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Luis M. Bautista - One of the best experts on this subject based on the ideXlab platform.

  • Sexual size dimorphism in the Common Crane, a monogamous, plumage-monomorphic bird
    2019
    Co-Authors: Juan C. Alonso López, Luis M. Bautista, Javier Alonso
    Abstract:

    Alonso JC, Bautista LM, Alonso JA. 2019. Sexual size dimorphism in the Common Crane, a monogamous, plumage-monomorphic bird. Ornis Fennica 96(4):194-204.

  • Foraging site displacement in Common Crane flocks
    Animal Behaviour, 1998
    Co-Authors: Luis M. Bautista, Juan C. Alonso, Javier A. Alonso
    Abstract:

    Optimal foraging theory predicts that an individual should resort to intraspecific kleptoparasitism when this foraging strategy helps to maximize its intake rate. Thus aggressor and victim should be foraging at lower and higher rates, respectively, than the flock average (intake rate maximization). Independent of the maximization principle, moreover, an aggressor should attack when its intake rate falls below a threshold critical for survival, and select a victim foraging at an intake rate high enough to ensure survival (starvation risk minimization). We tested both hypotheses using 324 aggressive displacements from feeding sites observed in flocks of Common Cranes, Grus grus, foraging on cereal fields. Aggressors attacked Cranes feeding at higher rates than average birds. The immediate consequences of a successful attack were an increase in intake rate for the aggressor and a decrease for the victim. The intake rate of the aggressor prior to the attack was lower than both the mean intake rate of the flock and the minimum intake rate necessary to cover basic metabolic needs. After displacing its victim, the intake rate of the aggressor was higher than before the attack and also higher than the average intake rate of the flock. The intake rate of the aggressor after the attack was not higher than the mean intake rate of the flock, however, when the time spent on the attack was included. We conclude that Cranes used a kleptoparasitic strategy to recover from temporary reductions in feeding rate. This was particularly the case below the threshold of intake necessary for survival. Copyright 1998 The Association for the Study of Animal Behaviour.

  • A 20-year study of wintering Common Crane fluctuations using time series analysis
    The Journal of Wildlife Management, 1992
    Co-Authors: Luis M. Bautista, Juan C. Alonso, Javier A. Alonso
    Abstract:

    The numbers of Common Cranes (Grus grus) staging and wintering at Laguna de Gallocanta (Gallocanta), northeastern Spain, have increased throughout the period 1970-90. Consequently, we modelled the use of this area by Cranes using Box-Jenkins Time Series Analysis to evaluate the influence of local food availability, duck hunting, and habitat and food conditions at other more traditional Crane wintering areas in southwestern Spain on Gallocanta Crane numbers. Food availability was not correlated with Crane numbers at Gallocanta except during mid-winter

  • Simulations on a Common Crane (Grus grus) population model
    1991
    Co-Authors: Javier A. Alonso López, Juan C. Alonso López, Silvio Martínez, Luis M. Bautista
    Abstract:

    Citacion completa: Alonso JA, Alonso JC, Martinez S, Bautista LM. 1991. Simulations on a Common Crane (Grus grus) population model. Proceedings of the IV International Crane Workshop in 1987 at Qiqihar, China. Pages: 277-283. International Crane Foundation, Wisconsin, USA

Xiaojun Yang - One of the best experts on this subject based on the ideXlab platform.

  • Vigilance strategy differentiation between sympatric threatened and Common Crane species.
    Behavioural processes, 2020
    Co-Authors: Dejun Kong, Weixiong Luo, Anders Pape Møller, Yanyun Zhang, Xiaojun Yang
    Abstract:

    Studies have indicated that threatened species may show reduced or elevated antipredator behavior compared with their close Common relatives, but remarkably few studies revealed such differences in behavior among populations. Exploring factors affecting behavior between phylogenetically related Common and threatened species could help understand such discrepancy. We tested for effects of external and internal variables including month, time of day, habitat type, distribution area, group composition status and group size on vigilance behavior (including group scan frequency and level) of two sympatric Common Grus grus and threatened G. nigricollis Cranes with generalized linear models. We detected significant species effect on group scan level, and grus was more vigilant than nigricollis. Model tests also indicated that group size had Common effect on group scan frequency for both species, and distribution area significantly correlated with the vigilance of nigricollis, while grus was more affected by time of day and group composition status in areas of sympatry with nigricollis. But when nigricollis was absent, time had no effects on behavior by individuals belonging to grus, implying existence of inter-specific competition. We also found that grus decreased individual vigilance efforts by foraging with other species (e.g., Bar-headed Goose Anser indicus) to share large group alertness benefits (collective vigilance). As our results demonstrated, we argued that, with diverse antipredation tactics e.g., foraging with other species, alternating time rhythm or partitioning spatial utilization to mitigate inter-specific competition, reducing time allocation to preening while maintaining foraging efforts, Common grus could maintain high level of vigilance, which may benefit their survival and population increase. Whereas less time spent vigilant antipredation strategy adopted by threatened nigricollis, this may have negative effects on their populations.

  • Habitat use, preference, and utilization distribution of two Crane species (Genus: Grus) in Huize National Nature Reserve, Yunnan-Guizhou Plateau, China.
    PeerJ, 2018
    Co-Authors: Dejun Kong, Weixiong Luo, Guoyue Huan, Xiaojun Yang
    Abstract:

    Understanding the habitat use and spatial distribution of wildlife can help conservationists determine high-priority areas and enhance conservation efforts. We studied the wintering habitat use, preference, and utilization distribution of two Crane species, that is, the black-necked Crane (Grus nigricollis, Przevalski, 1876) and Common Crane (Grus grus, Linnaeus, 1758), in Huize National Natural Reserve, Yunnan-Guizhou Plateau, southwestern China. Line transects indicated that anthropogenic farmland habitat was highly utilized and was positively selected by both Crane species (>90% of flocks observed for both species). Black-necked Cranes preferred marshland in spring (February and March) but avoided grassland during the entire wintering period, whereas Common Cranes avoided both marshland and grassland throughout the entire period. The two Cranes species had communal nightly roosting sites and separate daily foraging sites. Black-necked Cranes were distributed within two km (1.89 ± 0.08 km) of the roosting site, covering an area of 283.84 ha, with the core distribution area encompassing less than 100 ha. In contrast, Common Cranes were distributed far from the roosting site (4.38 ± 0.11 km), covering an area of 558.73 ha, with the core distribution area encompassing 224.81 ha. Thus, interspecies competition may have influenced the habitat preference and spatial distribution divergence of these two phylogenetically related species. This study should help guide habitat management as well as functional zoning development and adjustment in the future. Based on our results, we recommend restoration of additional wetlands, retention of large areas of farmland, and protection of areas that Cranes use most frequently.

Johan Månsson - One of the best experts on this subject based on the ideXlab platform.

  • Conservation success or increased crop damage risk? The Natura 2000 network for a thriving migratory and protected bird
    Biological Conservation, 2019
    Co-Authors: Lovisa Nilsson, Nils Bunnefeld, Jens Persson, Ramūnas Žydelis, Johan Månsson
    Abstract:

    Abstract Protected areas are important to support biodiversity and endangered species. However, they are often too small to fulfill the resource requirements of many large and mobile wildlife species, especially when congregating in large numbers. In such cases, wildlife may overflow onto surrounding human-dominated land and cause impacts. The aim of the EU Natura 2000 network is to increase supranational connectivity between protected areas for migratory and protected species such as the Common Crane (Grus grus). The Crane population along the Western European flyway has been increasing rapidly in recent decades, with peaks of 200,000 Cranes at specific Natura 2000 sites. We studied 32 GPS-tagged Cranes over four migration periods, to test the use of the network by Cranes and the potential for impacts on adjacent farmland. During the nighttime, the probability that roosting Cranes were located on Natura 2000 sites was 97%. During daytime, the probability of foraging Cranes being located on arable land was 68%. The probability of foraging Cranes occurring on agricultural fields close to Natura 2000 sites decreased with distance. Such foraging patterns may fuel conflicts between conservation and agricultural objectives. To resolve these conflicts we suggest improved cross-boundary collaboration and policy development among involved states, combined with stakeholder participation to implement effective compensation and damage prevention strategies which are focused upon networks of protected areas.

  • Territory size and habitat selection of breeding Common Cranes (Grus grus) in a boreal landscape
    2013
    Co-Authors: Johan Månsson, Lovisa Nilsson, Mikael Hake
    Abstract:

    Information on how birds use different types of habitat and move within landscapes is crucial for avian ecology, conservation and management. The Common Crane Grus grus has the widest distribution of all Crane species and covers both increasing and decreasing populations. Ecological knowledge is therefore necessary both for conservation and to mitigate bird-human conflicts. We studied territory size and habitat selection of breeding Common Cranes (n=11) at two spatial scales in south-central Sweden by using VHF and UPS transmitters. Breeding families of Cranes were strongly associated with farmlands and wetlands independent of spatial scale. However, 41% of positions were within forested habitats. According to a compositional analysis, moist and wet forests were selected more frequently than dry forests. Territory size was on average 250 ha +/- 47.8 SE. The territories showed little overlap between neighboring breeding pairs. Our study provides information necessary for estimating densities of breeding pairs, but also to indicate habitat types worth special attention by landscape managers and conservationists.

Jesús M. Avilés - One of the best experts on this subject based on the ideXlab platform.

  • Food selection of wintering Common Cranes (Grus grus) in holm oak (Quercus ilex) dehesas in south-west Spain in a rainy season
    Journal of Zoology, 2006
    Co-Authors: Jesús M. Avilés, J.m. Sánchez, Deseada Parejo
    Abstract:

    In the holm oak Quercus ilex dehesas of the Iberian Peninsula, several food types occur that can be selected by birds through the winter. In this framework, diet composition and diet selection of Common Cranes Grus grus was studied during a rainy wintering season. The winter diet of the Common Crane is mostly herbivorous in the holm oak dehesas of south-west Spain with

  • Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain
    Canadian Journal of Zoology, 2003
    Co-Authors: Jesús M. Avilés
    Abstract:

    In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile Cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult Cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult Cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also det...

Deseada Parejo - One of the best experts on this subject based on the ideXlab platform.