Oil preference in ants and arthropod diversity in urban environments is a well-researched Life Sciences Thesis/Dissertation topic, it is to be used as a guide or framework for your Academic Research.
The success of certain ant species in urban areas is largely unknown. Available food in the environment could affect the composition of ants in urban areas due to a possible relationship between and physiology and diet. I tested the oil preference of ants as a function of available arthropod prey in urban environments.
I hypothesized that as arthropod diversity decreased, ant abundance at oil baits would decrease. Oil is an important nutrient that can affect ant body functions and activities. Ant foraging activities have been found to be affected by lipid depletion. A food source where ants can obtain oil in an urban environment is arthropod prey. However, their diversity in urban areas can be low due to high impervious surfaces and low plant diversity.
A decrease in available arthropods could lead to an oil scarcity for ants, who need to fulfill their lipid requirements. To balance their nutrients ants will forage for a scarce nutrient the colony needs.
In my research baits of sugar, water, and different concentrations of oil were chosen at random and deployed throughout Chattanooga, TN. The oil baits consisted of either 0.1%, 0.5%, or 1%. The habitats the baits were deployed in were neighborhoods, parks, and street medians during the months of August and September.
Pitfall traps were also set up to measure available arthropod prey. Linear regression was used to view ant abundance against arthropod diversity, temperature, and soil moisture. Results showed that in most oil bait concentrations, there was a downwards trend in ant abundance as arthropod diversity increased. This demonstrates a weak relationship between oil preference of ants in regard to arthropod diversity. While my hypothesis was not supported, further research can still be done on lipid’s role in ant adaptability.
The human population is growing in large numbers; however, it is accumulating in dense areas. These are known as urban areas and they are expanding along with our population. Urbanization is increasing worldwide with predictions of 66% of the world’s population will live in urban areas by 2050 (United Nations, 2014).
Typically, urban areas are very developed, having a high density of human structures. These structures are known to absorb massive amounts of heat, which is released into the environment causing the heat-island effect. Another contributor to this effect is a structure’s low absorption of water.
These factors can lead to urban environments having a distinct microclimate due to intensified heat (Aminipouri et al., 2019). Another known contributor is the small number and size of green areas, which would normally help negate heat in their surroundings (Oliveira et al., 2011).
Ants are ideal study the effects of urbanization due to their quick ability to respond to environmental change, represent different trophic levels, are ecosystem engineers, can disrupt ecological communities, are successful invaders, and have large economic impacts (Menke, 2010; Buczkowski, 2010). The huge role ants play in an environment and their ability to affect their surroundings makes it imperative to understand how they function in urban environments.
While ants can quickly adapt and spread in urban environments, we have yet to find what makes certain species more successful than others. Some studies have found that the decrease in ant species diversity in urban environments and the understanding of invasive ant species is largely unknown due to the poor knowledge about their diets (Menke, 2010; Holway, 2002).
If diet can affect ants’ ability to adapt to urban environments, then their diet composition should be looked at. In the Integrative Ecology lab in Chattanooga, research by Guzman-Hernandez (2018) found that a high abundance of ants demonstrated a preference for oil in high traffic areas. This suggests that oil may be a limiting food resource in urbanized areas.
Oil is a vital nutrient for most organisms as hormones are lipid-soluble, make up cell membranes, and is a source of energy (Bayes et al., 2014). In insects, fatty acids can be used in waxes, pheromones, defensive secretions, development, and activities (Stanley-Samuelson et al., 1988). Lipids are essential in insects as they help prevent desiccation by making cuticular wax and can affect their chemical communication (Stanley-Samuelson et al., 1988).
Since ants mainly communicate through chemicals, it should be important for them to have enough oil resources in their environment. Oils have been found to be used in defensive secretions in Atta and Camponotus ants (Stanley-Samuelson et al., 1988).
Ants tend to monopolize limited resources that the colony needs (Kay, 2004). When an important nutrient like oil is missing from their environment, ant’s foraging behavior seems to be affected. Research done by Silberman (2016) found that foraging behavior is associated with lipid depletion for some ant species.
When foraging, ants are found to prefer seeds with high lipid content than those with lower lipid content (Pizo & Oliveira, 2000). This active search for high lipid sources demonstrates its importance to ants, as it affects their body functions and activities. Food sources capable of supplying their oil requirement should be looked at like arthropod prey.
However, the arthropod prey that ants may depend on to satisfy their oil requirement is affected by urbanization. Fragmented landscapes surrounded by a high density of built infrastructure are negatively associated with the abundance of most beetle taxa, Lepidoptera, and Hymenoptera (Delgado De La Flor et al., 2017; Lagucki et al., 2017).
Over usage of popular plants reduce plant diversity and also affect arthropod prey. Research has found that the relationship between plant diversity and arthropod diversity is positively correlated (Bennett & Gratton, 2016). Furthermore, urban development tends to affect unique environments in the same way.
This leads to biotic homogenization, where endemic species are replaced by widespread exotic species resulting in decreased diversity (McKinney & Lockwood, 1999). The changes urbanization has on arthropod availability could affect ants’ attempt to fulfill their lipid requirement.
Since ant’s foraging decision is based on the colony’s nutritional needs, they will search for nutrients that are difficult to acquire (Kay, 2004). Meaning that when a vital nutrient like oil is limited, they should specifically forage for it. Yet, it is not known what role oil plays in ants’ adaptability, especially in urban environments. The goal of this research was to test ant oil preference as a function of available arthropod prey diversity.
When arthropod abundance is low, caused by the effects of urbanization, I expected it to affect the ants’ oil preference. My hypothesis is that when arthropod abundance is high, there should be a lower abundance of ants in the oil baits as there is enough oil resources in their environment.
This would imply that as arthropod prey abundance declines, ants’ preference towards oil would increase due to its scarcity. Depending on the shortage of oil in the environment, I expect higher ant numbers in oil baits with higher oil concentration as they would satisfy their oil needs better.