One of the crucial processes in an organism's ecological and evolutionary effects is dispersal. In essence, because not all living things can disperse, seeds are created and must be transported by a vector to a new location (Reynolds, 2016). The propagules can then be carried to other locations by a variety of means, including wind, water, and animals. Animals are the most important method of seed dispersal, whether via ectozoochory or endozoochory, according to Reynolds (2016). The advantages and disadvantages of ectozoochory and endozoochory in seed mobility are therefore discussed in this work.
Waterbirds' Role in Dispersal
Waterbirds play a significant role in the dispersal of aquatic species as they help in enhancing connectivity among the isolated regions of the water bodies (Reynolds & Cumming, 2016). Importantly, distribution of propagules is vital in the biological activity of the numerous organism as it aids in preserving the diversity of the plants, movement of the genes, and reforestation of deforested habitats. Considerably, different methods are used to transport aquatic plant propagules, and they include ectozoochory and endozoochory (Reynolds & Cumming, 2016). Ectozoochory is a process by which the seeds of an organism is distributed externally by attaching itself to the feet, feathers, or bill of the water bird while endozoochory is defined by ingestion of the materials that eventually are released as fecal matter (Reynolds & Cumming, 2016).
Pros and Cons of Endozoochory
Conversely, endozoochory is the most used method since it aids in mass dispersal of the seeds due to the high level of ingestion process by the birds. Additionally, the technique supports the distribution of various plant species since the water birds consume different types of fruits (Reynolds & Cumming, 2016). Notably, the rate of germination of the seeds dispersed through the internal mechanism is substantial as most of the seeds contain hardcovers that prevent them from digestion. However, endozoochory can promote invasive plants in an area, hence, facilitate extinction of the species in that locality (Reynolds & Cumming, 2016). Significantly, it encourages the growth of diverse species of flora in an area causing plants to compete for nutrients and survival.
Pros and Cons of Ectozoochory
Consequently, ectozoochory enhance dispersal of smaller and spiked seeds that are not readily eaten by the birds by embedding on their feet and feathers (Costa, Ramos, Silva, Timoteo, Araújo, Felgueiras & Heleno, 2014). Moreover, ectozoochory facilitate distribution of a single plant species since it is characterized by fruits that can be attached to the aquatic bird. Similarly, the technique enhances long-distance dispersal of seeds as other propagules can stick onto the bird's body for an extended period (Costa et al., 2014). However, ectozoochory supports minimal dispersion of plants as it only enables seeds having hooks and spikes to be attracted to the animal's body. Significantly, seed viability is reduced in an external process as numerous species of flora contain hardcovers that are to soften before their germination.
Conclusion
In essence, dispersal is an essential mechanism in the living organism as it helps in enhancing translocation of seeds to different localities, maintain gene flow, and facilitate reforestation. Significantly, various techniques are used by the aquatic birds to transport propagules such as endozoochory and ectozoochory. However, internal mode of dispersal is paramount since it is the most widely used method by the water birds. The technique aids in the broad distribution of seeds through consumption, maintaining of seed viability, and dispersal of various plant species. Conversely, ectozoochory assists in dispersion of small and spiky fruits that are not readily consumed by the animals.
References
Costa, J. M., Ramos, J. A., da Silva, L. P., Timoteo, S., Araújo, P. M., Felgueiras, M. S., … & Heleno, R. H. (2014). Endozoochory largely outweighs epizoochory in migrating passerines. Journal of avian biology, 45(1), 59-64.
Reynolds, C. (2016). The role of waterbirds in the dispersal of aquatic organisms in southern Africa. Doctoral dissertation, University of Cape Town.
Reynolds, C., & Cumming, G. S. (2016). Seed dispersal by waterbirds in southern Africa: comparing the roles of ectozoochory and endozoochory. Freshwater biology, 61(4), 349-361.
