Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings

Almasi, Bettina; Béziers, Paul; Roulin, Alexandre; Jenni, Lukas

doi:10.1007/s00442-015-3318-2

Cited by 39 publications

(39 citation statements)

References 54 publications

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“…Earlier studies often tested the effect of human disturbance on bird species by inducing artificially different levels of noise, but without explicitly linking noise treatment levels to real life distribution of visitors on the ground (Lord et al, 2001;Verhulst et al, 2001;Baines and Richardson, 2007). Moreover, the direct effect of human disturbance at the individual level has largely focused on behavioural responses, where flush distance (Fernández-Juricic and Tellería, 2000;Miller et al, 2001;Tarjuelo et al, 2015), feeding patterns (Fernández-Juricic and Tellería, 2000) or physiological responses (e.g., increased corticosterone levels; Fowler, 1999;Walker et al, 2006;Ellenberg et al, 2007;Almasi et al, 2015) were measured. However, knowledge on the direct effect of human presence on individual fitness in an urban habitat is limited, as variation in life-history traits and reproductive success caused by human presence has been largely investigated in non-urban habitats and largely in noncavity nesting bird species ( Table 1).…”

Section: Introductionmentioning

confidence: 99%

Humans and Tits in the City: Quantifying the Effects of Human Presence on Great Tit and Blue Tit Reproductive Trait Variation

et al. 2017

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Environmental conditions are key drivers of life-history evolution, and the urban environment is an extreme form of land-use readily inhabited by avian wildlife, whose life-history variation in such altered environment is still poorly understood. Recently, the study of environmental variables associated with urban living-which include shifts in temperature, light, noise or food availability-has attracted increased attention. Another environmental axis that sets the urban space at odds relative to natural habitats is high human abundance, yet very little is known about its effect on avian fitness. We developed a protocol to quantify human presence by performing repeated counts of humans on the ground within a 15 m radius of nestboxes monitored in two centrally-located study areas of a European capital city. In parallel, a GIS-based approach was used to infer nestbox distance to the nearest path and road. Multiple counts of human presence around each nestbox yielded moderate to high repeatabilities (0.6 ≤ r ≤ 0.8) while requiring considerable resources time-and people-wise. In contrast, GIS-based estimates of nestbox distance to paths and roads were time efficient and generated highly repeatable results. The effects of (i) human presence around each nestbox, (ii) nestbox distance to the nearest path and (iii) nestbox distance to the nearest road were tested on reproductive traits of blue tits Cyanistes caeruleus and great tits Parus major breeding in two urban sites. Human presence did not influence blue tit or great tit life-history traits and reproductive success, suggesting reproductive habituation to humans in an urban landscape. In contrast, nestbox distance to roads shortened incubation time in great tits while nestbox distance to paths increased incubation time in blue tits. Moreover, blue tit offspring 2 weeks after hatching were lighter closer to roads. Our study confirms the reliability of a field protocol capturing human presence around multiple fixed locations that can be easily implemented in either urban or rural landscapes. At the same time, it appears that when applied to two urban sites where habituation to humans might have occurred, it is infrastructural networks rather than human presence per se that played a greater role in tit reproductive trait variation.

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Section: Introductionmentioning

confidence: 99%

Humans and Tits in the City: Quantifying the Effects of Human Presence on Great Tit and Blue Tit Reproductive Trait Variation

et al. 2017

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“…This time lapse corresponds to the peak of corticosterone response in the barn owl (Almasi et al, 2015).…”

Section: Assessment Of Baseline and Stress-induced Corticosterone Levelsmentioning

confidence: 95%

“…We used capture-recapture and dead recovery data collected during 13 years, with corticosterone measurements collected during 11 years in breeding adults. The barn owl breeds in human-made sites, which may have profound consequences on its survival given that human presence and landscape structure around breeding sites affect corticosterone levels in nestlings (Almasi et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Survival of adult barn owls is linked to corticosterone levels

Béziers

Korner-Nievergelt

Jenni

et al. 2019

Preprint

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Glucocorticoid hormones, such as corticosterone, are fundamental in the translation of external stimuli into physiological adjustments that promote the survival of an organism in face of changes in its environment. At baseline levels, corticosterone is crucial in regulating daily life metabolism and energy expenditure, whereas the acute corticosterone response promotes short-term physiological and behavioral responses to unpredictable environmental challenges. Given their different physiological effects and their role in mediating fitness components, it is still unclear whether and how inter-individual variation in baseline corticosterone levels and acute stress-response levels can affect the survival of organisms. We used 13 years of capture-recapture and dead recovery data combined with 11 years of corticosterone measurements taken on breeding barn owls (Tyto alba) to investigate how survival probability varies in relation to baseline and stress-induced corticosterone levels. Our study shows that males with a higher level of both baseline and stress-induced corticosterone levels have a higher probability of surviving than individuals with lower corticosterone levels. In females, survival probability was higher in individuals presenting elevated stress-induced corticosterone levels but was not significantly associated to baseline corticosterone levels. Our results suggest that in the barn owl the stress-induced corticosterone response is a better proxy of adult survival than baseline corticosterone levels. Further studies investigating the link between corticosterone levels and different fitness components as well as the environmental factors (e.g. weather, development conditions, disease and predation risk) leading to such endocrine phenotypes are needed to identify the costs and benefits of presenting high and low corticosterone profiles. † Estimates based on standardized data * Difference from female to male

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“…In the first part of the monitoring (visit 1-2), chicks manipulated by the same experimenters exhibited lower reactivity than those Figure 2. Behavioural and physiological responses of chicks could be influenced by the behavioural types of adults and their calls during nest visits or environmental conditions such as anthropic disturbances (Platzen and Magrath 2004, Almasi et al 2015, Arroyo et al 2017). manipulated by different people indicating lower stress.…”

Section: Different Dynamics In Chick Behaviour and Physiology Betweenmentioning

confidence: 99%

“…Indeed, chicks visited by identical experimenters were more stressed and aggressive at the end of the experiment suggesting a sensitization phenomenon (Blumstein 2016). Behavioural and physiological responses of chicks could be influenced by the behavioural types of adults and their calls during nest visits or environmental conditions such as anthropic disturbances (Platzen and Magrath 2004, Almasi et al 2015, Arroyo et al 2017). However, nests were randomly assigned to the two groups, thus these factors could not explain the differences we observed.…”

Section: Different Dynamics In Chick Behaviour and Physiology Betweenmentioning

confidence: 99%

To change or not to change experimenters: caveats for repeated behavioural and physiological measures in Montagu's harrier

Rabdeau

Badenhausser

Moreau

et al. 2019

Journal of Avian Biology

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Animals facing anthropogenic disturbances may exhibit different anti‐predator responses depending on their perception of the risk. Experimental measures of behavioural and physiological traits may be impacted by the disturbance due to experimenter handlings and activities. In this study, we assessed the behavioural and physiological responses of Montagu's harrier chicks Circus pygargus from 14 nests, visited four times from hatching to fledgling by either the same (group I) or different (group NI) experimenters. Escape, aggressiveness and stress‐induced corticosterone concentration increased for both groups over time but chicks from group I showed a higher increase in their behavioural and physiological responses than chicks from group NI. This increase occurred after the second visit when experimenters took the first blood sampling on nestlings. Handling by the same experimenters throughout the study did not result in habituation but in sensitization. Our results suggest that Montagu's harrier nestlings may discriminate between the people who visit their nest and respond to experimenters’ identity. Therefore, we urge researchers working on behaviour and/or the physiology of stress including repeated measurements (such as animal personality studies for instance) to consider whether the experiments should or should not be conducted by the same experimenters (as usually done to minimize bias) as it can influence the outcomes of the experiments.

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Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings

Cited by 39 publications

References 54 publications

Humans and Tits in the City: Quantifying the Effects of Human Presence on Great Tit and Blue Tit Reproductive Trait Variation

Humans and Tits in the City: Quantifying the Effects of Human Presence on Great Tit and Blue Tit Reproductive Trait Variation

Survival of adult barn owls is linked to corticosterone levels

To change or not to change experimenters: caveats for repeated behavioural and physiological measures in Montagu's harrier

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