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Hello,
I have been using the example from section 5 of the adehabitatLT to test run some code for animal movement data (found here: https://cloud.r-project.org/web/packages/adehabitatLT/vignettes/adehabitatLT.pdf)
I am using the NMs.randomCRW to create random simulations of the bird data within a spatial boundary prior to extracting environmental covariates. I was able to run previous code for the first null model with the NMs.randomshiftrotation function, but the spatial binding that involves the confun function for the second model failed:
confun <- function(x, par)
{
## Define a SpatialPointsDataFrame from the trajectory
coordinates(x) <- x[,1:2]
## overlap the relocations x to the elevation map par
jo <- join(x, par)
## checks that there are no missing value
res <- all(!is.na(jo))
## return this check
return(res)
}
nmo2 <- NMs.randomShiftRotation(na.omit(bird.traj), rshift = TRUE, rrot = TRUE,
rx = range(xo[,1]), ry = range(xo[,2]),
treatment.func = plotfun,
treatment.par = map[,1],
constraint.func = confun,
constraint.par= map[,1],
nrep=9)
nmo2
Error in FUN(X[[i]], ...) : The constraint function fails for animal 1 : it should work at least for all observed trajectories
The spatial pixels df object I'm using is the spatial boundary (map) and the bird data is an ltraj object where both are projected in the same crs. Anyone have this problem before?
Thanks for any help with this! Feel free to message me if you wish to get more info to provide assistance with this!
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Hi, I have the same issue! Did you ever figure it out?
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I am currently writing a research proposal for my master's thesis. I intend on investigating inter-individual differences in cownose ray (Rhinoptera bonasus) behavior in a touch pool setting. I have looked into a lot of different tracking software and ID methods, but none seem particularly reliable for the species I am attempting to use them for. Their kite-shaped body and low visual difference (especially above and from a distance) and my intention of using the least invasive marking techniques (preferably no marking techniques) have made it difficult to determine how best to track them.
Any suggestions for tracking software, ID software, or marking methods would be greatly appreciated.
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Hi Wren. How many (approximately) rays are you going to be looking at? It is all fine and well to try to distinguish between rays without markers at numbers, say, less than 4 -5, but once you get beyond that number it becomes a nightmare! I would strongly suggest that you consider a marking strategy, not only to be able to produce rigorous science, but also for the sake of your sanity! Having 'been there' in terms of identifying individual elasmobranchs on sight, I would highly recommend making your life easier and keeping your data unambiguous by using markers. I hope this helps! Best of luck.
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I am looking for a solution with the R programming environment that will allow me to simulate animal movement (using a correlated random walk or other chosen model) within a polygon boundary, which acts as a reflective boundary to the movement.
I did find a solution (http://tinyurl.com/jbyuty8), but this has ArcGIS has a program dependency. I prefer to use open-source solutions.
The "adehabitatLT" package has a number of simulation functions, but I cannot find one that allows specification of a bounday argument.
Any helpful hints out there?
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I used R package GLATOS to build Random Walk simulated tracks constrained into a defined polygon
See applcation in our paper:
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We have come across this issue that there really is not a way to perform seasonal comparisons among low resolution (i.e. telemetry) movement data in a quantitatively rigorous manner (for example people often use seasonal MCPs).
Does anyone have ideas for how to compare low resolution movement data correctly between seasons or at least eliminate this issue from the literature?
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Hi Colin,
Sorry for the slow reply -- I've been thinking a lot about your question. I study cow behavior and have seen others use area explored in the event of variable GPS time-lags. I think you'd find a lot in the literature about large ungulates that deals with this problem. That said, I think it would still be applicable to your cobra example in that you are tracking multiple snakes for multiple days throughout the breeding season (and perhaps across years, too?); I suspect that a daily MCP calculation for four fix locations per day between 0600-1800 would exaggerate the area explored, but would also offer a consistent metric between each snake and season. This way you could average the MCPs per season to see their general area explored. I think you could make a solid argument that a larger area explored would be facilitated by moving more. There is always the case that the animal is moving a lot in a small area and this would be the hardest thing to rule out, but I can't think of another metric that would account for the time-lagged dateset.
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I have time series GPS tracking data from a number of individuals, all with varying time between locations (i.e. certain individuals recording at 15 minutes intervals, others at 20 minutes or 1 hour). Tracking starts at sunrise and ends at sunset, omitting overnight locations. I would like to subset the data to 1 hour to make it comparable. I am currently doing this in excel although it is proving to be a rather tedious method. Is there a method in R that can speed up this process?
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There is a easy way to do this in PYTHON.
The function called "resample" and "groupby" are most used function for time series analysis.
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I mean all possible work with tagging data: GIS, tagging data pre-processing, visualisation, different types of modelling and modern analysis by using R, Python, etc.
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I second David's suggestion. Just to add: If you have really large data sets (TB) and or you want to run really complex simulations which may be parallelized, you might consider using a computer cluster. Universities often have such clusters, and there are possibilities to by access to commercial clusters. It saves you own investment and administration.
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I'm trying to review Temminck's Ground Pangolin (Smutsia temminckii) movements for a research job. But I couldn't find any research paper on this theme. Thank You.
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Check
2. A conservation assessment of Smutsia temminckii
3. Ethnozoological Survey of Traditional Uses of Temminck’s Ground Pangolin (Smutsia temminckii) in South Africa
4. IUCN Pangolin Specialist working group
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Movebank provides a simple yet effective tool for filtering outliers from telemetry data by speed between successive relocations. Is there a similar tool available in any animal movement analysis package? The closest I've been able to find is the 'argosfilter' package, which does have a speed filter that works, but is not very streamlined for processing large datasets.
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After some additional searching, I've found the "speedfilter" function in the new (April 2019) "trip" package to work well. More info here:
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Fences built by humans can become a barrier to animal movement. I am looking for publications that investigate how fences limit animal movement, but also show that populations decline after fencing. Send me any of your related publications.......Many thanks!
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Tongue on cheek, some might say the invasive animals are not what (or rather who) we think they are. Edward O. Wilson's (2017) most impassioned book to date argues we need to dedicate fully half the surface of the Earth to nature. That said, responses to this quite commonsensical query might be enriched by a look at the effects of conservation corridors.
Reference
Wilson, E. O. (2017). Half-Earth: Our planet's fight for life. Liveright.
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I'm doing a food preference study with some crabs and trying to find out how much time they spend in the presence of different food options.  I have an 11 hour long video, and I'm looking for a program to help me analyze it.  Ideally, I would like some sort of program that can track individuals, and that also allows me to mark "thresholds" or something similar, so it can detect when individuals cross from one area to another and let me know how much time each individual spends in each area.  Does such a program exist, or are there any recommendations for programs that could at least help me tackle the video?
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We offer a secure cloud-based app that allows you to automate your crab behavioral research.
It can be accessed anywhere in the world by a computer, smartphone, or tablet without downloading anything.
Wouldn't it be amazing to do your behavioral analysis in front of the TV watching Netflix...
You don't need anything fancy in order to get started, typically you can set up your smartphone, and let it record, while you're in a separate room. There is no fear of an interruptance caused by a researcher, etc.
Although we are not an open-source program. Our prices are very competitive when compared to Noldus' EthoVision. You can even share your data with your collaborators.
Please feel free to start your free trial at www.behaviorcloud.com or email me at chloe@behaviorcloud.com for more details.
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Hello every body,
I have got a set of GPS data containing the hourly locations of 74 terrestrial animals during the study period. Currently, I am looking over disparate models of movement modelings like BBMM. I need to study the interaction and movement pattern of each individual animal.
In addition, I will use Python for the implementation of the model.
Which model do you recommend?
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Hi, it appears that no one has really answered your question, so I am going to take a stab at it and hopefully it helps. If you are using Esri products in the Geoprocessing tools there are the Spatial Analyst and Tracking Analyst extensions that are really helpful. You can build a model, through modeling building and test how it works. They do require some level of knowledge with ArcGIS and GIS. However, there are online tutorials for ArcGIS extensions, and YouTube videos, for free. I have seen in other forums people suggesting Hawths’ tool for spatial ecology, but I am not familiar with that software at all that I am aware of.
Tracking analysis
Spatial analysis
or if you read enough which most college students do check out the choices in YouTube videos
Spatial analysis YouTube
Tracking Analysis YouTube
Animal movement article with resources
Also: a book is out on explaining Modeling suitability, movement and interaction
I hope this helps, Good luck with your project.
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EthoVision is software by the company Noldus.
Is anybody aware of anything better?
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Indrikis Krams We have developed an affordable option compared to Noldus, Anymaze, Cleversys, and allows you to access from any device as well as share with colleagues and collaborators. We also provide great technical support, training, and consulting services as well. Please check us out at www.behaviorcloud.com
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I want to evaluate and compare foraging efforts (i.e. random movement path) of animals between several macrohabitat types. We visualized movements using fluorescent pigments so we know the exact path of each individual but we do not have informations about temporal locations. I am searching for indexes that assess movements tortuosity taking into account that I can not record locations on a regular time scale. I am open to any suggestions.
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Thank you for your help! I will take a look at this package.
Regards
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spool and line tracking technique usually used in more woody and dense area so that researcher can get a clear animal movement. However in paddy field, the vegetation height and profile are not as same in forested area. Is it acceptable to use the technique to understand the animal movement and learn their micro habitat?
thanks.
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You are most welcome.
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Hi everyone, I want to automatically analyse video with beetle movement. Output should be matrix with x/y coordinates (pixels) of beetle position in time. I have a problem, because I am beginner in computer vision, so can you give me some advice how to solve this task?
Analyse for 1 object. More than 400 hours of video/camera, 8 cameras.
Is openCV/Python OK for this task?
Screenshot from video is in appendix.
Thanks in advance.
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@ Sang-Il Oh : In the computer vision field, object(s) tracking can be applied to solve your problem.
Yes, definitely. By triangulating (or tessellating) the frames in a video and applying shape detection, analysis and classification techniques, it is possible to organized video frames into clusters containing objects (e.g., ground beetles) with similar behavior. For more about this, see
Foundations of Computer Vision
  • March 2017
  • Intelligent Systems Reference Library 124
  • DOI:
  • 10.1007/978-3-319-52483-2
  • Edition: 1st
  • Publisher: Springer International Publishing Switzerland
  • Editor: Janusz Kacprzyk and Lakhmi C. Jain
  • ISBN: ISBN 978-3-319-30260-7, ISBN 978-3-319-30262-1 (eBook)
  • Projects:
  • Computer Vision and Image Analysis, Understanding and Processing
  • Shapes in Visual Scenes, Digital images and Videos
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I am currently investigating how to best discriminate between animal movement tracks based on space-use patterns and characteristics of the moves themselves. Ideally I would like to use several complementary (i.e. non-correlated) statistics to be able to come up with statements like: "these two tracks resembled each other, as they covered areas of similar size, but one of the tracks was characterised by a larger number of highly directed and highly area-restricted moves than the other". The first statement could be measured using home range statistics, but I have not found a good way to measure distribution of moves. And perhaps there are other independent characteristics of animal moves that I haven't thought about. Suggestions are warmly welcomed!
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Dear Jacob, make sure to have look at the recent papers by Justin Calabrese and coworkers. They use time-continuous, not time discrete ones, to fit tracking data, which allows them to better take autocorrelation into account. They also developed a powerful R script to actually use this new approach. I am not an expert on all this, but it seems to me that this is the best you can find in movement ecology. Cheers, Volker
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I've been working on a step selection function for animal movements in R as I haven't yet found anything that suits my needs. I'd like something that can take high-frequency animal GPS data, simulate available locations at each point, extract relevant spatial attributes at these points, and then compare used vs. available locations using logistic regression or something similar. Before I spend any more time developing this function I wanted to make sure I'm not re-inventing the wheel. Does anyone know of an r package or program that does what I'm describing? Thanks.
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the 'amt' package in R will do just that, see this preprint:
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I've come across a paper and it defines tortuosity as gross distance divided by net distance traveled. If I measure my parameters (say, microhabitat features) every 10 m, and the total spool used up by the animal is 200 m, does this mean that tortuosity for the first segment is 200/10? I'm sorry if this is so basic but I've never used tortuosity before. I will really appreciate your thoughts! Thank you.
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Hi Renee,
For apply the method that I am talking about, you need to have camera-trap data. This method have been applied in rodents, and I have applied it in ungulates, with nice results.
See "Bias in estimating animal travel distance: the effect of sampling frequency, Rowcliffe et al 2012" if you want more details.
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Hi,
I have a set of GPS fixes from GPS tagged owls. The GPS was programmed to send 3 GPS positions (fixes) during the night (2 hours before midnight, midnight and 2 hours after midnight). The GPS senders were active between 1- 3 years. I will calculate Kernel and minimum convex polygon (MCP) home ranges, and finally I will analyse habitat selection.
Within each home range I will create random points reflecting habitat availability. The habitat will be compared between owl fixes and random points to estimate habitat selection.
So far it is straightforward. Although the owl lives along the coast and alternates between being on mainland and group of islands. Hence, within the home range area there are large water bodies, which the owl are only crossing.
I think the best procedure for the habitat analysis is exclude the large water bodies. Although, I would be happy to get some recommendations.
Best regards,
Ronny
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I agree with you Ronny. We have to accept some dependence (literal meaning) between animal location at the time of a previous fix, where it is now, and where it can potentially go before the next fix. But I understand mathematical people focus on something different, statistical independence of points as a basic assumption of kernel density estimation. Nevertheless, in many previous animal tracking studies it was acceptable to use kernel methods with long intervals between fixes (reducing the issue of auto-correlation), and could okay for your fixes 3 times per night with 2 h intervals. Newer methods like aKDE from Fleming et al and Brownian Bridge movement models I think are more important for people who get high frequency fixes. Might be interesting to try both with your owl data. It sounds a very interesting study, best wishes for your analysis.
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Set to work on rattlesnake home range parameters. It appears the two most widely used software/extensions (For ArcView/ArcMap) are Animal Movement Extension (Hooge and Eichenlaub 1997/2000), Geospacial Modelling Environment (GME; Beyer 2012/2015) or Home Range Extension.
Anyone with experience using any or all of these extensions/software have any comments or suggestions?
Thanks.
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Dear Jared,
I second everything Julien said. If you know R or can afford the time to learn from the vignettes of the packages, use R (but indeed it would be critical to know what you want to do to direct you more precisely). If you don't know R, just have a few HR to compute, and you are fine with location-based kernel HR estimate (which are generally ok for a set of independent locations), you may want to try this:
which we made at the lab for user-friendly simple HR estimation (Credits go to C. Bernard). It's an online app, it runs R adehabitatHR package in the background, will allow you to play with the smoothing parameter, and you can select the %UD you want to get. You can export a shapefile of your UD.
Best,
simon
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For a study of nesting birds we consider using GPS tags with UHF download facility. I understand Pathtrack and Ecotone can supply them, maybe other manufacturers?
If you've used this kind of system on birds or other species:
Which system did you choose?
How easy/difficult to achieve successful download?
What distance for reliable download?
I will be grateful for your advice, warnings and recommendations, thanks!
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Hi Julia,
I have been using e-obs collars on Eurasian lynx in a montane area in Turkey. To my experience if you have severeal high hill tops ascendant to your study area it is very easy to download the data when your animals are in the inactive phase of the day. I could download data many times over more than 5kms away and once even from 16kms from a mountain slope to a hill top directly looking to each other!
I agree with Miha that if the animal is moving during the download, connection breaks very often. So, I always try around 11am to 3pm when the animals are generally inactive and resting on slopes.
As far as I know e-obs is very successful on bird tracking as well.
Cheers,
Deniz
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I thought about using two cameras to track a spider in a cube. One camera to track the x- and y-axis-movement of the spider and one to add the z-axis-movement. If there is a way to capture all the axises with only one camera that would be great, too. I couldn't find anything on either methods yet, though.
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SkillSpector can also be usefull. 
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I need as much data as possible. 
Thanks
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If you want species specific information try: http://www.fishbase.org
It's a good starting point.
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Suggest me recent and advanced bio-statistics method to analyse the field data of animal activity. I have more than 4 variables (abiotic factors) and would like to find most importang affecting factors of animal activity and rest pattern among those factors. 
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Dear Dr. Ashneel Ajay 
Thank you for your suggestion and send the article. 
Thank you
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I have tracking data for four wild dog packs in South Africa and my coordinates have been converted into latitude and longitude. I am following the example in the manual for Analysis of Animal Movements in R, however I do not understand how they formatted the X and Y data in the puechabonsp dataset. 
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Hi,
I would like some suggestions of good drop off mechanism for collar (e.g. designed for larger Cervidae)? Carrying a load of about 500 gram. 
Regards,
Ronny
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If a passive drop-off system would meet your needs, you might look at the attached publication.
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I am fitting exponential and Weibull models to animal movement data.
1. Should I worry about residual normality or anything like that?
(it seems to me that this is not important, since I do not assume normality)
2. Anyway, how should I analyze residuals to get a picture whether my fit is good or not?
Just for note, my model looks like:
y[i] ~ dexp(lambda[i])
lambda[i] = f(x[i]) (linear function)
Thanks in advance!
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Dear Bernardo,
You should always worry about residuals. If you are using GLMs (generalized linear models), then you need not assume iind (independently identically normally distributed) residuals. However, depending on the link function, you must assume some other residual distribution function. Looking at the residuals after fitting the model allows you to check how well the residual structure fits the assumption you made.
Some other comments: even in GLM, the parameters of the assumed distribution of the residuals must be the same across all predicted values. Sometimes (often in biology), this is not the case: the larger the predictor values, the larger the variance in the predicted values. If you have several predicted values for a predictor value, then you can estimate the variance at each predictor variable and perhaps scale accordingly.
The other issue has to do with the relation between sum of squared residuals and AIC (or AICc, depending on how many data points you have). I cannot write the general formula here (no formula editor available), but the general formula for the likelihood, not assuming normality, is available in Burnham and Anderson. Perhaps someone has programmed is in R (which I do not use). You will have to derive it, perhaps, depending on your link function. The warning: do not use the derived term (-n ln(RSS/n) + ln(2 pi) +1) in the formula for AIC (AICc), because this formula is valid for iind residuals.
Maybe some of this needs to be tailored to your modeling random walks.
If I can help any further, please contact me. Hermann
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I need to find a program that can track the movements of a bottlenose dolphin in Belize. The video was taken from drone from a moving boat. The program would need to have the capability to track the movements of a video that is not fixed on one location such as a tank. The program would need to be able to follow the movement of the animal in the video, move with the video, and create a downloadable track. 
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You can also try AnyMaze (expensive). There is also IDTracker, which runs on Matlab 2014 or higher, which is free. You need to download and compile it. 
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I'm working on a small project exploring the potential for coordinating the management and research of wolves in the Southern Caucasus (Georgia, Armenia and Azerbaijan) and Central Asia (Kyrgyzstan, Tajikistan, Kazakhstan and Uzbekistan) and want, first to get an idea of the current situation. I'm looking for paper/articles/chapters on the subject spanning the past 30 years or so (both Soviet and post-Soviet eras). Also, if you are currently working on wolf management in any of these countries, I'd like to hear from you.
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Dear Gareth,
As far as I know, there are not many things published on that topic in Central Asia, and of course only in Russian. 
you have that book chapter in English, a bit more recent than the 1970 one: Bibikov, D.I. (1982) ‘‘Wolf Ecology and Management in the USSR’’, in F.H. Harrington and P.C. Paquet (eds) Wolves of the World. Perspectives of Behavior, Ecology and Conservation, pp. 120–33. Park Ridge, NJ: Noyes.
I got a copy of Vyrypaev & Vorobjev book on wolves in Kyrgyzstan:
Vyrypajev VA, Vorobjev GG. 1983. Volk v Kirgizii. Frunze: Ilim. 94 p.
However I would be cautious in using it since I detected some mistakes in the tables they give inside.
I published two papers about human-wolves relationships in Kyrgyzstan (they are available on RG, and you may find something in the references...), as well as a PhD in French. If you have any question about that specific topic, you are welcome to contact me!
Nicolas
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I am looking for a way for “automatically” linking a pit-tag detection with its GPS position. “Automatically” means that recording GPS position of the reader  should be activated by the system each time a tag is detected (= in an unsupervised way). ID and date:time should be recorded too.
Note that GPS should be at the pit-tag reader and not at the pit-tag!
Is there any commercial device there?
Any home-made idea?
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Hi Miquel,
one solution is to synchronize time between your GPS and reader, and to have the GPS recording continuously the tracking path. When you export the data of your reader and GPS, you merge the two data files (GPS track and detections) by date/time. Maybe not the best solution, but it works fine! :)
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National Geographic' developed a research tool (Crittercam) designed to be worn by wild animals. It combines video and audio recording with collection of environmental data such as depth, temperature, and acceleration. What about doing the same using livestock? 
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Dear Sam, thanks so much for your reply. I will try to find out more about it. Best, Stefano
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Does anybody know about the different kinds of video tracking softwares, besides ethovision, for monitoring animal's movement in open field test? 
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I have a paper coming out with Lyons in Behavioral Research Methods describing how to use the Microsoft Kinect gaming device. You should observe the animal, then you need to writ the scoring program, so it is not off the shelf. The Kinect costs several hundred dollars. 
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I am researching the movement behavior of salamanders. I am first looking for a program, extension, or script that will allow me to determine the overall, straight-line direction, bearing, or trend for an animal movement path, taking into account the sinuosity of the path. From this information, I will also like to determine the angle between this formed line and another line that do not necessarily intersect. I have found a program called MB-Ruler Pro that will calculate the angle between two non-intersecting lines, but it is quite expensive.
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Another alternative is the Geospatial Modelling Environment from SpatialEcology.com. The download is free. Look for the command "movement.pathmetrics"
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Carcharhinus amblyrhynchos.
I've been looking but am struggling to find much on methods for this. If anyone also knows of data on the sharks' food intake, i.e weekly body mass % eaten, that would be great! .
Thank you.
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Thank you, I've sent an email :)
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Hi,
I'm currently using Alexander's 1976 formulae to determine dinosaur speeds from trackways.
The trackway I have in question is 11 tracks long. To determine the speed, do I use the formula on each set of prints and their stride, or just the one set?
Thank you,
Danny.
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You could measure the stride length for each step cycle - 3 consecutive imprints (or sets of manual + pedal imprints in case of quadruped animals) = 1 step cycle, 11 imprints = 9 step cycles - and then do an averaging over all step cycles (mean stride length).
If the trackway pattern shows considerable variation (e.g. curves) you should rather calculate distinct velocities for different parts of the trackway and discuss that.
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The main aim will be to study animal movements towards human infrastructures, so we will need to have fine scales movements.
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I guess you recover the devices. Then consider exploring the I-GotU,  a small, cheap (U$S 50) and good GPS originally designed for trekkers. You can made a cover to protect it find the way to deploy them in a small mammal. Our group used them with coromorants and worked well.
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Basically, I am new to 3D motion analysis and trying to figure out how to do it. This said, I lack basic knowledge regarding the issue. I only have experience with 2D gait analysis.
Say I already have video recording from multiple angles (and this is all I have), including video recordings for calibration purposes, and I now want to analyze a quadrupedal animal's motion, mainly focusing on joint movements of the limbs, and gait.
How would I proceed with this? What skills should I learn, what software should I use? File formats?
I am aware of this program:
But we do not have the budget to acquire it. So I am looking for workarounds and open-source/free programs.
I don't mind the learning curve or the requirements, I just need to figure out a way to do this.
Many thanks for your help. I am looking forward to your suggestions and comments.
P.S. I have tried SkillSpector, but I cannot import the videos. I tried several codecs/containers, but it just won't recognize them.
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hello Nikolaos
I used Kinovea (freeware) to retrieve the target coordinates in 2D on both camera.
Then I concatenate two 2D data with a DLT (direct linear transformation) to obtain 3D with matlab, labview or openCV (freeware) script
Abdel- Aziz Y. I, Karara H.M., 1971. Direct Linear Transformation from Comparator Coordinates into ObjectSpace Coordinates.ASP Symposium on Close- Range Photogrammtery, Falls Church, VA, pp.1-18.
enjoy
Patrick
Institut of Mouvement SciencesMarseille, France
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I am experiencing some trouble with the adhabitatLT package. The txt file contains GPS data of an animal over three years.
I set the date:
da <- as.POSIXct(strptime(as.character(ND$LMT_date), format="%d.%m.%Y %H:%M:%S"))
And the trajectory (there is only one animal, so the trajectorty is one burst of one animal):
NDx<-as.ltraj(xy=ND[,c("Locale_N","Locale_E")],da,id=ND$Object_ID)
*********** List of class ltraj ***********
Type of the traject: Type II (time recorded)
Irregular traject. Variable time lag between two locs
Characteristics of the bursts:
id burst nb.reloc NAs date.begin date.end
1 W0718 W0718 46511 0 2008-04-16 14:30:21 2011-09-02 16:01:29
head(NDx[[1]])
x y date dx dy dist dt R2n abs.angle rel.angle
1 6798891 1430501 2008-04-16 14:30:21 3.24 -3.56 4.813647 1798 0.0000 -0.8324223 NA
2 6798895 1430498 2008-04-16 15:00:19 -9.63 -0.72 9.656878 1823 23.1712 -3.0669651 -2.234543
3 6798885 1430497 2008-04-16 15:30:42 -0.35 3.15 3.169385 1767 59.1505 1.6814535 -1.534767
So far so good. I also took care of NAs and defined a regular trajectory.
Now I only want to look at a specific day or week at a time. I tried to extract this information using:
tr5<-set.limits(tr3,begin="2010-08-07 00:00:00",pattern="%Y-%m-%d
%H:%M:%S",dur=1,units="day")
The problem I am experiencing is that the date gets adjusted (date = 2010-08-07) but all the other parameters (coordinates, distance etc.) do not. These are the parameters for when the sampling started in 2008 and not the ones for the 2010-08-07.
head(tr5[[1]])
x y date dx dy dist dt R2n abs.angle rel.angle
1 6798891 1430501 2010-08-07 00:00:00 3.24 -3.56 4.813647 1800 0.0000 -0.8324223 NA
2 6798895 1430498 2010-08-07 00:30:00 -9.63 -0.72 9.656878 1800 23.1712 -3.0669651 -2.234543
3 6798885 1430497 2010-08-07 01:00:00 -0.35 3.15 3.169385 1800 59.1505 1.6814535 -1.534767
Has anybody encountered these kinds of problems before? Or is set.limit maybe the wrong function to subset the trajectory?
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Hi Anne,
Did you ever find a solution?
I'm only just reading this now, but I think the function you are looking for is actually gdltraj()
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I'm going to take samples of sloughed skin of breeding humpback whale in Perú, to have an idea of what feeding areas they come from. The problem is that only one feeding area has been analyzed isotopically. Is there any chance to have a rough idea of their migratory movements using stable isotopes of C and N, without having analyzed all their feeding areas?
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Sure.
There are many studies that used stable isotope of C and N isotopes for this.
Best and Schell (1996) with stable isotopes of carbon and nitrogen indicated the seasonal movements for southern right whale Eubalaena australis.
Ontogenetic migration of maturing and mature male of sperm whale Physeter macrocephalus to high latitude by segregating from natal groups in low latitudes, which was apparent but not conclusive for long, was decoded by Mendes et al. (2007) through stable isotope ratios of carbon and nitrogen from dentine collagen.
There are several other studies also, especially of Turtles, that underscored their migratory dependencies.
Migratory dichotomy, practiced by the sea turtles to understand their behaviour, ecology and demography. Zbinden et al. (2011) though the aid of stable nitrogen isotope discriminated the two foraging regions area preferred by the loggerhead seas turtle Caretta caretta in the Mediterranean region to understand the relative importance of geographically separated foraging regions and associated phenotypic variations accruing from this discrimination.
Similar, but ontogenetic dietary based oceanic–to–neritic migration has been confirmed by McClellan et al (2010) for juvenile loggerhead sea turtles, which has important bearing for the loggerhead individual survivorship, stage duration and time of maturity.
1. Best, P. B., & Schell, D. M. (1996). Stable isotopes in southern right whale (Eubalaena australis) baleen as indicators of seasonal movements, feeding and growth. Marine Biology, 124(4), 483-494.
2. Mendes, S., Newton, J., Reid, R. J., Zuur, A. F., & Pierce, G. J. (2007). Stable carbon and nitrogen isotope ratio profiling of sperm whale teeth reveals ontogenetic movements and trophic ecology. Oecologia, 151(4), 605-615.
3. Zbinden, J. A., Bearhop, S., Bradshaw, P., Gill, B., Margaritoulis, D., Newton, J., & Godley, B. J. (2011). Migratory dichotomy and associated phenotypic variation in marine turtles revealed by satellite tracking and stable isotope analysis. Marine Ecology Progress Series, 421, 291-302.
4. McClellan, C.M., Braun–McNeil, J. Avens, L., Wallace, B.P. and Read, A.J. 2010. Stable isotopes confirm a foraging dichotomy in juvenile loggerhead sea turtles. J Experiment Mar Biol Ecol, 387, 44–51.
Also follow K.A. Hobson work related with tropic linkages
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I am very interested about measuring the pressure produced by spiders when biting different prey. We are working with wolf spiders (body size about 25mm, fang size about 2-4mm) and we need an accurate way to measure the bite pressure. Unfortunately we do not have access to complex software, so I would like to know if somebody knows a relatively simple and cheap way to measure this.
Thanks in advance for your help!
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Dear Luis,
Unfortunately, there is no easy way to measure bite force.
An accurate form to measure bite force is using piezo force transducers mounted on a something that the animals can bite. Someone from the biophysics or engineering department should be able to build that for you.
However, that build will only you give the maximum bite force. You mentioned that you want to measure the bite force in different prey, and that is not an easy task. Perhaps you can mount the force transducers in a animal-shaped cast or something like that.
For more information I suggest you this paper:
Meijden, A.; Langer, F; Boistel, R; Vagovic, P; Heethoff, M (2012) Functional morphology and bite performance of raptorial chelicerae of camel spiders. Journal of Experimental Biology 215, 3411-3418.
I hope this helps.
Best wishes and good luck.
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I would like to track the movement of some spiders species. I wanted to know if maybe some of you know a relatively simple free software that would allow me to do this.
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Are you tracking videos? I have used this tracking software ^ too. If you have a pc and not a mac, the programme "Kinovea" (http://www.kinovea.org/) does an even better job. Although I like "Tracker" for its simplicity (and mac compatibility), I used it to analyse locomotion (specifically velocity) in Northern Quolls.
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I am looking for a paper that might detail the probability of catching an animal via live trapping (doesn't need to be a particular individual, just an example of a it's species) given the population density and trap effort (number of trap days etc.).
Also, a similar calculation or model for the likelihood of encountering a tagged individual via VHF or acoustic telemetry would also be very useful.
Thanks all.
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Hi. You can use the R package "scrbook" to simulate same dataset under different densities, trap configuration and maybe home range from target species. This is the link to download the package: https://sites.google.com/site/spatialcapturerecapture/home
In R, try:
library(scrbook)
?scrbook # Look for SCR0bayes
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Most of the scientific papers I have read do not include brands of pigment powders. The two I have seen are DayGlo and Radiant Color, but the specific powder types are not listed. This application will use UV light for tracking.
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I also used DayGlo a few years ago but the operator would not sell me the powder. I learned from another person that they will send you "samples" upon request. That's free! I received enough to try out a few colors and actually do a complete project. If you're in the experimental phase of learning what color is best, they may send you samples if you simply ask. From what they told me, it's just the powder before the paint is made. So this may be the same with any company that makes or uses fluorescent paint. If you find other means, please keep us updated.
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Dinoflagellates use flagella to move through the water. Although land plants are restricted by their roots, I find it interesting that plants have not evolved systems for movement at least in the water. Given that epiphytes can grow with their roots attached to rocks and collect water and nutrients through their leaves, not their roots, it seems technically feasible for even land plants to move at least very slowly perhaps carrying their rock with them. In over 500 million years of evolution why has selection failed to produce moving plants? Are moving plants impossible or energetically unlikely for some reason or something that evolution just neglected at the macro-scale?
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A plant that could move ever very slowly would seem to have many advantages so I am wondering why this has never evolved and if it would be possible to evolve such plants.
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I am analysing dingo tracking data and it would be very useful to be able to generate Biased Random Bridge Movement Models. An imminent thesis due date precludes me from learning how to to it in R, and I was hoping someone may know of a tool for ArcGIS which will do the job.
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Problem solved :) Simon Benhamou (who developed the method) provides a software package which does the job, and he has been very generous with suggestions, and offers of assistance should I need it:
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I am not sure if what I am trying to do is possible.. I have about 30 to 40 randomly distributed points in an area and I am trying to create a uniform kernel density surface that covers the points (i.e. the kernel density distribution will be constant for all points and taper off to zero around the edges - like a table top). I am sure I can adjust each point's weight (lower the weighting for points closer together and raise the weighting for points further apart) on an iterative basis to develop a uniform density surface but that will be time consuming and probably not be that accurate. Does anyone know if this is a) possible and b) if there is a package (in R or QGIS or ARCGIS etc.) available that automates a process like this? Please let me know if I have not been clear in my explanation as it all makes perfect sense to me in my mind.
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You may wish to pick up the thread in the literature for DEMP, Density Equalizing Map Projections. These can be thought of as "rubber sheeting" a surface so that the density of points on the surface is then of uniform density. You may also wish to read a bit about Cartograms, of which DEMP is a special case. It also is worth noting that most currently used spatial analysis methods can adjust for the underlying density of the thing being measured using heterogeneous Poisson models.
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I have a computer programmer who is designing a basic visual animal tracking software for use in my experiments. The reason is a cheap alternative to ethovision or alternative software. They are using free code from a library in openCV. It is basically just blob detection, converting the image to x,y coordinates within the arena at each time point. This can then be used to determine freeze time, entry into zones etc. Does anyone have any advice on this.
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Choosing openCV for your project seems to be a good choice for your setting. If you have already an experienced programmer doing the coding you are lucky. Nonetheless the overall costs of doing the customization for a single project are likely to exceed the 5 Tsd $ pricetag for the programmer, if you need to hire someone in Germany (50-100 hrs work). If you don't want to get to expensive with the software you might also think about continuos manual tracking using an video overlay or timelapse images for movement control. Here is one approach based on the ethovision software Brendele J., Annas E., Weirich C., Hoy S. (2009): Results of computer supported measurements of distances moved by VideoMotionTracker. Proceedings of the 41. Internationale Tagung Angewandte Ethologie, Freiburg, Germany, but the same effort can be coded with reasonable workload without using ethovison for the backgroundlayer and tracking.
Please keep us updated, how openCV managed the job.
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I'd like to track (in real-time) and record the movement of small beetles in a thin layer of flour. The beetles burrow in flour and would not be visible to the eye, so regular video recording is likely not an option. I do not have specific arenas built yet, but I'm imagining something roughly the size of a standard petri dish with flour thickness of ~0.5 cm. Has anyone explored infrared or other visualization techniques to do this?
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Test if your beetles walk in the glass of the petri dish, that is, all the flour is above them. In this case, you could use a regular video tracking from bellow, not above the flour.
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I am measuring kinematics and several locomotor variables in a small Sceloporine lizard using a racetrack with mirrors to film dorso-laterally. I am currently using mirrors angled at 45 degrees with cameras filming 300 frames per second. Are there any options more suitable than this?
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Hi, yes should be 45°. I agree with you. Position the mirror slightly above the lizard with the camera positioned laterally slightly above the height of the animal. Now you can record the lateral and the dorsal aspect with one camera simultaneously... I would try to avoid oblique views. Cheers