A comparison of nutritional value of native and alien food plants for a critically endangered island flying-fox

Abstract

Habitat loss and alteration are two of the biggest threats facing insular flying-foxes. Altered habitats are often re-vegetated with introduced or domestic plant species on which flying-foxes may forage. However, these alien food plants may not meet the nutritional requirements of flying-foxes. The critically endangered Christmas Island flying-fox (CIFF; Pteropus natalis) is subject to habitat alteration and the introduction of alien food plants, and therefore is a good model species to evaluate the potential impact of alien plant species on insular flying-foxes. In this study, we evaluated nutritional content of native food plants to determine how flying-foxes historically met their nutritional requirements. Furthermore, we compared the nutritional content of native and alien fruits to predict possible impacts of alien plants on insular flying-foxes. Native and alien fruits and flowers, and native foliage (leaves, petals, and petioles) commonly consumed by the CIFF were collected and evaluated for soluble sugars, crude protein, non-fiber carbohydrates, and nine minerals. Evaluation of native food plants suggests that flying-foxes meet energy requirements by consuming fruit and nectar. However, fruit and nectar are low in protein and essential minerals required for demanding life periods; therefore, flying-foxes likely supplement their diets with pollen and foliage. Thus, flying-foxes require a diverse array of plants to meet their nutritional requirements. Compared to native fruits, alien fruits contained significantly higher non-fiber carbohydrates, and this may provide an important energy source, particularly from species that bear fruit year-round. Median mineral concentrations in alien fruit species, however, were deficient compared to native fruits, suggesting major (or even seasonal) shifts in the proportion of alien species in the CIFF diet could lead to nutritional imbalances. This study confirms the need to quantify nutritional parameters in addition to feeding ecology when evaluating habitat quality to inform conservation actions that can be applied both locally and globally.

Impact of Invasive Plant Species on Ecosystems, Biodiversity Loss and Their Potential Industrial Applications

“…The accelerated degradation of their organic matter debris, as in the case of S. canadensis (Figure 3), cause imbalances in the feeding of organisms dependent on it (Dekanová et al, 2021). The same problem appear in the organisms whose diet includes certain amounts of native plant species matter, because of the induced decrease in their abundance (Pulscher et al, 2021). Sometimes, invasive plants can have a negative impact on water flows as in the case of Acacia sp.…”

The tongue morphology of Pteropus vampyrus from Timor Island, Indonesia: New insights from scanning electron and light microscopic studies

“…They have a sharp sense and echolocation system, which helps them locate ripe fruit from great distances. Apart from fruits, some flying fox species also consume nectar and pollen from flowering trees, which they collect by hovering over flowers with their wings flapping rapidly (Aboelnour et al 2020;Pulscher et al 2021).…”

“…While they do not eat insects or other animals directly, researchers have discovered that a small amount of their diet consists of insects because they often consume whole fruits, which may contain insects inside them. The large flying fox has developed an efficient way of finding food within its habitat through adaptations such as specialized diets and heightened senses (Pulscher et al 2021). Large flying foxes are magnificent creatures that play an important role in the ecosystem.…”

Ecological conditions predict the intensity of Hendra virus excretion over space and time from bat reservoir hosts

“…Bats have responded to these changes by splitting into smaller roosts that are closer to reliable, often introduced, food in agricultural areas and urban gardens (Eby et al, 1999; Páez et al, 2018). Bats in these newly established and continually occupied roosts supplement their diet with non‐native plants (Markus & Hall, 2004; Mcdonald‐Madden et al, 2005), which are likely of poorer nutritional quality than native nectar (Kessler et al, 2018; Pulscher et al, 2021). This change in host behaviour has expanded the winter distribution of flying foxes in subtropical Australia into areas that do not provide native winter food resources (Lunn et al, 2021; Tait et al, 2014).…”