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Understanding how weather conditions during early development influence reproductive success is essential for predicting avian responses to climate change. We used a 40-year dataset from a nest-box population of collared flycatchers ( Ficedula albicollis ) to examine how temperature and precipitation during the incubation and nestling periods affected three key components of reproductive performance: hatchling number, fledgling production, and local offspring recruitment. We found that higher ambient temperatures during the nestling period were associated with a decreased probability of brood failure and a higher number of recruits. In contrast, a higher sum of precipitation during the nestling stage was associated with an increased likelihood of brood failure. Interestingly, weather conditions during incubation had no statistically detectable influence on reproductive performance. Moreover, our results indicated that the within-season variation in climatic conditions, rather than the between-season variation, was primarily associated with reproductive outcomes. These findings underscore the importance of considering both overall climate conditions across seasons and short-term weather parameters within breeding seasons when evaluating reproductive success and predicting the ecological consequences of climate change.

Aim The joint threats of climate and land‐use change require an understanding of how environmental variation influences species abundance and distribution. However, most species distribution models use static data and methods without considering how species respond over multiple temporal and spatial scales. Using a novel analytical approach, we show how multiscalar environmental variation drives spatial population dynamics of mobile species. Location Great Plains, North America. Methods We developed a spatial hierarchical model of abundance using long‐term citizen science data for two severely declining species (Lark Bunting, Calamospiza melanocorys, Chestnut‐collared Longspur, Calcarius ornatus). Specifically, we (a) compared regional variation in range‐wide abundance and population trends, (b) evaluated the influence of short‐term and long‐term drought on range dynamics and (c) tested whether regional population dynamics are spatially autocorrelated by environmental conditions occurring in geographically separated areas. Results Both species exhibited long‐term range‐wide declines >70% with contraction towards the range core. Lark Buntings showed opposing responses to environmental variation; regional abundance increased with wetter conditions during arrival on the breeding grounds but also with longer‐term (4‐year) drought conditions. Chestnut‐collared Longspurs showed no response to drought at either temporal scale. We found strong evidence that Lark Bunting abundance in the southern portion of the range increases with favourable environmental conditions leading to subsequent declines in abundance in northern regions. Main conclusions Our results highlight how (a) species can show opposing responses to the same environmental variable at different temporal and spatial scales, (b) sympatric species vary in their propensity to track environmental conditions and (c) for latitudinal migrants, environmental conditions along the migration pathway can influence settlement patterns with conditions in southern regions impacting abundance in the north. Our analysis indicates that an understanding of how global change impacts mobile species distributions will require range‐wide assessments incorporating response to environmental conditions across temporal and spatial scales.

Understanding how land cover and potential competition with invasive species shape patterns of occupancy, extirpation, and colonization of native species across a landscape can help target management for declining native populations. Mourning dove (Zenaida macroura) populations have declined throughout the United States from 1965–2015. The expansion of the Eurasian collared-dove (Streptopelia decaocto), an introduced species with similar food preferences, may further threaten mourning dove populations. We analyzed data from 2009–2016 from a large-scale monitoring program in the Western Great Plains of the United States in a 2-species occupancy model to assess the effects of collared-doves on mourning dove distributions, while accounting for imperfect detection and variation in land cover across the landscape. Mourning dove occupancy was stable or increasing across our study area, and despite overlap in resource use and co-occurrence between mourning doves and Eurasian collared-doves, we found no evidence that collared-doves are extirpating mourning doves from preferred habitat during the breeding season.

Purpose To compare clinical and radiographic outcomes of propensity-matched patients undergoing THA using standard versus high offset stems at five years. Methods The authors retrospectively reviewed a consecutive series of primary THAs performed between 01/09/2015–31/12/2017 using a fully-hydroxyapatite coated collared stem, with either a standard ( n  = 365) or high ( n  = 110) offset. Outcomes collected included: modified Harris Hip Score (mHHS), Oxford Hip Score (OHS), Forgotten Joint Score (FJS), and radiographic measurements including limb length discrepancy (LLD), stem subsidence, and stem radiolucencies. Results Propensity score matching resulted in 80 hips per group. Preoperatively there were no significant differences in patient demographics, surgical data and radiographic measurements, except the standard offset group had significantly smaller femoral (40.0 ± 7.5 vs 48.4 ± 6.2, p  < 0.001), acetabular (92. ± 6.3 vs 94.8 ± 7.3, p  = 0.011) and global (132.0 ± 10.3 vs 143.2 ± 8.2, p  < 0.001) offsets compared to the high offset group. At a minimum five years follow-up, there were no significant differences in mHHS (93.2 ± 11.0 vs 93.1 ± 10.6, p  = 0.553), OHS (45.1 ± 4.1 vs 45.3 ± 4.6, p  = 0.623), and FJS (85.1 ± 19.3 vs 82.7 ± 23.0, p  = 0.910). There were also no differences in radiographic measurements, including LLD (1.5 ± 4.8 vs 1.1 ± 3.5, p  = 0.537), stem subsidence (0% vs 0%, p  = 1.000), and stem radiolucencies (severe: 6% vs 1%, p  = 0.152). Conclusion The present matched-cohort study found no significant differences between standard versus high offset straight fully-hydroxyapatite coated collared stems for primary THA in terms of clinical and radiographic outcomes at five years. These findings may suggest that uncemented collared high offset stems are not associated with an increased risk of radiolucencies and loosening compared to uncemented collared standard offset stems.

The use of social information for making decisions is common but can be constrained by behavioural traits via, for example, the ability to gather information. Such constrained information use has been described in foraging habitat selection; yet it remains unexplored in the breeding habitat selection context, despite potentially strong fitness consequences. We experimentally tested whether three behavioural traits (aggressiveness, boldness and neophobia) affected the use of heterospecific social information for nest site selection in wild collared flycatchers Ficedula albicollis . Flycatchers have previously been found to copy or reject an artificial apparent preference of tits (their main competitors) for a nest site feature: they preferred nest-boxes with the same or a different feature, depending on tit early reproductive investment. Here, we confirmed this result and showed that shy individuals and less aggressive old males (i.e. 2 years old or older) copied tit apparent preference, while more aggressive old males rejected the tit preference. Aggressiveness and boldness may allow males to access more information sources or affect males' interactions with dominant tits when selecting a nest site. Our study highlights the links between variation in behaviours and social information use for breeding habitat selection and calls for further work to explore underlying mechanisms.

Distribution models are increasingly being used to understand how landscape and climatic changes are affecting the processes driving spatial and temporal distributions of plants and animals. However, many modeling efforts ignore the dynamic processes that drive distributional patterns at different scales, which may result in misleading inference about the factors influencing species distributions. Current occupancy models allow estimation of occupancy at different scales and, separately, estimation of immigration and emigration. However, joint estimation of local extinction, colonization, and occupancy within a multi‐scale model is currently unpublished. We extended multi‐scale models to account for the dynamic processes governing species distributions, while concurrently modeling local‐scale availability. We fit the model to data for lark buntings and chestnut‐collared longspurs in the Great Plains, USA, collected under the Integrated Monitoring in Bird Conservation Regions program. We investigate how the amount of grassland and shrubland and annual vegetation conditions affect bird occupancy dynamics and local vegetation structure affects fine‐scale occupancy. Buntings were prevalent and longspurs rare in our study area, but both species were locally prevalent when present. Buntings colonized sites with preferred habitat configurations, longspurs colonized a wider range of landscape conditions, and site persistence of both was higher at sites with greener vegetation. Turnover rates were high for both species, quantifying the nomadic behavior of the species. Our model allows researchers to jointly investigate temporal dynamics of species distributions and hierarchical habitat use. Our results indicate that grassland birds respond to different covariates at landscape and local scales suggesting different conservation goals at each scale. High turnover rates of these species highlight the need to account for the dynamics of nomadic species, and our model can help inform how to coordinate management efforts to provide appropriate habitat configurations at the landscape scale and provide habitat targets for local managers. We combined multi‐scale and dynamic occupancy models to jointly estimate dynamic processes governing species distributions, while concurrently modeling local‐scale availability, and we applied this model to data collected on two nomadic grassland birds, the lark bunting and chestnut‐collared longspur, in the Northern Great Plains of the U.S. Our results suggest that both species expand into less ideal habitats and contract from those sites first, and high turnover rates imply that these species may benefit from coordinated, landscape‐level management efforts.

Animal colouration is subject to various selection pressures, which often result in the phenomena of sexual dichromatism and gradual colour development. Despite extensive knowledge about adult colouration, the significance of nestling or fledgling plumage colouration in birds remains understudied. Focusing on the collared flycatcher (Ficedula albicollis), this explorative study investigated colour variation in the pre‐fledgling stage of nestlings. We collected reflectance spectra from the brown primary coverts and the yellow tip of these coverts of the nestlings from 71 nests and applied DNA‐based sex determination. We revealed significant sex differences in offspring colour: females had brown coverts with higher brightness and lower UV chroma, and their yellow stripe had lower brightness, UV chroma and saturation. We detected significant but low repeatability of colouration between nestlings in the same broods. Nestlings did not show phenotypic integration between the colour variables of coverts and those of the terminal stripe, suggesting that these could be independent traits. The results also suggested that the yellow colouration of the stripe was probably caused by a white structural background and porphyrin pigmentation. Based on our results, we offer testable hypotheses on the potential adaptive functions of early‐life sex‐specific colouration patterns in birds for different contexts, including parent‐offspring communication or hiding from predators. ABSZTRAKT Az állatok színezetét különféle szelekciós nyomások formálják, és ez gyakran az ivari dikromatizmus, illetve az egyedfejlődés során bekövetkező színezetbeli változás jelenségét eredményezi. Az ivarérett állatok színezetére vonatkozó széles körű ismeretekkel szemben a madaraknál a fiókák tollazatának színezetét nem vizsgálták kellőképpen. Feltáró tanulmányunk az örvös légykapóra (Ficedula albicollis) összpontosítva elemezte a kirepülés előtt álló fiókák színezetét. 71 fészekalj fiókáinál a tollazat egy‐egy barna és sárga részéről gyűjtöttünk reflektanciaspektrumokat, valamint DNS‐alapú ivarmeghatározást is alkalmaztunk. A fiókák színezetében szignifikáns ivari különbségeket mutattunk ki: a nőstényeknél a barna fedőtollak világosabbak és egyben és alacsonyabb UV‐telítettségűek voltak, a fedők sárga csíkja pedig sötétebb és alacsonyabb UV‐telítettségű volt, mint a hímeknél. A fészekaljon belül a fiókák szignifikánsan jobban hasonlítottak egymásra, mint a fészekaljak között, ám e hasonlóság kis mértékűnek mutatkozott. A különböző testtájak színjellemzői között nem találtunk fenotípusos integrációt. Az eredmények azt sejtetik, hogy a sárga színt valószínűleg a tollszerkezetből eredő fehér fényvisszaverés és a porfirinek általi fényelnyelés okozta. Eredményeink alapján tesztelhető hipotéziseket kínálunk a madarak korai életkori ivarspecifikus színmintázatainak a különböző kontextusokban betöltött lehetséges adaptív funkcióiról, beleértve a szülő‐utód kommunikációt vagy a ragadozók elől való elrejtőzést. Selection pressures on animal colouration often lead to sexual dichromatism and gradual colour development, but the role of nestling colouration is understudied. In our study on collared flycatcher nestlings, we found sexual dichromatism and only a small degree of similarity between siblings. Our findings suggest the yellow colouration may result from microstructure and porphyrin, and the brown colouration from eu‐ and pheomelanin, and we propose hypotheses regarding potential adaptive functions, such as parent–offspring communication or predator concealment.

The study investigated the gut content and recorded morphometric and hematological parameters in the Eurasian collared dove ( ). 24 samples of healthy birds (12 from each sex) were collected from different wetlands in Punjab, Pakistan, from December 2022 until February 2023. Birds were captured live for blood samples, morphometric, and gut analyses. The current study revealed that mensural measurements showed no significant differences in all parameters except tail length, which was significantly longer in males (14.59 ± 0.30) compared to females (12.88 ± 0.43). Hematological parameters were hemoglobin, 23.95 gm/dl; red blood cells, 3.97 × 10 /μl; white blood cells, 429.9.67 × 10 /μl; hematocrit, 72.14%; mean corpuscular volume, 183.24 FL; mean corpuscular hemoglobin, 61.70 pg; mean corpuscular hemoglobin concentration, 32.37 pg; platelets, 7.01/μl; and red cell distribution width, 110.86/μl. The percentages of neutrophils, lymphocytes, monocytes, and eosinophils were 71.33%, 23.03%, 3.30%, and 1.43%, respectively. The gut content of the Eurasian collared dove mainly consisted of rice, wheat, corn, and millet seeds. Some stony materials were also present. Our study concluded that male and female Eurasian collared doves are alike in biometrics (except tail length) and hematological profiles. Gut content and weight were also similar. Males were slightly larger than females. The gut content showed that the Eurasian collared dove mainly feeds on rice, wheat, corn, and millet seeds. In this study, hematological parameters were also studied.

Collared femoral stems in total hip arthroplasty (THA) offer reduced subsidence and periprosthetic fractures but raise concerns about fit accuracy and stem sizing. This study compares collared and non-collared stems to assess the stem–canal fill ratio (CFR) and fixation indicators, aiming to guide implant selection and enhance THA outcomes. This retrospective single-center study examined primary THA patients who received Corail cementless stems between August 2015 and October 2020, with a minimum of two years of radiological follow-up. The study compared preoperative bone quality assessments, including the Dorr classification, the canal flare index (CFI), the morphological cortical index (MCI), and the canal bone ratio (CBR), as well as postoperative radiographic evaluations, such as the CFR and component fixation, between patients who received a collared or a non-collared femoral stem. The study analyzed 202 THAs, with 103 in the collared cohort and 99 in the non-collared cohort. Patients’ demographics showed differences in age (p = 0.02) and ASA classification (p = 0.01) but similar preoperative bone quality between groups, as suggested by the Dorr classification (p = 0.15), CFI (p = 0.12), MCI (p = 0.26), and CBR (p = 0.50). At the two-year follow-up, femoral stem CFRs (p = 0.59 and p = 0.27) were comparable between collared and non-collared cohorts. Subsidence rates were almost doubled for non-collared patients (19.2 vs. 11.7%, p = 0.17), however, not to a level of clinical significance. The findings of this study show that both collared and non-collared Corail stems produce comparable outcomes in terms of the CFR and radiographic indicators for stem fixation. These findings reduce concerns about stem under-sizing and micro-motion in collared stems. While this study provides insights into the collar design debate in THA, further research remains necessary.

Nest site selection significantly affects fitness, so adaptations for assessment of the qualities of available sites are expected. The assessment may be based on personal or social information, the latter referring to the observed location and performance of both conspecific and heterospecific individuals. Contrary to large-scale breeding habitat selection, small-scale nest site selection within habitat patches is insufficiently understood. We analyzed nest site selection in the migratory Collared Flycatcher Ficedula albicollis in relation to present and past cues provided by conspecifics and by resident tits within habitat patches by using long-term data. Collared Flycatchers preferred nest boxes that were occupied by conspecifics in the previous year. This preference was strongest in breeding pairs where both individuals bred in the same forest patch in the previous year. The results also suggest preference for nest boxes close to boxes where conspecifics had a high breeding success in the previous year, and for nest boxes which are presently surrounded by a high number of breeding Great Tits Parus major . The results indicate social information use in nest site selection at a small spatial scale, where Collared Flycatchers use conspecific cues with a time lag of one year and heterospecific cues instantly.