scholarly journals Peer Review #2 of "Effect of nest age and habitat variables on nest survival in Marsh Harrier (Circus aeruginosus) in a fishpond habitat (v0.1)"

2020 ◽  
Keyword(s):  
Peer Review ◽  
Nest Survival ◽  
Marsh Harrier ◽  
Circus Aeruginosus ◽  
Habitat Variables

scholarly journals Effect of nest age and habitat variables on nest survival in Marsh Harrier (Circus aeruginosus) in a fishpond habitat

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9929
Author(s):  
Urszula Zaremba ◽  
Zbigniew Kasprzykowski ◽  
Artur Golawski
Keyword(s):  
Water Depth ◽  
Site Selection ◽  
Nest Site ◽  
Nest Survival ◽  
Nest Site Selection ◽  
Conservation Strategies ◽  
Active Nest ◽  
Marsh Harrier ◽  
Circus Aeruginosus ◽  
Habitat Variables

Background One important anti‐predator strategy adopted by birds involves nest site selection and timing of breeding. Nest-site selection by marsh-nesting birds often involves nest concealment and water depth as key features influencing nest survival. Marsh Harrier (Circus aeruginosus) is an obligate ground nester, which sets it apart from other raptors. The aim of the present study was to identify for the first time possible temporal and habitat factors affecting nest survival in Marsh Harrier. Understanding features which affect nest survival are essential for assessing relevant conservation strategies. Methods To understand the relative contributions of different temporal and habitat variables to brood losses, it is useful to determine the daily survival rate (DSR). We examined 82 Marsh Harrier nests located on fishponds in eastern Poland, where predation is the main cause of nest loss. Six habitat variables were measured for each active nest. DSR was calculated using known-fate models with the RMark package. Results The best-supported model predicted that DSR decreased with nest age and was positively affected by the water depth and the diameter of reed stems, but not by the height or density of vegetation at the nest site. The distances of nests to the fishpond dyke and to open water received no support in the models. The chances of nest survival were lower if a neighbouring nest had been depredated. This result suggests that the Marsh Harrier is more susceptible to mammalian than avian predation and confirms the high level of predator pressure in fishpond habitats.

Close to the Madding Crowd: How Resilient are Imperilled Mediterranean Urban Wetlands?

2021 ◽  
Author(s):  
Abdallah Aouadi ◽  
Farrah Samraoui ◽  
Laid Touati ◽  
Riad Nedjah ◽  
Lynda Souiki ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Substantial Reduction ◽  
Anthropogenic Pressures ◽  
Conservation Action ◽  
Marsh Harrier ◽  
Long Term Study ◽  
Circus Aeruginosus ◽  
Ixobrychus Minutus ◽  
The Impact

Abstract Investigating how Mediterranean wetlands respond to adjacent land use conversion, is an important first step in mitigating the impact of human encroachment and other environmental stressors. We monitored the composition and structure of waterbird assemblages, in a Mediterranean urban marsh, subjected to severe anthropogenic pressures. Remote sensing indicated that in the last two decades Boussedra Pond was subjected to landfill, resulting in a substantial reduction (~ 50%) of the marsh, while due to a lack of urban planning urban built-up and agriculture areas expanded considerably in its surroundings. Seasonal changes in the diversity of waterbirds, including the globally Endangered (EN) White-headed Duck Oxyura leucocephala and the Near-Threatened (NT) Ferruginous Duck Aythya nyroca, reflected the importance of the site as a staging and wintering area for many migratory species. The long-term study also suggested that breeding waterbirds species respond differentially to the loss and degradation of habitats, as highlighted by the resilience of the synanthropic Moorhen Gallinula chloropus and the disappearance of several breeding marsh specialists, like the Little Bittern Ixobrychus minutus and the Western Marsh Harrier Circus aeruginosus. The study points out the need for both a coordinated cross-sectorial land use planning and an immediate, affordable and sustainable wetland conservation action.

scholarly journals How hazardous is the Sahara Desert crossing for migratory birds? Indications from satellite tracking of raptors

2009 ◽  
Vol 6 (3) ◽  
pp. 297-300 ◽  
Author(s):  
Roine Strandberg ◽  
Raymond H. G. Klaassen ◽  
Mikael Hake ◽  
Thomas Alerstam
Keyword(s):  
Migratory Birds ◽  
Satellite Telemetry ◽  
Satellite Tracking ◽  
Sahara Desert ◽  
Annual Cycles ◽  
Marsh Harrier ◽  
Circus Aeruginosus ◽  
Course Changes ◽  
Carry Over ◽  
Migrating Birds

We investigated the risk associated with crossing the Sahara Desert for migrating birds by evaluating more than 90 journeys across this desert by four species of raptors (osprey Pandion haliaetus , honey buzzard Pernis apivorus , marsh harrier Circus aeruginosus and Eurasian hobby Falco subbuteo ) recorded by satellite telemetry. Forty per cent of the crossings included events of aberrant behaviours, such as abrupt course changes, slow travel speeds, interruptions, aborted crossings followed by retreats from the desert and failed crossings due to death, indicating difficulties for the migrants. The mortality during the Sahara crossing was 31 per cent per crossing attempt for juveniles (first autumn migration), compared with only 2 per cent for adults (autumn and spring combined). Mortality associated with the Sahara passage made up a substantial fraction (up to about half for juveniles) of the total annual mortality, demonstrating that this passage has a profound influence on survival and fitness of migrants. Aberrant behaviours resulted in late arrival at the breeding grounds and an increased probability of breeding failure (carry-over effects). This study also demonstrates that satellite tracking can be a powerful method to reveal when and where birds are exposed to enhanced risk and mortality during their annual cycles.

scholarly journals Changes in the waterbird community of the Parc National du Banc d’Arguin, Mauritania, 1980–2017

2020 ◽  
Vol 30 (4) ◽  
pp. 618-633 ◽  
Author(s):  
THOMAS OUDMAN ◽  
HANS SCHEKKERMAN ◽  
AMADOU KIDEE ◽  
MARC VAN ROOMEN ◽  
MOHAMED CAMARA ◽  
...  
Keyword(s):  
East Atlantic ◽  
The Past ◽  
Marsh Harrier ◽  
Circus Aeruginosus ◽  
Atlantic Flyway ◽  
Banc D’Arguin ◽  
East Atlantic Flyway ◽  
Red Knot ◽  
Made In ◽  
Banc D'arguin

SummaryThe Parc National du Banc d’Arguin in Mauritania hosts the largest concentrations of coastal waterbirds along the East Atlantic Flyway. In spite of this importance, a review of the changes in the numbers of waterbirds in the area is lacking since the first complete count in 1980. Here we analysed the seven complete waterbird counts made since then, and the additional yearly counts made in one subunit (Iwik region) since 2003. We present evidence for changes in the community composition of waterbirds over the past four decades. Total waterbird numbers showed a decrease between 1980 and 2017, with only Great White Pelican Pelecanus onocrotalus showing a significant increase in numbers. Five species showed significant declines: Long-tailed Cormorant Phalacrocorax africanus, Red Knot Calidris canutus, Bar-tailed Godwit Limosa lapponica, Eurasian Curlew Numenius arquata, and Western Marsh Harrier Circus aeruginosus. In the remaining species, the variation in numbers between counts was too large, and the number of complete counts too small, for trends to be detected. The yearly counts at Iwik region also showed sharp decreases in the numbers of Red Knot, Bar-tailed Godwit, and Marsh Harrier, but not of Long-tailed Cormorant and Eurasian Curlew. A multivariate analysis revealed a significant change in species composition over time, which was caused mainly by changes in the species depending on the intertidal mudflats for feeding (generally in decline) vs. the species depending on fish and crustaceans in the sublittoral and offshore zones (often showing increases).

scholarly journals Polychlorinated biphenyls in raptor and owl eggs in the Czech Republic

2012 ◽  
Vol 48 (No. 12) ◽  
pp. 363-368 ◽  
Author(s):  
I. Kustova ◽  
M. Vavrova ◽  
ILiterak
Keyword(s):  
Czech Republic ◽  
Tyto Alba ◽  
The Czech Republic ◽  
Pcb Congeners ◽  
Milvus Migrans ◽  
Marsh Harrier ◽  
Black Kite ◽  
Circus Aeruginosus ◽  
Lipid Weight ◽  
Aquila Heliaca

In 2001, raptor and owl eggs were collected for the purpose of detection of contamination by poly­chlorinated biphenyls (PCBs) at 15 sites in the southeastern area of the Czech Republic. In total 31 unhatched eggs of 4 raptor species and 3 owl species were examined. PCB determination was carried out by high-resolution gas chromatography. PCB content was expressed in μg per 1 kg of lipid weight for the major PCB congeners 28, 52, 101, 118, 138, 153 and 180, serving as indicators. In all examined eggs the indicator PCB congeners were found. The ranges of total values of indicator PCB congeners found in different raptor and owl species were as follows: kestrel (Falco tinnunculus) 37.0 and 44.3 (n = 2), black kite (Milvus migrans) 28.3–40.5 (n = 3), imperial eagle (Aquila heliaca) 66.4 (n = 1), marsh harrier (Circus aeruginosus) 45.1 (n = 1), barn owl (Tyto alba) 20.6–46.1 (n = 17), long-eared owl (Asio otus) 32.0–41.9 (n = 6) and tawny owl (Strix aluco) 47.5 (n = 1) μg/kg of lipid weight. PCB congener 153 was the one most frequently found.

Sign in / Sign up

Export Citation Format

Share Document