Editing Mark and recapture (section)

{{Short description|Animal population estimation method}}
{{More footnotes|date=March 2008}}

'''Mark and recapture''' is a method commonly used in [[ecology]] to estimate an animal [[population]]'s size where it is impractical to count every individual.<ref>{{cite web |url=http://www2.nau.edu/lrm22/lessons/mark_recapture/mark_recapture.html |title = Mark-Recapture}}</ref> A portion of the population is captured, marked, and released. Later, another portion will be captured and the number of marked individuals within the sample is counted. Since the number of marked individuals within the second sample should be proportional to the number of marked individuals in the whole population, an estimate of the total population size can be obtained by dividing the number of marked individuals by the proportion of marked individuals in the second sample.  The method assumes, rightly or wrongly, that the probability of capture is the same for all individuals.<ref name="Southwood"/> Other names for this method, or closely related methods, include '''capture-recapture''', '''capture-mark-recapture''', '''mark-recapture''', '''sight-resight''', '''mark-release-recapture''', '''multiple systems estimation''', '''band recovery''', '''the Petersen method''',<ref name="Krebs2009">{{cite book |title=Ecology |last1=Krebs |first1=Charles J. |edition=6th |isbn=978-0-321-50743-3 |page=119 |year=2009 |publisher=Pearson Benjamin Cummings }}</ref> and '''the Lincoln method'''.

Another major application for these methods is in [[epidemiology]],<ref name="Chao">{{cite journal |last1=Chao |first1=A. |author1-link=Anne Chao|last2=Tsay |first2=P. K. |last3=Lin |first3=S. H. |last4=Shau |first4=W. Y. |last5=Chao |first5=D. Y. |year=2001 |title=The applications of capture-recapture models to epidemiological data |journal=[[Statistics in Medicine (journal)|Statistics in Medicine]] |volume=20 |issue=20 |pages=3123–3157 |doi=10.1002/sim.996 |pmid=11590637|s2cid=78437 }}</ref> where they are used to estimate the completeness of ascertainment of disease registers. Typical applications include [[estimating]] the number of people needing particular services (e.g. services for children with [[learning disabilities]], services for [[medically frail]] elderly living in the community), or with particular conditions (e.g. illegal drug addicts, people infected with [[HIV]], etc.).<ref name="Allen">{{cite journal |last=Allen  |display-authors=etal| year = 2019| title=Estimating the Number of People Who Inject Drugs in A Rural County in Appalachia | journal=American Journal of Public Health |volume=109|issue=3|pages=445–450|doi=10.2105/AJPH.2018.304873|pmid=30676803|pmc=6366498}}</ref>