don't forget that the basic assumption that the dorm or the room is a closed population is probably COMPLETELY false, so pick your model accordingly!
On Mon, Jul 16, 2012 at 8:03 AM, JASON M. HILL <[email protected]> wrote: > Hello, > I would consider a removal model instead. Unless you have a small population > of > roaches, it will be challenging to mark enough individuals to compute a > reasonable population estimate. I think you'll end up with a population > estimate of something akin to N(hat) = 600, 95% CI: 240 to 12,000. > > Acknowledging Malcolm's concern about angering higher-ups, a removal model > would actually result in a population reduction because you would squash each > cockroach when you "remove" it from the population at each sampling interval. > So you'll be teaching ecology and performing pest control! > > To get a reasonable population estimate with a removal model, though, you will > need to remove a substantial portion of the population on each 'pass' (i.e., a > downward trend in the number of roaches "captured" each time) or you'll have > the same troubles as mentioned above for the mark-recap (actually mark-resight > in your example). > > Why not do both. Have one set of dorms do a mark-resight experiment and the > other set of dorms complete a removal experiment. You won't be able to compare > the accuracy of the two estimators (since you'll be estimating two different > populations), but you'll expose the students to two types of models and expose > them to the uncertainty that goes into designing an experiment with wild > organisms. > > Jason > > On Sun, Jul 15, 2012 05:31 PM "=?ISO-8859-1?Q?Brett_A._McMillan?=" > <[email protected]> wrote: >> >>I was thinking of having students do a mark-recapture population size > estimation of the cockroaches >>in their dorms for my intro ecology class. Anyone ever try this for a class > (or otherwise) and have any >>advice (say about the best marking technique)? >>Thanks! >> >> > > > 'Nothing in biology makes sense, except in the light of evolution' > --Theodosius Dobzhansky-- > > Jason Hill > www.coopunits.org/Pennsylvania/People/Jason_Hill/index.html > PA Cooperative Fish and Wildlife Research Unit > 221 Forest Resources Building > University Park, PA 16802-4705 > Office: 814-865-0772 > Fax: 814-863-4710 > Ecology Program - PhD Candidate > Pennsylvania State University > School of Forest Resources -- Malcolm L. McCallum Department of Molecular Biology and Biochemistry School of Biological Sciences University of Missouri at Kansas City Managing Editor, Herpetological Conservation and Biology "Peer pressure is designed to contain anyone with a sense of drive" - Allan Nation 1880's: "There's lots of good fish in the sea" W.S. Gilbert 1990's: Many fish stocks depleted due to overfishing, habitat loss, and pollution. 2000: Marine reserves, ecosystem restoration, and pollution reduction MAY help restore populations. 2022: Soylent Green is People! The Seven Blunders of the World (Mohandas Gandhi) Wealth w/o work Pleasure w/o conscience Knowledge w/o character Commerce w/o morality Science w/o humanity Worship w/o sacrifice Politics w/o principle Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
