Restoration Potential: Generally have responded well to restoration efforts. Recovery plans for the U.S. populations have been implemented and selected problematic organochlorines (e.g., DDT) have been banned/regulated. These actions enabled population recovery and led to federal delisting of populations along the Atlantic coast and in Florida and Alabama. Populations along the U.S. west coast have rebounded strongly and have been recommended for downgrading (from endangered to threatened) (D.W. Anderson, pers. comm.). Gulf coast populations are exhibiting increasing trends and successful reintroduction efforts continue (McNease et al. 1992). However, restoration actions implemented so far have not resulted in the recovery of populations in the U.S. Caribbean, where foraging habitat quality may be a problem. In many instances, habitat can be enhanced or created (e.g., spoil islands, jetties). These habitats provide important habitat for both roosting and nesting populations (Jaques and Anderson 1987, Parnell and Shields 1990).
Preserve Selection and Design Considerations: Elements for preserve selection and design include vegetation characteristics, size of island, distance to mainland, distance to nearest human disturbance, availability of sand bars, use patterns in the vicinity of the site in question, and historical use of the site (Collazo and Klaas 1986, Hingtgen and Mulholland 1983, Schreiber 1979, Schreiber and Schreiber 1982). Schreiber and Schreiber (1982) stressed the need to protect not only nesting sites but also loafing and roosting sites because these sites could eventually become nesting sites. They also suggested that sand bars are important to juveniles lacking sufficient skills to land on trees. Traditional sites deserve special protection because they tend to be re-used for many years.
In the tropics and subtropics, mangroves constitute an important nesting and roosting substrate. In the U.S. Caribbean, structural suitability of mangrove sites can be assessed by using a linear classification rule (discriminant function analysis) based on structural variables of roosting and nesting sites (Collazo and Klaas 1985).
Human disturbance is a critical factor in the suitability of roosting and nesting habitat (Schreiber 1979, Schreiber and Schreiber 1982). Precise figures of undesirable levels of human disturbance are difficult to assess a priori. Available information suggests that human disturbance should not be allowed within 100 to 600 meters of roosting or nesting site (Jaques and Anderson 1987, Anderson 1988, Collazo and Klaas 1986, Schreiber 1979). Variability in threshold distances is attributed to the levels of disturbance to which pelicans previously have been exposed. In some cases (e.g., U.S. Caribbean, California), high levels of human disturbance is tolerated because there is vertical separation between birds (e.g., roosting/nesting on a cliff) and the source of disturbance. In those cases, efforts should be made to avoid providing access to humans (e.g., recreational) (Jaques and Anderson 1987).
Management Requirements: The recovery plans for each population (i.e., California, Eastern, Caribbean) outline recovery and conservation actions required to delist the species. See also California Department of Fish and Game (1990) for information on management actions and needs for the Southern California Bight population.
Environmental contaminants are not considered limiting factors for any population at present. Recovery and management efforts for those populations still designated as endangered are more focused on habitat degradation, human disturbance, and maintaining consistent monitoring efforts (e.g., numbers, productivity). Human disturbance (e.g., recreational boating, poaching) disrupts pelican reproductive output. Disturbance is not only detrimental to nesting efforts, but it may affect distribution patterns and age structure of pelicans using roosting sites during the nonreproductive season (Jaques and Anderson 1987).
Management Research Needs: Management/research needs are outlined in the recovery plans. Needs for California and Gulf populations are focused on monitoring efforts. For the California population, there is a need to revise the operational definition for a recovered population such that it is based on cumulative information (D.W. Anderson, pers. comm.).
In the U.S. Caribbean, recovery efforts should be directed to monitoring breeding productivity and evaluating foraging habitat quality. It is necessary to partition the potential effects of foraging habitat degradation from oceanic influences. The following specific research needs have been identified as a result of the ongoing status review of the species sponsored by the U.S. Fish and Wildlife Service:
1) Productivity: There is a need to obtain accurate estimates of breeding productivity (i.e., chicks per breeding pair). These estimates, as in the early 1980s, should be obtained from as many colonies as possible.
2) Food availability: This is perhaps the underlying factor affecting pelicans in the U.S. Caribbean at present. While difficult to tackle, there is a need to gain insights on the quality and quantity of resources by focusing on the following: a) monitor prey levels at selected sites--there are baseline data from these sites for comparative purposes; b) monitor prey species composition and size frequency brought to young by adults at selected colonies--this would be considered an index of present conditions vs. early 1980s (there are baseline data on these metrics); ancillary data could consist of monitoring where pelicans are going to get their prey and develop an index to evaluate prey availability at feeding sites; c) monitor "bait" fish landings in Puerto Rico--this is a broad category including anchovies and sardines; both groups, however, are consumed by pelicans; data should be useful to test for trends (after applying correction factors) and as an index of general food availability; data could be broken down by point of origin (e.g., fishermen village).
3) Habitat degradation: Research available literature on causes and effects of siltation on tropical coastal ecosystems, and identify any ongoing work documenting and/or monitoring such effects.
4) Movements: There is a possibility that dispersal patterns of U.S. Virgin Islands birds may have changed. In the 1980s, 47% of the juveniles banded in the U.S. Virgin Islands were recorded in Puerto Rico. A decrease in the proportion of birds moving to Puerto Rico coupled with lower productivity in the U.S. Virgin Islands could help explain the low numbers recorded during recent surveys (i.e., 1993-95).
Biological Research Needs: Continued research needed range wide on the effects of poisons and pesticides, disease, and parasitism in the population. Life history study of this long-lived species is needed to determine better habitat requirements, limiting factors, and natural mortality.
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