THE SHIFTING DIVERSITY OF WILDLIFE IN SOUTHERN MANHATTAN Vadim Seylanov Macaulay Honors College Seminar 3 Discussion Abstract Food Availability Maps Materials and Methodology NOTE: red circles denote areas of high density known as “spheres of sustenance” The tabulated data shows that every area from Chinatown to Kip’s Bay Human beings affect their environment more than nay other animal on Earth, Kip’s Bay/Rose Hill/Gramercy/Flatiron District has a visible pigeon population. Feral pigeons have a diet that consists and as such, it is important to note the effects that civilization has on the creatures Following our urban ecology seminar protocol, I almost entirely of seeds and grain, but urban pigeons tend to eat whatever that live among us in our societies, particularly big cities such as New York. The documented the encounters with individual species along eight they can find in their immediate environment including bread, cooked goal of this project was to observe how the diversity of three of New York’s most assigned half-mile long North-South or East-West transects of rice, popcorn, nuts, and various fruits (Murton et al). Taking into account that nearly every part of Manhattan located within the three subsections common creatures—namely pigeons, rats, and squirrels—fluctuate from one Manhattan (each group in my class was assigned such a sector). neighborhood to another, as well as to understand what factors might be observed contains some form of food cart or outdoor grocery containing Our resulting data was combined into an Excel sheet covering one or more of the aforementioned items, it can be inferred that rock responsible for these changes. all 13.7 miles of Manhattan’s length that includes, of course, the pigeons in southern Manhattan are so abundantly spread out partly three subsections of land that I observed. because they have a readily available food supply. Compared to rats and In order to do this, the data from the protocol my class used to observe and list Using websites such as Google Maps and Yelp, I was able to squirrels, pigeons are also less associated with vermin and therefore are individual species in Manhattan was compared to topographical information note and measure all green areas in the three subsections more actively fed by human being, learning to be less afraid of them. I relating to the distribution of food sources (restaurants, food carts, fruit stands, believe this could also explain their apparent abundance as they are more etc.) and green spaces. During the course of this project, several areas were where rats, pigeons, and squirrels could potentially nest. I was inclined to forage for food out in the open around people. identified in each subsection that contained the highest recorded density of food also able to compartmentalize all locations that qualify as availability as well as areas of highest proximity to green spaces such as parks and sources of food (restaurants, bars, food carts). “Spheres of East Village/NoHo The data regarding the brown rat, however, is surprisingly different, playgrounds. The end results showed a very interesting variation of data in which, sustenance” could be seen on very busy, tourist-oriented showing almost no sightings of the creatures apart from two particular for example, one species would prefer areas with a high density of food streets such as St. Mark’s Place. transverses. One stands out specifically because another transverse shares the entirety of its length and strangely enough does not have availability and few green spaces while another species preferred the opposite. By comparing my classmates’ data concerning the similar results. For some reason, rats were openly sighted in between 23rd One species was even found throughout all areas observed, leading to the organisms found on specific Manhattan transects with my data St. and 30th St. by one student but not by another. This seems irregular for conclusion that is adaptability allowed it to flourish regardless of the two factors. regarding the southeastern concentrations of available food what is considered to be one if not the most adaptable and widely Ultimately, this project proved that the three species, despite all sharing the and habitats, patterns emerged that denoted where diversity of proliferated species on the planet, but I believe this peculiarity actually quality of being most adapted to urban life, are different enough from each other the three species increases or decreases. The “spheres of offers evidence to the bigger question of why the brown rat scarcely that they make southern Manhattan’s overall diversity of wildlife too complex to appears at all during student observations. A 2006 study of brown rat sustenance” were most intriguing to observe in their location be judged by the arguably two most important population-affecting aspects of populations in Salzburg, Austria stated the idea that "Many small and makeup. food and habitat availability, leading to the question of what truly is the most mammals are restricted to patches within habitats which most closely deciding factor, if it exists at all. resemble those present before urbanization" (Traweger et al). I believe this perhaps explains that rats were so minimally spotted because the majority of the paths taken by students did not intersect “patches” of high rat density. Looking at the two transects where rats were sighted, each Background Urban Ecology Diversity Protocol Transects Chinatown/Little Italy/NoLIta area contains an aforementioned “sphere of sustenance” where density of Show below are the eight transects that divided southern restaurants and food carts is effectively the highest. I postulate that Manhattan during original observations. The area in blue is the because urban rats are able to eat a very wide variety of foodstuffs, they All three of the species observed in this experiment are scavengers that are not tend to settle largely in areas that coincide both with food availability and total area utilized during the course of this project. Subsections naturally indigenous to the NYC area: rock pigeons, of which there is estimated to be familiarity of habitat as mentioned by Traweger. are made up as follows: over a million in the city, were originally brought to Manhattan as barnyard animals Northern – VI, VII, VIII by European settlers in the 16th century. Squirrels were a rare and fascinating sight Squirrels were by far the most variable of the three species observed, to be found in public parks for most the 19th century up until 1877 when the Middle – IV, V appearing sporadically from north to south. Interestingly enough, the squirrel data showed some striking resemblance to that of the rat. Of the popularity of pet squirrels released into the wild started a fad resulting in Southern – I, II, III eight transects explored, six had identical results, Chambers St. – Canal St. populations of Eastern Gray, fox (brown), and American Red squirrels being VIII and 4th St. – 10th St. being the only exceptions where squirrels were introduced to non-native habitats in public parks all across the country. Black rats sighted and rats were not. Perhaps this shows that rodents in general and brown rats were both spread across the world by European settlers who first share many similar habits when searching for food and shelter in urban brought both species to their homelands from tropical Asia and later to the New VII environments. The two aforementioned transects also happen to World when searching for new trade routes and resources. Out of the two, the brown encompass much of the tree-containing green space found in southern rat’s larger size and more adaptable nature to both extreme weather and human- VI Manhattan including Thomas Paine Park, Columbus Park, Tompkins made structures establish it as the more dominant and omnipresent species of rat Square Park, leading me to believe that squirrels were sighted in these both in NYC and worldwide. Because of the difficulty in estimating rodent areas primarily because of their proximity to their natural habitats. populations, the amount of both squirrels and rats found in NYC varies with accounts V Results Contrary to my hypothesis, it seems that squirrels do not prefer areas of ranging from the low millions up to 100 million. It is, however, widely regarded that high restaurant and food cart density. Being arboreal, squirrels might prefer “natural” types of sustenance such as acorns and conifer cones. A the brown rat is most successfully ingrained animal in the city, matching if not Comparing the information from the shared Excel file IV 1985 study at the University of Rochester “…found that grey squirrels superseding the city’s permanent human population. with the areas encompassed by the three subsections of (Sciurus carolinensis) may reject more energetically profitable, but small land in my observations, I was able to categorize two to III food items in favour of locating larger, less energetically profitable items The stretch of land observed in this experiment has been steadily populated by three recorded transverses for each subsection. The data that can be carried to protective cover for consumption without greatly human beings since the beginning of the 1800’s. Looking at it today, the area can be for the appearance of each animal is tabulated below: sacrificing foraging efficiency” (Lima et al). This could potentially explain divided by the major roads and avenues that run perpendicularly though it into II why squirrels were not sighted around “spheres of sustenance” where three significant subsections: the southern section which includes Chinatown, Little such small morsels as grains of cooked rice and scraps of bread are Italy, Nolita, and the northwestern corner of the Lower East side, the middle section commonly discarded, instead searching for bigger and worthier prey. which is dominated by the East Village but contains a small part of NoHo, and the R.K. Murton & N.J. Westwood (1966) The foods of the Rock Dove and Feral Pigeon, Bird Study, northern section which is made up of Gramercy, Kip’s Bay, Rose Hill, and the eastern I 13:2, 130-146, DOI: 10.1080/00063656609476116 D. Traweger, R. Travnitzky, C. Moser, C. Walzer & G. Bernatzky “Habitat preferences and parts of the Flatiron district. These three subsections contain many smaller areas in distribution of the brown rat (Rattus norvegicus Berk.) in the city of Salzburg (Austria): which restaurants crowd side-by-side for blocks on end, resulting in what I call implications for an urban rat management” Journal of Pest Science (2006) Volume 79, Issue 3, pp 113-125 DOI: 10.1007/s10340-006-0123-z “spheres of sustenance” that I believe theoretically contain that largest diversity of S.L. Lima & T.J. Valone “Influence of predation risk on diet selection: a simple example in the scavengers who come frequently in their daily search for food. grey squirrel” University of Rochester (1985) Volume 34, Issue 2, Pages 536–544 DOI: 10.1016/S0003-3472(86)80122-1