05 de julio de 2023

Histogram case study: variation in molting strategy of flight feathers and body feathers in North American Anseriformes

Hi all! I’m in Maryland right now and when I walk along the Chesapeake Bay, I notice that the Mallard ducks seem to be going into eclipse plumage. Information online on exactly when this eclipse plumage happens wasn’t super specific, so I used the histogram method outlined in my previous post to see when Found Feathers observations of waterfowl feathers had been made in the North American region.


This first graph made some sense, but I was thinking that there might have been a peak in July and not June since I’ve only just started seeing body feathers personally. So I filtered for "Feather Placement: Body” and lo and behold:


A late-summer peak beginning in July! And a second (or first?) peak in late winter/early spring, perhaps in preparation for the breeding season.

This made me wonder about the flight feathers, since I have heard that waterfowl drop them all at once, and in fact the eclipse plumage happens as a defensive measure during this time of vulnerability. So I filtered for primary and secondary wing feathers, respectively:



So these seem to peak in June, right before the body feathers are shed. Also note that they really do get dropped in a very narrow, very similar time frame. Interesting to see that in the same bird, there are different strategies for molting different kinds of feathers.

Side note: you can go a little more granular and look at week-of-year histograms, which reveal some differences between the primary/secondary molt timing not seen in the month-of year graphs (see below). However, with the very small n-count I think that the month-of-year view is probably more appropriate/useful.



What this view does tell you, though, is that you need to be out on the 24th week of the year to see the most waterfowl feathers in North America!


That was the week of June 12. Darn! I’ll have to plan ahead for next year :)

Publicado el 05 de julio de 2023 por featherenthusiast featherenthusiast | 1 observación | 0 comentarios | Deja un comentario

24 de junio de 2023

Using iNat histograms to forecast feathers found

I’m messing around with this histogram tool by @pisum (thank you!!) and was able to get the settings so that you can see observations from the Found Feathers project by month. By modifying the parameters, you can get views of various taxons and locations, among other things.

This is exciting to me because I’ve explored the question of “when do you find the most feathers?” casually before (by which I mean throwing iNat numbers into Excel and cobbling together bar charts) and preliminary results suggest that the time that birds lose feathers varies by region and type of bird. This is great news! Because it suggests that maybe there are certain times that it might be easier to look for certain kinds of feathers, and we can go beyond simply saying that it is “molting season” by identifying exactly when that molting season happens for specific hemispheres/continents/countries/states, right down to the species level with enough data!

I haven’t dug into this all the way yet (hence why I’m not posting to Found Feathers)—but I hypothesize the following:

  • Northern/Southern hemisphere should be roughly flipped in timing of the molting season
  • Molting timing should differ most greatly at the order level, with species in the same genus/family being generally similar in molting strategy
  • The time at which different types of feathers are molted may vary in the same species (i.e. a Gray Catbird might molt its primaries in a different window than its tail feathers or body feathers)
  • Molting timing may change according to climate, with a hotter year shifting molting earlier

All hypothetical! But all answerable with enough tinkering with URLs.

Anyways, here are links to histograms that I think are interesting—flip through them quickly to see the differences!

All birds, everywhere: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=any&project_id=found-feathers&quality_grade=research&taxon_id=3

All birds, Northern Hemisphere: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?nelat=90&nelng=180&swlat=0&swlng=-180&project_id=found-feathers&quality_grade=research&taxon_id=3

All birds, Southern Hemisphere: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?nelat=0&nelng=180&swlat=-90&swlng=-180&project_id=found-feathers&quality_grade=research&taxon_id=3

Feral Pigeons, Northern Hemisphere: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?nelat=90&nelng=180&swlat=0&swlng=-180&project_id=found-feathers&quality_grade=research&taxon_id=122767

Feral Pigeons, Southern Hemisphere: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?nelat=0&nelng=180&swlat=-90&swlng=-180&project_id=found-feathers&quality_grade=research&taxon_id=122767

Accipitriformes (hawks/eagles/osprey) in the American Southeast (my region): https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=90754&project_id=found-feathers&quality_grade=research&taxon_id=71261

Passeriformes (songbirds) in the American Southeast: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=90754&project_id=found-feathers&quality_grade=research&taxon_id=7251

Strigiformes (owls) in the American Southeast: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=90754&project_id=found-feathers&quality_grade=research&taxon_id=19350

Columbiformes (pigeon/doves) in the American Southeast (apparently they peak in September!): https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=90754&project_id=found-feathers&quality_grade=research&taxon_id=2708

Accipitriformes in Europe: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=97391&project_id=found-feathers&quality_grade=research&taxon_id=71261

Passeriformes in Europe: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=97391&project_id=found-feathers&quality_grade=research&taxon_id=7251

Strigiformes in Europe: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=97391&project_id=found-feathers&quality_grade=research&taxon_id=19350

Columbiformes in Europe (still peaking in September, but barely): https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?place_id=97391&project_id=found-feathers&quality_grade=research&taxon_id=2708

By the way—to make your own custom queries, create a search query using the iNaturalist Explore page (prepopulated link for RG Found Feathers: https://www.inaturalist.org/observations?project_id=found-feathers&quality_grade=research), grab the query string from the URL (i.e. everything after the question mark), and paste it at the end of this URL: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?

For any long-term analysis of these histograms, I would like to see a tool with functionality implemented for the following:

  • overlay of multiple histograms for (normalized) comparison (i.e. how does this taxon stack up to birds at large? or this other taxon?)
  • ability to choose taxon/location codes without having to look them up each time on the iNat explore page
    Ideally I’ll fork pisum’s tool and do it myself, but I haven’t tried a project like this in HTML yet. Perhaps this will be my opportunity to be a good CompSci major and get well-acquainted with the iNat API (:

Publicado el 24 de junio de 2023 por featherenthusiast featherenthusiast | 1 comentario | Deja un comentario

22 de abril de 2023

University bird strike projects

Just a thought—there should be an umbrella project to organize all the university bird strike projects on iNat. Would love to hear if anyone involved in such projects has had any success in mitigating collisions and spreading awareness. As I recall, Duke both installed film and received news coverage on the issue in 2016. It would be great to see more of the same at more institutions!

I’m going to set up an umbrella project now with as many projects as I can find. But please let me know if I miss any!

Edit: project here

Publicado el 22 de abril de 2023 por featherenthusiast featherenthusiast | 0 comentarios | Deja un comentario

30 de marzo de 2023

Regarding the camera trap observations

If you follow my observations or identify in the Atlanta area, you may have noticed a recent uptick in camera trap observations. These are the product of a project at my university which seeks to document (primarily mammalian) biodiversity in an urban landscape.

In Fall 2022, we deployed a set of roughly 20 cameras in collaboration with the Snapshot USA project. We uploaded and identified our observations through that platform but are now cross listing them on iNaturalist to improve portability and allow for the review of identifications.

In Spring 2023, we are continuing this work but with a closer focus on our own campus. We hope to be able to compare biodiversity across seasons and locations and explore a few taxon-specific queries.

For example, Gray Foxes (Urocyon cinereoargenteus) seem to be the only wild canid species present on our campus, but they have not been observed anywhere else within the 285 border as of this post. Keeping records of observations could help inform what a healthy population of foxes might look like on campus while corroborating existing research on the subject of Gray Fox ecology in the Southeastern US.

Feral cats pose a well-documented risk to native birds, but have similarly little research-grade documentation on iNaturalist both locally on our campus and more broadly in the Atlanta area. We know of a feral cat TNR and feeding initiative on our campus, but more work could be probably done to improve population counts and identification of their interactions with other wildlife.

I do want to offer my apologies to anyone who finds the bulk uploads bothersome. If you do not wish to see these observations or receive notifications from me, you may use the “Mark All As Reviewed” feature on the Identify page and/or mute me (see button on my user profile @featherenthusiast). Please feel free to reach out if I can be of any assistance in this process. I want to make it clear that no one is obligated to review these observations, and that my team will eventually get around to identification (though we are only two people so this will take some time). A million thanks to anyone who has taken the time to review one or many of these observations!

Despite the possible annoyance, I hope that the observations generated by this project can provide an accessible snapshot of the state of biodiversity in Atlanta.

Further reading:
Wildlife at Home on Campus

Publicado el 30 de marzo de 2023 por featherenthusiast featherenthusiast | 2 observaciones | 0 comentarios | Deja un comentario