White-tail-deer

Simple!! 5 female deer and 5 male deer

I assume the numbers you give in your question (I used to hate word problems in math class[:@]) are the deer herd after hunting season. So with 10 additional deer the next year, 5 doe and 5 buck need to be harvested to keep the herd at the same OW and B/D.

My best effort, do you give partial credit DD!! LOL!!!

Sylvan

ddear wrote: I haven't taken a crack at your example because you have not framed an answerable question. In order to project what a deer herd will do over time it is necessary to describe in detail what the herd is that you are starting with and then make some assumptions with regard to birth rates and mortality rates. You simply said you had 11 adult doe and 3 fawn doe. How old are they? How long can they live if they are not killed by hunters? How many buck and doe do 18 month old doe give birth to. How about 2 1/2 year old doe? Do they give birth when they are 8 years old? What is the post season mortality rates? You said the total initial population was 21 deer so that means there must be 7 buck. How old are they? Maybe its not as simple as you think.

Just for kicks here is a sample scenario filling in for a lot of blanks that you left out.

The initial population will consist of 11 1 1/2 year old doe 3 6 month old female fawns and 7 1 1/2 year old buck. Thats the 21 you wanted. I think you also indicated that the newborn mortality rate is 48% so I will set that. Just for the purpose of running the model I'll say that hunters will kill 80% of all antlered deer and 20% of antlerless deer. I will set a 7% post season mortality for both male and females younger than 6 1/2. No deer will live beyond 6 1/2. With regard to births I'll assume adult females 5 1/2 or under give birth to 1 buck and 1 doe fawn.

This of course is an initial population that is not very balanced age wise so we would expect it to take time to stabilize. Any way, here are the initial settings and away we go...

Sylvan

Here are some results...

Sylvan

Some more results:

Sylvan

After 10 years here is the population broken down by age...

Sylvan

I don't think that a mortality rate for newborns of 48% is very realistic. With it that high (and given the other asumptions) I had to set the doe harvest rate relatively low or the population would go into a rapid decline.

Anyway, after making a lot of initial assumptions and in answer to your question a 20% harvest rate for antlerless deer would begin to stabilize this scenario after about 6 years. At that point the population would be in a very gradual decline and one might want to tweek the harvest rates at that point.

Note the spike in Doe:Buck ratios in year 1. This is due to initially starting with only 18 month old buck in the population. Because there were no button buck in year 0 the antlered deer that were either harvested or died post season were not replaced. If this was a real situation where there truly were no button buck in the population I would not allow the killing of any antlered deer the first year and then put a longer term plan in place but because this is just hypothetical and not very realistic at that, I didn't bother.

ARROWCHUCKER

Well I'll try, let's see, if it's the 3rd saturday in november,and it rains only in the morning,but changes to snow,and the deer are in nocturnal mode,provided they're hungry,but the moon is in it's full phase,and the tide is out in California,but the Gulf stream is close to the Eastern shore, my answer would be ......10

But that's just a guess.

I'm just saying,there is way too many variables.

Sylvan

If you are not interested in the topic, then why bother to post. I'm sure there are other threads around that you could enjoy. Actually I think this sort of attitude is not all that atypical. Too many people want the 30 second sound bites for a solution and if it goes much beyond that they loose interest. Well lots of things, and sound deer management is one, require a little more care and thought if you truly want to understand enough to make good decisions.

Actually, the model I'm using is about as simple as they get. You can find really sophisticated ones that consider far more detail. For example this model simply has post season mortality, some models break it down in to reasons like predation, deer/car etc. Some will allow you to set rates that are not simply a percentage but rather a fucntion of some other variables.

doughboysigep

no need to chastise Sylvan

I think the BIG point is: deer herd management is a complex, complicated, not for the "layman" type of thing. some understand the basics (many only think they do). this should be the take home message for all of those who think they "KNOW" the solution for managing state X's deer herd. can people now see why it is difficult to manage the herd, even in somewhat small units (ie DMUs in NY)?

Sylvan

doughboysigep,
You are absolutely right and I appologize. I sometimes let my passion for deer get in the way of tact. To ARROWCHUCKER, ddear and anybody else I may have offended please accept my appology.