730
REPORTS
fourth that observed in the morning. Because of these
apparent differences in feeding rates, a series of experi­
ments was run every 4 hr with separate groups of 30
snails for a 24-hr period. This series of experiments
showed that the snails ingested the greatest quantity of
food at about 0400 hr and that they ingested the least
food in the experiment starting at 1600 hr. An analysis
of variance showed these differences to be highly signifi­
cant (P < 0.001) . All other feeding rates during the
24-hr period fell quite evenly between the high and low
rates. Although snails crawled over rocks at all times,
they apparently did not feed uniformly at all times, and
the presence of a snail on the food substratum offered no
assurance that the animal was feeding.
The short-term technique described here for the in­
direct determination of feeding rates supplements existing
radioisotope methods based on rate constants. Estimates
of food ingestion rates based upon radionuclide uptake
or elimination rates necessitate repeated determinations
of body burdens of radionuclides in animals and assume
uniform feeding rates throughout the experiment. The
short-term method utilizes a single radionuclide deter­
mination and appears to possess sufficient sensitivity for
describing feeding chronologies over brief time periods,
such as .24-hr cycles, and for detecting variations in feed­
ing rates induced by differences in food availability or
quality. The technique may be adaptable to the study of
Ecology, Vo!' 50, No.4
small invertebrates in addition to aquatic snails. Radio­
nuclides other than C060 could be used as long as they
became bound to the food and were readily detectable.
LITERATURE CITED
1966. Radioisotope measurement
of food consumption by a leaf beetle species, Chrysomel(/)
knabi. Ecology 47: 1--8.
Kevern, N. R. 1966. Feeding rate of carp estimated
by a radioisotopic method. Trans. Amer. Fish. Soc.
Crossley, D. A., Jr.
95: 363-37l.
Kowal, N. E.
1969. Ingestion rate of a pine-mor ori­
Amer. Mid!. Naturalist 81: 595-598.
McMahon, J. W. and F. H. Rigler. 1 965. Feeding rate
of Daphnia magna Straus in different foods labeled
with radioactive phosphorus. Limno!. Oceanogr. 10:
batid mite.
105-113.
Reichle, D. E.
1967 Radioisotope turnover and energy
flow in terrestrial isopod populations. Ecology 48:
351-366.
Rice, T. R. and R. J. Smith. 1958. Filtering rates of
Venus mercenaria determined with radioactive plankton.
U. S. Fish Wild!. Servo Bull. 129, 58: 73--82.
Smith, R. J. 1958. Filtering efficiency of hard clams
in mixed suspensions of radioactive phytoplankton.
Proc. Nat. Shellfish. Soc. 90: 49-57.
EFFECT OF SEA WATER ON SEED GERMINATION IN TWO
PACIFIC ATOLL BEACH SPECIES
G. L. LESKO! AND R. B. WALKER
College of Forestry and Department of Botany, University of Washington, Seattle
(MS submitted December 26, 1968; accepted June 9, 1969)
Abstract. The structure of the fruits and the physiology of the seeds of Scaevola taccada
(Gaertn.) Roxb. and Messerschmidia argentea (L.) I. M. Johnst. facilitate dispersal by sea
currents and subsequent germination. Fruits were floated on sea water for 120 days without
significant loss in germination capacity. The seeds of fruits floated on sea water germinated
1-2 weeks sooner than dry seeds, when placed in nonsaline conditions. Both rate and per­
centage of germination in these species decreased sharply with the increase of salinity in the
substratum, and became nil at a salt concentration less than half that of sea water.
The data and the observations make possible a reasonable reconstruction of the transport
of these species to the Marshall Islands and their establishment on the atoll beaches. The
fruits are capable of drifting the length of the dissemination route suggested by Wiens (1962) ,
and the seeds would not germinate en route. Exposure to rain on the beaches would result
in rapid germination.
This investigation was stimulated by observations of
colonization of beaches in the northern Marshall Islands
by several shrubby trees, notably Scaevola taccada and
Messerschmi. dia argentea. The ability of these species to
establish on open beaches only slightly above the usual
high tide line and subjected to storms and salt spray
clearly demonstrates their salt tolerance.
This report is part of a larger study directed toward
understanding the ecology of these plants� Specifically
the objectives of this part were the determination of
retention of viability under saline treatments, measure­
ment of germination under various salinities, and possible
1 Present address: Department of Fisheries and For­
estry, Canadian Forestry Service, Calgary, Alberta, Can­
ada.
use of these data to help explain patterns of germination
in the field.
The study was supported by U.S. Atomic Energy Com­
mission grant No. AT (45-1) 1385 to the Laboratory of
Radiation Biology, University of Washington. Appre­
ciation is expressed for the assistance of E. E. Held and
S. P. Gessel in various aspects of the investigation.
Seed d
l1p
ersal
�
Unoccupied land areas may be colonized by vegeta
through marginal or centrifugal' invasion (Braun-Blan­
quet 1932) . In the case of marginal invasion the sur­
rounding vegetation closes in on the open area, whereas
the centrifugal invasion proceeds outward with the aid of
wind, water and animals. In the original colonization of
731
REPORTS
Summer 1969
isolated atoll islands, only centrifugal invasion can play
a role, since they are surrounded with large areas unsuit­
able for the establishment of terrestrial vegetation. Ac­
cording to Ridley (1928), the sea dispersal of plants,
mostly trees and shrubs, is the most important in the
colonization of new islands. After these pioneer trees
and shrubs are established on an island, land birds in­
troductJ plants with baccate or drupaceous fruits.
Merrill ( 1954) states that the vegetation of the Pa­
cific islands is made up primarily of western elements,
and that the floras of the islands in the tropical Pacific.
basin are greatly attenuated Malaysian ones. According
to Wiens (1962), if the oceanic currents are postulated
as the chief distribution agency for the tropical strand­
plant seeds and fruits from the western Pacific to the
central and southern Pacific islands, one must give the
equatorial countercurrents primary responsibility for their
distribution to such areas as the Marshalls and Gilberts.
His map shows this countercurrent running eastward in
the vicinity of the southern Marshalls. He further cites
the development of large surface vortices or whirls in
that area in the zone of convergence where the counter­
current begins to sink. These whirls help to distribute
floating seeds and fruits to any island in their path. The
tropical hurricanes in the Marshalls in general move west­
northwest, thus aiding in the further dispersal of water­
borne seeds and fruits in the hurricane-blown drift
through the remaining islands of this group.
Ridley (1928) studied the means of seed dispersal as
influenced by the distance from large land masses in the
Malay region and found that floating was the most im­
portant over large distances. Among the sea-dispersal
plants on Cocos-Keeling Island, 1,100 km from Java, were
the species belonging to the genera of Hibiscus, Trium­
fetta, Pemphis, Guettarda, Scaevola, Cordia, Messer­
schmidia, and Lepturus. Polunin ( 1960) emphasizes that
sea currents can be very effective in long distance dis­
persal of suitably modified disseminules, in some known
cases for over 1,600 km.
According to Guppy (1917) fruits of Scaevola koenigii
Vahl. Symb. (
taccada) may float for a year without
losing their germination capacity. Fruits of this species
and of Scaevola plumieri Vahl float as stones because the
beach sand usually wears off the fleshy outer portions
before they become sea borne. This loss is advantageous
for Scaevola plumieri because the entire fruits do not
float. The stone without the fleshy parts is buoyant
because one of the two cells in the fruit is filled with
air instead of a seed. Fruits of Scaevola taccada float
with or without the fleshy tissues. Large air-filled cells
in the hard outer layer give buoyancy to these fruits.
=
Germination of halophytes
Germination of the seeds of land halophytes is strongly
affected by salinity. The best germination occurs under
nonsaline conditions, and in their natural habitat most
seeds germinate during the fall, winter or early spring,
when the temperatures are lower and the moisture con­
ditions are optimal (Chapman 1954, 1960; Adriani 1958;
Ward 1967). The germination of most halophyte seeds
is inhibited by 1.0-1.5% salt solutions, but the seeds re­
tain their viability and germinate if the salinity is later
reduced (Chapman 1954). Seeds of a few halophytes
germinate at much higher salt concentrations. Aster
tripolium L. germinated in 2% salt and Salicornia her­
bacea L. germinated in large numbers at 2.8-3.20/0 sa­
linity of the soil solution (Montfort and Brandrup 1927).
The highest salinity levels were tolerated by Salicornia
stricta Dumart, which attained 120/0 germination at 100/0
salinity of the soil water (Chapman 1960).
MATERIALS AND METHODS
Preliminary trials indicated that untreated Scaevola
seeds germinated readily in about 4 weeks when pla�te.d
in sand and irrigated with tap water. Messerschm�dw
seeds germinated irregularly beginning about 3 weeks
after imbibing. Exposure to light on the surface of the
sand and irrigation with dilute sea water appeared to
stimulate germination of these species. To test system­
atically the influence of salinity on the germination of
these plants the following experiments were conducted:
Experiment No. 1.-Approximately 200 fruits of each
species (two seeds per fruit) were floated for 120 days
in 3.6 liters of aerated sea water. The sea water was
collected from the Pacific Ocean about 375 'km off the
coast of British Columbia. Two samples of 20 fruits
of each species were withdrawn from the sea water at
three week intervals and tested for germination capacity.
Dry fruits from the same collection stored in a refriger­
ator were germinated as controls at each time interval.
The fruits were sown in coral sand in 12.5 cm plastic pots
and watered with tap water. The number of emerging
seedlings was recorded every second day until the cessa­
tion of germination or for a minimum of 30 days.
Experiment No. 2.-Germination tests at different sa­
linity levels were conducted in crushed limestone ( 1020 mesh; ca. 95% CaC03, 20/0 MgC03) . Dry fruits were
sown into the lime-stand in 15 cm plastic pots with free
drainage; irrigation was with distilled water and 20, 40,
50, 60, 80 and 100% sea water (0, 9, 18, 23, 26, 34, and
42 millimhos electrical conductivity respectively) . The
pots were irrigated every second day with an excess of
solution to prevent salt accumulation in the substratum.
All treatments included four replicates with 50 Messer­
schmidia or 30 Scaevola fruits in each. Two replicates
in each treatment were changed to distilled water irriga­
tion after 83 days treatment and the test continued for
another 38 days. All pots were covered with glass plates
to reduce evaporation from the sand. The emergence of
the plumule was taken as the sign of successful ger­
mination.
Fruits for the experiments were collected at Kabelle
and Rongelap islands, Rongelap Atoll, Marshall Islands
in 1963, from the soil surface under the trees. Sections
of some fruits were examined for anatomical adaptation
to dispersal by sea currents.
RESULTS
Anatomy of the fruits
The structure of Scaevola and Messerschmidia fruits
indicates adaptation to dissemination by water. In the
I em
FIG. 1.
Longitudinal sections of Scaevola (left) and
fruits (right) .
Messerschmidia
732
REPORTS
genus Scaevola, family Goodeniaceae, the fruit develop
from inferior ovaries (Lawrence 1951). The fruit is
drupe-like, having a thin "epicarp," a thick "mesocarp"
of air-filled parenchyma cells and a thick, stone-hard
"endocarp" (Carolin 1966). The fruit have two loculi
with one seed in each loculus (Fig. 1).
In the genus Messerschmidia, family Boraginaceae,
fruits develop from a superior ovary of two carpels form­
ing four loculi at maturity (Lawrence 1951). Some
fruits with three carpels were found in the Rongelap
collection. The number of seeds is one per loculus, but
usually about 500/0 of the loculi are empty. The pericarp
of the fruits is separated into a thin epicarp, a thick cork­
like mesocarp and a stone hard endocarp (Fig. 1). These
fruits easily split into halves when the epicarp is weak­
ened by weathering.
Days required to attain 50 percent
of the total germination capacity
Scaevola
Days of
treatment
30 .... . . .. .
60. . . . . . . . .
90.........
120.........
Extended floating on sea water
TABLE 1. The effect of floating on sea water upon the
germination capacity of Scaevola and M esserschmidia
seeds. Each value is the mean of two 40-seed samples
Germination capacity in percent
------- -------
30.. . ..... .........
60 . ... . ...... . . . ..
90 . .. . .... . ...... . .
120 ..... .. . ..... . . . .
Scaevola
Messerschmidia
----
Treated
Control
Treated
Control
47.5
45.0
51.2
57.5
47.5
42.5
35.0
22.5
33.7
12.5
7.5
5.0
28.5
22.7
3.6
46.2
Messerschmidia
Treated
Control
Treated
Control
26
22
26
29
30
35
36
35
12
19
16
15
26
28
31
30
70
The ability of seeds to withstand floating on sea water
was investigated in the first experiment. The results
indicate that seeds of both species are well adapted to
dissemination by ocean currents. All fruits remained
afloat up to the 120-day maximum exposure time of the
experiment. Soaking in sea water did not reduce the
germination capacity in Scaevola and probably did not
cause a true reduction in M esserschmidia (Table 1).
Germination of Messerschmidia seeds was erratic, but
Days of
floating on
sea water
Ecology, Vol. 50, No.4
TABLE 2. The effect of sea water upon the germination
speed of Scaevola and M esserschmidia fruits. Each
value is the mean of two 40-seed samples
the similar germination pattern of the control seeds sug­
gests that the poor performance of the Messerschmidia
seeds was not caused by the sea water treatment. Scae­
vola seeds germinated at a steady rate during the whole
experiment. Floating on sea water increased the germi­
nation speed of both species. The time requirement of
treated seeds to attain 50% of the total germination ca­
pacity was about 8 days shorter for Scaevola and 14 days
shorter for M esserschmidia in comparison to the control
(Table 2).
Seed germination under saline conditions
The effect of salinity on seed germination was studied
in the second experiment.
Germination of Scaevola seeds decreased from 580/0
under distilled water treatment to nil in the solution with
23 millimhos eelctrical conductivity. (Conductivity of the
sea water at Rongelap Atoll is about 50 millimhos). The
germination percentage began to decrease rapidly at 10
millimhos conductivity in the substratum. Twelve per­
cent of the Messerschmidia seeds germinated under dis­
tilled water treatment, and germination decreased to nil
at 18 millimhos conductivity (Figure 2).
The time between the commencement of the test and
the first germination was long for both species, and the
60
0 ____...
°
SCAEVOLA
50
z
o
I­
«
Z
�
0:
W
<.!)
40
I
30
I
20
10
o
l
MES SERSCHMIDIA
1----1-5
?� I
10
ELECTRICAL
15
9 ......
20
25
CO NDUC TIVITY
IN MIL LlMHO S
FIG. 2. The effect of different salinity levels on the
germination of Scaevola and Messerschmidia seeds. Means
with standard deviations.
delay increased with rising salinity. The first seedling
of both species did not emerge until 20 days even in the
distilled water treatment. The delay increased to 70
days for Scaevola in 50% sea water, and to 105 days for
M esserschmidia in the 40% sea water treatment (Figures
3 and 4).
Seeds which had not germinated after 83 days of irri­
gation with 50, 60, 80, and 100% sea water, started
t? &"erminate 10 days after t11,e irr �gation �as cha?ged to
.
distilled water. The course 'bf thiS germinatIOn IS com­
pared to the germination oi seeds treated with disti�ed
water from the beginning of the experiment in Figure'S
and 6. Pretreated seeds started germination within a
shorter time than seeds under distilled water irrigation
from the beginning, and the steeper slopes of the germi­
nation curves indicate an increase in germination speed.
Thus, the sea water pretreatment decreased the time re-
Summer 1969
�O
DISTILLED
12
I
/
'o!
z
�
�
z
:::il
II:
1&J
'"
1&J
>
i=
<I
-'
:>
:::il
:>
0
10
8
6
/
2
0
O
WATER
--
20%
SEA
/
!
i
�/
/
40%
SEA WATER
120
100
80
DAYS
FIG. 3.
OJ
>
4
::>
2
Cumulative germination percentage of Mes­
seeds as affected by distilled water, 20% and
40% sea water. Each point represents the mean of four
replicate values.
serschmidia
::>
<>
o
z
60
!;:x
z
50
0
�
w
'"
w
>
I<I
-'
:>
:::il
:>
0
DISTILLED
0"'-
/
40
20
o
0
)
/
�
40'/.
0
0_
S
0
60
00
80
100
50 %
� I�g�: .
10
/:r/.'�/ : .
20
30
40
60
50
DAYS
70
80
70
z
o
60
� 50
OJ
<0
A
0
�/
FIG. 5. Germination of Messerschmidia seeds irrigated
with distilled water following 83 days pretreatment irri­
gation with 50, 60, 80 and 100% sea water. Each point
represents the mean of two observations.
�
/c:
]�
PRETREATMENTS:
0 NIL
SEA WATER
z
0
0_
: /
�
�
40
�
O
WATE
0
�O
20
/
0
/
10
SEA
WATER
j /
o
30
0
�
/ 20%
0
WATER
0
0_0--0---
. I...
�/�
�'
�
'o!
i
.
::;
o
0
0- -0/ 0.--0
60
40
,/j t
'" 6
�
-'
0
�.
8
II:
OJ
o
WATER
o
«
z
o
o___ o-----
! �
/ : ��;.
/ /j�o
j:10
�
20
..
�12
z
o
/
4
733
REPORTS
SEA
WATER
0
120
DAYS
FIG. 4. Cumulative germination percentage of Scaevola
seeds as affected by distilled water, 20%, 40% and 50%
sea water. Each point represents the mean of four repli­
cate values.
quirement from the beginning of fresh water irrigation
to the first germination, and increased the rate of subse­
quent germination.
DISCUSSION
Seed dissemination
Fruits or seeds must have the following properties in
order to be disseminated by sea currents: ( 1) ability to
float on the surface of the sea water for many days;
(2) inhibition of germination by sea water; (3) reten­
tion of germination capacity after many days of soaking
in sea water. The species of Scaevola and Messer­
schmidia under consideration here were most likely trans­
ported to atoll groups such as the Marshall Islands via
the ocean. Thus it is interesting to see, from the experi­
mental results, that their fruits and seeds possess the
three properties listed.
Further, approximate calculations indicate that these
fruits could have covered the distances necessary for the
proposed migration. If the velocity of an ocean current is
considered as only 1.5 km/hr, Scaevola and Messer­
schmidia fruits may cQver about 4,200 km in 120 days.
This would be sufficient time to transport the fruits from
the East Indian Archipelago to the Marshall Islands
with a favorable current. As stated previously, Wiens
OJ
>
40
PRETREATMENTS:
o NIL
50 % SEA WATER
o
60%
•
80 %
t:. 100'"1..
.
30
g
;::
20
«
-'
i 10
::>
<>
10
20
30
40
50
DAYS
FIG. 6. Germination of Scaevola seeds irrigated with
distilled water following 83 day pretreatment irrigation
with SO, 60, 80, and 100% sea water. Each point repre­
sents the mean of two observations.
( 1962) points out that the equatorial countercurrents
can be postulated as the chief agent of such distribution.
Smaller movements within the island groups may be
presumed to have recurred because of storms or large
surface vortices.
Seed germination
and Messerschmidia seeds washed ashore on
beaches must find the substrate favorable for their ger­
mination in order to become successful colonizers. Either
the seeds must germinate under strongly saline conditions,
or the soil water has to become less saline, at least pe­
riodically, for germination to occur.
In our experiments, Scaevola and Messerschmidia seedS
germinated best under nonsaline conditions, as seems to
be the case with all halophytes. The germination speed
and germination percentage progressively decreased 'with
rising salinity. Salinity levels equivalent about 20 mil­
limhos conductivity (ca. 50% sea water) prevent the germination of the seeds.
,
Some salt marsh halophytes such as members of the
genus Salicornia germinate at sal lhity levels equivalent
to or higher than that of sea water (Montfort and
Brandrup 1927, Chapman 1960). The ability to germi­
nate at such salinity levels would be disadvantageous for
Messerschmidia and Scaevola because it would allow the
germination of the seeds while floating on the sea. Fur­
ther, germination at high salinity levels is not required
for colonizers of coral sand beaches, because electrical
Scaevola
REPORTS
734
conductivities of soil extracts collected during the rainy
seasons on Rongelap Atoll beaches were not higher than
3 millimhos. Such a salinity does not depress the ger­
mination of Messerschmidia and Scaevola (Figure 2) .
Young seedlings are rarely found under well developed
Messerschmidia and Scaevola thickets in the northern
Marshall Islands, even though the ground is covered with
seeds under the shrubs. In contrast, there are always a
considerable number of seedlings on the beaches after the
rainy season. This difference in germination may be ex­
plained, at least in part, by the difference in the seed
source. Seeds under the thickets originate from the
shrubs above, while seeds on the beach are probably
washed ashore after floating in the water for some time.
The data in Table 2 indicate that seeds floated in sea
water need 1 or 2 weeks less time of favorable soil mois­
ture conditions for germination than dry seeds. This
difference in time requirements may decide the success
or failure of the young seedlings in a droughty habitat.
LITERATURE CITED
M. J.
1958.
Halophyten, in Ruhland, W.
(Ed.) Handb. der Pflanzenphysiol. 4: 709-736.
Braun-Blanquet, J. 1932. Plant sociology. Translated
by C. D. Fuller and H. S. Conrad. McGraw-Hill
Adriani,
Co., 439.
Seeds and fruit of the Goodenia­
Proc. Linn. Soc. N.S.W. 91 (1) : 58-83.
Carolin, R. C.
ceae.
1966.
Ecology, Vol. SO, No.4
Chapman, V. J.
1954.
terrestrial halophytes.
The influence of salts upon the
VIn Congr. Intern. Bot. 1954.
189-199.
. 1960. Salt marshes and salt deserts of the
world. London, Leonard Hall (Books) Limited,
392 p.
Guppy, H. B. 1917. Plants, seeds and currents in the
West Indies and Azores. London: Williams and
Norgate, 531 p.
Lawrence, H. M. 1951. Taxonomy of vascular plants.
The Macmillan Company, New York.
Merrill, E. D. 1954. The botany of Cook's voyages.
Chronica Botanica 14.
Polunin, N.
1960. Introduction to plant geography,
McGraw Hill, N.Y. p. 107.
Montfort, C. and W. Brandrup. 1927. Physiologische
und pflanzengeographische Seesalzwirkungen.
II.
"Oekologische Studien" tiber Keimung und erste
Entwicklung bei Halophyten. Jahrb. Wiss. Bot. 66:
902-946.
Ridley, H. N. 1928. The dispersal of plants through­
out the world. L. Reeve & Co., Ltd. Lloyds Bank
Buildings, Ashford, Kent. 474 p.
Ward, G. M. 1967. Studies in the ecology on a shell
barrier beach. Section I. Physiography and vegeta­
tion of shell barrier beaches. Veget. Act. Geobot. 14:
---
241-297.
Wiens, H. J.
1962. Atoll environment and ecology.
Yale University Press. 504 p.
DIFFERENCES IN THE LIFE TABLES OF TROPICAL AND TEMPERATE
MILKWEED BUGS, GENUS ONCOPELTUS (HEMIPTERA:LYGAEIDAE)
JOHN T. LANDAHLl AND RI C HARD B. ROOT
Departm,ent of Entomology and Limnology, Cornell University, Ithaca, N. Y. 14850
(MS submitted February 5, 1969; accepted June 16, 1969)
Abstract. The life tables of Oncopeltus fasciatus from a temperate locality (Ithaca, New
York) and O. unifasciatellus from a tropical locality (Cali, Colombia) are compared. When
reared under controlled conditions approximating those they experience during the summer
in their natural environments, the two species exhibit remarkably similar rates of development
and mortality. The temperate species, however, which begins ovipositing sooner and produces
more eggs, has a higher instantaneous rate of population increase (r). These results extend
some theories advanced to explain latitudinal differences in the clutch size of birds.
Latitudinal gradients in clutch size have long been
noted in birds and several theories have been advanced
(Skutch 1949, Lack 1954, Cody 1966) to explain this
phenomenon. Few investigations have been made of ter­
�estrial invertebrates, however, to determine whether or
not they conform to the same pattern.
In this study we compare the life table of an Oncopel­
tus fasciatus population from a temperate zone locality
with that of an O. unifasciatellus population collected at
a tropical locality. These closely related species are quite
similar in appearance and behavior. Both species feed
primarily on the seeds of milkweeds, Asclepias spp. which
grow in habitats where the vegetation is relatively open.
Oncopeltus fasciatus, whose biology is well known (sum­
marized by Andre 1934, and Dingle 1968b) has a large
geographical range extending from southern Canada to
1 Present address: Department of Zoology, University
'of Washington, Seattle, Washington 98105.
Argentina (Slater 1964) . Oncopeltus unifasciatellus,
whose biology is poorly known, is widely distributed in
Latin America, from Mexico to Argentina (Slater 1964) .
MATERIALS AND METHODS
Our O. fasciatus culture was established in the autumn
of 1966 from collections made on Asclepias syriaca grow­
ing in old fields near Ithaca, New York (42°N). The
O. unifasciatellus were collected on Asclepias curassavica
growing in a rough pa ture at the lower end of the
Pichind6 Valley, near Call, Colombia (3°N) on March 22,
1967.
The climate in the Pichind6 Valley (attitude
1,570 m) is moderate throughout the year: the natural
vegetation is a montane tropical forest ("bosque muy
humedo subtropical" in the classification of Espinal T.
and Montenegro M. 1963) . Miller (1963) has described
the climate and the seasonal reproduction activities of
birds at a nearby locality, San Antonio, Colombia (alti-
f