After a full day of drudging through thick vegetation, battling mosquitos and stinging hair caterpillars, and working hours beneath the blazing summer sun, our team finally exited the research plot. Walking through an open patch leading to our temporary base, sharp thorns from the invasive Mile-A-Minute vine still clung to my pants like unwanted mementos from a rough day in the field. We all met below the shade of a large black gum tree, finally taking the time to gather both our thoughts and data sheets. “Anyone else want a cold drink from the bodega?” our team leader Sanpisa asked. Twenty minutes later we were driving across the Brooklyn Bridge, A/C cooling our faces, Michael Jackson’s Thriller playing on the radio, enjoying some well-deserved frozen ices we picked up on Flatbush Ave. Just a typical day in the life of an urban ecologist.
Our research team has found our way to this plot in Marine Park Brooklyn as a result of the MillionTreesNYC initiative to plant new multi-layered forests in the five city boroughs. In each research plot, we are sampling invasive herbs and measuring planted tree growth since last season. My work focuses on sampling ant communities within these urban forest fragments. Do ants inhabit transitioning urban landscapes? If so, what species are most abundant? Although we understand that urbanization threatens biodiversity, very little is known about insect and particularly ant diversity in cities. These questions I hoped to investigate during my time in the field, through careful measurements and recording of data. Despite these focused intentions, I often stumbled upon more unique and surprising examples of how species interact, interactions occurring daily and unbeknownst to most of us.
While taking the measurement of a small oak tree at Marine Park, I knelt below the vegetation to catch a quick drink of water. As I tipped my hat and raised my Nalgene, a dark glob hidden beneath a single oak leaf flickered past my peripheral vision. I quickly removed my sunglasses for a closer look, squinting to get a better look at this odd biological feature. A cache of small, brown, antennaed insects sat there, huddled together and surrounded by a small band of ants raising their heads and brushing their jaws. Had these ants stumbled upon the ultimate insect-meal jackpot and are now literally licking their chops with anticipation? As it turns out, this was not the case. Their hunger was not for the insects themselves, but for the drops of honeydew about to release from their abdomens. These tiny plant parasites are known as aphids and the ants surrounding them are their protectors, keeping a close eye on them like a shepherd to his herd. Despite what some may understand of natural selection, nature does not occur as just a battle of the fittest, to eat or be eaten, and this mutualistic relationship between ants and aphids pleasantly highlights this fact.
As a student of urban ecology, it is often difficult to explain why someone would study the natural environment of a city. The title itself may even seem paradoxical: How exactly do you study nature in a place so void of it? Yet as our world grows the value of studying ecology in the urban environment is becoming more and more apparent. New York City may not be the Peruvian Amazon or Great Barrier Reef of Australia, but the information we can gather here is equally valuable to our understanding of not only the natural world, but more importantly, of our own interactions with our urban neighbors. Observing this relationship between ants and aphids highlights the types of interactions taking place in our backyards and in our homes. As humans we are interacting with our natural world in a similar manner, even though our relationships with other species are not always as apparent to us. The more we come to understand these interactions, the better we will come to understand ourselves and our need to live sustainably with the many other species that inhabit our world.