Marcel E. Visser

Figure 1 Both (2026): (a) Correlation between the annual average hatching date and the date of the caterpillar peak (open dots are experimental years: 2015 (intermediate in caterpillar peak date of the three experimental years), 2021 (latest caterpillar peak date) and 2022 (earliest caterpillar peak date), (b) the interval between arrival and laying in response to the caterpillar peak, (c) the annual strength of selection on laying date, measured as the linear slope of standardized laying date on relative fitness (measured as the number of locally recruiting offspring per female) (open dots are experimental years: 2015, 2021 and 2022), (d) example of the correlation between individual interval between arrival and laying in response to variation in arrival date for two experimental years: blue triangles: 2021, a cold spring, and red dots: 2022, a relatively warm spring.

New publication: Supplemental #feeding as #experimental #tool to understand why #birds do not #lay earlier in the #season, by @mevisser.bsky.social and others.
doi.org/10.1002/jav....

Investigating behaviour and badge size in House sparrows (International fieldwork internship/thesis) I am looking for a motivated Masters or HBO student to take part in the upcoming field season in the United Kingdom. Fieldwork will take place between April and May 2026 for 1.5 months on Lundy Island...

Looking for a student to develop a project on house sparrow behaviour and badge size! This project would include field work on the lovely Lundy Island in the Uk. For more information: nioo.knaw.nl/en/vacancies...

Figure 2 Radchuk (2026): A selection of studied species is shown, with each inset giving information for that species on its generation time (T, in years; also depicted by the black bar next to it), its diet (carnivore: C, herbivore: H, and omnivore: O) and whether the species is a migrant (M) or a resident (R). The inset shows the number of studies per taxon and trait category. Illustration credits for the species pictures taken from Wikipedia: Svalbard reindeer—Bjørn Christian Tørrissen, four-striped grass mouse—C.R. Selvakumar, silver gull—JJ Harrison, snow petrel—Samuel Blanc, northern giant petrel—Liam Quinn, green turtle—Brocken Inaglory, green-rumped parrotlet—Jam.mohd, Columbian ground squirrel—Martin Pot, red-winged fairy-wren—John Anderson, grey-headed albatross—John Harrison. Two species pictures were provided by the co-authors of this study: painted turtle (credit: FJ) and Atlantic yellow-nosed albatross (credit: SOp). The remaining pictures were taken from Pixabay (https://pixabay.com/photos/).

New publication: Changes in #phenology mediate #vertebrate #population responses to #temperature globally, by @stefanvriend.bsky.social, @mevisser.bsky.social, and others.
doi.org/10.1038/s414...

Source: Oldiefan, Pixabay (CC0)

New publication: Female #chronotype relates to lay date but not #fitness in an island population of great tits, by @aureliastrauss.bsky.social, @babimt.bsky.social, @mevisser.bsky.social, and others. #greattits #laydate
doi.org/10.1007/s004...

🚨3 Lectureships in Biology 🚨

Come join us in Bristol @bristolbiosci.bsky.social!

We are looking for new collegues working across a broad spectum of topics in biology, including ecology & environmental change. Get in touch if you have Qs!

Apply here by 8 March: www.bristol.ac.uk/jobs/find/de...

Well done @aureliastrauss.bsky.social Glad this is out now.

Thanks Viktoriia for leading this excellent project.

🚨🚨🚨 Field Assistant positions - four of them!! - working with the long-term Wytham project this coming spring. Details below. Previous year's field team - come and join us! Details below ⬇️

The University of Vienna awards at least 20 four-year and full-time (40h/week) postdoctoral positions to outstanding female scientists in natural sciences, life sciences, and economics.

Restoring nature and reversing biodiversity loss are urgent societal challenges. Utrecht University invites applications for an Assistant Professor in Wildlife Ecology and Nature Restoration. In this role, you contribute to help solve these challenges through research and education by linking fundamental wildlife ecology to biodiversity recovery and nature restoration. As an Assistant Professor, you will join a young, enthusiastic team that is eager to make an impact. You will help strengthen the team’s mission to connect fundamental wildlife ecology with the challenges of nature restoration in human-dominated multifunctional forest landscapes, especially in north-western Europe. Your research will focus on restoration-relevant themes, such as wildlife responses to anthropogenic change, the effectiveness of conservation interventions, and the contribution of wildlife to biodiversity recovery and nature restoration. Close collaboration with colleagues within and beyond Utrecht University is an important part of this role, as well as building sustainable partnerships with conservation practitioners and policymakers. You will combine fieldwork, experiments and biomonitoring (e.g. using sensor technologies) with laboratory, statistical and theoretical approaches. There is ample opportunity to initiate research projects and to acquire funding. In education, you will teach in the Biology programs, develop and coordinate a new course, and supervise research projects of BSc, MSc and PhD students.

Are you a PhD-level #wildlife ecologist committed to research and education for #biodiversity and nature restoration?
Our group at @utrechtuniversity.bsky.social has a #vacancy for an assistant professor!
Deadline for applications is February 19.
Please spread the word.
www.uu.nl/en/organisat...

Senior Lecturer/Associate Professor in Biodiversity The Department of Biology was established in 2010 through the merger of the Departments of Ecology, Cell and Organism Biology, Biological Undergraduate Education, and the Biological Museums. The depar

Come and join me and my colleagues at the Department of Biology, #LundUniversity in #sweden! We have am open position as Senior Lecturer/Associate Professor in Biodiversity.

Apply here no later than February 11 2026:

https://lu.varbi.com/en/what:job/jobID:848749/type:job/where:4/apply:1

NEW JOB in #ornithology with @vogelwarte.bsky.social to unravel the demographic drivers of population change in Alpine #swifts in #Switzerland: buff.ly/crV1rT8

Empseb is simply the best. If you're a PhD student of evolutionary biology, do go there!

Figure 1 in Buddendorf et al. (2025): "Nightly counts of flying insects (left), pipistrelle bat passes (middle) and their feeding buzzes (right) per treatment (dark control: 0.16 ± 0.03 lx, low: LED 3000 K, 4.4 ± 1.4 lx, high: LED 3000 K, 17 ± 3.8 lx). Significance levels indicated as ns: p > .05, ***: p < .001."

New publication: Dimming #streetlights in urban areas reduces #insect attraction but pipistrelle #bats forage more in darkness, by @mevisser.bsky.social and others. #ALAN #foraging #lightpollution
doi.org/10.1016/j.bi...

The date is set for the next EOU Fledglings Meeting 🐥 in Gdansk, Poland! Share the news with your peers! 🦆

Figure 1 in Cuchot et al. (2025): "Locations of constant capture effort sites (CES). Colors represent the number of years of monitoring per site. Map lines delineate study areas and do not necessarily depict accepted national boundaries."

New publication: Phenological Plasticity and Its #Temperature-Related Drivers in Common #Songbirds Across Europe. #climatechange #phenology
doi.org/10.1111/gcb....

Are you involved in ecological forecasting or prediction in Europe?
We’re mapping forecasting applications across the continent — from SDMs to observatories with predictive potential.
Submit here 👉 euro-ecoforecast.wordpress.com/forecasting-...
#EcologicalForecasting #EEFI #OpenScience

Antimicrobial Resistance (AMR) in Gamebirds: A One Health Approach to Understanding and Mitigating the Risk of AMR Evolution and Spread through Ecosystems at University of Exeter on FindAPhD.com PhD Project - Antimicrobial Resistance (AMR) in Gamebirds: A One Health Approach to Understanding and Mitigating the Risk of AMR Evolution and Spread through Ecosystems at University of Exeter, list...

*PhD opportunity @uniexecec.bsky.social* How does antimicrobial resistance spread through ecosystems?

Combine fieldwork (rodent trapping 🐭, habitat surveys 🌳, pheasant sampling 🦤), molecular techniques, GIS, and spatial modelling to understand AMR evolution and spread. 🔬🦠🧪
Please repost!

There are two LTER platforms in the Netherlands: Veluwe and Wadden Sea. See www.lter-nl.nl and www.lter-life.nl

PhD Seasonal Timing of Egg Overwintering Insects under Climate Change Climate change is exerting strong selection on wild populations, with many species showing shifts in the seasonal timing of development. One particularly vulnerable group are insect species that overw...

PhD candidate #vacancy alert:

Insect species that overwinter as eggs are particularly vulnerable to climate change. We are looking for a PhD candidate to collect more data to predict whether these insects can adapt to climate change.

Read the vacancy on our website: nioo.knaw.nl/en/vacancies...

Excellent project led by @disnatalie.bsky.social Come and work with us at @niooknaw.bsky.social @animalecol-nioo.bsky.social!

Well done Cherine, Youri, Maartje and all the way from Lyon: Marlene!

Male pied flycatcher

Should I stay or should I go?🐦 Fancy a #PhD studying Pied flycatchers in the Peak District to help better understand what drives individual & population performance? Think #habitat #movement #ecology #genetics 🌍 Make use of this nestbox PIT tag study system and join us! Email me #LJMU #NationalTrust

We’re hiring a doctoral researcher in the area of migration ecology.
The work will focus on the question of how and when migratory songbirds learn where their home is using #Motus.
Part of the Cluster of Excellence NaviSense and linked with @sfb1372.bsky.social

uol.de/job788en

#ornithology

Examples of some recent papers from graduate students in my group - a full list of recent papers and preprints can be found here (https://scholar.google.co.uk/citations?hl=en&user=pTdxVdIAAAAJ) and profile of the group here: https://egioxford.web.ox.ac.uk/members

The annual Wytham Field Team Photo!

Celebrating a successful field season with great food & good company - May 2025

Front view of the Life & Mind Building, which opened in Oct 2025: The new home of Biology at Oxford

Interested in a PhD in ornithology? Funding available for projects at the interface of ecology, behaviour & evolution from Oct '26 working on long-term population studies of tits at Wytham, based in @biology.ox.ac.uk in the new Life & Mind Building in Oxford
www.findaphd.com/phds/project...

Figure 1 in Linssen et al. (2025): "Spring migrations and tracking data of five Arctic-breeding waterfowl species."

New publication: Scope for #waterfowl to speed up migration to a warming Arctic. #climatechange #avianmigration
doi.org/10.1038/s415...

Fully funded PhD working on insectivorous bird declines with a broad range of stakeholders. Starting ASAP #ornithology #zoology #biodiversity #science #ecology
www.exeter.ac.uk/study/fundin...

Thanks Milos & Peter for organising this wonderful meeting!

Thanks Milos & Peter for organising this wonderful meeting!

PhD position available to study the migration ecology and year-round demography of blackpoll warblers.