Dependence on humans
The ducks become used to being fed by humans and no longer search for food sources on their own. They become bolder in the winter months when food is more scarce, even going so far as to jump on top of people. Some may think this is cute, but others are scared by this, especially when there are many ducks jumping at the same time. During storms and very cold winter days, there are fewer people out feeding the ducks and they are left hungry because humans have become their only source of food. Furthermore, there has been a high rate of ducks being hit by cars during the winter at Rockwood Park because they assume all cars are stopping to feed them.
Delayed/ failed migration
Under wild conditions, the food sources become scarcer in the fall, encouraging the ducks to forage further and further from their home pond. Eventually, they will migrate to a new home pond for the winter where food sources are more reliable and abundant. Unfortunately, as a result of being fed during the summer and fall, ducks have been found frozen in the ice because they have not followed the natural cycle of migration to a more temperate climate. We, at Rockwood Park, understand that the ducks have been fed by humans for many years and are dependent on them for food. We hope to educate well-intentioned people to stop feeding the ducks during the fall season at the very least so that we can try and mimic more ‘natural’ food conditions. While some duck species such as black ducks will remain in the area, they tend to go to salt water that does not freeze and feed on the snails, etc., in the mud. Mallards, however, do tend to migrate further south in search of places still providing vegetation for them to feed on.
A crowded habitat can lead to issues with disease as the rate of bird to bird contact is greatly increased. Like kids at a crowded daycare, once one gets a cold, they all do. Bread is also the most common food of choice that people bring for the ducks. Although the ducks enjoy the bread, it is the equivalent to them eating cupcakes every day and does not offer proper nutrition. Malnutrition in ducks only increases their chances of getting sick, especially during the winter months when no other food options are available. Alternative more nutritional food sources to bread are grapes cut in half, cracked corn, barley, oats, birdseed or other grains, frozen peas that have been defrosted, or duck feed pellets available from farm supply stores.
The Rockwood Park duck pond habitat is able to sustain approximately 2-3 pairs of ducks at one time based on size and available food sources. Currently, there are over 50 pairs of ducks that call the pond home because of an increase in food availability. The size of the pond, however, has not changed and this creates a stress on the pond as well as on the ducks that are crowded into a smaller space than is normal under wild conditions.
A large amount of ducks can create a pollution problem in the water because of the amount of feces they produce. The duck pond and Fisher lakes at Rockwood Park have been identified as having higher than normal levels of phosphorous, a nutrient which can be attributed in part to the duck feces. These lakes are associated with other waterways-which are in turn contaminated by the feces (for example, the duck pond drains into Marsh Creek). Higher nutrient levels can also cause algae blooms, which will eventually reduce the oxygen in the pond to a point that no other animals or plants will be able to survive.
Swimmer’s itch for humans
Swimmer’s itch, or duck itch, is a rash that shows up in humans when they share a freshwater swimming area with ducks. A larger than normal amount of ducks increases the chances of swimmer’s itch because it is caused by a parasite schistosomatidae that lives on the ducks. An increase in ducks is associated with an increase in these flatworm parasites. Symptoms usually occur within hours of swimming in the water, and last about a week. Although the parasites do not infect humans, an itchy rash is certainly not a memory you want to take from your day at the beach!