Data, Walker, 1862

Data View in CoL collection

The nest boxes were checked every 2 days after nest material was first found in the boxes. We simultaneously searched for potential natural nest-cavities in the surrounding forest ( Figure 1 View Figure 1 (b)). Tree cavities were considered actively used if giant nuthatch frequently visited and added nest materials. We combined direct observation and filming with Miniature video cameras (HD99S-10, LooSafe, Dongguan, Guangzhou, China) to record nesting activity and parental behaviour. The cameras were set up to take video 24 hours a day and each was fixed to the inside of the nest box flap. The camera recorded the nestlings from egg laying until the nestlings fledged. Incubation and fledging dates were obtained from the video and field observations of the nests. The frequency and duration of each behaviour was estimated from the total number of observations made between 6.00am and 8.00pm (GMT+8), covering the main activity period of the giant nuthatch. The nest temperature was measured using a probe-type electronic thermometer (WS-C, CKR, Penghe Electronics, Shanghai, China), with the probe placed inside the nest box.

We determined habitat type by the habitat type map in the general planning of the nature reserve. For nest trees, we photographed and collected specimens of leaves and branches. Nest materials were collected after fledging and identified, where possible. We determined egg colour by comparing with standard colorimetric cards (PANTONE formula guide, coated and uncoated) ( Mo et al. 2023).

Nest size, egg and nestling size were measured using vernier callipers accurate to 0.01 mm without damage. Nest height was measured using tape accurate to 0.01 m and nest tree diameter at breast height ( DBH) was measured using diameter tape accurate to 0.01 cm . Egg, nestling and nest material mass were measured using an electronic scale accurate to 0.01 g. Egg mass was measured on the second day of the incubation period. Nestlings were taken from the nest-box nest using a small cardboard box, measured daily for mass and tarsus length and ringed at 15 days old. After the fledging of the nestlings, we weighed and classified the nesting materials in the nest box (artificial and other), identifying plant material to species where possible by consulting the Flora of China (eFloras 2008). We used an electronic scale for weighing and both direct and microscopic examination for classification.