Birds

11 pages, 2047 KiB

Open AccessArticle

Life History and Sociality Predict Variation in Eye Size across Birds

by Guy Beauchamp

Birds 2023, 4(3), 284-294; https://doi.org/10.3390/birds4030024 - 23 Aug 2023

Cited by 2 | Viewed by 1375

Over evolutionary times, the eye has acquired several adaptations to improve feeding efficiency and reduce predation pressure. Eye size, in particular, represents a target for selection, as it affects light capture and image resolution. Previous research on variation in eye size across species [...] Read more.

Over evolutionary times, the eye has acquired several adaptations to improve feeding efficiency and reduce predation pressure. Eye size, in particular, represents a target for selection, as it affects light capture and image resolution. Previous research on variation in eye size across species has focused on ecological factors related to light availability and foraging needs. Larger eyes are also thought to allow species to detect distant predators more easily, but this conjecture has not been examined across species. I predicted that risk-averse species or those exposed to high predation risk benefit from relatively larger eyes to enhance predator detection. To test the prediction, I performed a comparative analysis involving 660 species of birds while controlling for phylogeny, body size and other known ecological correlates of eye size. The results show that species at the slow end of the life history continuum, which emphasize survival over reproduction and are expected to be risk-averse, have evolved relatively larger eyes. In addition, solitary species, which cannot rely on others in their groups to decrease predation risk, are also characterized by relatively larger eyes. The results indicate that predation risk, through its association with life history and sociality, is an important ecological factor in the evolution of eye size across species. Full article

(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)

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7 pages, 456 KiB

Open AccessCommunication

Leash Status of Approaching Dogs Mediates Escape Modality but Not Flight-Initiation Distance in a Common Urban Bird

by Skye C. Barnett, Wouter F. D. van Dongen, Roan D. Plotz and Michael A. Weston

Birds 2023, 4(3), 277-283; https://doi.org/10.3390/birds4030023 - 25 Jul 2023

Viewed by 1565

Abstract

Controversy exists around owned dogs’ impacts in public open spaces, with concerns about dogs’ impact on wildlife, including birds. Leashing dogs in public open spaces offers a tractable way of reducing dogs’ deleterious impacts on birds. Although dogs in public spaces are often [...] Read more.

Controversy exists around owned dogs’ impacts in public open spaces, with concerns about dogs’ impact on wildlife, including birds. Leashing dogs in public open spaces offers a tractable way of reducing dogs’ deleterious impacts on birds. Although dogs in public spaces are often unleashed, some dogs roam freely, whilst other unleashed dogs remain close to their owners. It is currently unknown whether birds can perceive and incorporate subtle differences in the leash status of approaching, but non-roaming, dogs into their escape decisions. We compare escape responses of a common urban bird, the magpie-lark Grallina cyanoleuca, in parks in Melbourne, Australia, to standardized approaches by a walker and a dog, which was either leashed or not leashed (but with the dog at the same distance from the walker). Flight-initiation distances, the distance between the lark and dog when escape commenced, did not vary between treatments. However, the unleashed dog evoked more intense responses (mostly flying away) than the leashed dog (mostly walking away). Thus, this species appears to perceive unleashed dogs as especially threatening, independent of their roaming behavior. Our findings suggest that leashing may be an effective way to reduce dog disturbance to wildlife, even for non-roaming dogs. Full article

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15 pages, 1960 KiB

Open AccessArticle

Perceptions of Birds by Urban Residents in an Australian Regional City and Implications for Conservation

by Brendan S. Champness, James A. Fitzsimons, Dave Kendal and Grant C. Palmer

Birds 2023, 4(3), 262-276; https://doi.org/10.3390/birds4030022 - 13 Jul 2023

Cited by 2 | Viewed by 2115

Abstract

Given the prevalence of common and threatened bird species within cities, more research is necessary to determine human attitudes to urban birds and how this may affect conservation in urban areas In Australia, few studies have considered the impact of human attitudes on [...] Read more.

Given the prevalence of common and threatened bird species within cities, more research is necessary to determine human attitudes to urban birds and how this may affect conservation in urban areas In Australia, few studies have considered the impact of human attitudes on birds; those that have focused primarily on particular species. In this study, we aim to understand the perceptions of urban residents of an Australian city (Ballarat) by examining the ways they categorise birds (using the multiple sorting technique). We found that people were particularly enamored by large, exotic species, but if familiar to them, native species were positively perceived by people. People tended to view aggressive species negatively, but only where this aggression was directed at humans. This approach gained important insight into the attitudes of these urban residents to local birds and their conservation. We used this insight to suggest how attitudes to avian species conservation may inform conservation initiatives and methods for maintaining biological diversity in urban areas. Full article

(This article belongs to the Special Issue Birds and People)

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Birds, Volume 4, Issue 3 (September 2023) – 3 articles

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