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This group provides support for those using geolocator technology to study animal movement and behavior.

  1. What's new in this group
  2. Hi, I'm analysing some geolocator data from a common sandpiper using the geolight package. When I run my analysis I get a weird migration pattern, the individual appears to stop in two locations (one of which is in the sea) before settling in West Africa. I'm not sure whether these are true movements from west to east or if something else is going on. Does anyone have any suggestions? These movements are not around the equinoxes either. The output of siteMap() and schedule() are attached. Thanks, Thomas ADplot.tiff AD_migration_schedule.csv
  3. Hi Ana, these cut-off probs just measure how many particles movet between time t and t+1. 0.1 will say that there was movement between two periods if at least 10% of particles moved >25 km. 0.5 would mean 50% chance. Generally you better make it higher than lower. There is so far no established approach on how to select a proper value here. Hope this helps, Eldar
  4. Hi all, I estimated stopover locations by using 0.1, 0.2, and 0.3 cutt-off prob. Results are quite consistent specially during the first part of migration. Can the 0.1, 0.2, and 0.3 values be translated into something more "meaningful"? Like km? I'm not quite sure how to explain these three values. Many thanks, Ana
  5. Finally, an almost complete user`s guide for geolocator analyses. Check out the paper: https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2656.13036 As well as the online manual: https://geolocationmanual.vogelwarte.ch/ Lisovski_et_al-2019-JAnimEcol.pdf
  6. So you can install it directly from there with the install.packages(). 0.4.9 version introduces FLightR2Movebank( ) function that saves result formovebank upload. The latest version is on GitHub, as always.
  7. Sorry - I am not sure what is happening.. are you working on a mac? If not try gr.Device = "default"
  8. Thanks for your help, Eldar! Distance does seem to be key. Increasing max distance in particle.filter has improved the return track. Now working on adjusting mean and sd. Forgive a beginner question, but is there an easy way to estimate appropriate values? I have the result of a particle.filter run that produced an OK-looking track, but not quite sure what I should use. Should I include all movements in my estimates? These are birds that remain in a relatively small area for most of the year, but travel long distances quickly during migration...
  9. Hi Simeon, Thank you so much for responding. I checked my NA's and didn't get any. summary(raw) Date Light Min. :2013-02-22 00:00:02 Min. : 0.0002 1st Qu.:2013-04-28 17:58:47 1st Qu.: 0.0002 Median :2013-07-03 11:57:32 Median : 6.4847 Mean :2013-07-03 11:57:32 Mean : 5.1559 3rd Qu.:2013-09-07 05:56:17 3rd Qu.: 8.8506 Max. :2013-11-11 23:55:02 Max. :11.2176 I set the threshold to -.6, .6, 1, 2. I went through the steps to select the beginning, ending date and the darkest spot in the no light area in order for the package to select the sunrise and sunsets. I accepted all the other screens and then the error keeps happening particularly when I hit (a)accept for stage depicted in the attached image.
  10. Hi Jenny, 1. You could try increasing the distance they are allowed to fly. The maximum distance can be fixed in particle.filter and the mean and sd in make.prerun.object. 2. Try running first without any spatial constrains. It sometimes happen that particle filter just cannot find a proper solution if bir migrated to far every day for a long period. Hope this helps, Eldar
  11. Hi, all I'm using FLightR 0.4.9 to track migration of shorebirds. Tags were deployed in Alaska and recovered at the same site a year later. FLightR gives me nice-looking tracks for the breeding season in Alaska, fall migration to Chile, and the non-breeding season in Chile. But the track for spring migration is consistently problematic -- instead of returning north to Alaska, it heads south toward Antarctica. Has anyone experienced something similar? Any ideas for what I can do? Calibration periods are from the study site (lon = -150.725, lat = 61.272): one from the beginning of the study (shortly after tag deployment) and another from the end (shortly before tag recovery). Both verified by plot_slopes_by_location. > Calibration.periods <- data.frame(calibration.start=as.POSIXct(c("2009-05-17", "2010-05-10")), calibration.stop=as.POSIXct(c("2009-06-15", NA)),lon=-150.725, lat=61.272) > print(Calibration.periods) calibration.start calibration.stop lon lat 1 2009-05-17 2009-06-15 -150.725 61.272 2 2010-05-10 <NA> -150.725 61.272 Calibrating from pre-deployment data instead yields similar results. For the particle filter run I've tried known.last=TRUE and known.last=FALSE. Changing behavioral masks, outlier check, nParticles, etc. also do not seem to help. > all.in <- make.prerun.object(Proc.data, Grid, start=c(-150.725, 61.272), Calibration=Calibration) > nParticles=1e6 > Result <- run.particle.filter(all.in, threads=-1, nParticles=nParticles, known.last=TRUE, check.outliers=TRUE) Since I'm using the correct lon/lat at the end of the track to calibrate, why might the output show my end coordinates so far away from there? Jenny
  12. Hi Diane, have you plotted your light data to make sure that the threshold is within the range of measured light. And have you got any NA's in your time column (check for sum(is.na(raw$Date))). Simeon
  13. Hi I'm working on my thesis playing with the GCSP tag data sets, trying to process them with GeoLocTools and FLightR. I am coming up on an error message when I selecting my twilight threshold. I have tried changing the threshold a variety of different times and still receive the same error message. > threshold <- 0.6 > twl <- preprocessLight(raw, + threshold = threshold, + offset = offset, + lmax = 20, # max. light value (adjust if contrast between night and day is weak) + gr.Device = "x11") Waiting for input Error in class(xx) <- cl : attempt to set an attribute on NULL Any thoughts or suggestion would be greatly appreciated. Thank you so much Diane Nelson
  14. That is correct, median deviation for thresholdPath, since it ignores the error structure and zero devotion for the Estelle model. Running calibration during the equinox ist actually a good thing, if you have enough time around the equinox. Given the structure of errors around the equinox, estimates of latitude are very sensitive to zenith angles (sun elevation angles). Hope that helps, Simeon
  15. Hi! I am running my data with SGAT, but I am not sure which zenith should I use in the thresholdPath and which in the Estelle model. I think I should use the median deviation zenith in the thresholdPath and the zero deviation in the Estelle? Also, which could it be the effect of running my calibration during the spring equinox? Thank you in advance!!! Melina
  16. This is strange. I have just tried installing from GitHub and got the 0.4.9... It is not on CRAN yet, so do not try there. Eldar
  17. Hi Eldar, I just tried updating to FLightR version 0.4.9 but can only get 0.4.8 to install via GitHub and CRAN. Any ideas about what might be happening?
  18. Please note that there was a bug in FLightR 0.4.8 that creared weird resuls with point jumping all over the place - Please update FLightR to 0.4.9: devtools::install_github('eldarrak/FLightR') Eldar
  19. Hi Dan, I have discovered a bug in FLightR 0.4.8. Please reinstall from Grithub with devtools::install_github('eldarrak/FLightR') and report whether you still have problems. Sorry for the inconvenience. Eldar
  20. I am part of a long-term study monitoring Cerulean Warbler populations using point counts, a geolocator study, and nest monitoring. For the past 10 or so years, we have been using mini Radioshack amplifiers connected to an mp3 player with an auxiliary cable for our playback surveys and target netting. Since the start of the study, Radioshack has gone out of business, and we are unable to purchase replacements of the amplifiers when they break. I am asking for recommendations of speakers/amplifiers that others have field-tested with success. The speaker/amplifier must be able to project sound for a minimum of 100 m, be easily transported in the field, and have an auxiliary cable port. Thank you!
  21. The move is done now. Let me know if you have any questions about how this new Groups feature works.
  22. Hi- I am usingTwGeos (findTwilights and twilightEdit) to determine twlights. I define my capture locations and define those for the start and end period calibrations. CapLocs=c(-73.091342, 42.680602); FLightR generates start and end locations that are not even close to the capture locations. Also, the locations zigzag all over during periods I think should be stationary. Any ideas where I should start looking? Thanks, Dan FlightR output:
  23. Recently we started using a new application on OE called Groups. As a result, you now see a Groups tab on the navigation menu above. With this application, users can start their own sub-communities on OE, like this Geolocator Discussion & Support group. Several new groups have already been created, and more are on the way. I a now beginning to transition our existing groups to this new app. On Friday February 15 I will pull the trigger and have this forum moved over to the Groups app. Here is what to expect: The forum will be moved from the Forums page to the Groups page. When you click on Groups in the navigation menu, you will see a list of groups, including the new Geolocator Discussion & Support group. When you click on the group, there will be a home page, a members page, and a forum page. The forum page will look just like the current one does. All the past forum topics will be there too. Anybody who is signed up for notifications on the current forum will be added to the new group and your personal notification settings for the forum will be maintained as they currently are. Eli Bridge will be the owner of the group, and the moderator. If anybody else wants to help moderate, talk to Eli. If anybody has any questions or concerns, please reply to this message or contact me directly. And if anybody has an I can use as either a logo or a banner for the new group, please send it to me.
  24. Thanks, Eldar! I installed Rtools from the website you sent. Then, per the subsequent error messages trying to install TwGeos, I also had to run: install.packages("SGAT"); install.packages("zoo"); devtools::install_github("SLisovski/TwGeos"); It looks like Twgeos is successfully loaded. > search() [1] ".GlobalEnv" "package:SGAT" "package:zoo" [4] "package:TwGeos" "package:stats" "package:graphics" [7] "package:grDevices" "package:utils" "package:datasets" [10] "package:methods" "Autoloads" "package:base" Now I just have to figure out how to use it! thanks! Dan
  25. Hi Dan, rtools is not a package, so you should download it from here https://cran.r-project.org/bin/windows/Rtools/ and install manually. Hope this helps, Cheers, Eldar
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