72 
It seems valid from this evidence and other banding records to as¬ 
sume that nonbreeding adults and subadults regularly disperse tnousands 
of miles from the home island and furthermore it might be conjectured 
that the main direction of dispersion is go one north# me *i.g 
philopatric "homing" tendency already demonstrated by banding records 
makes this species somewhat unique as a navigator. If ohe pOo^mai/ed 
radio-telemetry plans are ever realized, this robust strong flyer might 
prove to be an ideal test subject# 
Blue-faced Booby 
Sula aactylatra 
# Obs. - 288 
(See Graphs IOC, $C) 
The at-sea distribution of birds is a general function ox tnree 
major land breeding areas; l) Hawaiian Leewards and Johnston-Sand; 
2) Dry Line Islands, Jarvis, Malden and Christmas); 3) Pnoenix Islands 
and Howland—Baker# The sulk of the observation^ in this ^urvey (77 
cent) was divided between the waters in the vicinity of the latter two, 
birds being chiefly seen near Jarvis and Phoenix-Enderbury. no oxrao 
recorded west or south ox ohe Phoenix group c*rea. 
The northern pelagic region appears to be an interesting ix^oerplay 
between birds from all three breeding grounds. The overall densities 
for the five problem sections are virtually identical (l to S:^ .020, 
. 024 , .015, .018, .014). Birds in the north half are very probably 
mostly from Sand-Johnston and Hawaii. The southern section has many 
birds undoubtedly from nearby Howland (one Howland banded immature vas^ 
collected in the 5° N. area in April). I suspect also a good number of 
Jarvis birds enter the 5° N. area to the east and move out west alo^g 
the food-rich areas joining Phoenix-Howland birds which come irom the. 
north. I think this route may be partly responsible for the fairly nxgn 
rate of interisland movement between Howland and Jarvis. 
The pelagic densities are high compared to other times in me yeaj: • 
Most of the pelagic observations were of immatures which evidently dis¬ 
perse widely some nine months or so ax oer haucnlix^,. 
An orange-streamered immature was observed just north of Palmyra. 
There is supposedly a small remote breeding area on Palmyra vnich has 
never been worked. I suspect that more Sand-Johnston birds mighL be 
found there. If this were to be the case I would suggest that tne 12 
area serves, as the main road of interisland exchange between the two 
areas. 
# Obs. - 17 
Brown Booby 
Sula leucogaster 
Most of the sightings are of birds near their breeding areas. .Three 
birds in February and one bird in January were found unusually iar mom 
land in the northern part of the north pelagic region. One bird was 
seen in the "desert” region 500+ miles from land. The other sightings 
seem to be connected with the 12° H. zone. As with Blue-faced Booby, 
either Palmyra or Sand-Johnston could be the home landfall oi tnese 
birds, and again the "12° L." linkage is suggested. 
