O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
11 
phylloides (Banack, 1998). The importance of flowers in the diet relative to fruit is not known, but 
several species of plants are used for nectar, pollen, or consumption of entire flowers, particularly 
at times when fruit resources are low. These may include Erythina variegata, Freycinetia reinecki, 
Palaquium stehlinii, Planchonella samoensis, and Syzygium inophylloides (Banack, 1998). Agri¬ 
cultural fruits may be utilized at some times of year, but fruits of primary forest trees are selected 
over those from agricultural forest or secondary forest, and P. samoensis shows lower use of agri¬ 
cultural plants than the sympatric P. tonganus on Samoa. This may be because the nutritional value 
of native fruits used in the diet of P samoensis is higher than the nutritional value of agricultural 
fruits (Nelson et al., 2000a). Consumption of unripe fruit and leaves during dry seasons and after 
hurricanes may provide many key nutrients in amounts comparable to those found in ripe fruits 
(Nelson et al., 2000b). Plants utilized by the closely related P. samoensis nawaiensis for fruit and 
forage on Fiji are also highly valued by human residents for food, medicine, and other cultural uses 
(Scanlon et al., 2014). 
Roosting Habits. — Mature primary forest is favored as roosting habitat as well as for for¬ 
aging. Individual Samoan flying foxes can shift roost sites among trees within forest patches up to 
12 times in a day; roost sites include branches in dead trees and at least eight species of living trees, 
with roosting branches typically from five to 20 meters above ground (Brooke et al., 2000). Roost 
trees are often located at the edges of cliffs or ridge-tops that allow good conditions for dropping 
into flight (Banack and Grant, 2003). Unlike many species of flying foxes, Samoan flying foxes do 
not form large colonies. They roost primarily as solitary individuals, pairs (most common), or in 
small groups (Pierson and Rainey, 1992). Brooke (1997, 2001) and Banack and Grant (2003) 
described roosting patterns. Most solitary individuals are adult males. Pairs can consist of male- 
female dyads from August to March or mothers and young from April to July. The largest roosting 
group consisted of a transitory aggregation of up to 60 bats of both sexes (Brooke, 1997, 2001). 
Dead branches in ridge-top trees exposed to sunlight are conspicuous roosts for single males, par¬ 
ticularly in early daylight, but bats make nearby movements to other less-exposed branches when 
temperatures increase during the day or under windy and rainy conditions. Females and dependent 
young typically roost in the canopy under less-exposed conditions. Individuals may repeatedly use 
the same branch (Brooke, 2001). This species can be tolerant of people and human activity beneath 
their roost sites (Brooke et al., 2000). 
Population Ecology. — Litter Size, Natality, and Female Reproduction: Litter size is one 
in nearly all pteropid fruit bats (Pierson and Rainey, 1992; Racey and Entwistle, 2000). Female 
Samoan flying foxes can be observed carrying single young in all months of the year. However, 
observations with young peak in March through September, with most nonvolant young seen in 
June through August (Pierson et al., 1992, 1996a; Brooke, 2001). Copulations have been observed 
in September and October (Brooke, 2001). A study in 1992-1994 that included Tutuila reported 
diffusely seasonal reproduction, with a peak of births in May and June with no newborns in 
November through February, and volant young (who continue to suckle after becoming volant) first 
appearing in August (Banack and Grant, 2003). August and September weaning coincides with 
fruit production in an important food plant, Syzygium inophylloides (Banack and Grant, 2003). We 
are unaware of any published literature with quantitative data concerning other demographic 
aspects of female reproduction, such as natality, age at first reproduction, and inter-birth intervals. 
Survival: We are unaware of any published literature with quantitative data on survival for this 
species. 
Mortality Factors: Impacts of predation, disease or parasitism on Samoan flying fox mortal¬ 
ity are undocumented in American Samoa. In the Fiji Islands, fruit bats are a major prey item of 
peregrine falcons ( Falco peregrinus; White et al., 1988) and are taken by bam owls (Tyto alba; 
