Wading Bird simulates behaviors (such as feeding nestlings, searching for fish, flying to nest, foraging, and idle time) of a nesting colony of birds. The model is an individual–oriented model, in which a population of interest is modeled as an assemblage of individuals. Each bird in the colony is simulated individually. The user can modify characteristics of the bird population, including incubation period for eggs, time to fledge, and amount of fish required for nestlings, as well as environmental characteristics such as rainfall, elevation, nest location, and abundance of fish.
The Bird Actions window (below) displays a histogram with the distribution of the current actions of the birds in the colony, the day and time, the amount of time that the birds spend engaged in various categories of behaviors. All possible actions (“behaviors”) are aggregated into five categories. For example, the first category, denoted by “idle,” contains all birds that are currently at the rookery site, but do not feed their young. This includes birds that incubate eggs, guard their nests, wait for their mate to finish feeding, or have returned from (foraging) trips and are staying at the colony for the rest of the day.
The window also displays the number of birds in the colony, the number of nests with eggs and/or nestlings, the number of nestlings, and, finally, the number of fledglings (“young birds”). The entire window is updated at each time step.
The individual actions of some of the birds in the colony are stored for the entire run. (The default is five birds, but the actions of up to half of the birds can be stored.) The stored actions are displayed in a window similar to the one below for Bird 2. The program also provides average information on the activities of all birds in the colony, including fledglings, summary statistics (average, average deviation, standard deviation, variance, skewness) of the various distributions, and population values for the entire colony. The user can change a wide variety of parameters both for the environment and for the birds themselves.
A detailed user’s manual is now available on the Library CD. This manual gives complete information for setting up and running the simulations as well as a detailed description of the model.
Macintosh (Unstable on the Power Macintosh)