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Tree Swallows (Tachycineta bicolor) are migratory aerial insectivores that breed across North America and have experienced long-term population declines. Although the mechanisms behind these declines have proved difficult to identify, emerging methods for studying migration staging areas could provide new insights. Tree Swallows congregate in staging roosts during fall migration, gathering at sunset to roost overnight, then leaving at sunrise to feed or continue their migration south. Using a particularly large roost site in Connecticut, USA, we used NEXRAD Level III data to calculate metrics of reflectivity corresponding to snapshots of morning roost size each day. Using these metrics as measures of relative abundance, we tested predictions about the effects of wind and date on daily roost size and day-to-day changes in relative abundance. We found that radar reflectivity around the roost decreased with higher wind speeds during the morning emergence and when wind speeds were high the previous day. In addition, we found a temporal pattern of roost abundance corresponding to a peak of migration around the end of August for this stopover site. Our results provide insight into the sensitivity of Tree Swallow responses to wind conditions and lay the groundwork for future studies using NEXRAD to examine links between migratory behavior and declines in swallow populations. Received II August 2021. Accepted 23 September 2022. Key words: aerial insectivore. aeroecology. radar, roost, stopover Las golondrinas Tachycineta bicolor son aves migratorias insectivoras que se reproducer! a lo largo dc Norteamerica y han sufrido declivcs poblacionales a largo plazo. Aunque los mecanismos de cstos declives ha sido ditlciles dc identificar. mctodos allergenics para csmdiar sitios dc descanso migratorio podrian dar nucvas perspectivas. Estas golondrinas se congrcgan en dormideros tcmporalcs durante la migracion de otono. reuniendose al atardeccr para pasar juntas la nochc. posteriormente dejando el sitio al amanecer para alimcntarse o continuar su migracion hacia el sur. Utilizando un dormidero particulanncnte grande en Connecticut, USA, utilizamos dalos NEXRAD Level III para calcular metricas dc rcflcctividad que corrcspondian a inslantaneas diarias del tamano del dormidero matutino. Usando csos datos como medida dc abundancia relativa. probamos las prcdicciones acerca dc los efectos del viento y la fecha en cl tamano diario del donnidero y cambios diarios en la abundancia relativa. Encontranios que la rcflcctividad del radar alrcdcdor del dormidero decreeia con vclocidades mayorcs de vientos durante las cmergencias y cuando las velocidadcs de vicnlos eran mayorcs el dia anterior. Adcmas. encontranios un patron temporal en la abundancia del dormidero corrcspondiente al pico migratorio alrcdcdor de finales de agoslo para este sitio dc parada. Nuestros rcsultados brindan una vision de la sensibilidad de la respucsta de la golondrina Tachycineta bicolor a las condicioncs de viento y sienta las bases para futuros cstudios utilizando NEXRAD para cxaminar los vinculos cntrc el comportamicnto migratorio y los declives poblacionales de golondrinas. Palabras clave: aeroecologia. insectivoros aereos, parada. radar, donnidero., Populations of aerial insectivores in North America have been declining since the 1980s, prompting searches for the factors driving these trends (Nebel et al. 2010, Spiller and Dettmers 2019). Like [...]

Aim: Citizen science data are increasingly used for modelling species distributions because they offer broad spatiotemporal coverage of local observations. However, such data are often collected without experimental design or set survey methods, raising the risk that bias and noise will compromise modelled predictions. We tested the ability of species distribution models (SDMs) built from these low-structure citizen science data to match the quality of SDMs from systematically collected data and tested whether stringent data filtering improved predictions. Location: Northeastern USA. Methods: We evaluated models built from a rapidly growing dataset of avian occurrences reported by birders—eBird—against models built from four independent, systematically collected datasets. We developed SDMs for 96 species using both data sources and compared their predictive abilities. We also tested whether culling eBird data by applying stringent data filters on survey effort or observer expertise improved predictions. Results: We found that SDMs built from low-structure citizen science data matched or exceeded performance of SDMs from systematically collected datasets for 12%–31% of species ((Formula presented.) = 22%), depending on the dataset. At least one culling option produced equivalent or better performance for 40%–70% of species ((Formula presented.) = 49%). Data culling by restricting survey effort improved predictions more than restricting by observer expertise. The optimal effort restriction differed by dataset, and for three of the datasets was further informed by species traits. Main conclusions: Species distribution models developed using low-structure citizen science data sometimes performed as well as those from systematic data. Culling generally improved models, but results were heterogeneous, prohibiting clear recommendations for how to cull. Our results indicate that the growing availability of citizen science data holds potential for creating high-quality spatial predictions, but that time should be invested in determining how best to cull datasets and that one-size-fits-all solutions beyond basic outlier filtering may be hard to find.

'Stereotyped or repetitive motor movements' are characterised as core features in the diagnosis of autism, yet many autistic adults (and the neurodiversity movement) have reclaimed them as 'stimming'. Supported by a growing body of scientific research, autistic adults argue that these behaviours may serve as useful coping mechanisms, yet little research has examined stimming from the perspective of autistic adults. Through interviews and focus groups, we asked 32 autistic adults to share their perceptions and experiences of stimming, including the reasons they stim, any value doing so may hold for them and their perceptions of others' reactions to stimming. Using thematic analysis, we identified two themes: stimming as (1) a self-regulatory mechanism and (2) lacking in social acceptance, but can become accepted through understanding. Autistic adults highlighted the importance of stimming as an adaptive mechanism that helps them to soothe or communicate intense emotions or thoughts and thus objected to treatment that aims to eliminate the behaviour.