Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Thinning the herd.

  1. Jun 20, 2007 #1
    The day before last I struck a deer with my car. I was going about 40mph and had no time at all to react. By the time my foot hit the brake, the deer was behind me having been thrown over the car. It took off back into the woods. It was smallish, I would guess it was a yearling doe.

    Today the insurance inspector will tell me how much the damage to my car will cost. There were a few hairs of the deer stuck between the fender and the headlight, but there was no blood on the car. My guess is $2000. I imagine the deer soon after lay down to die.

    I work just north of Princeton, NJ and I drive a long way on rural roads. I have come close to hitting deer many times, but this is the first time I hit one. I see carcasses along the way all the time though. A few years back there was a kill in Princeton to reduce the size of the herd. It was an issue that split the town pretty good.

    Anyone else here hit a deer with their car?
     
  2. jcsd
  3. Jun 20, 2007 #2

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I have never hit one with my car, but yes, Princeton has a HUGE overpopulation of deer, and too many animal rights goofballs who would prefer you risk people's lives with motor vehicle collisions (not to mention the suffering the animal will experience in cases like yours where they are probably badly injured, but don't die immediately and instead wander into the woods to die), than that someone make a clean kill with a rifle to keep the population down. There is nothing natural about the deer overpopulation there...it's because of the unnatural habitat formed by all the suburbs where they are protected from predators (including hunters) and have an endless supply of tasty landscaping. Deer collisions are very common there. When I still lived there, everyone knew someone who had had a collision with a deer (my father did, I didn't...I've had near misses). When you wonder why car insurance is so high in the state, it's not JUST all the crazy drivers on the road with you...deer collisions are a pretty expensive problem there.

    NJ in general has a huge overpopulation problem. Have you ever seen the deer overpass up in the Watchung mountains? I'm trying to remember which road it was over. It's basically an overpass covered with trees, grass and other natural plantings (apparently no small feat to support that amount of weight, especially since the growing trees will continue to add weight over the years) to encourage the deer to cross the highway on the overpass rather than in the middle of traffic. Other segments of roadways have long stretches of fences...those aren't there to keep out hitchhikers as a lot of people probably assume...it's to keep the deer from crossing major roads.

    However, one of the problems with culling the herd with hunting isn't just the animal rights folks, but just the density of housing. It's hard to find suitable places where hunting can be done safely away from homes. It doesn't take long for the deer to learn to hide close to the houses when a hunt becomes a regular occurrence in some area. I used to be involved in research trying to find ways to control fertility in deer in the state, but that was pretty unsuccessful. We could find ways to control fertility in a captive herd, but couldn't find a way to deliver it consistently enough in a wild herd for it to be effective...we don't want to make them permanently infertile, as then we could cause the opposite problem of completely decimating the deer herd if too many are treated and no way to undo it, so that eliminated a lot of options that would have been more effective. Reversibility meant they needed repeated dosing to keep them infertile. There was also the concern of human safety...since we can't control where the deer go after being treated, it needs to be something that someone who hunts one of those deer can eat without causing harm to those people. I wish we could have developed something that would fit all those criteria to control the deer population without hunting (I'd be rich selling that to the state of NJ!), but those are not small challenges to overcome.
     
    Last edited: Jun 20, 2007
  4. Jun 20, 2007 #3

    JasonRox

    User Avatar
    Homework Helper
    Gold Member

    I'm with keeping the deers. Sure it's unsafe for driving, but how many environments did we make unsafe for them... hmmmm... plenty more.
     
  5. Jun 20, 2007 #4
    Moonbear, is this it? I'll probably take my family to the Watchung reservation in any case.

    http://socialight.com/note/2007/2/27/0GCMy_animal-overpass

    JasonRox, there are no serious proposals to get rid of the deer in Princeton, and it would be quite impractical to do. It's just that some people want to thin the herd.

    Where I hit the deer is north of Princeton. It's very rural and so there is a hunting season every year. There is no reason to hold a kill as they did in town. Deer probably outnumber people and as far as I know, there is no will to thin the herd. However, if you drive through that area, you are in danger of hitting one at any moment.
     
  6. Jun 20, 2007 #5

    Art

    User Avatar

    Out of interest what were the problems? Presumably as one lead stag mates with ~80% of the herd it's only the herd leaders you need to treat so was the problem developing a slow release hormone to render them temporarily infertile? If so why not make the leaders permanently infertile and allow the 20% to breed?
     
  7. Jun 20, 2007 #6

    russ_watters

    User Avatar

    Staff: Mentor

    You have it backwards: we made their environment much, much safer and better suited for them overall. That's why there is overpopulation.
     
    Last edited: Jun 20, 2007
  8. Jun 20, 2007 #7

    Danger

    User Avatar
    Gold Member

    A large percentage of the population around here uses deer whistles on their vehicles. Above 50kph, they emit an ultrasonic tone that animals can hear more than a km away. It's an early warning device that makes them aware of an approaching vehicle so they get away from the road. You still have to be watchful, of course, but they work very well. Considering that a lot of deer collisions are fatal for the occupants of the car, it's $5 well-spent. I've never encountered a deer or cow or horse on the road since installing them, but I can see them off to the side watching me.
     
  9. Jun 20, 2007 #8

    turbo

    User Avatar
    Gold Member

    I hit a deer with my Nissan pickup last fall. I saw his mother and sibling coming out of the ditch and hit the brakes HARD (luckily the guy behind me was on his toes) and those two made it across. I had probably gotten slowed down to about 20mph and still braking when the laggard tried to make it. I hit him with the driver's side front and he rolled up onto my hood just as the truck stopped, pitching him back onto the pavement. He ran off with a broken leg.

    The truck ended up with a broken bug-deflector (threw that away) broken headlight (replaced that) and slightly bowed-up hood (bent it back as well as I could). This happened in an area where there is a large art school complex with lots of acreage, and they have forbidden hunting on all that property, so it's loaded with deer.
     
  10. Jun 20, 2007 #9
    Someone at work told me about these. I'm going to look into the matter. I wonder if a deer's thought process is as advanced as your description implies.
     
  11. Jun 20, 2007 #10
    New Jersey should send their extra deer to Michigan, we know what to do with them. :)

    That being said, a friend of mine got hit by a deer. Yes, the deer hit HER - not the other way around. She was driving home and the deer ran into her passenger side door. It did a number on the door, but luckily she wasn't hurt at all by it.
     
  12. Jun 20, 2007 #11

    Danger

    User Avatar
    Gold Member

    It doesn't actually have anything to do with the deer 'thinking'. Prey animals don't have much in the way of depth perception and most cars are pretty quiet, so deer often don't even know that something is coming. They also are not instinctually able to comprehend just how fast a car can move. The net result is that the car 'sneaks up' on them at incredible speed, then startles them into bolting any which way in blind panic. The whistles merely get their attention early enough for them to recognize a threat and move away from it in good time.
     
  13. Jun 20, 2007 #12

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Precisely! This isn't a case of not wanting any deer in the backyard and complaining because we moved into their space, but that they have completely overpopulated the area. It's not just problems of interactions with people (and their cars or landscaping), but that they're destroying forests and habitat for other animals. If you visit forests in NJ, you'll notice there is very little vegetation growing in a range from the ground level up to about 3-4 ft up, because deer have browsed it all. This is habitat that other ground-dwelling animals use for nesting. Normally, that by itself would have been the end of the deer overpopulation problem, but when they run out of tasty treats in the woods, they just head over to the nicely manicured lawns and landscaping and enjoy the lovely buffet selection which keeps getting replenished. There's also more risk to the deer herd itself long-term. When a population gets that overcrowded, if they do start spreading a disease through the herd, it'll affect a lot of them. Again, while that may ultimately solve the overpopulation problem, it could also easily wipe out far more of the herd as well, so just keeping their numbers down to a sustainable level for the land and their own population is the best approach.


    There's no point at all in targetting males unless you can target 100%. One male can breed a lot of does. If you render 80% of the males infertile, the remaining 20% can still breed every doe in the state. Instead, we were targetting the does, which has the best chance of controlling population in a predictable way...we know each doe has 1-2 fawns in a year, so if you want to slow population growth by a certain percent, you know exactly how many does you'll need to target to do that.

    If you read the entirety of my post, you'd see there were multiple problems. One is a reversible drug, another is actually getting it into the deer. You can't just hand out planned parenthood pamphlets to deer...in a captive population, you can dart them, but a frequent problem we noted with the deer captured using dart guns to anesthetize them for shipment is that they develop abcesses at the dart site, so darting isn't really viable if you have no way to bring them back to treat abcesses. All long-term contraceptives in people are administered subcutaneously as injections or implants, so neither of those is viable. In addition, any long-acting hormone would be present in the meat for a long time too, putting anyone or anything that eats the meat at risk. We tried oral dosing with baits spiked with shorter acting drugs, and the problem we had is one deer would find the bait so tasty, it would gobble down all of it, getting an overdose, while the rest would find it completely uninteresting and not get enough. We couldn't reliably get the same animals to return to the bait station every day either. We also couldn't prevent other non-target species from using the bait stations for snacks, and the last thing we want to do is endanger other species that aren't overpopulated. Another issue with oral dosing is that deer are ruminants, so it's really hard to get a drug to survive digestion and be effective. A lot of long-acting, slow-release capsules and compounding used for drugs that people take would not work because of the different stomach environment in deer. Besides, we can't make them take pills. The best we were trying to do was dissolve it into a drink for them, or incorporate it into a salt lick.

    Contraceptives for humans are continuously improving and changing too, so I wouldn't say this will never be viable, but with the available compounds at the time, it isn't. We were never looking for 100% efficacy, but it did need to keep at least a portion of the does infertile the entire breeding season, otherwise, all they'd need is one fertile cycle to get pregnant (most deer get pregnant on their first cycle of the season, but if they don't they'll keep mating until they are).
     
  14. Jun 20, 2007 #13

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Yep, that's it. Gosh, 1985...I remember people making such a fuss over it when it was built....didn't feel like it had been that long ago! :bugeye:
     
  15. Jun 20, 2007 #14
    What a coincidence. I traveled to Liberty Park last Saturday and had planned a route that would have taken me right under that overpass. But I took a wrong turn and ended up going a different way.
     
  16. Jun 20, 2007 #15

    Art

    User Avatar

    I was looking at it from the viewpoint that as dominant males run harems of ~20 does which only they mate with, it would lessen the problem by a factor of 20 if the dominant males were targeted. By statistical analysis one could determine how many dominant males of the population to perhaps surgically render permanently infertile allowing them to continue to mate but with no offspring and thus avoid the problems associated with drug application, dosages and spoiled meat etc. One could even breed infertile dominant males (whose characteristics are known) for release into the wild.

    They currently control mosquito populations using a similar process which itself follows on from the successful project to eradicate the screwfly in the US.
     
    Last edited: Jun 20, 2007
  17. Jun 20, 2007 #16

    Integral

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Wonderful solution, should work like a champ. Just but up sign, saying "dominate males report to the forest service station for your box of condums."

    The problem is finding the dominate males. :surprised This of course is the exact goal of a very popular sport...called hunting. If you have ever engaged in this sport you would now that this solution is non trivial.
     
  18. Jun 21, 2007 #17

    Art

    User Avatar

    I doubt signs would work plus of course they might all be catholic and opposed to birth control. Funnily enough they had the same problem with mosquitos; it seems they can't read either. :biggrin: So perhaps a less trivial way of identifying dominant males would be best, such as for example through acoustics - studies have shown the dominant stags are louder than other males unlike the human species wherin the loudest tend to be the most inferior.
    There is also the second part of my suggestion that they breed infertile males with dominant characteristics for release into the wild which is exactly what they did with the illiterate mosquitos.
     
  19. Jun 21, 2007 #18

    Integral

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    So you do not recognize any difference between breeding deer and mosquitos?

    I would be interesting to hear more of just how you think this would work. You seem to be neglecting the fact that these are wild deer, not a captive herd. Can you see the differenc? I am thinking you are not and never have been a hunter.
     
  20. Jun 21, 2007 #19

    Art

    User Avatar

    An interesting perspective :rolleyes: and yes I had noticed deers are bigger than mosquitos; conversely there's a lot less of them; and to my knowledge mosquitos also live in the wild.

    When faced with conundrums one has the choice of;

    a) Flog a dead horse - Continue trying a solution already proven not to work.
    B) Use your imagination - Think outside the box and try something new.
    C) The Gallic approach - Throw up one's hands in despair and say 'c'est impossible'.

    Personally I opt for option B each time what do you do? :biggrin:
     
  21. Jun 21, 2007 #20

    turbo

    User Avatar
    Gold Member

    You could think outside the box and allow hunters who can pass some stringent marksmanship tests to cull the herd year-round, and their "pay" would be the venison. I'd participate in such a cull program to keep my freezers full.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Thinning the herd.
  1. Cat Herding (Replies: 22)

Loading...