About 120 non-native plants and likely a similar number of animals (mostly insects) have been naturalized on the Brandeis campus.

Of the top 20 animals observed this year at Brandeis, 6 were invasive/naturalized: 3 birds (the house sparrow, mute swan, and European starling), a woodlouse, the gypsy moth, and the earthworm.

Of the top 20 plants, 12 were invasive, such as dandelions, English Ivy, and henbit.

The most common invasive species on campus based on iNaturalist sightings appears to be garlic mustard, which is only surpassed in observation count by the Eastern Gray Squirrel and the American Robin.

Garlic mustard (Alliaria petiolata) is an introduced European plant first recorded in North America in 1868. By 1991, garlic mustard was known in 28 eastern states of the United States. Garlic mustard--a good source of nutrients and seasoning--was historically eaten in Europe as a pot herb and likely deliberately entered and spread within North America. Without interference, garlic mustard plants drop seeds nearby, which at best are carried off by moving water. The seeds may attach to hikers and motor vehicles, which carry them on to roadsides and developed areas. As a result, garlic mustard growth is concentrated near human transportation routes.

Garlic mustard is one of the first woodland plants to emerge in the spring. In the second year of its life cycle, garlic mustard produces beautiful white flowers in the spring which develop into upright, elongate pods as the summer develops, and the plant dies back as fall approaches.

Last spring at Brandeis, garlic mustard had already begun flowering on April 24. When will this occur this year?

How have participants been partitioning the natural world in their work for our project? As you can see, just over a third of observations were of flowering plants. Fungi, mosses, and conifers make another third, and animals the rest. Captive-cultivated observations are not included.

How many different species were observed? The next chart chart reveals that nearly half of the species are flowering plants. Mammals, on the other hand, made up 11 % of observations but now only 2% of species.

The last chart shows the percentages of observations representing a new species for this project, calculated by dividing the number of species by the number of observations. The higher the number, the less attention observers are paying them in proportion to the number of species out there--or else fewer new species would be found so often. The arthropods predictably appear to require the most attention due to high insect biodiversity.

What this suggests is that if we want to maximize the number of species found by the project, we may want to shift our attention further toward ferns and arthropods, and away from mammals and mosses (mammals simply have low biodiversity; mosses are diverse but won't get ID'd on iNaturalist).