```Estimación de Supervivencia
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Recuentos sucesivos
Tablas de Vida H & V
Identificación de individuos
Closed populations
No individuals enter or leave the
population between surveys
Survey 1
Survey 2
Open populations
Individuals enter or leave the
population between surveys
Survey 1
Survey 2
What makes a population closed?
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Dispersal barriers
Philopatry
Large surveyed area
Slow reproductive/death rate
Short time between surveys
Petersen method: Closed population
Survey 1:
Catch several animals
Mark all M animals
Return animals to
population
Survey 2:
Catch C animals
Count recaptures (R)
Return animals to
population
Survey 1:
M = 12
Survey 2:
C = 15
R=4
What is the total population size (N)?
Note that the proportion marked in the population
equals the proportion marked in the 2nd sample
M =R
N C
M = 12
N =MC
R
C = 15
R=4
What is the total population size (N)?
Note that the proportion marked in the population
equals the proportion marked in the 2nd sample
N = 13 * 16
5
M = 12
-1
N = (M+1) (C+1) -1
(R+1)
C = 15
R=4
When would Petersen give you a bad
estimate?

Population not closed

Marked animals likely to be re-trapped
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Marked animals likely to die
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Marks fall off
Schnabel method: closed population
Survey 1
Survey 2
Survey 3
Survey 4
Survey 5
Essentially, Petersen estimates on multiple surveys
Schnabel method: closed population
Survey t:
Catch Ct animals
Record Rt recaptures
Mark Ut unmarked
animals
Return animals to
population
Schnabel method: closed population
Survey t:
Catch Ct animals
Record Rt recaptures
What’s the
relationship between
Ct, Rt, and Ut ?
Mark Ut unmarked
animals
Ct = Rt + Ut
Return animals to
population
Schnabel method: example
Time Ct
(t)
1
20
Rt
Ut
Mt
0
20
0
2
20
5
15
20
3
20
7
13
35
4
20
10
10
48
CtMt
Schnabel method: example
Time Ct
(t)
1
20
Rt
Ut
Mt
CtMt
0
20
0
0
2
20
5
15
20
400
3
20
7
13
35
700
4
20
10
10
48
960
Σ = 22
Σ = 2060
Schnabel method: example
Time Ct
(t)
1
20
2
3
4
Rt
Ut
0
20
Mt
0
CtMt
0
N20
= Σ (C5t Mt) =15206020
= 94 400
Σ Rt
22
20
7
13
35
700
20
10
10
48
960
Σ = 22
Σ = 2060
Mark recapture lectures
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Petersen method
Closed population
Schnabel method
Schumacher-Eschmeyer
Jolly Seber Open population
múltiple
Población cerrada o abierta (emigración sin
retorno)
 Identificación individual sin errores
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Marcas fáciles de identificar
Muestra y mezcla aleatoria de individuos
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Marcas imperdibles y fáciles de detectar
múltiple
 Se obtiene Supervivencia y Capturabilidad (en
ambos casos, uno o más parámetros)
 Se obtienen los Errores Estándar de los
parámetros (consejos y estrategias)
 Se puede obtener Abundancia poblacional
(precauciones)

Diseño robusto de
captura-recaptura
Períodos
Primarios
Períodos
secundarios
1
1
2… t
2
1
2… t
….
K
1
2… t
La
población se considera cerrada entre períodos secundarios de
un mismo período primario: muy buen estimador de tamaño
poblacional para el período primario
Buen
estimador de supervivencia entre períodos primarios
haciendo un pool de sus períodos secundarios
```