scholarly journals Human disturbance and conspecifics influence display site selection by Great Bustards Otis tarda

2013 ◽  
Vol 24 (1) ◽  
pp. 32-44 ◽  
Author(s):  
ROBERT J. BURNSIDE ◽  
ZSOLT VÉGVÁRI ◽  
RICHARD JAMES ◽  
SANDOR KONYHÁS ◽  
GÁBOR KOVÁCS ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Habitat Quality ◽  
Site Selection ◽  
Human Disturbance ◽  
Habitat Management ◽  
Habitat Choice ◽  
Social Cues ◽  
Great Bustard ◽  
Otis Tarda ◽  
Social Species

SummaryUnderstanding habitat selection and assessing habitat quality have an important role in habitat management and prioritisation of areas for protection. However, interpretations of habitat selection and habitat quality can be confounded by social effects such as conspecific attraction. Using 7 years’ data from a well monitored Great Bustard Otis tarda population in Central Europe, we investigated the roles of human disturbance and social cues in display site selection of male Great Bustards Otis tarda. The spatial distribution of displaying males was best predicted by human disturbance. In addition, the number of males attending display sites was strongly correlated to the number of females present and not with disturbance. This suggests that abundance could be a misleading metric for habitat quality in social species. Our results highlight the roles of disturbance and social cues in male habitat choice, and suggest that social factors need to be taken into consideration for management of endangered populations.

scholarly journals Impacts of survival and reproductive success on the long-term population viability of reintroduced great bustards Otis tarda in the UK

Oryx ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Kate Ashbrook ◽  
Andrew Taylor ◽  
Louise Jane ◽  
Ian Carter ◽  
Tamás Székely
Keyword(s):  
Habitat Management ◽  
Bird Species ◽  
Population Viability ◽  
Adult Survival ◽  
Wild Populations ◽  
Great Bustard ◽  
Otis Tarda ◽  
Demographic Rates ◽  
The Uk

AbstractReintroductions aim to re-establish species within their historical ranges through the release of wild- or captive-bred individuals following extirpation (or extinction) in the wild. There is no general agreement on what constitutes a successful reintroduction but the probability of the population achieving long-term persistence should be addressed. Here we review a 10-year trial reintroduction of the great bustard Otis tarda, a globally threatened bird species, to the UK and assess the long-term population viability. Despite changes in rearing and release strategy, initial post-release survival probability remained consistently low, with only 11.3% of bustards (n = 167) surviving from release to 1 year post-release. Nineteen breeding attempts were made by eight females; however, only one chick survived > 100 days after hatching, and no wild juveniles have recruited into the population. Using demographic rates from the UK population and wild populations elsewhere, and stochastic population modelling, we investigate the viability of this reintroduced population by predicting population size over the next 10 years. Under current demographic rates the population was predicted to decline rapidly. Self-sufficiency was predicted only using the highest estimates from the UK population for first-year and adult survival, and recruitment rates from wild populations elsewhere. Although changes have been made in rearing, release strategies, habitat management and release sites used, these changes appear to have a modest effect on long-term viability. Substantial improvements in survival rates and productivity are necessary to establish a viable great bustard population in the UK, and we consider this unlikely.

scholarly journals Heterospecific song quality as social information for settlement decisions: an experimental approach in a wild bird

2019 ◽  
Author(s):  
Jennifer Morinay ◽  
Jukka T. Forsman ◽  
Blandine Doligez
Keyword(s):  
Habitat Selection ◽  
Habitat Quality ◽  
Social Information ◽  
Great Tit ◽  
Social Cues ◽  
Breeding Habitat ◽  
Site Quality ◽  
Ficedula Albicollis ◽  
High Quality ◽  
Local Habitat

AbstractAssessing local habitat quality via social cues provided by con- or heterospecific individuals sharing the same needs is a widespread strategy of social information use for breeding habitat selection. However, gathering information about putative competitors may involve agonistic costs. The use of social cues reflecting local habitat quality acquired from a distance, such as acoustic cues, could therefore be favoured. Bird songs are conspicuous signals commonly assumed to reliably reflect producer quality, and thereby local site quality. Birds of different species have been shown to be attracted to breeding sites by heterospecific songs, but whether they can use fine heterospecific song features as information on producer (and by extension habitat) quality remains unknown. We used a playback experiment in a wild population of collared flycatchers (Ficedula albicollis), a species known to eavesdrop on dominant great tits’ (Parus major) presence and performance, to test whether flycatchers preferred to settle near broadcasts of a high quality great tit song (i.e. song with large repertoire size, long strophes, high song rate), a low quality great tit song or a chaffinch song (control). Among old females, aggressive ones preferred to settle near broadcasts of high quality tit song and avoided broadcasts of low quality tit song, while less aggressive females preferred to settle near broadcasts of low quality tit song. Male personality or age did not influence settlement decisions. Our results show that collared flycatcher females use great tit song quality features as information for settlement decisions, though differently depending on their own competitive ability and/or previous experience with great tit songs. Our study therefore further illustrates the complex condition-dependent use of heterospecific social information for breeding habitat selection.

Effects of Land Use and Wildfires on the Habitat Selection of Great Bustard (Otis tarda l.)-Implications for Species Conservation

2016 ◽  
Vol 27 (4) ◽  
pp. 910-918 ◽  
Author(s):  
Zsolt Végvári ◽  
Orsolya Valkó ◽  
Balázs Deák ◽  
Péter Török ◽  
Sándor Konyhás ◽  
...  
Keyword(s):  
Land Use ◽  
Habitat Selection ◽  
Species Conservation ◽  
Great Bustard ◽  
Otis Tarda ◽  
Effects Of Land Use ◽  
Selection Of

Great bustard Otis tarda habitat selection in relation to agricultural use in southern Portugal

2004 ◽  
Vol 10 (1) ◽  
pp. 251-260 ◽  
Author(s):  
Francisco Moreira ◽  
Rui Morgado ◽  
Stephen Arthur
Keyword(s):  
Habitat Selection ◽  
Great Bustard ◽  
Otis Tarda ◽  
Southern Portugal ◽  
Agricultural Use

scholarly journals Habitat selection of the Great Bustard (Otis tarda) in Körös-Maros National Park

2018 ◽  
Vol 26 (1) ◽  
pp. 89-94
Author(s):  
Zoltán Szenek ◽  
Zsolt Végvári
Keyword(s):  
Habitat Selection ◽  
National Park ◽  
Landscape Connectivity ◽  
Habitat Type ◽  
Habitat Choice ◽  
Geometrical Approach ◽  
Great Bustard ◽  
Geometric Properties ◽  
Habitat Patches ◽  
Presence Data

Abstract We investigated relationships among bustard presence data as response as well as properties of habitat patches such as shape, size, type of land use and landscape connectivity in 2015, employing bustard occurrence data in Körös-Maros National Park (KMNP hereafter). Additionally, we aimed to present a geometrical approach of habitat choice in animals, focusing on geometric properties rather than vegetation structure. Here we applied landscape metrics approach, providing landscape classification by analysing spatial patterns in potentially important landscape objects, disregarding linear constructions. Our findings show insignificant differences between shape metrics of selected and non-selected habitat patches, in line with previous studies concluding that bustards choose habitats based on habitat type classes rather than on geometric properties. Further, our results indicate that the original habitats of the study species, adapted to extensive, open steppes, became strongly fragmented, resulting in the absence of large contiguous areas. Within the study area, landscape connectivity values represent optimal habitat conditions, probably as a result of highly patchy structure of the landscape and relatively small nearest neighbour distances of habitat patches. Thus, our findings also indicate that Great Bustards adapted to modified landscape structures. Our landscape analytical approach provides a methodological framework which can be applied on habitat selection tactics in a number of species of key conservation importance.

scholarly journals Nest site habitat selection and nesting performance of the Great Bustard Otis tarda in southern Portugal: implications for conservation

2012 ◽  
Vol 23 (3) ◽  
pp. 323-336 ◽  
Author(s):  
PEDRO ROCHA ◽  
MANUEL B. MORALES ◽  
FRANCISCO MOREIRA
Keyword(s):  
Habitat Selection ◽  
Clutch Size ◽  
Great Bustard ◽  
Otis Tarda ◽  
Breeding Parameters ◽  
Water Point ◽  
Southern Portugal ◽  
Hatching Percentage ◽  
Cereal Fields ◽  
Selection Of

SummaryWe present results on breeding parameters, nesting performance and nest habitat selection of the globally threatened Great Bustard Otis tarda, gathered during a 3-year study in Castro Verde (southern Portugal). A total of 107 nests were located. The estimated average onset of laying was 22 April (SD = 12 days, n = 8). The incubation period ranged from 25 March to 15 June. Nearly 95% of females incubated between 1 April and 31 May. Mean clutch size was 2.12 (SD = 0.69, n = 86), showing no significant inter-annual differences. There was no significant relationship between clutch size and average nest finding date, although, on average, nests were found later each year. Hatching occurred between 21 April and 26 June. The estimated proportion of eggs hatched per nest (hatching percentage) was 87.5% in 2002 (n = 8), 64.0% in 2003 (n = 33) and 75.8% in 2004 (n = 33). Overall nesting success for the three years was 71% (n = 107). The main causes of nesting failure were agricultural activities, mainly ploughing and harvesting, followed by corvid predation. Nests were spatially aggregated up to 800–1,500 m. At larger scales, the spatial distribution of nests can be considered random or uniform. Females showed a clear preference for nesting in cereal fields, followed by young fallows, old fallows, ploughed fields and then other habitats, although the intensity of selection of particular habitats varied between years. Nests were associated with both cereals and fallows, thus aggregating where those habitat types occurred within the study area. These results provide the first complete description of the nesting process in a Great Bustard population, as well as important cues to the assessment of conservation measures implemented in Castro Verde, an area holding around 80% of the Portuguese population of this species (application of EU agri-environmental schemes, power line signalling, water-point provision in dry years).

Great Bustard (Otis tarda)

2020 ◽  
Author(s):  
Nigel Collar ◽  
Ernest Garcia
Keyword(s):  
Great Bustard ◽  
Otis Tarda

Tradeoffs between homing and habitat quality for spawning site selection by hatchery-origin Chinook salmon

2012 ◽  
Vol 96 (1) ◽  
pp. 109-122 ◽  
Author(s):  
Jeremy M. Cram ◽  
Christian E. Torgersen ◽  
Ryan S. Klett ◽  
George R. Pess ◽  
Darran May ◽  
...  
Keyword(s):  
Habitat Quality ◽  
Chinook Salmon ◽  
Site Selection ◽  
Spawning Site

scholarly journals Key Mortality Causes of the Great Bustard (Otis Tarda) in Central Hungary: An Analysis of Known Fatalities

2015 ◽  
Vol 22 (2) ◽  
pp. 32-41 ◽  
Author(s):  
Csaba Vadász ◽  
Miklós Lóránt
Keyword(s):  
Data Collection ◽  
Anthropogenic Factors ◽  
Relative Importance ◽  
Great Bustard ◽  
Systematic Data ◽  
Otis Tarda ◽  
Negative Effect ◽  
Breeding Attempt ◽  
Mortality Causes ◽  
Systematic Data Collection

Abstract In this study, we identified the key mortality causes of eggs, juveniles and adults of the Great Bustard (Otis tarda) and quantified the relative importance of those, based on systematic data collection that have been carried out during the period between 2005 and 2014 at the Upper-Kiskunság region in Central Hungary. Rate of mortality regarding juveniles and adults was 39.71% caused by anthropogenic factors. Within the anthropogenic factors leading to mortality, collision was represented by 81.48% of fatalities, whereas mowing/hay making represented by 18.52%. Hay making/mowing was the factor leading to unsuccessful breeding attempt with the strongest negative effect on the breeding success of the investigated population of the Great Bustard, as it was represented by 50.96% of all known mortality cases. Chemical treatment had the factor with the second strongest effect, as it was represented by 12.33% of all known mortality cases. The rate of unsuccessful breeding (hatching) caused by particular activities (hay making/mowing, tillage, harvesting) varied between 68.42% and 75.00%. It was the disturbance by passers-by which led to the highest portion of unsuccessful breeding with 83.33% unsuccessful nests.

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