Table 2.—-Methods of Constructing a Composite Life Table -—- II 
This hypothetical set of data illustrates how percentages (or their 
equivalent) can be used to set up a life table. 
Both dynamic and 
time-specific analyses are possible, but only the former is carried 
Mortality rates are given as per cent per annum, age 
intervals as years. 
out here. 
ear Reported Dea 


ear Number Total No. 
? Banded Banded 190-41 1941-42 192-43 1943-h Dead 
Original 1940 1000 100 30 10 3 143 
Data 191 1000 - 95 25 ll 131 
192 1000 = - 100 20 120 
Total 3000 100 1s 135 3h 39 
ear Number Number Repo e y Age Interva 
Banded Banded Owl 1-2 a=3 3-4 Total 
II Same | 
Data on 190 1000 100 30 10 3 143 
Age- 191 1000 95 25 11 - 131 
Interval 192 1000 100 20 - ~ 120 
Breakdown (d,) Total 295 75 21 3 39h 
(a) Number banded 
birds available per 
interval 3000 3000 2000 1000 
III Life 
Tablet (d',) % Reported dead 9.83 2.50 1.05 0.30 13.68 
(1'¥) @ Alive at start 1348 3.85 1.35 0.30 19.18 
(q',) Mortality rate 72 65 78 100 71 
(dF) No. dead per , 
1000 banded birds 
available 98.3 25.0 10.5 3 136.8 
(1",) No. alive at 
start per 
1000 available 136 ° 8 38 ° 5 13. 5 3 191. 8 
(q",) Mortality rate 72 65 78 100 71 
w dt, =< d,ra. This technique was independently worked not only in the 
present study but also by Edward G. Wellein (unpubl. ms.), by Bellrose 
and Chase (1950), and by Paludin (1951). 
Extent of avian life tables 
Ornithological life tables can also be classified according to 
the thoroughness with which they span a bird's entire life. Complete 
life tables include survival data on eggs, nestlings, fledglings, sub- 

adults, and adults. During the fall of 1947, Mrs. M. M. Nice generously 
reworked her field data on the song sparrow and helped me construct such 
ll 
