The flicker fusion frequency of budgerigars (Melopsittacus undulatus) revisited

Abstract

While color vision and spatial resolution have been studied in many bird species, less is known about the temporal aspects of bird vision. High temporal resolution has been described in three species of passerines but it is unknown whether this is specific to passerines, to small actively flying birds, to insectivores or to birds living in bright habitats. Temporal resolution of vision is commonly tested by determining the flicker fusion frequency (FFF), at which the eye can no longer distinguish a flickering light from a constant light of equal intensity at different luminances. Using a food reward, we trained the birds to discriminate a constant light from a flickering light, at four different luminances between 750 and 7500 cd/m2. The highest FFF found in one bird at 3500 cd/m2 was 93 Hz. Three birds had higher FFF (82 Hz) at 7500 cd/m2 than at 3500 cd/m2. Six human subjects had lower FFF than the birds at 1500 but similar FFF at 750 cd/m2. These results indicate that high temporal resolution is not a common trait for all small and active birds living in bright light habitats. Whether it is typical for passerines or for insectivorous birds remains to be tested.

Temporal vision: measures, mechanisms and meaning

“…3 B). Over the last decade, Ödeen, Kelber and co-workers have published a series of elegant behavioural CFF studies on birds with attention to ecology and taxonomy ( Rubene et al, 2010 ; Lisney et al, 2011 ; Boström et al, 2016 , 2017 ; Potier et al, 2020 ). Chicken do not have a very high CFF, but interestingly, an old non-selected breed has higher resolution than modern commercial laying hens ( Lisney et al, 2011 ).…”

“…Insectivorous passerines have high CFFs, with one individual pied flycatcher ( Ficedula hypoleuca ) reaching 146 Hz ( Boström et al, 2016 ; see Fig. 5 A), whereas the budgerigar ( Melopsittacus undulatus ; also a small bird, but feeding on seeds and slow-moving insects) does not reach more than ∼90 Hz ( Boström et al, 2017 ). Among diurnal raptors, the peregrine falcon ( Falco peregrinus ), which catches fast-moving, manoeuvrable prey in flight, has higher CFF (129 Hz) than two species catching slower prey ( Potier et al, 2020 ).…”

Coevolution of coloration and colour vision?

“…KOðlÞPðlÞ(1 À e ÀkAðlÞl )LðlÞ, ð2:2Þ [55,73]. We set integration time Dt to 0.014 s (assuming a flicker fusion frequency of roughly 70 Hz) [74]. We set the acceptance angle R to 0.003 (which we assume is the acceptance angle in radians of one integrative unit for a chromatic spatial resolution of about Receptor abundance is given relative to the abundance of UVS cones.…”

Wild bats briefly decouple sound production from wingbeats to increase sensory flow during prey captures

“…During the final stage of capture, the tagged bats combine faster sampling with a slower flight speed resulting in a 70-fold increase in size-specific sampling rate in comparison to the search phase. This suggests that high temporal update rates may be necessary for capturing aerial prey in a three-dimensional space, as has recently been proposed in different taxa of visually hunting predators (dragonflies, flies, small birds ( Boström et al., 2017 )). The high size-specific update rates in toothed whales during commute and capture may reflect that whales due to their cheap sound production ( Foskolos et al., 2019 ) might over-sample their surroundings, thereby supporting better discrimination of their prey and allowing faster and more precise guidance of their less maneuverable bodies compared to the agile aerial hunters ( Madsen and Surlykke, 2013 ).…”