Saturday, July 20, 2013

Wildlife Babies 2013: Twin Critters

I've gotten twins of several species numerous times in the past.  In fact, last year I had a mother with five baby Raccoons at two of my study sites (see here).  Furthermore, at one of these sites, the baby raccoons were a constant fixture in front of my camera traps.

This year, however, there have been very few Raccoon babies to speak of.  One of the sites with the momma and five offspring is now devoid of Raccoons....so I wonder if she got hit by a car, or met some other untimely demise.

Regardless, it was not until a little over a week ago, that a camera at a completely new study location yielded some baby raccoons.  Not quintuplets this time, but twins....


White-Tailed Deer offspring also seem to come in "multiples" frequently.  I had twins at two sites last year (here)....and have even had triplets at a site in North Carolina (here).

This year, however, I have gotten relatively little in the way of fawns (in general) at the site where they were very common last year.  In fact, at a site where I not only had twins last year, but several other fawns, I've only got pictures of a momma with a single baby once (here).

Once again, the completely different sites (with the twin Raccoons) is where I've gotten pics of twin fawns this year.
 
On a different subject, it appears that a large buck who was at one of my study sites last year survived the hunting season and is back.  This could be the third year in a row that he's been around (see 2011 shots here, and 2012 examples here).....
 
 
You may remember that there were two at this site last year, but one was taken down by an automobile in late fall (here).


6 comments:

  1. Those fawns sure are adorable. Glad the brute above survived another year as well. I noticed in the first two videos that there is a lot of taller foliage in the center of the screen. Do you get a lot of trigger trips from the wind blowing?

    Bill

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    1. Yes and it drives me crazy! Sometimes in a week things will shoot up and start triggering the camera (grr). The camera in these vids had it happen constantly. Wastes alot of time and batteries. I think my students cut the veg down with a sickle this last time out.

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  2. Ok, I have questions. Are deer polygamous? Or I guess more specifically polyandrous? Is that a word? Do the girls have lots of boyfriends? Ok here's where my train of thought is going: A black bear sow will potentially breed with multiple males during the breeding season. So then her cubs, assuming she has multiples, are likely to have differing paternity. Are they considered twins or trips or quads? Does this happen with deer? Is it enough to share the womb with your sibling, as in human fraternal twins, to be considered a multiple? Or must you share all the same genes?

    Just some late night pondering. :) Nice videos.

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    1. Great questions! I didn't know the answers to all and had to look them up!

      The breeding system for White-Tailed deer is complicated (so we'll see if I actually get this right). They are often referred to as polygynous (one male, multiple females....which is a form of Polygamy...and YES...Polyandrous IS a word..see below... :) ). One male pairs up with a female...defends her from others and mates with her when in estrus, and then moves on to the next receptive female. Males set up dominance hierarchies (through sparring) during the rut and the dominant male gets first dibs. Dominant males that have to constantly guard a female, are (obviously) leaving other females untended so that the sub-dominant males still get breeding opportunities.

      However....and this is what I didn't know....Polyandry (one female, multiple males) could happen if the currently dominant male that has bred with a female gets displaced and a new male breeds with her. Apparently, yearling males will sire offspring....and they get these opportunities while the dominant male is pre-occuppied. Genetic work has supported that non-dominant males in a population sire young, probably because dominant males can't completely monopolize females all of the time.

      More stuff I didn't know....regarding Multiple Paternities in Twins or Triplets. I found two sources in a quick review that used DNA to confirm it occurs in White-tailed deer. However, these were captive....I couldn't find anything about free-range deer. Interestingly, the latter of the two citations below found a set of triplets that came from three different males.

      For example: sample of 115 deer, only three multiple paternities detected (Irwin 2011). And DeYoung et al.(2002) found multiple paternity in 7 of 27 litters.

      Folks with more knowledge on deer reproduction, please chime in!!!!

      DeYoung et al. 2002. Multiple paternity in white-tailed deer (Odocoileus virginianus) revealed by DNA microsatellites. Journal of Mammalogy 83:884-892.

      Irwin. 2011. Evaluation of reproductive behavior in white-tailed deer through genetic parentage analysis. Master's Thesis. Auburn University.

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    2. I so wish Blogger had some way that informed you when a reply was left on a comment you made! Ugh!

      Thanks for looking into that for me. It's really interesting to think about. Just for the heck of it, I looked up the definition of "twin". Generally, the first few definitions that popped up on Google were "one of two (or 3, 4, etc) offspring at the same birth", so genetic make up was not considered in these definitions.

      I suppose that even human woman could um...give birth to two or more children at the same time...with different paternity. But we won't go into that. I'm sure there's a daytime sitcom out there dedicated to JUST that.

      I am going to ask my boss, who is the NY's lead big game biologist what he thinks. I will get back to you with his thoughts.

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    3. So I spoke with my boss (Jeremy Hurst, NY Big Game Biologist) and he confirmed that deer are definitely polygynous/androus/ygamous...etc etc!

      Cool!

      See you in Milwaukee!

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