Mammalogy - Science topic

Nicholas; Pardon me! I submitted an answer to a different question.

Sorry, Jim Des Lauriers

Fetomaternal interdigitations in placentas refer to the intricate connections between fetal and maternal tissues that facilitate nutrient and gas exchange during pregnancy. There are several types:Villous interdigitation: This occurs at the microscopic level within the placental villi, where fetal chorionic villi project into maternal blood spaces, increasing surface area for exchange.Decidual interdigitation: Involves the maternal decidua, which is the lining of the uterus during pregnancy. Decidual cells extend between fetal villi, contributing to the structural integrity of the placenta.Placental barrier interdigitation: This refers to the physical and biochemical barriers between maternal and fetal circulations within the placenta, ensuring selective exchange of nutrients, gases, and waste products while preventing direct mixing of blood.

The capybara, capybara, chigüiro or chigüire, which is a species of rodent of the Caviidae family typical of South America, being the largest rodent in the world

I would check other values like head-body length to see if there is intrapopulational variation. If the discrepancy is really due to intraspecific variation you would expect linear dimensions to show a similar pattern to body mass, since you would be measuring bigger dimensions on bigger animals.

However, it's also possible that the reported body masses are just plain discrepancies. I've noticed a lot of second-hand databases like PanTheria can be extremely inaccurate when it comes to reporting body mass values because they often just collate them from the previously published literature. A lot of times studies will use ballpark values or the midpoint of guestimated ranges from sources like Walker's Mammals of the World, which aren't very accurate or precise. A good example of this is the South American rodent Dinomys branickii. Most studies using body mass for Dinomys will report a value of 10-15 kg or 13-14 kg, which seems to be drawn from a ballpark range of 10-15 kg mentioned in a paper from the early 20th century (maybe Allen 1942). This doesn't appear to be based on any measured specimens, and no studies list specimens from where these data were collected. However, actual weights of Dinomys based on first-hand measurements of collected wild individuals (e.g., Osbahr et al. 2009, Gottdenker et al. 2001) finds that the body mass of Dinomys is actually only about 9.5 +/- 1.1 kg, a much lower estimate. Larger individuals are known but are highly gravid, captive ones. Nevertheless, people have been reporting a 13-15 kg body mass for Dinomys as if it were gospel.

Hello Russell: Tungsten carbide is used as an abrasive. It comes in grit sizes that vary from extremely fine powder to pretty coarse grit. If you can get permission from collection managers, a heat sterilized jar of the grit of whatever sizes you determine to be appropriate, non-toxic and pest-free. A graduated cylinder provides the volume directly. Were I a collections manager, I can't imagine what the problem would be.

Apparently specimen loans are out of the question. Hmmm.

Best regards, Jim Des Lauriers.

First two images may be Aelurostrongylus abstrusus,

third one is Capillaria aerophila

with all best wishes

Afkar

I know this is now quite old, but you could try Frank Grutzner at the University of Adelaide, or Paul Waters at University of NSW (I think). Also, Kathy Belov.

Many thanks for all of your feedbacks!

Hein, forest elephants are not our only studied species. We focus more broadly on forest large mammals, such as forest antelopes, small primates, gorillas, chimpanzees and forest elephants. We point our cameras to animal tracks.

Mary, your recommendations exactly correspond to our first sampling plan for the “community forests” land tenure! We are just still wondering if it is not a problem to use a different design of camera grid for this land tenure (split in 3 sub-grids), compared with the three others where we will use regular grids of 11 cameras.

Fructueux, oui chaque forêt communautaire fait entre 4000 et 5000 ha, mais elles ne sont pas contigües. L’idée de diviser l’échantillonnage des 11 caméras entre trois forêts communautaires distinctes relève d’une perspective d’échantillonnage relative au régime foncier étudié (en acceptant une certaine variabilité due aux différences intrinsèques entre ces trois forêts communautaires), et non une étude du terroir au sens propre. Effectivement, c’est un problème d’installer une grille de 11 caméras dans chaque forêt communautaire durant un mois chacune en alternance, et nous éliminons donc cette possibilité. Il reste donc à voir si l’utilisation de 11 caméras dans une seule grille dans une seule des forêts communautaires serait plus pertinent ou non que d’utiliser 4 caméras par forêt communautaire avec une logique « agrégation par régime foncier ».

Kalinga, thanks for this confirmation and those recommendations! I agree with your comment!

Try articles at http://www/panearth.org;

I also prefer Tomahawk traps.  Just make sure to check the ends of the wires - sometimes they can be pretty sharp, and can injure little paws as they try to dig around the trap.  A flat file can be used to take off the sharp edges.  Too large a trap can be a problem if the mesh size is big enough to get their nose through.

Dear Isaac, interesting point that sometime is difficult to answer.

In your commnet I dont understand if the population of this subspecies (28) are in captivity? or in nature?

Many species have been in neckle bottle during thier evolution and letter had recovered thier population with a reduced genetic variability.

However is not the same to talk about species variability than subspecies variability. The level of genetic variation is different.  Have been the subspecie variability studied?

My experience is with rodents, in which you can study both thigmotaxis and novel object recognition in the arena. For dogs, you could study object recognition memory. Here is a protocol adapted for the dog (the size of the arena was 0.609m x 1.1.5m x 1.08m):

Development of a protocol for studying object recognition memory in the dog, Callahan et al., 2000 (http://www.sciencedirect.com/science/article/pii/S0278584600001020)

I think so and agree with the above viewpoints.

... And you will find some people loooking and looooooooooooking to all genes of their dataset until they find THAT marker (in the middle of a neutral global result) that will show that HIS/HER SPECIES is statistically "real" (for example, frequencies of an allele coding for color under a strongly selective environment for that color). And the worse part: they get published in more-than-good journals. Now with RADs, for example, you could "find" a species almost everywhere, if you look enough.

By spatial association, do you mean social association (existing in the same group at the same time) or general spatial proximity (existing in a similar place)? What exactly did you do for your analysis for for "association strength?" I can think of a number of different metrics that I could call "association strength" and some would be weaker than others. And there are some statistical approaches that make more sense than others, as well.

So, if I've done my math right, you have n = 32 adult deer (assuming the 982 is a typo for 992, because 992 would give a half matrix of 32 individuals)? What's this in context of your overall population density? If we sampled Toronto for 30 people, we'd get very few individuals that are related to each other by chance. However, in a village of 300, for the same average family size, obviously there's going to be more per-capita relatives. My first suspicion is that given a mere 6 individuals have high relatedness, your sampling density was low (unless mortality is high and you have a stationary or declining population density). However, this assumes you sampled your deer at random. If your sampling protocol involved exhaustively sampling all animals that had contact with a group of focal individuals, and you were comparing them to random non-contacted controls from the same population, then suddenly you're looking at a decent number. It all depends on your sampling design.

A word of caution on the contact rate stuff: 0 < r < 0.125 puts you in a foxy place. Since you're thinking about mechanistic action (the animals makes decision x based on characteristic y), you need to think how that factor is going to be assayed in nature. You can make some argument based on odour cues and imprinting for close relatives, but once you get past 2nd degree kindred you need to consider whether the animal might reliably distinguish anything further than a cousin. You might consider using "cousin level or greater" as a binary predictive factor. Also, I'm assuming that you've stripped known parent/offspring-at-heel pairs out, since it wouldn't be very surprising to see that mom pays a lot of attention to her still-young fawns. If you don't strip that, you run the risk that your effect is entirely does with fawns or yearlings at heel; while technically, that's relatedness predicting contact rate, it's a very specific type of relatedness.

The group membership thing is most interesting. There was a recent paper (Biosa et al 2015 in J. Zool.) that found that their spatial segregation had a temporal component to it, with opposite sex relatives negatively associated during breeding periods. Without knowing much more about your study and study system, I'd wonder if you considered what the deer are 'trying to do' life-history-wise the time of year you observed/sampled them.

Dear Jeyathilakan,

The bat is most likely a juvenile Taphozous sp. while the fly is a Nycteribiidae.

Best

Bogdan:

You may find this link useful:

Best

Syed

Andrew,

We know that martens have predated black throated diver nests on the Loch Maree Islands and must have crossed ~150m of water at some point to get to these islands. See SNH commissioned report 379 http://www.snh.org.uk/pdfs/publications/commissioned_reports/379.pdf.

The report suggests that crossing 30m of water (between 2 of the islands) is not a problem. This is standing water of course, so a 30m wide fast-flowing river would be different matter entirely. The report also refers to an American study in which American martens crossed either 30 or 64m of standing water.

Would they utilize road bridges? - of course! Pine martens began to colonize the Isle of Skye soon after the bridge was built.

Hope this helps.

Rob

Dear Haya Rashed,

Welcome. I am waiting to read the result of your study. 

Dear all,

My Gauthier-lab at Laval University studies lemming populations in an Arctic island since ~15 years now. Lemmings are ~ 20-50g. They are using a trapping grid and live-trap with baits (piece of apple as bait and they put cotton wool for a cosier trap ^^). Here are 2 references (with pdf) of their published study. They marked lemming with PIT-tag and use readers for individual recognition.

You could try to contact Dominique Fauteaux (current PhD student on lemming - present in ResearchGate) for more details about the study design.

For what I've seen during fieldwork (I was working on goose but also help sometimes on lemming project), there were some death due to heart attack but none due to infection.

Cheers,

Guillaume

Tanvir -

I am glad you found our paper interesting, but I have to add that these are relative densities, which is not the same as absolute densities let alone population size. Relative densities and absence-presence data are important, but in order to get the absolute population size you have to use other methods as indicated in the previous discussion.

Cheers, Andreas

For anyone who's still interested, I think I may have tracked down where this rumor got started. In their 2007 paper on the ptolemaiid Kelba, Cote et al. mention the fact that (at least according to their study) researchers have tended to look outside Africa for the sister taxa of various African groups rather than looking for possible relationships with other African taxa. They mention Afrotheria as the prime example of how the previous idea may not be the case, and also mention that hyaenodontids may have originated in Africa, and they word it in such a way that it might be ambiguously interpreted as hyaenodontids possibly being afrotherians.

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

Humans have a thickened band in the scalp skin, approximately following the hair line over the ears. Sweat from this region has a peculiar navel-like odor, but I know no reports of the presence of apocrine sweat glands in there. It may be worth investigating.

Russell, perhaps not the best phrased question given the responses you are getting, but I understand what you mean. Beavers eat bark as well as the cambium layer beneath it, roots, as well as many other plants and plant parts. Xylophagy may be a better fit for something like woodworm species (of which there are quite a few).

EsEstimado Jose, 

Hi, recce is simply a way of getting apriory knowledge about your study area before starting your study. It does not have a statistical apparatus for you to calculate abundance of any species since it is not among any kind of sampling techniques. Even though it is not very statistically sound way, what you could do is, map and mark the whole recce area through GPS and also mark GPS locations of your target animal. You could then calculate the encounter rate as no. of Ind. Per km. 

Try one of these authors (ms available on ResearchGate):

Hi,

you can see here

serge

The enamel isn't uniformly thick in upper or lower teeth, so I doubt you'll find any studies that have measures of this from exactly homologous points that could be comparable. Plus, a worn tooth is showing a section of an enamel band often at oblique sections, not a real measure of enamel thickness. And, that thickness will change from crown tip to base, so the real answer would be in estimating enamel thickness from something like microCT. That has been done with some primates and crocs, but not really for much in the context of ungulates, as far as I know. would be great to see done.

Robert Barton has published several comparative works that looked at specific (usually sensory) brain structures:

1 Barton R, Purvis A, Harvey PH. 1995. Evolutionary radiation of visual and olfactory brain systems in primates, bats and insectivores. Philos Trans R Soc Lond B Biol Sci 348:381–392. 

2 Barton R. 2006. Olfactory evolution and behavioral ecology in primates. Am J Primatol 68:545–558.

3 Barton R, Harvey PH. 2000. Mosaic evolution of brain structure in mammals. Nature 405:1055–1058.

Yes , especially the reproductive system related behavior .

Cats are seasonal , so  high temperatures changes endocrine and reproductive system. What reflects the general behavior .

The NCBI has a summary site at http://www.ncbi.nlm.nih.gov/genome/browse/, and you could look at genomesonline.org (which I think is also run by the JGI, but certainly should have more than 40 species).

Hi,

I rank the threats in the following way:

1) habitat deterioration - very important threat for many species, especially forest species or those with highly specialised habitat requirements, globally important.

2) climate change - may led to shifting distributions and habitat loss.

3) wind energy - important threat to some open space foragers, however a limited number of species is affected.

4) WNS: although huge numbers of bats die, a limited number of species is affected, the disease is still geographically restricted and hopefully the species can recover.

I would like to add traffic (casualties, fragmentation), poisoning (direct and indirect) and pets (especially cats) as additional threats, all three rank for me higher than wind energy.

While there may not be exactly the data you are looking for, the Feeding Experiments End-User Database (FEED) may have some information that would provide the basis for a first approximation "one-off" calculation.

Wow, that article says "even dimensions of essentially

bony elements are affected by the preservation process (Lee, 1982)". (LCC. J. C. (1982). Accuracy and precision in anuran morphometrics: artifacts of preservation. Syst. Zool. 31: 266-281. )

That makes it sound like all bone measurements from preserved specimens have to be taken with a grain of salt.

Well its possible if Boa constrictor can catch jaguarundi and kill him. I suppose his body shape mach to gape size of Boa snakes. Maybe its possible that Boa find fresh dead body of jaguarundi and constricted them (sometimes constrictors do this) and then going to swallow it?

Very interesting new tool to consider: Carrion fly sentinels of mammalian diversity...

Sorry Dionisios! if I find recent information about your search I'll share it with you.