Capsule The Ring Ouzel has declined to near extinction on the island of Ireland, with just nine occupied sites recorded during a national survey in 2021, all in County Donegal in north-west Ireland.Aims Little is known about the status and population trends of the Ring Ouzel in Ireland. The aim of the 2021 survey in the Republic of Ireland was to determine its current breeding population size and range.Methods We identified tetrads that had records of breeding Ring Ouzels in Ireland in the previous 20 years. Using a standard methodology, including playback, we visited tetrads at least twice to record occupancy and evidence of breeding as well as to record habitat associations and land use.Results Ring Ouzels were detected in just nine of 75 tetrads surveyed, with probable/confirmed breeding in four and possible breeding in five tetrads, all in County Donegal in north-west Ireland. Habitats at Ring Ouzel breeding sites (139-530 m a.s.l.) were predominantly dry heath, blanket bog and scree. Sheep Ovies aries grazing (in 87% of tetrads) was the most widespread land use.Conclusion The Ring Ouzel is in imminent risk of extinction in Ireland, after the loss of the breeding population in County Kerry in south-west Ireland within the last decade, and a tiny, remnant population now confined to north and south-west Donegal. The conversion of heath to grass moorland appears to be an important factor driving the decline in Ireland. Climate change effects, such as drier summers, may also be impacting the accessibility and availability of invertebrate prey. Urgent conservation actions are needed to halt further decline to extinction, especially in the few remaining breeding areas.
Capsule Operator errors when taking morphometric measurements are more important for larger species and for mass measurements.Aims To quantify operator effects on morphometric measurements during ringing sessions, depending on species size and morphometric characters.Methods Three morphometric characters (wing length, body mass and body condition index) had been measured during ringing sessions on 17,818 individuals of 14 different species in southern France. The deviation from the mean and the variation, both absolute and by percentage, of measurements taken by operators were estimated for each bird species and age and sex categories.Results We detected operator effects on measurements. Wing length showed a deviation from the mean, reaching less than 1% of total measurement and a small variation. However, body mass showed a large deviation from the mean, and a large variation reaching up to 10% of total measurement. Body condition index showed broadly the same results as body mass, with the same proportion. Larger species were the most affected by measurement errors, both in absolute and in percentage terms.Conclusion Errors in morphological measurements are common during ringing sessions and are related to the characteristics of the species, particularly their size, the tools used (such as dynamometers for body mass) and the characteristics of the operators.
Capsule Artificial nests are often used in ecological studies, but our research on Estonian coastal grasslands shows they differ significantly from natural nests in predation rates and predator identity, highlighting the importance of studying natural nests whenever possible.Aims Artificial nests may serve as an alternative to natural ones in studies of nest predation, but it is crucial to evaluate their suitability within specific local contexts.Methods We conducted a comparative analysis of daily survival rates between artificial and natural nests of waders in coastal grassland habitat in Estonia over two breeding seasons. Additionally, we employed camera traps to identify predators on a subset of nests.Results Our findings reveal discrepancies in nest survival and observed predators between artificial and natural nests, as well as annual differences. These results indicate that, at least in our study area, artificial nests are not an adequate substitute for natural nests when studying nest survival or when identifying nest predators.Conclusions Consistent with previous authors' conclusions, we encourage ornithologists to invest time and effort in locating and studying natural nests whenever it is feasible to do so.
Capsule Individual Common Swifts show high fidelity to nest sites (94-95%), and lesser fidelity to partners (59%).Aims To determine the extent of individual fidelity to nest sites and partners by Common Swifts, and to identify any predictors of nest site fidelity.Methods We monitored nest boxes and captured adult Common Swifts over the 15-year period 2010-2024. Fidelity analyses were based on 243 breeding events and capture data from 190 adults matched to nest sites and pairings. Predictors of nest site fidelity were examined using logistic regression.Results From 243 breeding events, 91 individuals bred in multiple years. Across 216 breeding events involving at least one breeding individual captured in multiple years, 94.5% re-used a previously used nest site. Among 213 breeding events involving an individual captured in consecutive years, 94.3% re-used the previous year's nest site. Nest site fidelity between consecutive years was significantly lower at higher colony densities, but was not predicted by individual age or previous breeding success. Of 36 consecutive year pairings involving the same two individuals, 89% re-used the same nest site. Among 168 breeding events where both pair members were identified, 39 unique pairings bred together in multiple years. Of 55 consecutive year pairings, 94.5% remained faithful and 5.5% divorced.Conclusions Common Swifts are declining in the UK, with nest site loss being a hypothesized contributory factor. We show that breeding swifts have very high rates of fidelity to nest sites and partners, and hence colonies, and the loss of nest sites is therefore likely to have impacts on individuals and colonies due to the need to find alternatives. We provide some evidence of local relocation by breeding individuals after nest site loss, suggesting that local provision of nest sites may help maintain local populations.
