Tolerant to humans? Assessment of alert and flight initiation distances of two bird species in relation to sex, flock size, and environmental characteristics

2020 ◽  
Vol 32 (5) ◽  
pp. 445-456
Author(s):  
Michelle García-Arroyo ◽  
Ian MacGregor-Fors
Keyword(s):  
Bird Species ◽  
Flock Size ◽  
Environmental Characteristics ◽  
Flight Initiation

scholarly journals Anti-predator behavior along elevational and latitudinal gradients in dark-eyed juncos

2019 ◽  
Vol 66 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Madelin Andrade ◽  
Daniel T Blumstein
Keyword(s):  
Human Impacts ◽  
Bird Species ◽  
Passerine Bird ◽  
Latitudinal Gradients ◽  
Junco Hyemalis ◽  
Predator Density ◽  
Elevational Gradients ◽  
Main Driver ◽  
Flight Initiation ◽  
Predator Behavior

Abstract Flight-initiation distance (FID), the distance between an individual and experimenter when it begins to flee, can be used to quantify risk-assessment. Among other factors, prior studies have shown that latitude explains significant variation in avian FID: at lower latitudes, individuals and species have longer FIDs than those living at higher latitudes. No prior studies have focused on the effect of elevation on FID. Given the similar patterns of seasonality, climate, and potentially predator density, that covary between latitude and elevation, birds at higher elevations might tolerate closer approaches. We asked whether elevation or latitude would explain more variation in the FID of a common passerine bird species, dark-eyed juncos (Junco hyemalis). Juncos live in a variety of habitats along both latitudinal and elevational gradients. We found that statistical models containing elevation as a variable explained more of the variation in FID than did models containing latitude. We also found, unexpectedly, that birds at higher elevation fled at greater distances. While more predators were sighted per hour at higher elevations than at lower elevations, the frequency of predator sightings did not explain a significant amount of variation in FID. This result questions whether predator density is the main driver of risk perception along elevational gradients. Nonetheless, because elevation explains more variation in FID than latitude in at least one species, these findings have direct implications on how human impacts on birds are managed. Specifically, those designing set-back zones to reduce human impact on birds may consider modifying them based on both latitude and elevation.

Flock formation and the role of plumage colouration in Ardeidae

2005 ◽  
Vol 83 (5) ◽  
pp. 683-693 ◽  
Author(s):  
M Clay Green ◽  
Paul L Leberg
Keyword(s):  
Bird Species ◽  
Flock Size ◽  
Wading Birds ◽  
Plumage Colouration ◽  
Wading Bird ◽  
White Plumage ◽  
Fourth Experiment ◽  
Species Specific ◽  
Colour Morphs ◽  
Egretta Rufescens

It has been hypothesized that white plumage facilitates flock formation in Ardeidae. We conducted four experiments using decoys to test factors involved in attracting wading birds to a specific pond. The first three experiments tested the effects of plumage colouration, flock size, and species-specific decoys on flock formation. The fourth experiment examined intraspecific differences in flock choice between the two colour morphs of the reddish egret, Egretta rufescens (Gmelin, 1789). Wading birds landed at flocks of decoys more often than single or no decoys (P < 0.001) but exhibited no overall attraction to white plumage (P > 0.05). White-plumaged species were attracted to white decoys (P < 0.001) and dark-plumaged species were attracted to dark decoys (P < 0.001). Snowy egrets (E. thula (Molina, 1782)), great egrets (Ardea alba L., 1758), and little blue herons (E. caerulea (L., 1758)) landed more often at ponds that contained decoys resembling conspecifics. At the intraspecific level, all observed reddish egrets selected flocks with like-plumaged decoys. Our results suggest that plumage colouration is an attractant for species with similar plumage, but white plumage is not an attractant for all wading bird species. White plumage may facilitate flock formation in certain species but does not serve as a universal attractant for wading birds of varying plumage colouration and size.

scholarly journals Gallant geese, fearful flocks? Flock size and heterospecifics alter the escape behaviour of an invasive goose

2018 ◽  
Vol 148 (2) ◽  
Author(s):  
Evelien Deboelpaep ◽  
Pieter-Jan Keleman ◽  
Bram Vanschoenwinkel ◽  
Nico Koedam
Keyword(s):  
Human Disturbance ◽  
Nature Reserve ◽  
Species Assemblages ◽  
Canada Goose ◽  
Flock Size ◽  
Escape Behaviour ◽  
Buffer Zones ◽  
Local Species ◽  
Escape Responses ◽  
Flight Initiation

While escape responses are shown to differ in areas with varying levels of human disturbance, it is not known to what extent these reactions depend on the composition of local species assemblages. We investigated variation in three flight response metrics for the invasive Canada Goose (Branta canadensis) in Belgium in three locations with different human accessibility. Results indicate that heterospecific birds and flock size affected flight initiation distances of the Canada Goose, but that these effects are location-specific. Escape responses were most pronounced in the nature reserve with the lowest human accessibility, and highly reduced in the recreational park. This study illustrates that, when buffer zones are being developed, generalising escape behaviour of birds may lead to potentially dangerous overestimations of their tolerance to human disturbance.

scholarly journals Individual consistency in flight initiation distances in burrowing owls: a new hypothesis on disturbance-induced habitat selection

2009 ◽  
Vol 6 (2) ◽  
pp. 167-170 ◽  
Author(s):  
Martina Carrete ◽  
José L. Tella
Keyword(s):  
Habitat Selection ◽  
Human Disturbance ◽  
Human Impacts ◽  
Bird Species ◽  
Individual Variability ◽  
Buffer Zones ◽  
Predatory Behaviour ◽  
Trade Offs ◽  
Individual Consistency ◽  
Flight Initiation

Individuals often consistently differ in personalities and behaviours that allow them to cope with environmental variation. Flight initiation distance (FID) has been measured in a variety of taxa as an estimate of the risk that an individual is willing to take when facing a predator. FID has been used to test life-history trade-offs related to anti-predatory behaviour and for conservation purposes such as to establish buffer zones to minimize human disturbance, given its species-specific consistency. Individual consistency in FID, however, has been largely overlooked. Here we show that, even after controlling for several confounding effects, this behaviour has a strong individual component (repeatability = 0.84–0.92) in a bird species, leaving a small margin for behavioural flexibility. We hypothesize that individuals may distribute themselves among breeding sites depending on their individual susceptibility to human disturbance. This habitat selection hypothesis merits further research, given its implications on both evolutionary and applied ecology research. For example, selection of human-tolerant phenotypes may be promoted through the humanization of habitats occurring worldwide, and when population means instead of individual variability in FID are considered for designing buffer zones to reduce human impacts on wildlife.

scholarly journals Effects of climate variation on bird escape distances modulate community responses to global change

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Díaz ◽  
T. Grim ◽  
G. Markó ◽  
F. Morelli ◽  
J. D. Ibáñez-Alamo ◽  
...  
Keyword(s):  
Global Change ◽  
Food Webs ◽  
Interspecific Interactions ◽  
Bird Species ◽  
Antipredator Behaviour ◽  
Bird Populations ◽  
Temperature And Precipitation ◽  
Increasing Temperature ◽  
Flight Initiation

AbstractClimate and land use are rapidly changing environmental conditions. Behavioral responses to such global perturbations can be used to incorporate interspecific interactions into predictive models of population responses to global change. Flight initiation distance (FID) reflects antipredator behaviour defined as the distance at which an individual takes flight when approached by a human, under standardized conditions. This behavioural trait results from a balance between disturbance, predation risk, food availability and physiological needs, and it is related to geographical range and population trends in European birds. Using 32,145 records of flight initiation distances for 229 bird species during 2006–2019 in 24 European localities, we show that FIDs decreased with increasing temperature and precipitation, as expected if foraging success decreased under warm and humid conditions. Trends were further altered by latitude, urbanisation and body mass, as expected if climate effects on FIDs were mediated by food abundance and need, differing according to position in food webs, supporting foraging models. This provides evidence for a role of behavioural responses within food webs on how bird populations and communities are affected by global change.

scholarly journals On fearfulness and patterns of bird urbanisation in an Australian metropolis

2015 ◽  
Author(s):  
Lawrence E Conole
Keyword(s):  
Explanatory Power ◽  
Bird Species ◽  
Predictive Ability ◽  
Landscape Scale ◽  
Bird Flight ◽  
Rural And Urban ◽  
Behavioural Factors ◽  
Urban Exploiter ◽  
Acting In Concert ◽  
Flight Initiation

I have utilised an assemblage of 91 bird species, their urban tolerance status objectively classified, with data on bird flight initiation distance (FID), to test questions of the importance of birds’ fearfulness of humans in determining urban tolerance or intolerance in the metropolis of Melbourne, Australia. While several studies have shown that mean FID for bird species (mFID) differs between rural and urban populations of bird species, stronger predictive ability is shown by variability in FID (cvFID) in modelling urban invasiveness. I test two hypotheses. Firstly, that mFID will be shorter in urban exploiter bird species than urban adapters and avoiders. Secondly that cvFID is positively correlated with bird incidence at the landscape scale in Melbourne. Relatively weak explanatory power of cvFID found in this study suggest that environmental and behavioural factors acting in concert better explain the urban tolerance of bird species and assemblages, rather than fearfulness alone.

Database of Bird Flight Initiation Distances to Assist in Estimating Effects from Human Disturbance and Delineating Buffer Areas

2016 ◽  
Vol 7 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Kent B. Livezey ◽  
Esteban Fernández-Juricic ◽  
Daniel T. Blumstein
Keyword(s):  
Human Activity ◽  
Land Management ◽  
Human Disturbance ◽  
Human Activities ◽  
Escape Behavior ◽  
Bird Species ◽  
State Agencies ◽  
Bird Flight ◽  
Fish And Wildlife Service ◽  
Flight Initiation

Abstract U.S. Fish and Wildlife Service biologists determine effects from disturbance to threatened and endangered bird species, and staffs of federal and state agencies estimate these effects when delineating protective buffers around habitat of bird species of concern on land management areas. These efforts can be informed by the distances at which human activities cause birds to react or move away. To that end, here we present a database of published alert distances (distances at which birds exposed to an approaching human activity exhibit alert behavior), flight initiation distances (distances at which birds exposed to an approaching human activity initiate escape behavior), and minimum approach distances (distances at which humans should be separated from wildlife). The database distinguishes between nesting and nonnesting situations. The nesting database includes 578 alert distances and 2,177 flight initiation distances from 45 studies representing 11 orders, 27 families, and 49 species of birds. The nonnesting database comprises 1,419 alert distances and 34,775 flight initiation distances from 50 studies representing 19 orders, 89 families, and 650 species.

Resource seasonality and the structure of mixed species bird flocks in a coastal Atlantic forest of southeastern Brazil

2000 ◽  
Vol 16 (1) ◽  
pp. 33-53 ◽  
Author(s):  
Pedro Ferreira Develey ◽  
Carlos Augusto Peres
Keyword(s):  
Seasonal Variation ◽  
Breeding Season ◽  
Atlantic Forest ◽  
Bird Species ◽  
Southeastern Brazil ◽  
Individual Species ◽  
Flock Size ◽  
Fruit Availability ◽  
Ecological Requirements ◽  
Arthropod Abundance

ABSTRACT. Multi-species bird flocks in tropical forests are maintained throughout the annual cycle despite seasonal differences in resource availability, and the reproductive schedules and ecological requirements of individual species. This study examines the relationship between seasonal variation in flock structure and the availability of fruits and arthropods over a 12-mo period at a coastal Atlantic forest within the Juréia–Itatins Ecological Station, São Paulo, Brazil. Fruit abundance was estimated by a phenological survey of both canopy and understory trees, whereas arthropod abundance was quantified monthly on the basis of a nocturnal visual census technique. The seasonal variation in flock structure and composition was affected by both the breeding seasons of different core and attendant species, and the availability of food resources. The number of bird species attending flocks was greater during the dry season, declining thereafter during the breeding season. Understorey fruit availability exhibited a marked seasonal fluctuation with the lowest levels between the late dry and early wet season. Seasonal variation in canopy fruit availability, on the other hand, was far less demarcated than that of understorey plants. Arthropod abundance was greatest during the wettest months of the year, which apparently determined the timing of the main breeding season. Bird species richness attending flocks was, therefore, significantly correlated with the availability of understorey arthropods, but not with that of either understorey and canopy fruits. Arthropod abundance thus appears to affect profoundly the reproductive schedules of the understorey avifauna, which in turn influences the seasonal variation of flock size and composition.RESUMO. Nas florestas tropicais a formação de bandos mistos de aves ocorre ao longo de todo o ano, porém existem variações sazonais na composição e estrutura destes bandos. Tais variações estão ligadas ao período reprodutivo das aves, à disponibilidade de recursos alimentares e a requisitos ecológicos inerentes a cada espécie. Este trabalho analisou a dinâmica sazonal destes bandos durante um ano, relacionando estes dados com a disponibilidade de recursos alimentares em uma área de Mata Atlântica na Estação Ecológica Juréia–Itatins. A disponibilidade de frutos foi estimada através de acompanhamento fenológico de espécies de dossel e de sub-bosque, enquanto a abundância de artrópodos foi feita através de censos noturnos mensais. A variação sazonal na estrutura e composição dos bandos foi afetada pela atividade reprodutiva das espécies mais freqüentes e pela disponibilidade de recursos alimentares. Nos meses mais secos ocorreu um aumento do número de espécies nos bandos, ocorrendo um declínio durante o período de reprodução das aves. A quantidade de frutos de sub-bosque apresentou maior escassez entre o final do período seco e o início do período chuvoso, variando de maneira muito mais drástica quando comparada aos frutos de dossel. A abundância de artrópodos foi maior durante os meses mais chuvosos do ano, coincidindo com a época reprodutiva das aves. A riqueza das espécies de aves associadas a bandos mistos foi significativamente correlacionada com a abundância de artrópodos, mas não com a disponibilidade de frutos de dossel e sub-bosque. A abundância de artrópodos deve ter influenciado o início das atividades reprodutivas das aves, que por sua vez, causou as variações sazonais na composição e tamanho dos bandos.

When and how do predator starting distances affect flight initiation distances?

2005 ◽  
Vol 83 (8) ◽  
pp. 1045-1050 ◽  
Author(s):  
W E Cooper, Jr.
Keyword(s):  
Bird Species ◽  
Ecological Factors ◽  
Flight Initiation Distance ◽  
Lizard Species ◽  
Urosaurus Ornatus ◽  
Approach Speed ◽  
Monitoring Costs ◽  
Sceloporus Virgatus ◽  
The Relationship ◽  
Flight Initiation

The distance separating predator and prey when the predator begins to approach, starting distance, was recently shown to affect flight initiation distance in many bird species, raising questions about the effect's generality, variation with ecological factors, and economic basis. I studied the effect in two lizard species that forage by ambush and escape into nearby refuges. Monitoring costs during approach are absent because ambushers remain immobile while scanning for prey and predators. Risks are minimized because of the proximity to refuge. Flight initiation distance increased weakly with starting distance in Sceloporus virgatus Smith, 1938 significantly only at rapid approach speed. It was not significant in Urosaurus ornatus (Baird and Girard, 1852) at slow approach speed. Flight initiation distance is predicted to increase with starting distance, owing to monitoring costs and assessment by prey of greater risk during prolonged approaches. The significant effect in S. virgatus, which lacks monitoring costs, is the first indication that risk affects the relationship between starting distance and flight initiation distance. Conditions in which starting distance is important and its possible effects in earlier studies are discussed, as well as standardizing approaches and possible artifactual effects of starting distance.

scholarly journals Boat disturbance effects on moulting common eiders Somateria mollissima

2019 ◽  
Vol 167 (1) ◽  
Author(s):  
Nina Dehnhard ◽  
Jørgen Skei ◽  
Signe Christensen-Dalsgaard ◽  
Roel May ◽  
Duncan Halley ◽  
...  
Keyword(s):  
Somateria Mollissima ◽  
Flock Size ◽  
Foraging Habitat ◽  
Policy Makers ◽  
Wind Speeds ◽  
Resting Behaviour ◽  
Disturbance Effects ◽  
Common Eiders ◽  
Boat Traffic ◽  
Flight Initiation

AbstractShip and boat traffic are increasing sources of disturbance to marine wildlife. During moult, sea ducks are flightless and rely on productive and shallow feeding areas. However, this period coincides with the peak of the recreational boating season. This is the first study to investigate the escape behaviour of moulting common eiders (Somateria mollissima) to the approach of small boats. We quantified flight initiation distances (flock-to-boat distance at which an energy-demanding escape occurred), displacement distances (distance between the pre- and post-disturbance position of the flock) and the time it took flocks to return to pre-disturbance (foraging- or resting-) behaviour. Moulting common eiders showed average flight initiation distances of 177 m and displacement distances of 771 m. Displacement distances decreased with flock size, under higher wind speeds and when previous foraging habitat was shallower. Time-to-return to pre-disturbance behaviour decreased with flock size but increased with wind speed and accessibility of foraging habitat at the previous location. Most (75%) of flocks returned to pre-disturbance behaviour within 10 min after the disturbance, while three flocks kept disturbed even 45 min after the approach. Finally, flocks encountered less accessible (deeper) habitats after disturbance than before. Our results suggest that approaching boats imply considerable disturbance effects for moulting common eiders through increased locomotion costs, displacement from accessible foraging habitat and/or time lost for foraging or resting. We provide valuable information for policy makers and marine spatial planning and highlight the need for awareness among recreational boat drivers on their impact on wildlife.

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