Emphasis on publication as a means of "spreading knowledge" was expressed by the first Secretary of the Smithsonian. Demography and natural history of the common fruit bat, Artibeus jamaicensis, on Barro Colorado Island, Panama.
BARRO COLORADO ISLAND
Physiology
Among the phyllostomids, members of the primarily frugivorous/nectaric subfamilies Glossophaginae, Carolliinae and Stenodermatinae (including A. jamaicensis), most of which have low-protein diets, have renal medullae that cannot be readily subdivided into inner and outer zones. There is no indication that A. jamaicensis must consume free water when feeding on figs.
Reproduction in a Captive Colony Lucinda Keast Taft and Charles O. Handley, Jr
The associated disturbance of the mothers sometimes caused the abandonment of the mother and the death of the young. BG-I I of the NZP bats approximately corresponded to the birth dates of the free-living Panamanian population (Table 3-4).
LOG ADULT MASS (g)
LOG ADULT FOREARM (mm)
I 1 * III
When a mother with a baby attached to one of her nipples was netted in flight, the infant was usually found in a position parallel to its mother's body, its feet clutching her femoral or inguinal region. The skin on the underside darkened around seven days of age and hair growth began after 12 days.
Young had full pelage at 30 days of age and white facial streaks were visible in some individuals. Forearm growth stabilized around 50 days of age at X = 61 mm, 1 mm less than the average forearm length of bats of the original adult colony (Tables 3-1 and 3-12).
AGE (days)
The general and superciliary vibrissae were just red spots around the corners of the mouth and eyes until day 25, when they began to emerge. Data extracted from deformed or clearly underdeveloped young that died within days of birth were not included in the calculations.
50 AGE (days)
The second deciduous teeth were the last deciduous teeth to be shed, followed by the eruption of the permanent second incisors, which in adults are small and probably non-functional. We examined pairs of variables separately for mass and forearm length in the vespertilionids (Figures 3-10 and 3-11).
Reproduction on Barro Colorado Island
In 1971, Fleming provided evidence that embryos of A. jamaicensis undergo delayed development during part of the year, and Fleming et al. 1972) showed that bimodal polyestry is the basic reproductive pattern in this species. Our large data sets from BCI and the adjacent mainland, together with the results of the study of our NZP colony (see section 3, Reproduction in a captive colony) allow us to examine this cycle in some detail.
Jan Feb Mar Apr May Jun Jiil Aug Sep Oct Nov Dec
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
In the Old World, an ecologically equivalent species, Haplonycteris fischeri from the Philippines, has a monstrous cycle with delayed development (Heideman, 1988). This is one of the more intriguing questions that remains to be answered about the reproductive cycle of A.
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
JAN FEB MAR APR MAY JUN JUL
AUG SEP OCT NOV DEC
The individual catch rates of the first five groups (one or more catches by five or more catches) differ little. However, the catch rates for each of the remaining catch cohorts are lower Table 5-2) and more variable. We used the derived mean number of catches per individual for one to five catches (1.77) and for six or more catches (1.57) to estimate the expected numbers (Table 5-2, line D) in each catch cohort.
The probability of recapturing a bat is approximately the same regardless of the number of previous captures.
HALF YEARS AFTER MARK
Survival from combined data from autumn 1977 to spring 1980 suggests that approx. 68% of the youth cohort is lost by the time youth enter their second half year (Tables 5-3 and 5-4). Survival from the second to sixth six months after marking among bats marked as juveniles is on average lower than for adults and subadults (Figure 5-6). Dispersal during the first year of life is the most likely explanation for this higher observed "mortality" or disappearance rate.
However, factors such as death, learned web avoidance and collar loss (making the individual unrecognizable), as well as dispersal away from our study area, contribute to the extinction of these bats.
Adults
Population Estimates
Then m'(x)p(t-x) is the total number of bats marked in half-year x that survive to half-year t. Half of the females (those born in the second reproductive episode) can give birth to a young half a year after birth ;. 83 of the 227 subadult bats marked in autumn 1976 were recaptured in the following six months, while 87 of 178.
Another minimum estimate of the number of adult female bats is the number needed to produce the numbers of juvenile and subadult bats marked in a given year.
Movements
2 3 kilometers
94 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY TABLE 7-3.—Percentages of other catches of Artibeus jamaicensis for selected locality groups weighted on BCI. Adjusted percentages were derived by dividing the number of other captures (data from Table 7-1) by the number of total captures for that locality group and reducing that value to a percentage of its column total. The name of each locality group analyzed is followed by the total number of other surveys in parentheses.
However, the decline in other captures by distance in each data set (Figures 7-4 and 7-9) indicates that the population of A.
3 4 KILOMETERS
Each entry includes the central locality (UPPER LETTERS), percentage of others captured* there, rank among all localities in terms of number of individual A. The greater the number of individual bats involved, the greater the likelihood that other-captures will be widely distributed, thus also reducing the proportion of other-captures at a central location. The high percentages of other surveys at Buena Vista and Pefia Blanca simply demonstrate fidelity to those sites, which are day sites in channel markers.
There is a dichotomy of core areas into those whose central localities have both lower percentages and fewer other catches than other localities in the core (Table 7-5) and those whose central localities have higher percentages and more other catches than neighboring localities ( Table 7-6).
Number of individuals in each capture category 1
Number of records in each 1
CAPTURE CATEGORIES (%)
During three of the net attacks at Standley End, when more than two bats were captured, males outnumbered females by 30 to 1. We believe that the males at Standley End were predominantly bachelors, and that most or all of the females present were members of harems. The resulting map (Figure 7-20) shows the frequency (from one to five) of occurrence of individual bats in each of the squares.
We also mapped the same type of information from 11 day roost bats at the Buena Vista Light Tower (Figure 7-21).
2 3 4 kilometers
Roosting Behavior
Using the two techniques together has increased our confidence in the accuracy of the resulting image. When finally found, the bat was always in the darkest of the countless recesses overhead. All three harem males spent more than 90% of the night within 50–100 m of their respective home burrows.
The foraging activities of the two males with radio-tagged harems were closely correlated with those of their females.
Foraging Behavior
Long-duration flights began either from nocturnal roosts (n = 3) or with emergence at dusk from diurnal roosts (jn = 3). This may simply be the result of the patchy distribution of vegetation preferred for residences. Adult bachelor males may attempt to copulate with females at feeding sites away from the day cage and its defensive male harem because they are unlikely to have other access to females (Morrison and Morrison, 1981).
Foraging theory suggests that foraging roosts may be information centers for finding mature fruit trees (short-lived, locally abundant foraging holidays), especially if bats using a nocturnal roost are making foraging passes in various fruit trees.
Food Habits
APR MAY AUG SEP OCT NOV DEC 3 A
Diet and Food Supply
Moreover, we can infer from the elegant theory developed by May (1974) and May and MacArthur (1972) on warm overlap that canopy frugivores coexist because of the differences that Bonaccorso observed in the size of fruits eaten by these bats. night. Sometime between July and November, a month may pass during which no more than one of the 130 fig trees in the Lutz catchment will produce fruit. Based on the overall data set for the Bat Project, we believe that about one-third of fruit bats foraging in the forest canopy at BCI are A.
In total, the fruiting bats of the forest canopy on BCI eat about 40 kg dry mass of fruit per hectare per year when all sources are considered.
Appendix
The effectiveness of the bird call to bats may be limited by its absolute intensity rather than its frequency output (bats squeak louder). We found that slightly opening the unattached end of the plug with needle nose pliers or a hemostat made closing the necklace much easier when wrapped around a bat's neck. The necklace holds the bat on his knee with one hand while he grasps the connecting end of the necklace with the fingers of the same hand, the free end of the necklace can be brought around the neck and secured with the help of hemostats held in the other hand.
Because BCI is located in the center of the grid (identified as point 50.0 x 50.0), we never had to deal with negative numbers.
AMNH3-4
Moon phase: We recorded moon phase from the calendar, and added the number of nights since the start of the current phase. The main factor that distinguishes juveniles from the other age groups is that the epiphyses of the fingers are open (uninfected), with the joints swollen and tapered. When the epiphysis of the last joint (usually on finger V) ossifies, the bat is classified as a subadult.
By palpating male bats, you can learn about the position and shape of the kidney.
NIPPLE GAUGE UNMEASUR
A fetus can be felt by gentle pressure (down, back and inside) on the abdomen, just posterior to the ribs. If the head of a fetus (a hard lump) could be felt, the bat was palpably pregnant. The left kidney is approximately 10 x 5 mm in its larger dimensions and can be felt and moved by gentle pressure on the abdomen near the spine.
SMALL nipples range from 0.5 to 3mm in length and from 1 to 6mm in diameter at the base.
BLE R G E
Pregnancy: The abdomen of each woman, regardless of age and reproductive status, was palpated to determine pregnancy in the following manner. The bat was grasped at the elbows with the right hand, with the belly facing to the left. When a fetus is too small to expand the abdomen, CR length can be estimated.
It is possible to be misled by the left kidney, which can easily be felt and mistaken for a small fetus.
Population ecology of the Little Brown Bat, Myotis lucifugus, in Indiana and north-central Kentucky. Biology of Bats of the New World Family Phyllostomatidae, Part IL Special Publications of the Museum, Texas Tech University. Observations on the feeding behavior and avian prey of the neotropical carnivorous bat, Vampyrum spectrum.
