Related Experiment Video
Updated: Aug 8, 2026
07:19
Field Experiments of Pollination Ecology: The Case of Lycoris sanguinea var. sanguinea
Published on: November 25, 2016
Mutualism and Antagonism in a Post-Extinction Hawaiian Bird-Lobelioid Pollination System
Samuel B Case1,2,3,4, Donald R Drake5,6, Kevin Epperly1,2
1University of Washington Seattle WA USA.
Ecology and Evolution
|August 7, 2026
Summary
The extinction of specialized pollinators impacts plant-bird interactions. While nectar robbing by birds alters floral resources, endangered Hawaiian lobelioids maintained high fruit and seed viability, showing complex ecological persistence.
Area of Science:
- Ecology
- Evolutionary Biology
- Conservation Biology
Background:
- Specialized pollinator extinction can disrupt plant-animal mutualisms, shifting interactions towards antagonism.
- Historical pollination dynamics of endangered Hawaiian lobelioids by extinct honeycreepers are poorly understood.
- Extant nectarivorous birds may interact differently with these plants, impacting pollination and resource dynamics.
Purpose of the Study:
- To investigate contemporary plant-bird interactions in endangered Hawaiian lobelioids on Hawai'i Island.
- To quantify floral visitation, nectar robbing, and its consequences on nectar replenishment and plant reproduction.
- To assess the functional roles of extant birds ('I'iwi and Hawai'i 'Amakihi) in a post-extinction pollination system.
Main Methods:
- Motion-triggered cameras monitored floral visitation by 'I'iwi (Drepanis coccinea) and Hawai'i 'Amakihi (Chlorodrepanis virens).
- Nectar acquisition, contact with reproductive structures, and nectar robbing frequency were quantified.
- Experimental simulation of nectar robbing using a 3D-printed model assessed effects on nectar replenishment, fruit development, and seed viability.
Main Results:
- Floral visitation by extant birds resulted in contact with fertile structures in 43% of visits.
- Nectar robbing occurred in 39% of visits, with Hawai'i 'Amakihi being more frequent robbers.
- Experimental nectar robbing altered nectar replenishment dynamics, but fruit production and seed viability remained high.
Conclusions:
- Co-occurring nectarivores play distinct functional roles, influencing floral resource dynamics and reproductive outcomes.
- Despite frequent antagonistic behaviors and altered nectar dynamics, endangered lobelioids exhibited reproductive resilience.
- Mechanistic evaluation is crucial for understanding species interaction persistence amidst biodiversity loss and extinction events.
Related Concept Videos
02:40Pollination and Flower Structure
Flowers are the reproductive, seed-producing structures of angiosperms. Typically, flowers consist of sepals, petals, stamens, and carpels. Sepals and petals are the vegetative flower organs. Stamens and carpels are the reproductive organs.
00:58Symbiosis
Symbiotic relationships are long-term, close interactions between individuals of different species that affect the distribution and abundance of those species. When a relationship is beneficial to both species, this is called mutualism. When the relationship is beneficial to one species but neither beneficial nor harmful to the other species, this is called commensalism. When one organism is harmed to benefit another, the relationship is known as parasitism. These types of relationships often...
02:34Competition
When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. Even if two competing individuals or populations do not interact directly, the overall fitness of both competitors is lowered as a result of not having full access to the limited resource.Intraspecific competition, which occurs between individuals of the same species, serves as a natural mechanism for regulating population size. Too much...
01:25Microbial Interactions: Mutualism
Mutualism is a symbiotic interaction in which all participating organisms benefit. These relationships can be obligate or facultative and are fundamental to ecosystem functions across diverse biological systems.Plant–Fungi MutualismOne well-known example is the association between plant roots and mycorrhizal fungi, such as Rhizophagus species. The fungal hyphae penetrate the root hairs and the epidermis, forming an extensive hyphal network that establishes a symbiotic association. Through this...
02:39Predator-Prey Interactions
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.Although predation is commonly associated with carnivory, for...
02:29Hybrid Zones
Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.Gene flow and natural selection are evolutionary mechanisms that shape the outcome of a hybrid zone. Gene flow...