Comparative Breeding Bata -- Laysan and Lisianski 
Date of 
Survey 
Population and Breeding 
Data -- Laysan 
Brown Poddy 
early Mar. 100, ea. 10 n/e, 2 nr. 
196 ^ fleging young seen 
Population and Breeding 
Data -- Lisianski 
25, Dot breeding 
Relationship of Lisi- 
anski cycle to Laysan 
Possibly earlier on 
Laysan but clear 
summer breeding peak 
not well begun either 
island. 
mid 
2000 , a few e & yg fd. 
3000 , eggs to fly. yg. 
Dot clearly different 
Sept. 
Most non-breeding 
1964 
196 ^ summ 
- Data insufficient to show 
any clear difference 
early 
500-1000 - e to fly imm. 
200-500 - e & sm yg. 
Data looks poor. 
Mar. 
poss. earlier on Laysan 
1965 
mid 
15000 - l /2 inc. e to fig 
10000 , ca. 3000 yg.. 
Laysan earlier if fldg 
July 
yg. est. ca. 5000 yg. 
partly inc. e to 
yg. vs non fig. yg. real. 
1965 
nr. flging yg. 
Probably not seen on 
Lis. cause of poor qual. 
of bos. 
1965 summ 
- Data poor, faint indication of earlier cycle on Laysan 
mid 
20000- Pr.e to nr.fig yg. 
15000 , est. 5000 n/e, 
Cycle seems clearly 
June 
est ca. 5000 n/e, 5000 
ca. 100 with rhy yg. 
earlier on Laysan 
1966 
w/yg, most rec. hatched 
Do lg. yg. seen. 
late 
800 - only fly imm. pres. 
^4-000, not br. est incl 
Dot clearly different. 
Oct. 
fly imm. 
Pop ests seem to go along 
1966 
with idea that cycle 
earlier on Laysan 
1966 summ 
Tends to indicate earlier 
cycle of Laysan 
mid 
Mar 
1967 
sev. 100s, 1 e fd. 
75 no evid. of br. 
Slight suggestion of 
earlier cycle on Laysan 
early 
r^-0000] e to fig. Most n 
15000 e to med. yg. 
Very similar, slight 
June 
with e, est. 10000 n. 
more than 90 $ of n/e 
suggestion that Laysan 
1967 
1967 summ. slight suggestion 
est. 5000 n 
that Laysan cycle earlier 
cycle earlier. 
early 
Sept. 
1967 
10000 e to fig. imm. 
ca. 10 n/e, 50 sm yg, 
200 Ig yg. ca. l /5 
of flying pop was imm, 
10000, e to fly yg. mostly Overall supports that 
£1 lg yg and dep imm, Laysan cycle slag htly 
many rec. fig. est. 100 sdy earlier 
1000 lg yg, ca. 2000 
dep. imm. 
