The white-winged dove (Zenaida asiatica) is a medium-sized dove native to the warmer parts of the Americas. It is known for its distinctive white wing patches that are clearly visible during flight. The white-winged dove exhibits an interesting relationship with flowering plants that could be characterized as a mutualism.
What is mutualism?
In ecology, a mutualism refers to a symbiotic relationship between two species in which both species benefit. Mutualisms can take many forms, but often involve one species providing food or shelter to another species in exchange for services like pollination or seed dispersal.
Some key features of mutualistic relationships include:
- Two species interact closely and depend on one another
- The relationship evolves through natural selection
- Both species benefit in some way
- The benefits outweigh the costs for both partners
Well-known examples of mutualism include bees pollinating flowers in exchange for nectar, and acacia trees providing ants with shelter and food in exchange for protection from herbivores.
The white-winged dove’s relationship with plants
The white-winged dove displays several behaviors that suggest it participates in mutualistic relationships with flowering plants:
- It consumes the fruits, seeds, and flowers of multiple plant species
- It migrates long distances and has a broad geographic range, which allows it to interact with many plant populations
- It often functions as an important seed disperser for plants it consumes
- Its seasonal movements track peak fruiting periods across different regions
In ecological terms, the dove consumes the fruits and flowers of plants and offers pollination and seed dispersal services in return. This fulfills the definition of a facultative mutualism, in which two species participate in a symbiotic relationship but are not obligated to do so. Both partners can benefit even if the other is absent.
Fruit and seed consumption
The white-winged dove’s diet consists largely of seeds, fruits, and flowers from a variety of plant species. Important food plants include:
Plant genus | Example species |
---|---|
Opuntia | Prickly pear |
Prosopis | Mesquite |
Ziziphus | Jujube |
Condalia | Brasil |
Capsicum | Chili pepper |
This diverse diet allows the dove to obtain nutrition across different biomes and seasons. The plants in turn benefit from seed dispersal away from the parent plant, which reduces competition and leads to wider distribution of offspring.
Seed dispersal
The white-winged dove’s migratory nature makes it an excellent seed disperser for many plants. The birds ingest fruits and seeds as they forage and then fly substantial distances before excreting the seeds. This dispersal away from the parent plant enhances the seed’s chance of finding favorable germination conditions.
Research has shown the white-winged dove effectively disperses seeds for a variety of plants, including:
- Giant cardon cactus
- Desert olive
- Mesquite
- Cat claw acacia
- Chichipe
The dove’s digestive system does not fully destroy all seeds, allowing many to emerge unharmed in new locations. The birds can transport seeds over 75 km in some cases, greatly expanding the plant’s range.
Pollination
In addition to dispersing seeds, the white-winged dove also pollinates flowers for some plant species. The birds often forage on nectar and pollen from sources like:
- Saguaro cactus
- Agave
- Ocotillo
- Brush peppergrass
As the doves move between plants gathering nectar, they transfer pollen grains on their beaks and heads. This facilitates cross-pollination between different individuals of the plant species.
Benefits for each partner
This relationship confers multiple benefits to both the white-winged dove and the various plants involved:
Benefits for the white-winged dove
- Reliable food source during seasonal movements and in new habitats
- Nutrition from fruits, seeds, nectar, and pollen
- Increased abundance and distribution of food plants through enhanced seed dispersal and pollination
Benefits for plants
- Dispersal of seeds away from parent plant
- Reduced offspring competition and mortality under parent plant
- Wider geographic distribution and range expansion
- Increased genetic diversity through outcross pollination
The interactions are not obligate, but both species gain significant advantages from the relationship when it occurs. This fulfills the definition of a true facultative mutualism.
Conclusion
The available evidence suggests the white-winged dove participates in a facultative mutualism with many plant species. The birds gain nutrition by consuming fruits, seeds, nectar, and flowers, while the plants benefit from seed dispersal and pollination over long distances. This enhances genetic diversity, range expansion, and offspring survival for the plants. Due to the migratory habits of the doves, these interactions take place across much of the Americas in multiple habitat types.
It is important to note, however, that the interactions are not obligate. The doves can survive without any one plant species, and the plants can reproduce without the doves’ assistance, though at a potential disadvantage. Both partners gain significant benefits when the mutualism does occur. This type of facultative mutualism is common in nature and represents an important ecological relationship.