Robert E. Bennetts
U.S. Department of Agriculture - Natural Resources Conservation Service (NRCS) Department of the Interior - U.S. Geological Survey Department of Commerce - National Oceanic and Atmospheric Administration (NOAA) Environmental Protection Agency (EPA) Smithsonian Institution - National Museum of Natural History (NMNH)
Estimation of nesting success using the two largest colonies of each colony group.
Flight line counts will be made at the two largest colonies in each colony group.
Nestlings will banded with both USFWS and individually-numbered PVC bands between 7 and 14 days of age. Resighting of banded nestlings in FY 2003 is planned to occur just prior to dispersal to enable estimation of survival.
No funding was available for work on Limpkins in FY 2003.
All islands previously reported to have spoonbill colonies will be surveyed at least twice during the nesting season and the number of spoonbill nests counted. Colonies will be grouped into five subregions based on proximal foraging location for each. The two largest colonies within each of five subregions will be used to estimate nesting success for each group.
Work planned for FY2004-05 includes:
1. Spoonbill nests are generally located in dense red mangrove stands and are not generally visible from outside the colony. Therefore, all possible colonies locations must be visited by researchers in order to get an accurate nest count for Florida Bay. While traversing Florida Bay by boat, locations of Roseate Spoonbill activity will be investigated for new nesting sites.
2. The two largest colonies within each colony group will be used to estimate nesting success for each group. Survey transects will be established in each of these colonies so that representative samples of nests can be monitored. Each colony will be visited approximately every ten days and the contents of each nest were recorded.
In order to use nesting effort and nest success as criteria for ecosystem evaluation, the location of primary foraging grounds must be known for each colony group. This enables predictions about the response of mangrove fishes and nesting spoonbills to be directly evaluated in relation to hydrologic conditions relevant to a particular colony.
Work planned for FY2004-05 includes:
1. Flight line counts will be made at the two largest colonies in each colony group. Initially, the colony island will be circumnavigated by boat in order to determine the least number of positions needed to observe birds arriving and leaving the colony from any direction. Once identified, the boat will be anchored at each position for a predetermined amount of time and the number and direction (compass heading) of Roseate Spoonbills arriving and leaving the colony counted. The results of these observation will indicate the direction of the primary foraging grounds for the colony groups.
2. Although the flight line count technique is widely accepted in the study of wading bird foraging pattern, supplemental data from following flights would greatly increase the credibility of these observations and enable specific foraging destinations to be determined. Individual birds will be followed using a fixed-wing aircraft from their nesting colonies to the first foraging location
Nesting activity for Roseate Spoonbills has been monitored since 1950; however, there has been no effort to date to directly relate demography and environmental conditions, with the exception of nesting success. Direct estimation of demographic parameters would enable us to better understand the demographic mechanisms of observed responses by spoonbills (e.g., to distinguish numerical from behavioral responses). Consequently, we will use capture-resighting to estimate (1) survival of nestlings from branching until fledging, (2) survival of juveniles and adults, (3) recruitment into the breeding population, and (4) breeding dispersal.
Work planned for FY 2004-05 includes:
1.Nestlings would be banded with both USFWS and individually-numbered PVC bands between the ages of 7-14 days. This would be concurrent with nest checks used to determine nesting success.
2. Resighting of banded nestlings during FY2003 would occur just prior to dispersal to enable estimation of survival from the time of branching to the time of dispersal. In subsequent years, resightings of adults will also occur at the nest and during staging just prior to nest initiation.
Based on previous research, an initial conceptual model will be developed that summarizes the relationship among the distribution and success of nesting spoonbills, the abundance and availability of mangrove fishes, and hydrology. This model should enable predictions about how nesting spoonbills and fishes should respond to a given set of hydrologic conditions. As such, the data collected during this study will constitutes a validation of the initial conceptual model. The validation process, then also serves as a mechanism by which this initial model can be refined.
Work planned for FY 2003-04 includes:
1.Synthesis of existing research on the relationship between water levels, mangrove fishes, and the distribution and success of nesting spoonbills. Expression of these relationships in terms of hypotheses regarding wet and dry season water levels and the response by fishes and spoonbills. Establishment of preliminary quantitative relationship among relevant parameters which enable predictions of hypothesized relationships.
2. Collaboration with ATLSS modeling team to formalize the conceptual model into a preliminary working model that can be used to compare hypothesized and observed responses to hydrologic variation.
U.S. Department of the Interior, U.S. Geological Survey, Center for
Coastal Geology
Comments and suggestions? Contact: Heather
Henkel - Webmaster
Generated by mp version 2.7.33 on Wed Apr 21 15:46:22 2004