Light affects parental provisioning behaviour in a cavity‐nesting Passerine

Abstract

Nocturnal bird species possess special adaptations to maximise visual efficiency under low light levels. However, some typically diurnal species also experience low‐light environments. For example, cavity‐nesting Passerines raise broods in dark cavities and search for food in light‐abundant surroundings. It is not clear whether they possess special adaptations for low light vision or breed in cavities at the expense of impaired parental care. In this study, we tested whether light conditions affect the provisioning efficiency of great tits. We experimentally tested how the level of natural and artificially increased illumination inside nest boxes affects parental feeding duration, frequency and timing. We monitored 15‐h of provisioning activity of great tit parents when nestlings were day seven post hatch. We used traditional ‘dark’ nest boxes and ‘bright’ nest boxes with increased illumination obtained by using semi‐transparent plastic windows. The duration of single feedings were, on average, shorter in brightened nest boxes compared to dark ones. This difference tended to be higher early in the morning and in the evening, when the illumination in dark nest boxes was the lowest. Nest box type, however, did not influence feeding frequency or times of the onset and the end of feeding. Our findings provide new evidence for impaired efficiency of parental care due to lowered light conditions. Further research is needed to test whether prolonged feeding duration has negative effects on adult time budgets and nestling energy expenditures.

The use of trail cameras to monitor species inhabiting artificial nest boxes

“…To investigate the effect of hatching time on nestling mass, we calculated the daytime (minutes) spent by the first hatched nestling throughout the day (hereafter, day-time exposure). Daytime was the time between the sunrise and the sunset, which roughly corresponds to feeding hours in this population (Podkowa et al, 2019). Then we correlated it with mean nestling's mass in the brood in the 2nd and 12th day of life (hatching day = 0).…”

“…To process eggs or nestlings, the drawer with a nest was removed from the nest box. Because of a concurrent study of nest illumination (Podkowa et al, 2019; Podkowa & Surmacki, 2017), nest boxes were fitted with two 5.0‐cm‐diameter resin windows 15 cm above the floor located in the side walls, which were equipped with an adjustable shutter made of 9 × 9 cm black plastic sheets (Figure 2). In nest boxes where windows were open, internal illumination was about 50 times higher compared to nest boxes with windows shut and in which the only source of light was the entrance hole (Podkowa & Surmacki, 2017).…”

“…The presented method can be applied for a variety of purposes and animal taxa. The continuous motion-triggered video data could be used to survey the frequency and duration of activities like nest building, offspring provisioning (Podkowa et al, 2019), nest sanitation, and nest box occupancy by roosting animals (Video S1, Video S3, Video S4). Time-lapse photos can be used to monitor incubation attentiveness or to determine the fledging time in birds (Figure S1).…”

Quantitative analysis of the orientation of white stork nestlings’ parents from video monitoring

“…Few studies have looked into breeding correlation with weather conditions by storks (Tobolka et al 2018, Kaminski et al 2019). However parental behavior has yet to be considered in these studies, which is a point especially prone to modifications with climate changes (Durant et al 2019, Mueller et al 2019, Podkowa et al 2019. Our objective was first to understand the choice of placement of the stork parent on its nest, as preliminary observations suggested changes over the day.…”

Effect of Luminance on Visual Performance by Secondary Cavity and Non-Cavity Nesting Passerines

“…Most species of birds use rods for brightness detection under low light conditions and cones for color vision (Podkowa et al, 2019). However, it has been documented in previous studies that the tendency to encounter with this rapidly fluctuating level of light has evolved only in cavity nesters (Zhang et al, 2019;Larsen et al, 2020).…”