperature. These incubation strategies of the Sclater’s monal suggested that they increased parental care in coping with harsh conditions in the alpine environment. Combing the strict nesting site requirements, nesting site constraints as indicated by intense male-male fighting and nest reuse, and high incubation attendance of females, it suggested that the nesting site could act as a limiting factor for the population growth of this species, and the conservation of suitable nesting habitat is of great importance.