The austral thrush (Turdus falcklandii) reduces the seed germination for the urban ornamental tree glossy privet (Ligustrum lucidum) in Santiago, Chile

Abstract

Seed dispersal by endozoochory is an important mechanism promoting the spread of exotic fleshy-fruit plants. Although the invasiveness of glossy privet (Ligustrum lucidum W.T. Aiton) in several regions has been associated with the presence of disperser birds, only a few studies have examined their seed germination after dispersal. In Central Chile, the privet grown is an ornamental species, but to date, it has not been observed to settle in natural or seminatural habitats. In Santiago city, the fruits of glossy privet are mainly consumed by the austral thrush (Turdus falcklandii Quoy & Gaimard), which could act as dispersers of their seeds. For this reason, we analyzed the role of endozoochory by the austral thrushes on the germination of glossy privet. We collected seeds from trees and feces of austral thrushes, and then we compared their viabilities and germination percentages. Viability was established using the tetrazolium test, while germination was studied using a factorial experiment (10 seeds in Petri dishes, replicated nine times for both sources). Our results showed that the germination of seeds from feces (58.3 %) was 12 % lower than those from trees (77.7 %), indicating that austral thrushes reduces significantly the germination percentage of the glossy privet. The viabilities of seeds from fruits and feces were 100 %. Because these values may be high enough to allow the population establishment, we suggest that further studies are necessary to examine the role of the endozoochory in the (unsuccessful) spread of the glossy privet in Chile.

Seed Dispersal by Frugivores and Germination Success of the Invasive Alien Shrub Pyracantha Angustifolia in the Eastern Free State Province, South Africa

“…Similar results were observed when Solanum mauritianum, Cinnamomum camphora, Psidium guajava, and Morus alba L., were fed to Knysna (Tauraco corythaix) and Purple-crested Turacos in which germination success was unaffected(Thabethe et al 2015). Contrary results were reported whenCastro et al (2016) found that germination success of the glossy privet tree Ligustrum lucidum W.T. Aiton.…”

“…Such contrasts show that seeds of different plant species respond differently to ingestion by different bird species and, therefore, affect germination. Findings presented in our study highlight the importance of frugivorous bird species in facilitating the spread of IAPs (Castro et al 2016). Factors that might have affected the results are highlighted in a review by Traveset (1998), including size and thickness of the seed coat, differences in gut passage times, diets of birds, and seed age.…”

Frugivorous birds disperse seeds of Ligustrum lucidum, seed‐feeding weevils, and parasitic wasps of weevils via endozoochory

“…Previous studies indicated that frugivorous birds were seed dispersers and/or predators of Ligustrum species (MacRae 1980; Castro et al . 2016; Fernandez et al . 2020).…”

“…In general, seed dispersal brings 3 main benefits to plants (Howe & Smallwood 1982): (i) escape from seed predators, pathogens, or seedling competition; (ii) colonization of new habitats; and (iii) directed dispersal to specific sites. Previous studies indicated that frugivorous birds were seed dispersers and/or predators of Ligustrum species (MacRae 1980;Castro et al 2016;Fernandez et al 2020). Therefore, the ecological functions of frugivorous birds to seeds or O. suturalis weevils should be variable according to different contexts.…”