Supersize Me: Does Anthropogenic Food Change the Body Condition of Silver Gulls? A Comparison Between Urbanized and Remote, Non-urbanized Areas

Auman, Heidi J.; Meathrel, Catherine E.; Richardson, Amm

doi:10.1675/1524-4695(2008)31[122:smdafc]2.0.co;2

Cited by 111 publications

(75 citation statements)

References 7 publications

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“…On the other hand, many of the foods exploited by urban birds are designed to be easily digestible; a few fatty chips or slices of salami may have a disproportionate dietary effect than a far greater amount of natural foods (Ottoni et al 2009). In a Tasmanian study, Silver Gulls (Chroicocephalus novaehollandiae) consuming a large proportion of human foods in their diet tended to be heavier on average than those with a mainly natural diet (Auman et al 2008). Similar findings have been associated with specific sites where supplementary foods have been used to attract certain species for easy viewing (Orams 2002).…”

Section: Feeding Really Does Change Thingsmentioning

confidence: 75%

An appetite for connection: why we need to understand the effect and value of feeding wild birds

Jones

2011

Emu - Austral Ornithology

107

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Section: Feeding Really Does Change Thingsmentioning

confidence: 75%

An appetite for connection: why we need to understand the effect and value of feeding wild birds

Jones

2011

Emu - Austral Ornithology

107

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“…The nature of these accessible foods, usually high in easily digestible fat and sugar content (Voragen 1998), as well as the over-utilization thereof by wildlife species, can lead to increases in body mass in provisioned compared to non-provisioned populations (Auman et al 2008;Boutin 1990;Orams 2002). In humans, excessive body mass has been shown to lead to the chronic activation of the HPA-axis and glucocorticoid secretion (Björntorp and Rosmond 2000).…”

Section: Discussionmentioning

confidence: 99%

The hustle and bustle of city life: monitoring the effects of urbanisation in the African lesser bushbaby

Scheun

Bennett

Ganswindt

et al. 2015

Sci Nat

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Urbanisation has become a severe threat to pristine natural areas, causing habitat loss and affecting indigenous animals. Species occurring within an urban fragmented landscape must cope with changes in vegetation type as well as high degrees of anthropogenic disturbance, both of which are possible key mechanisms contributing to behavioural changes and perceived stressors. We attempted to elucidate the effects of urbanisation on the African lesser bushbaby, Galago moholi, by (1) recording activity budgets and body condition (body mass index, BMI) of individuals of urban and rural populations and (2) further determining adrenocortical activity in both populations as a measure of stress via faecal glucocorticoid metabolite (fGCM) levels, following successful validation of an appropriate enzyme immunoassay test system (ACTH challenge test). We found that both sexes of the urban population had significantly higher BMIs than their rural counterparts, while urban females had significantly higher fGCM concentrations than rural females. While individuals in the urban population fed mainly on provisioned anthropogenic food sources and spent comparatively more time resting and engaging in aggressive interactions, rural individuals fed almost exclusively on tree exudates and spent more time moving between food sources. Although interactions with humans are likely to be lower in 2 nocturnal than in diurnal species, our findings show that the impact of urbanisation on nocturnal species is still considerable, affecting a range of ecological and physiological aspects.

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“…For example the Eurasian Sparrowhawk is known to be one of the principal predators of smaller bodied songbird species, and its numbers are increasing in several urbanized habitats (Chamberlain et al 2009b), reaching high densities in large European cities like Hamburg (Risch et al 1996) or Prague (Kelcey & Rheinwald 2005). In Budapest, Hungary, breeding Sparrowhawks are present from the early 1980's (Bagyura 1985) and in 2007, the number of breeding birds was estimated around 200 pairs (Bérces 2007) which exceeds the breeding density of sparrowhawks in many natural habitats (Newton 1986). Furthermore, the number of sparrowhawks hunting in Budapest during winters is assumed to reach 500-600 individuals (Z. Bajor, pers.…”

Section: Changes In Consumer-based Forcesmentioning

confidence: 99%

Habitat urbanization and its effects on birds

Seress

Liker²

2015

Acta Zool Acad Sci H

186

135

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By transforming landscapes, human activity creates new types of habitats with altered environmental characteristics that never existed before. As the process of habitat urbanization bears impact on more and more natural habitats, it is essential for us to understand the changes we bring forth in the ecological forces shaping urban animal communities. Birds are perhaps the most frequently studied model organisms by urban ecologists. It is a well known general pattern that urban avian communities have typically reduced species richness, while the density of a few successful species is often higher in cities than in adjacent more natural habitats. But it is less understood which mechanisms generate and uphold these community-level changes. In this review we discuss the most important components of the urban environment influencing birds' physiology, behaviour or morphology, and compile several recent studies to illustrate their effects. To understand urban food webs we also review the results of bottom-up and top-down approach which suggest that altered food availability and predation may play key roles in forming recent urban bird communities. We encourage future research to focus more on experimental, manipulative studies, that would help us not just to realize general patterns but shed more light on the mechanisms, the underlying processes prompting changes in urban bird communities.

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Supersize Me: Does Anthropogenic Food Change the Body Condition of Silver Gulls? A Comparison Between Urbanized and Remote, Non-urbanized Areas

Cited by 111 publications

References 7 publications

An appetite for connection: why we need to understand the effect and value of feeding wild birds

An appetite for connection: why we need to understand the effect and value of feeding wild birds

The hustle and bustle of city life: monitoring the effects of urbanisation in the African lesser bushbaby

Habitat urbanization and its effects on birds

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