Stavros Xirouchakis | University of Crete (original) (raw)
Papers by Stavros Xirouchakis
The European Zoological Journal
The European Zoological Journal, 2020
The winter months are an important part of the year for raptors as survival throughout this perio... more The winter months are an important part of the year for raptors as survival throughout this period is critical for the succeeding year's population recruitment. We reveal novel insights into the wintering of kites (Milvus spp.) on the Mediterranean island of Crete, Greece. We use a combination of 1) direct field observations, 2) online photograph searches and 3) analysis of satellite telemetry data from a tagged hybrid Red Kite × Black Kite (Milvus milvus × M. migrans migrans). The number of observations of wintering kites has increased since 1998. The wintering of numerous Black Kites with morphological features of both subspecies (M. migrans migrans and M. migrans lineatus) and a hybrid Red Kite × Black Kite is a new phenomenon on Crete.
European Journal of Wildlife Research
Ornithological Science, 2019
Abstract The diet composition and dietary patterns of the Long-eared Owl Asio otus were studied i... more Abstract The diet composition and dietary patterns of the Long-eared Owl Asio otus were studied in Mediterranean agrosystems in central Crete (Greece) over the winters of 2009–2015. Overall, 2,819 prey items were recovered from 1,207 pellets, belonging to six taxa of mammals, 22 taxa of birds and four taxa of insects. Small mammals were the most common prey species, accounting for 75.8% by frequency and 79.7% by biomass, followed by birds (23.2% and 20.1%); the latter being rather an island component compared to continental regions. The House Mouse Mus musculus was the most important prey species in the owl's diet (56.3%) ahead of the Wood Mouse apodemus sylvaticus (9.51%) and the Black Rat Rattus rattus (7.9%). The species proved to be a significant rodent predator in olive groves and vineyards during winter months, selecting Wood Mouse and young Black Rat more than expected. Long-eared Owl feeding ecology studies could lead to improved land management and agricultural practices in the rural landscapes of the Mediterranean.
Avian Biology Research, 2018
The Long-eared Owl (Asio otus) in Crete (Greece) is a common agricultural species affected by the... more The Long-eared Owl (Asio otus) in Crete (Greece) is a common agricultural species affected by the recent changes in agro-forestry systems. Concrete studies of habitat selection are needed in order to improve our knowledge of its foraging behaviour in managed rural landscapes. In the present study, we analysed the home range size and habitat selection of 11 Long-eared Owls inside olive groves in the plain of central Crete using radio tracking data and remote sensing images. Six nominal scale and 11 landscape scale predictors were used for habitat selection analysis, using a maximum entropy approach. Home range size ranged between 337 and 969 ha while a 52% of home range overlap was observed suggesting that Long-eared Owls do not defend hunting territories. At the nominal scale, distance to potential roosts (trees) was the most important contributor to model performance, followed by vegetation heterogeneity. Furthermore, local heterogeneity of greenness was a better predictor than sim...
Diversity
Aquila chrysaetos and Aquila fasciata are two congeneric eagle species distributed in the Mediter... more Aquila chrysaetos and Aquila fasciata are two congeneric eagle species distributed in the Mediterranean region which are supposed to compete for similar breeding and foraging resources. In the present study, bioclimatic, topographic, and human-related habitat parameters were investigated for 64 and 75 nest sites of Golden and Bonelli’s eagles, respectively. The nests were found during fieldwork undertaken from 1995–2020. Overall, the habitat parameters that best discriminated nest site selection were associated with elevation, temperature, and land use with topographic variables being most powerful for niche separation. Univariate analysis, regression, and species distribution modeling identified a strong association of the species with altitude pinpointing the Golden eagle’s mountainous and continental character and the Bonelli’s eagle being a lowland and coastal species. Golden eagle nests were situated away from human settlements on steep cliffs in higher altitude areas with tran...
Diversity and Distributions
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Book of Abstracts, 1st European Congress of Conservation Biology, 2006
Pernatye Hiŝniki i Ih Ohrana, 2018
In the current study we present data collected during the last two decades on the island of Crete... more In the current study we present data collected during the last two decades on the island of Crete (Greece) regarding the nesting habitat of two sympatric species namely the Golden Eagle (Aquila chrysaetos) and the Bonelli's Eagle (Aquila fasciata). The factors that determine the species nest site selection were identified via a logistic regression model and nesting habitat suitability maps were constructed by using maximum entropy models and a Geographic Information System. At the spatial scale considered, the best predictors of nesting habitat were topographical variables such as altitude and slope indicative for the requirement of rugged terrain. The predictive maps represented by the subset of topographic variables were also able to predict nest-site selection by both species more adequately than subsets of bioclimatic or human disturbance variables. Based on the overlap of the available nesting habitat of the two eagle species, an ecological separation was detected most prob...
In the current study we present data collected during the last two decades on the island of Crete... more In the current study we present data collected during the last two decades on the island of Crete (Greece) regarding the nesting habitat of two sympatric species namely the Golden Eagle (Aquila chrysaetos) and the Bonelli’s Eagle (Aquila fasciata). The factors that determine the species nest site selection were identified via a logistic regression model and nesting habitat suitability maps were constructed by using maximum entropy models and a Geographic Information System. At the spatial scale considered, the best predictors of nesting habitat were topographical variables such as altitude and slope indicative for the requirement of rugged terrain. The predictive maps represented by the subset of topographic variables were also able to predict nest-site selection by both species more adequately than subsets of bioclimatic or human disturbance variables. Based on the overlap of the available nesting habitat of the two eagle species, an ecological separation was detected most probably...
In the framework of LIFE+ Biodiversity project on “Innovative actions against illegal poisoning i... more In the framework of LIFE+ Biodiversity project on “Innovative actions against illegal poisoning in EU Mediterranean pilot areas” [LIFE09 NAT/ES/000533], the Spanish organization “Fundacion Gypaetus”, acting as coordinating beneficiary, along with the Portuguese partners “Quercus” and “Centro de Estudos da Avifauna Iberica” (CEAI) and the Greek partners “Arcturos” and “University of Crete – Natural History Museum of Crete” (NHMC), are implementing specific actions on this issue since October 2010 for a 5-years’ project. The main goal of the project is to evaluate and spread the effectiveness of several innovative actions based on voluntary agreements with the main rural groups related with the fight against the illegal use of poisoned baits (municipalities, hunters, stockbreeders, etc.). Thanks to the demonstrative character of the foreseen actions, it is expected to relevantly improve the current anti-illegal poisoning strategies and so diminish the biodiversity loss related with th...
12TH INTERNATIONAL CONGRESS ON THE ZOOGEOGRAPHY AND ECOLOGY OF GREECE AND ADJACENT REGIONS, 2012
Book of Abstracts. 10th International Congress on the Zoogeography and Ecology of Greece and Adjacent Regions, 2006
All European vulture species occur in Greece, which is the only Balkan country that still harbors... more All European vulture species occur in Greece, which is the only Balkan country that still harbors breeding populations. However since the last status review in the mid 1980s all species have undergone a substantial shrinkage in their distribution and a dramatic decline in their population. Based on data from various sources and field surveys carried out during the period 1994-2005, numbers of all four species have decreased except for the Black Vulture (Aegypius monachus) which holds a localized population of 22-27 breeding pairs in the Dadia National Park, region of Thrace. In fact the Black Vulture has been the only species, at the brink of extinction that exhibited stable population trends due to a long-term project for the conservation of its nesting habitat and breeding nuclei. On the contrary the Bearded Vulture (Gypaetus barbatus), which was regarded as stable and not immediately threatened, became extinct in 75% of its breeding range apart from the island of Crete where 6 breeding pairs still remain. Similarly the Egyptian Vulture (Neophron percnopterus), once common in certain areas, has experienced a large population decline (44-60%) presently numbering ca. 100-140 breeding pairs. The Griffon Vulture (Gyps fulvus) formerly widespread in central and western Greece has suffered a considerable contraction of its distribution (50-60%) and loss of its breeding groups (ca. 60%). Its current population size has been estimated at 175-192 breeding pairs with Crete being its main stronghold hosting more than 80% of them. Poisoning comprised the main mortality factor for all species devastating their numbers almost throughout the country. Land use changes which resulted in food shortage, habitat loss and direct persecution by man, have additionally kept vulture populations under pressure.
Science of The Total Environment, 2021
The COST Action 'European Raptor Biomonitoring Facility' (ERBFacility) aims to develop pan-Europe... more The COST Action 'European Raptor Biomonitoring Facility' (ERBFacility) aims to develop pan-European raptor biomonitoring in support of better chemicals management in Europe, using raptors as sentinel species. This presents a significant challenge involving a range of constraints that must be identified and addressed. The aims of this study were to: (1) carry out a comprehensive review of the constraints that may limit the gathering in the field of raptor samples and contextual data, and assess their relative importance across Europe; and (2) identify and discuss possible solutions to the key constraints that were identified. We applied a participatory approach to identify constraints and to discuss feasible solutions. Thirty-one constraints were identified, which were divided into four categories: legal, methodological, spatial coverage, and skills constraints. To assess the importance of the constraints and their possible solutions, we collected information through scientific workshops and by distributing a questionnaire to stakeholders in all the countries involved in ERBFacility. We obtained 74 answers to the questionnaire, from 24 of the 39 COST participating countries. The most important constraints identified were related to the collection of complex contextual data about sources of contamination, and the low number of existing raptor population national/regional monitoring schemes and ecological studies that could provide raptor samples. Legal constraints, such as permits to allow the collection of invasive samples, and skills constraints, such as the lack of expertise to practice necropsies, were also highlighted. Here, we present solutions for all the constraints identified, thus suggesting the feasibility of establishing a long-term European Raptor Sampling Programme as a key element of the planned European Raptor Biomonitoring Facility.
Marine ornithology, 2017
XIROUCHAKIS, S.M., KASAPIDIS, P., CHRISTIDIS, A., ANDREOU, G., KONTOGEORGOS, I. & LYMBERAKIS, P. ... more XIROUCHAKIS, S.M., KASAPIDIS, P., CHRISTIDIS, A., ANDREOU, G., KONTOGEORGOS, I. & LYMBERAKIS, P. 2017. Status and diet of the European Shag (Mediterranean subspecies) Phalacrocorax aristotelis desmarestii in the Libyan Sea (south Crete) during the breeding season. Marine Ornithology 45: 1–9. During 2010–2012 we collected data on the population status and ecology of the European Shag (Mediterranean subspecies) Phalacrocorax aristotelis desmarestii on Gavdos Island (south Crete), conducting boat-based surveys, nest monitoring, and diet analysis. The species’ population was estimated at 80–110 pairs, with 59% breeding success and 1.6 fledglings per successful nest. Pellet morphological and genetic analysis of otoliths and fish bones, respectively, showed that the shags’ diet consisted of 31 species. A total of 4 223 otoliths were identified to species level; 47.2% belonged to sand smelts Atherina boyeri, 14.2% to bogues Boops boops, 11.3% to picarels Spicara smaris, and 10.5% to damsel...
Wind Energy and Wildlife Impacts, 2019
Crete has been characterized as an area with a high wind energy capacity due to its mountainous t... more Crete has been characterized as an area with a high wind energy capacity due to its mountainous terrain and the strong prevailing winds throughout the year. At the same time, the island constitutes the last stronghold for vulture species in Greece, currently holding the largest insular population of Eurasian griffons (Gyps fulvus) worldwide (ca. 1000 individuals). Given the empirical data on the mortality of large raptors due to collisions with wind turbine blades, the aim of the present study was to predict the potential impact of wind energy installations on the griffon vulture population on the island. The study was developed in two steps, namely, (a) the spatial mapping of the existing and planned wind energy projects up to the year 2012 and the delineation of their risk area and (b) the calculation of the annual collision rate based on the expected number of vulture risk flights and the probability of being killed. Overall, the minimum number of fatalities due to collision of v...
This document describes work undertaken as part of a programme of study at the Faculty of Geo-Inf... more This document describes work undertaken as part of a programme of study at the Faculty of Geo-Information Science and Earth Observation of the University of Twente. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the Faculty.
The European Zoological Journal
The European Zoological Journal, 2020
The winter months are an important part of the year for raptors as survival throughout this perio... more The winter months are an important part of the year for raptors as survival throughout this period is critical for the succeeding year's population recruitment. We reveal novel insights into the wintering of kites (Milvus spp.) on the Mediterranean island of Crete, Greece. We use a combination of 1) direct field observations, 2) online photograph searches and 3) analysis of satellite telemetry data from a tagged hybrid Red Kite × Black Kite (Milvus milvus × M. migrans migrans). The number of observations of wintering kites has increased since 1998. The wintering of numerous Black Kites with morphological features of both subspecies (M. migrans migrans and M. migrans lineatus) and a hybrid Red Kite × Black Kite is a new phenomenon on Crete.
European Journal of Wildlife Research
Ornithological Science, 2019
Abstract The diet composition and dietary patterns of the Long-eared Owl Asio otus were studied i... more Abstract The diet composition and dietary patterns of the Long-eared Owl Asio otus were studied in Mediterranean agrosystems in central Crete (Greece) over the winters of 2009–2015. Overall, 2,819 prey items were recovered from 1,207 pellets, belonging to six taxa of mammals, 22 taxa of birds and four taxa of insects. Small mammals were the most common prey species, accounting for 75.8% by frequency and 79.7% by biomass, followed by birds (23.2% and 20.1%); the latter being rather an island component compared to continental regions. The House Mouse Mus musculus was the most important prey species in the owl's diet (56.3%) ahead of the Wood Mouse apodemus sylvaticus (9.51%) and the Black Rat Rattus rattus (7.9%). The species proved to be a significant rodent predator in olive groves and vineyards during winter months, selecting Wood Mouse and young Black Rat more than expected. Long-eared Owl feeding ecology studies could lead to improved land management and agricultural practices in the rural landscapes of the Mediterranean.
Avian Biology Research, 2018
The Long-eared Owl (Asio otus) in Crete (Greece) is a common agricultural species affected by the... more The Long-eared Owl (Asio otus) in Crete (Greece) is a common agricultural species affected by the recent changes in agro-forestry systems. Concrete studies of habitat selection are needed in order to improve our knowledge of its foraging behaviour in managed rural landscapes. In the present study, we analysed the home range size and habitat selection of 11 Long-eared Owls inside olive groves in the plain of central Crete using radio tracking data and remote sensing images. Six nominal scale and 11 landscape scale predictors were used for habitat selection analysis, using a maximum entropy approach. Home range size ranged between 337 and 969 ha while a 52% of home range overlap was observed suggesting that Long-eared Owls do not defend hunting territories. At the nominal scale, distance to potential roosts (trees) was the most important contributor to model performance, followed by vegetation heterogeneity. Furthermore, local heterogeneity of greenness was a better predictor than sim...
Diversity
Aquila chrysaetos and Aquila fasciata are two congeneric eagle species distributed in the Mediter... more Aquila chrysaetos and Aquila fasciata are two congeneric eagle species distributed in the Mediterranean region which are supposed to compete for similar breeding and foraging resources. In the present study, bioclimatic, topographic, and human-related habitat parameters were investigated for 64 and 75 nest sites of Golden and Bonelli’s eagles, respectively. The nests were found during fieldwork undertaken from 1995–2020. Overall, the habitat parameters that best discriminated nest site selection were associated with elevation, temperature, and land use with topographic variables being most powerful for niche separation. Univariate analysis, regression, and species distribution modeling identified a strong association of the species with altitude pinpointing the Golden eagle’s mountainous and continental character and the Bonelli’s eagle being a lowland and coastal species. Golden eagle nests were situated away from human settlements on steep cliffs in higher altitude areas with tran...
Diversity and Distributions
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Book of Abstracts, 1st European Congress of Conservation Biology, 2006
Pernatye Hiŝniki i Ih Ohrana, 2018
In the current study we present data collected during the last two decades on the island of Crete... more In the current study we present data collected during the last two decades on the island of Crete (Greece) regarding the nesting habitat of two sympatric species namely the Golden Eagle (Aquila chrysaetos) and the Bonelli's Eagle (Aquila fasciata). The factors that determine the species nest site selection were identified via a logistic regression model and nesting habitat suitability maps were constructed by using maximum entropy models and a Geographic Information System. At the spatial scale considered, the best predictors of nesting habitat were topographical variables such as altitude and slope indicative for the requirement of rugged terrain. The predictive maps represented by the subset of topographic variables were also able to predict nest-site selection by both species more adequately than subsets of bioclimatic or human disturbance variables. Based on the overlap of the available nesting habitat of the two eagle species, an ecological separation was detected most prob...
In the current study we present data collected during the last two decades on the island of Crete... more In the current study we present data collected during the last two decades on the island of Crete (Greece) regarding the nesting habitat of two sympatric species namely the Golden Eagle (Aquila chrysaetos) and the Bonelli’s Eagle (Aquila fasciata). The factors that determine the species nest site selection were identified via a logistic regression model and nesting habitat suitability maps were constructed by using maximum entropy models and a Geographic Information System. At the spatial scale considered, the best predictors of nesting habitat were topographical variables such as altitude and slope indicative for the requirement of rugged terrain. The predictive maps represented by the subset of topographic variables were also able to predict nest-site selection by both species more adequately than subsets of bioclimatic or human disturbance variables. Based on the overlap of the available nesting habitat of the two eagle species, an ecological separation was detected most probably...
In the framework of LIFE+ Biodiversity project on “Innovative actions against illegal poisoning i... more In the framework of LIFE+ Biodiversity project on “Innovative actions against illegal poisoning in EU Mediterranean pilot areas” [LIFE09 NAT/ES/000533], the Spanish organization “Fundacion Gypaetus”, acting as coordinating beneficiary, along with the Portuguese partners “Quercus” and “Centro de Estudos da Avifauna Iberica” (CEAI) and the Greek partners “Arcturos” and “University of Crete – Natural History Museum of Crete” (NHMC), are implementing specific actions on this issue since October 2010 for a 5-years’ project. The main goal of the project is to evaluate and spread the effectiveness of several innovative actions based on voluntary agreements with the main rural groups related with the fight against the illegal use of poisoned baits (municipalities, hunters, stockbreeders, etc.). Thanks to the demonstrative character of the foreseen actions, it is expected to relevantly improve the current anti-illegal poisoning strategies and so diminish the biodiversity loss related with th...
12TH INTERNATIONAL CONGRESS ON THE ZOOGEOGRAPHY AND ECOLOGY OF GREECE AND ADJACENT REGIONS, 2012
Book of Abstracts. 10th International Congress on the Zoogeography and Ecology of Greece and Adjacent Regions, 2006
All European vulture species occur in Greece, which is the only Balkan country that still harbors... more All European vulture species occur in Greece, which is the only Balkan country that still harbors breeding populations. However since the last status review in the mid 1980s all species have undergone a substantial shrinkage in their distribution and a dramatic decline in their population. Based on data from various sources and field surveys carried out during the period 1994-2005, numbers of all four species have decreased except for the Black Vulture (Aegypius monachus) which holds a localized population of 22-27 breeding pairs in the Dadia National Park, region of Thrace. In fact the Black Vulture has been the only species, at the brink of extinction that exhibited stable population trends due to a long-term project for the conservation of its nesting habitat and breeding nuclei. On the contrary the Bearded Vulture (Gypaetus barbatus), which was regarded as stable and not immediately threatened, became extinct in 75% of its breeding range apart from the island of Crete where 6 breeding pairs still remain. Similarly the Egyptian Vulture (Neophron percnopterus), once common in certain areas, has experienced a large population decline (44-60%) presently numbering ca. 100-140 breeding pairs. The Griffon Vulture (Gyps fulvus) formerly widespread in central and western Greece has suffered a considerable contraction of its distribution (50-60%) and loss of its breeding groups (ca. 60%). Its current population size has been estimated at 175-192 breeding pairs with Crete being its main stronghold hosting more than 80% of them. Poisoning comprised the main mortality factor for all species devastating their numbers almost throughout the country. Land use changes which resulted in food shortage, habitat loss and direct persecution by man, have additionally kept vulture populations under pressure.
Science of The Total Environment, 2021
The COST Action 'European Raptor Biomonitoring Facility' (ERBFacility) aims to develop pan-Europe... more The COST Action 'European Raptor Biomonitoring Facility' (ERBFacility) aims to develop pan-European raptor biomonitoring in support of better chemicals management in Europe, using raptors as sentinel species. This presents a significant challenge involving a range of constraints that must be identified and addressed. The aims of this study were to: (1) carry out a comprehensive review of the constraints that may limit the gathering in the field of raptor samples and contextual data, and assess their relative importance across Europe; and (2) identify and discuss possible solutions to the key constraints that were identified. We applied a participatory approach to identify constraints and to discuss feasible solutions. Thirty-one constraints were identified, which were divided into four categories: legal, methodological, spatial coverage, and skills constraints. To assess the importance of the constraints and their possible solutions, we collected information through scientific workshops and by distributing a questionnaire to stakeholders in all the countries involved in ERBFacility. We obtained 74 answers to the questionnaire, from 24 of the 39 COST participating countries. The most important constraints identified were related to the collection of complex contextual data about sources of contamination, and the low number of existing raptor population national/regional monitoring schemes and ecological studies that could provide raptor samples. Legal constraints, such as permits to allow the collection of invasive samples, and skills constraints, such as the lack of expertise to practice necropsies, were also highlighted. Here, we present solutions for all the constraints identified, thus suggesting the feasibility of establishing a long-term European Raptor Sampling Programme as a key element of the planned European Raptor Biomonitoring Facility.
Marine ornithology, 2017
XIROUCHAKIS, S.M., KASAPIDIS, P., CHRISTIDIS, A., ANDREOU, G., KONTOGEORGOS, I. & LYMBERAKIS, P. ... more XIROUCHAKIS, S.M., KASAPIDIS, P., CHRISTIDIS, A., ANDREOU, G., KONTOGEORGOS, I. & LYMBERAKIS, P. 2017. Status and diet of the European Shag (Mediterranean subspecies) Phalacrocorax aristotelis desmarestii in the Libyan Sea (south Crete) during the breeding season. Marine Ornithology 45: 1–9. During 2010–2012 we collected data on the population status and ecology of the European Shag (Mediterranean subspecies) Phalacrocorax aristotelis desmarestii on Gavdos Island (south Crete), conducting boat-based surveys, nest monitoring, and diet analysis. The species’ population was estimated at 80–110 pairs, with 59% breeding success and 1.6 fledglings per successful nest. Pellet morphological and genetic analysis of otoliths and fish bones, respectively, showed that the shags’ diet consisted of 31 species. A total of 4 223 otoliths were identified to species level; 47.2% belonged to sand smelts Atherina boyeri, 14.2% to bogues Boops boops, 11.3% to picarels Spicara smaris, and 10.5% to damsel...
Wind Energy and Wildlife Impacts, 2019
Crete has been characterized as an area with a high wind energy capacity due to its mountainous t... more Crete has been characterized as an area with a high wind energy capacity due to its mountainous terrain and the strong prevailing winds throughout the year. At the same time, the island constitutes the last stronghold for vulture species in Greece, currently holding the largest insular population of Eurasian griffons (Gyps fulvus) worldwide (ca. 1000 individuals). Given the empirical data on the mortality of large raptors due to collisions with wind turbine blades, the aim of the present study was to predict the potential impact of wind energy installations on the griffon vulture population on the island. The study was developed in two steps, namely, (a) the spatial mapping of the existing and planned wind energy projects up to the year 2012 and the delineation of their risk area and (b) the calculation of the annual collision rate based on the expected number of vulture risk flights and the probability of being killed. Overall, the minimum number of fatalities due to collision of v...
This document describes work undertaken as part of a programme of study at the Faculty of Geo-Inf... more This document describes work undertaken as part of a programme of study at the Faculty of Geo-Information Science and Earth Observation of the University of Twente. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the Faculty.