The uplands of KSC and the adjacent Cape Canaveral provide one of the four largest populations of the threatened Florida scrub-jay species. This is an indicator of scrub ecosystem integrity. Space program construction projects and operations directly influence the habitat and its management. Although it is possible to estimate annual changes in population size, these estimates produce confidence limits that are too great to describe annual variation that is influenced by stochastic natural processes (rainfall) and deterministic factos (changes in habitat quality). Censusing the entire population to detect annual trends is not feasible, but is is possible to quantify habitat quality of the entire area and to predict population trends based on habitat-specific demography and dispersal relationships developed from samples of the landscape. Understanding these habitat-specific relationships also allows the formulation of KSC impact evaluation, minimization, and compensation techniques, as well as recovery actions used across the species range.

Testing ecological theories facilitates model construction to extrapolate data from the uniquely colorbanded birds at the territory scale (8 hectares [ha]) and apply it to the scale of the larger population. Habitat potential of scrub-jay territories is ranked into three classes of scrub oak cover (primary, secondary, and tertiary) that result from variation in soils and topography. Territory quality also varies with fire history categorized by four classes of shrub height arrangement: all short (less than 1.2 meters), short and optimal mix (1.2 to 1.7 meters), tall mixed, and all tall (greater than 1.7 meters). Sequences of aerial photography are evaluated to quantify annual changes in territory quality using Markov Chain models that describe different habitat management scenarios. Territories on primary and secondary ridges are usually population sources, provided they have a mixture of short and optimal scrub and no tall scrub. Population sources have reproductive success that exceeds mortality and have emigration that exceeds immigration, making them net exporters of individuals to populations sinks. Territories on tertiary ridges and territories with all short, tall mix, or all tall scrub are population sinks because mortality exceeds reproductive success. Territories in many areas are becoming unoccupied because habitat is of poor quality and there are too few immigrants to sustain them. Thus, improving habitat quality provides a mechanism to compensate for habitat losses associated with facility construction. However, Florida scrub-jays have short dispersal distances and a reluctance to colonize vacant territories, so sociobiology must be considered to allocate habitat management in an optimal geographical context. These calculations are complex and best performed using a spatially explicit, individual-based population model, which is being linked to a landscape change model. These studies were published in a dozen scientific journal articles. Future field studies will continue demographic monitoring and quantify how habitat quality, population density, and distance to vacant territories influence dispersal.

• 1991: Developed habitat maps of the most important areas on KSC.
• 1992: Developed a scrub restoration and monitoring program.
• 1995: Developed techniques to map habitat suitability.
• 1996: Developed models to predict demographic success using maps.
• 1997: Tested the ability of maps and models to predict populations.
• 1998: Developed procedures to include uncertainty into decisionmaking.
• 2000: Developed procedures to project landscape changes
• 2001: Developed an approach to link habitat and population dynamics.

Key milestones:

This figure shows population changes among potential habitats from 1989 to 2000 near Tel-4 at Cape Canaveral Air Force Station. Study years begin on April 1 and end on March 31. The number of breeding pairs remained stable in primary habitat and fluctuated most in tertiary habitat because of a flux of immigrants in 1995. Density-dependent reductions in demographic success associated with crowding effects greatly reduced population size following this event. Extensive wildfires in 1998 also reduced habitat suitability for the short term but increased habitat suitability across the long term. Reproductive success and survival improved greatly in 1999 and 2000 as population density declined and scrub oaks recovered from fire.