USGS



BIOLOGICAL AND ECOTOXICOLOGICAL CHARACTERISTICS OF TERRESTRIAL VERTEBRATE SPECIES RESIDING IN ESTUARIES

Brown Pelican Brown Pelican photo, Photo Courtesy of Francine K. Rattner
Photo Courtesy of Francine K. Rattner
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Biological Characteristics

Species

Pelecanus occidentalis is a large bird, about 114-137 cm in length. Males tend to have a greater average mass (3.7 kg) than females (3.2 kg) (Dunning, 1993). In adults, the body is brown and the head is white, and in young both are brown. The most prominent feature of this bird is its large bill and throat pouch (Bull and Farrand, 1977).

Status in Estuaries

Brown pelicans are colonial breeders that typically nest in vegetation located on coastal islands or on sandy beaches and lagoons. Nests are usually found in trees or in low bushes, but can occasionally be found on the ground (Williams, 1980; Bull and Farrand, 1977). Typical clutch size is 3 eggs. Young are altricial (Ehrlich et al., 1988). The maximum age of brown pelican recorded from nature is 19 years (Clapp et al., 1982).

Abundance and Range

Historically, the species was found nesting south of Virginia, yet since 1987 colonies have also been found in Maryland and Virginia (Bull and Farrand, 1977; Wilkinson, 1994). As of 1991, about 27 brown pelican colonies were found in Maryland, Virginia, North Carolina, South Carolina, Georgia, and Floridas Atlantic coast. The total Atlantic coast population was estimated at 13,737 individuals in 1991 (Wilkinson, 1994). Recent census estimates populations of 93,000 individuals, with 31,340 on the Atlantic coast and 43,524 on the Gulf coast (NACWCP, 2001)

Site Fidelity

Moderate

Ease of Census

Simple. Its large size and unique features such as the throat pouch make this a relatively easy to species to census (Williams, 1980).

Feeding Habits

Piscivorous. This species primarily feeds in shallow estuarine waters, but may be seen up to 40 miles offshore (Clapp et al., 1982). Fish, the main prey of the pelican, is caught by diving, and menhaden is a particular preference. The pelican will occasionally feed on prawns (Palmer, 1976).


Brown Pelican Contaminant Exposure Data

I.

Organochlorine Contaminants

A.

Concentrations in Adults, Juveniles, and Nestlings

1.

In 1969, apparently healthy brown pelicans from the Anacapa Islands were analyzed for PCBs (Bischoff et al., 1970). Average concentrations were found to be 144 g/g in the fat and 163 g/g in the flesh. In addition to analyzing healthy birds, brown pelicans found dead along the coast of California were also analyzed for PCBs. Concentrations averaged 60.4 g/g in the brain and 179.0 g/g in the flesh.

2.

In 1970, carcasses of brown pelicans from Florida and South Carolina were examined for organochlorine contamination (Blus et al., 1974a). Adult and immature birds had higher concentrations of organochlorines in their tissues than newly hatched birds (1 to 13 weeks old). In general, low levels of DDD, DDT, mirex, and dieldrin were detected in all birds sampled. DDE was highest in an immature bird from Florida's Gulf Coast at 31.00 g/g wet weight. PCBs were highest at 35.0 g/g in an adult bird collected from South Carolina. One pelican exhibited tremors immediately prior to death and had concentrations of 11.04 g/g DDE and 20.0 g/g PCBs in the carcass. In the brain of this bird, levels of DDE were similar and levels of PCBs were lower. All other organochlorines occurred at lower concentrations.

3.

Organochlorine concentrations were measured in the brain, fat, liver, and muscle of adult and nestling brown pelicans collected from Florida in 1971 and 1972 (Nesbitt et al., 1981). The highest levels of organochlorines were found in the fat. DDE was 5.339 g/g wet weight in the fat of healthy birds sampled from the juvenile, sub-adult and adult age groups and 13.193 g/g for the nestlings. No age-related differences in contaminant burden were detected between healthy groups, though higher residue levels were found in "sick" and dying birds. All values detected in the brown pelicans were found to be less than those known to cause reproductive failure.

4.

Pelicans found dead from South Carolina, Georgia, the Atlantic coast of Florida and from Florida Bay between 1971 and 1973 were analyzed for organochlorine contaminants (Blus et al., 1977). The highest concentrations of DDE and PCBs were found in birds collected from Florida's Atlantic Coast. DDE levels reached 10.00 g/g wet weight and PCBs reached 25.0 g/g in the carcass of the same adult female. In South Carolina, values of all organochlorines tested were <1 g/g, with the exception of PCBs, which were 4.0 g/g in the carcass of a male collected in 1971. Concentrations of organochlorines were generally higher in the single adult female collected from Georgia, at levels of 5.50 g/g DDE, 5.30 g/g dieldrin and 10.0 g/g PCBs. Low levels of organochlorines were detected in all birds collected from Florida Bay.

5.

Organochlorine residues were measured in adipose tissue and breast muscle of adult brown pelicans collected in 1972, 1973 and 1975 from nesting locations on the Gulf of California (Keith., 1978). DDE was highest in the adipose tissue at 161 g/g wet weight in 1973. DDD was also highest in adipose tissue at 3.6 g/g in 1972 and in 1973. DDT (4.0 g/g), endrin (1.1 g/g), dieldrin (2.1 g/g) and PCBs (53 g/g) were all highest in 1973.

6.

Seven brown pelicans found dead between 1974 and 1975 in South Carolina were collected for organochlorine analysis (Blus et al., 1979b). Organochlorine contaminant concentrations were higher in adults collected in 1975 than in nestlings collected in 1974, though still lower than established lethal levels. Highest individual levels detected were in adult males, at 3.43 g/g wet weight DDE in the brain, and 1.25 g/g TDE, 1.87 g/g dieldrin, and 38.80 g/g PCBs in the carcass.

7.

Nine brown pelicans collected from the Gulf of California in 1980 and one pelican found dead from Anacapa Island all contained <1 g/g wet weight DDE in the carcass homogenate, breast muscle, and wing muscle (Ohlendorf et al., 1985).

B.

Concentration in Eggs

1.

In 1969, 10 brown pelican eggs were collected from Anacapa Island, California (Lamont et al., 1970). Residue levels in the eggs ranged from 39.5 g/g to 135.0 g/g wet weight p,p-DDE, 0.3-3.4 g/g p,p-DDD and 0.6-3.8 g/g p,p-DDT. Concentrations of o,p-DDT and o,p-DDD were 0.1 g/g and concentrations of dieldrin 0.2 g/g. PCBs were present in all samples.

2.

In 1969, eggs were collected from Los Coronados, San Martin Island, and San Benito Islands located in northwest Baja California (Jehl, 1973). Mean DDE (1310 g/g lipid weight), DDT (22.0 g/g), DDD (37.6 g/g), PCBs (361 g/g) and dieldrin (20 g/g) were highest from Los Coronados. Endrin was not detected at Los Coronados and at San Benito Islands but averaged 1.7 g/g from San Martin Island. In 1970 eggs were again collected from Los Coronados and all contaminants analyzed (DDE, DDT, DDD, and PCBs) were lower than 1969 values.

3.

From 1969 to 1974, eggs were collected from South California, Northwestern Baja California, and West-central Baja California (Anderson et al., 1975). In 1969, total DDT from southern California and northwestern Baja California was 1204.3 g/g lipid weight in crushed eggs and 906.7 g/g in intact eggs. A decline in total DDT occurred steadily and by 1974 residues measured 96.6 g/g, all eggs intact. In West-central Baja California total DDT in 1969 measured 96.1 g/g, all eggs intact.

4.

From 1969 to 1970, eggs were collected from South Carolina, numerous locations throughout Florida, and in California (Blus et al., 1974b). Residues in South Carolina eggs were highest in Deveaux Bank, reaching geometric means of 6.36 g/g wet weight DDE, 1.81 g/g DDD, and 6.99 g/g PCBs. Low concentrations of DDT and dieldrin were detected at all locations. Residues in eggs from various locations throughout Florida were highest from an Atlantic coast colony at geometric means of 2.44 g/g DDE and 1.98 g/g PCBs. Low levels of DDD, DDT, and dieldrin were detected at all locations. Residues in eggs from Anacapa, California had geometric means of 71.35 g/g DDE was wet weight and 3.60 g/g PCBs. All other organochlorines were detected at lower concentrations.

5.

From 1969 to 1970, 172 eggs were collected from brown pelicans located in Florida (Schreiber and Risebrough, 1972). Mean total DDT was detected in all Florida locations at concentrations ranging from 1.19 to 2.90 g/g wet weight. PCBs were highest in Saint Petersburg in 1969 at 6.21 g/g and lowest in Key Charlotte Harbor in 1970 at 2.20 g/g.

6.

In 1970, eleven brown pelican eggs were collected from various locations in Texas (King et al., 1978). Mean contaminant concentrations were 3.23 g/g wet weight DDT (sum of DDD, DDE and DDT) and 9.73 g/g PCB. Dieldrin was not detected.

7.

Eggs were collected in 1970 (N=11) and 1974 (N=5) from the Gulf Coast of Texas (King and Flickinger, 1977). In 1970, mean (range) residues concentrations were 3.2 (2.4-4.2) g/g wet weight DDE and 10 (3-20) g/g PCB. In 1974, residues had dropped to 0.86 (0.29-1.40) g/g DDE and 3.0 (1.30-4.70) g/g PCB. In 1974 low levels of dieldrin, endrin and DDD were also detected.

8.

In 1971, 40 "apparently viable" and 3 "apparently non-viable" brown pelican eggs were collected, and in general the more contaminated eggs were from the eastern coast of Florida (Thompson et al., 1977a). Total DDT was 1.318 g/g wet weight along the eastern coast of Florida and 1.191 g/g along the western coast. Dieldrin was detected at concentrations <1 g/g along both coasts and PCBs (1254) were significantly greater along the eastern coast at 2.241 g/g than the western coast at 1.038 g/g .

9.

In 1971, 1972, and 1973, brown pelican eggs were collected from Marsh Island and Deveaux Bank, South Carolina (Blus et al., 1977). In 1971, the geometric mean for DDE was 2.48 g/g wet weight at both locations and PCBs were highest in eggs from Deveaux Bank at 6.48 g/g. In 1972, a slight increase in DDE and PCB concentrations were seen. Geometric means were highest for both substances at Deveaux Bank at 3.05 g/g DDE and 8.79 g/g PCBs. This slight increase reversed in 1973 when the geometric means dropped to 2.16 g/g for DDE and to 4.62 g/g for PCBs. All other organochlorines were <1 g/g in all three years.

10.

In 1971 and 1972, freshly laid eggs were collected from the Cape Romain National Wildlife Refuge (Blus et al., 1974b). Geometric mean values for DDE were significantly higher in eggs from unsuccessful nests, 3.43 g/g wet weight, than from successful nests, 1.77 g/g. Dieldrin and DDD were also significantly higher in unsuccessful nests. PCBs were suggested to be higher in unsuccessful nests, 7.94 g/g, than in successful nests, 5.50 g/g, but the apparent difference was not statistically significant.

11.

In order to restore the Louisiana population of brown pelicans, 465 nestlings were transplanted from Florida to Louisiana from 1968 to 1973 (Blus et al., 1975). From 1971 to 1973, 36 eggs of brown pelicans in Louisiana were collected for contaminant analysis. The geometric mean concentration of DDE was greatest in 1972 at 1.36 g/g wet weight. DDD, DDT, dieldrin, heptachlor epoxide, cis-chlordane, cis-nonachlor, and toxaphene were all detected at <1 g/g. PCBs were highest in 1971 at 3.91 g/g. Endrin, which was hypothesized to be the cause of the previous population crash in Louisiana, was not detected any of the eggs examined. It should be noted however that in a later paper (Blus et al., 1979a) the authors stated "we previously reported an absence of endrin in brown pelican eggs collected in Louisiana from 1971 through 1973. Since then, we reanalyzed those eggs and found endrin in all of them."

12.

From 1971 to 1976, organochlorine contaminants were measured in brown pelican eggs laid in Louisiana (Blus et al., 1979a). The geometric mean was highest for DDE in 1972 at 1.36 g/g wet weight and for dieldrin in 1975 at 1.08 g/g. DDD, DDT, heptachlor epoxide, chlordanes, toxaphene, and endrin were all detected at means <1 g/g wet weight. PCBs were detected at a high concentration of 3.91 g/g.

13.

A brown pelican egg collected in 1972 along the west coast of Florida contained concentrations of 2.46 g/g dry weight DDE, 1.30 g/g PCB, and 0.10 g/g dieldrin (Lincer and Salkind, 1973).

14.

Eggs were collected from two locations in South Carolina and along the coast of Florida in 1974, and again from South Carolina in 1975 (Blus et al., 1979b). For South Carolina in 1974, the average geometric mean concentrations for DDE were 2.35 g/g wet weight in eggs from Marsh Island and 1.96 g/g from Deveaux Bank. The geometric mean for PCBs was highest at 8.32 g/g from Marsh Island. In 1975, residue levels were again highest at Marsh Island, with geometric means of 1.30 g/g DDE, and 7.23 g/g PCBs. In Florida, the geometric means of both residues were highest on the Atlantic Coast at 1.32 g/g DDE at Port Orange and 7.79 g/g PCBs at Fort Pierce. All other organochlorines were detected at levels <1 g/g in both states for both years.

15.

From 1975 to 1981, 103 addled eggs were collected from coastal areas of Texas (King et al., 1985). Variations in DDE concentrations were observed during the sampling years, yet no significant decrease was seen between 1975 and 1981. Specifically, geometric mean concentrations ranged from 0.9 g/g wet weight in 1979 up to 2.3 g/g in 1977. Very low concentrations of DDD, DDT, dieldrin and chlordane were detected in all eggs sampled. A drop in PCB concentration occurred between 1975 (4.0 g/g) and 1981 (1.1 g/g) yet was not found to be significant.

16.

In 1977, eggs were collected from two South Carolina colonies: Deveaux Banks and Cape Romain National Wildlife Refuge (Mendenhall et al., 1978). Geometric means for DDE, DDD, DDT, dieldrin, cis-chlordane, trans-nonachlor, cis-nonachlor, and toxaphene were <1 g/g wet weight. PCBs occurred at a geometric mean concentration of 5.3 g/g. When examining contaminant trends in these colonies between 1969 and 1977 a significant decrease in DDE and dieldrin occurred. No significant drop in PCBs was seen. The author noted that the eggs collected in 1977 represented the first sampling in which all eggs had DDE residues lower than 2.5 g/g and dieldrin below 0.54 g/g, levels that have previously been associated with nest failure in this species.

17.

From 1980-82 and 1992-93, brown pelican eggs (N=46) were collected from one site in Puerto Rico (Montalva Bay), and three sites in the U.S. Virgin Islands (Congo Cay, Ducthcap Cay, and Conejo Cay) (Collazo et al., 1998).  In eggs collected between 1980-82, concentrations of DDE and PCB were significantly higher at the Puerto Rico site (0.65 and 7.84 g/g wet weight, respectively), than the Virgin Islands sites (0.06 and 1.00 g/g).  Contaminant concentrations were significantly lower in eggs collected in 1992-93, and there were no significant geographic differences.  Concentrations of DDE and PCB were 0.01 and 0.13 g/g at Puerto Rico, and 0.02 and 0.30 g/g in the Virgin Islands.

18.

Eggs were taken from a dredge spoil island and a control site off the South Carolina coast in 1994 (Wickliffe and Bickham, 1998).  The mean concentration of TCDD-EQ was below detection at the control site and 4.5 pg/g wet weight at the spoil site.

II.

Cholinesterase-Inhibiting Pesticides

 

No direct exposure data available

III.

Trace Elements, Metals, and Metalloids

A.

Concentrations in Adults and Nestlings

1.

In 1970, hepatic metal concentrations were determined in four brown pelicans found dead in Florida and South Carolina (Blus et al., 1977). Low concentrations of Cr, Ni, As, Cd, Cu, Zn and Mg were detected. Selenium occurred at a high concentration of 4.42 g/g wet weight, Hg at 4.10 g/g, and Pb was detected at 0.10 g/g in all four birds.

2.

Metal concentrations in livers of nestling, immature and adult brown pelicans were measured in birds found dead in South Carolina, Florida, and Georgia in 1972 and 1973 (Blus et al., 1977). Chromium and Ni concentrations were <0.1 g/g wet weight. Selenium was highest (4.04 g/g) in an immature male collected from Florida. Arsenic had a maximum at 1.02 g/g, Hg at 6.30 g/g and Pb at 0.27 g/g. Low concentrations of Cd, Cu, Zn, and Mg were detected. Mercury was also measured in the liver of birds shot in Florida and South Carolina in 1970, and the maximum value was 4.10 g/g in a bird from Florida.

3.

In 1980, nine brown pelicans (collected by shotgun) and one found dead from the Gulf of California were analyzed for metals (Ohlendorf et al., 1985). Arsenic occurred at similar concentrations in the liver and in the kidney at 0.32 and 0.21 g/g dry weight. Copper (23.5 g/g) and Se (21.1 g/g) were highest in the liver and Cd (18.2 g/g) and Cr (3.71 g/g) were highest in the kidney. Lead and Zn were highest in the humerus at arithmetic means of 7.44 and 108.1 g/g, respectively.

4.

In 1996, liver and kidneys were collected from terminally ill (from type C botulism) brown pelicans from Salton Sea National Wildlife Refuge (n=9), and healthy brown pelicans at Sea World of California, San Diego (n=4) (Bruehler and de Peyster, 1999).   Elements were detected in all samples unless noted.  Liver and kidney geometric mean concentrations and ranges of Se were 16.9 (13.0 - 34.3) and 18.8 (13.8 27.2) g/g dry weight from Salton Sea, and 9.3 (4.4 - 13.1) and 13.9 (6.5 28.7) g/g from Sea World.  Liver and kidney concentrations of Zn were 148 (71 - 294) and 86 (30 156) g/g from Salton Sea, and 238 (139 - 422) and 86 (67 110) g/g from Sea World.  Liver concentrations of Fe were 2,513 (942 - 4,927) g/g from the Salton Sea, and 7,342 (5,570 - 13,189) g/g from Sea World.  Liver and kidney concentrations of Cd were 0.58 (0.27 1.62) and 2.3 (0.96 7.22) g/g for Salton Sea, and 0.59 (0.4 1.5) and 3.6 (2.7 4.8) g/g for Sea World.  Liver concentrations of Cr were <0.0025 0.478 g/g for Salton Sea (n = 1/9), and <0.0025 0.323 g/g for Sea World (n = 2/4).  Liver concentrations for Pb were <0.0125 g/g for Salton Sea (n = 0/9), and <0.0125 g/g for Sea World (n = 0/4). Liver and kidney concentrations of Cu were 18.6 (8.5 34.4) and 9.2 (6.7 11.3) g/g for Salton Sea, and 15.1 (9.1 38.8) and 7.2 (6.2 9.5) g/g for Sea World.

B.

Concentrations in Eggs

1.

In 1969, eggs collected from South Carolina, Florida, and California were analyzed for metal content (Blus et al., 1974a). The geometric mean for Hg reached a maximum of 0.83 g/g wet weight at Matlacha located on Florida's Gulf Coast. Lead was detected at trace concentrations from all locations. The only measurable concentration of Pb, 0.17 g/g, occurred at Anacapa, California. In 1970, eggs collected from South Carolina and Florida Bay had Hg concentrations of 0.44 and 0.46 g/g, respectively. Lead was not reported in South Carolina samples, and was only detected in trace quantities in samples from Florida.

2.

Brown pelican eggs collected from Florida, between 1969 and 1970, and from South Carolina, between 1971 and 1972, were analyzed for metals (Blus et al., 1977). Arsenic occurred at higher concentrations in South Carolina, 0.31 g/g wet weight, than in Florida, 0.10 g/g. Little difference existed between sites for all metals analyzed.

3.

In 1972, metals were measured in the eggs of brown pelicans transplanted to Louisiana from Florida (Blus et al., 1975). Metals were detected at the following geometric mean concentrations (g/g wet weight): 0.004 Cd, 1.15 Cu, 5.9 Zn, 0.024 Ni, 0.08 Hg, and 0.016 Pb. The author notes that based on their incomplete knowlege of the effects of metals on brown pelicans, it is not believed that these concentrations pose a threat.

4.

From 1975 to 1978, metal analysis was completed on 33 brown pelican eggs collected from the coast of Texas (King et al., 1985). Arsenic was at a maximum concentration in 1977 at 0.25 g/g wet weight, Hg in 1978 at 0.28 g/g, and Se and Zn in 1976 at 0.50 and 8.82 g/g, respectively. The author notes that these concentrations are lower than those known to adversely affect hatchability and nestling survival in other bird species.

5.

From 1980-82 and 1992-93, brown pelican eggs (N=46) were collected from one site in Puerto Rico (Montalva Bay), and three sites in the U.S. Virgin Islands (Congo Cay, Ducthcap Cay, and Conejo Cay) (Collazo et al., 1998).  Concentrations of Hg were significantly greater in eggs collected in 1980-82 (0.205 g/g wet weight) than in those collected in 1992-92 (0.0001 g/g).    Concentrations of Hg did not differ between sites.

6.

Eggs were taken from a dredge spoil island and a control site off the South Carolina coast in 1994 (Wickliffe and Bickham, 1998).  Mean concentrations of As, Se, and Hg were 0.01, 0.34, and 0.26 g/g wet weight, respectively, at the spoil site and 0.03, 0.38, and 0.34 g/g at the control site.

IV.

Petroleum

1.

Interactions of brown pelicans with floating oil were studied in an area of naturally-occurring oil seeps off Coal Oil Point, Santa Barbara Channel, California (Varoujean, 1982). Juveniles were found to make more contact with oil seepage slicks than adults. Of pelicans resting and feeding in the vicinity of the slicks, 40% made contact with the oil.

V.

Other Contaminants

1.

Brown pelican livers had the following concentrations (in ng/g) of perfluorooctane sulfonate: 48, 106, 125, 134, and 159 from Miami, Florida; <6, 6, 16, 32, and 36 from Calipatra, California; and 31, 71, 75, 91, and 194 from Ft. Lauderdale, Florida (Minnesota Mining and Manufacturing Company 2000).

Brown Pelican Contaminant Response Data

I.

Organochlorine Contaminants

A.

Eggshell Thinning and Reproductive Success

1.

A series of population declines and extirpations have occurred (Blus, 1970). The subspecies Pelecanus occidentalis carolinensis was extirpated in the Gulf of Mexico in the early 1960's. In South Carolina, breeding birds dropped from over 5000 pairs in the early 1960's to 1250 pairs by 1969. In California, brown pelicans experienced total reproductive failure in the late 1960's.

2.

Significant decreases in shell thickness were measured in brown pelican eggs collected from Florida (N=81) and from South Carolina (N=49) (Blus., 1970). When compared to pre-1947 eggs, a 7.5 % decrease was seen in Florida eggs and a 16.9% decrease in South Carolina eggs.

3.

Eighty-seven eggs collected from various locations in Florida from 1969 to 1970 showed a 9% decrease in mean shell thickness when compared to pre-1943 eggs from Florida (Schreiber and Risebrough, 1972).

4.

In 1969 and 1970, brown pelican eggs from Florida and South Carolina were significantly thinner than the pre-1947 eggs (Blus et al., 1974a).

5.

From 1969 to 1971 productivity and eggshell thickness was measured in three brown pelican colonies, Los Coronados, San Marin, and San Benito Island, located in northwestern Baja California (Jehl, 1973). In 1969, no young were produced from Los Coronados, 80-100 were produced from San Martin, and 50-100 were produced from San Benito Island. In 1970, only 3-5 young were produced from Los Coronados, none from San Martin and only 1 from San Benito Island. In 1971, the number of young produced in all three colonies rose to 30-40 from Los Coronados, 10 from San Martin, and 260 from San Benito Island. Eggshell thickness values for all three colonies ranged from 0.303 to 0.468 mm, compared a pre-1943 mean of 0.57 mm.

6.

After major reproductive problems, an increase in brown pelican productivity on the Pacific coast of southern California and in northwest Baja California from 1969 to 1974 was found to occur with an increase in eggshell thickness (Anderson et al., 1975). The number of young fledged rose from 4 in 1969 to 1185 in 1974. By 1980, this number had risen to 1865 (Anderson and Gress, 1983). Though shell thickness had increased, measurements in 1974 were still significantly less than normal.

7.

From 1969 to 1976, shell thickness from 150 Tampa Bay, Florida eggs was measured and compared to pre-1943 values (Schreiber, 1977). From 1969 through 1973 shells were found to be 5% to 12% thinner than historical values. A steady increase in thickness occurred from 1974 (6% thinner) until 1976 (2% thinner).

8.

From 1969 to 1977, significant declines in South Carolina organochlorine residues (except PCBs) were coupled with an increase in shell thickness, reproductive success, and population levels (Blus, 1982). By 1980, the South Carolina breeding population had increased to about 4800 breeding pairs.

9.

The number of brown pelican nests observed from 1969 to 1978 in South Carolina increased from 1266 to 3353 (Mendenhall et al., 1978). An increase in nest success was also observed in that time period in that the number of fledged young per nest rose from 0.78 to 1.35. Despite these improvements, eggs measured from this colony in 1978 were still 6% thinner than pre-1947 eggs.

10.

To determine average shell thickness, 14 pelican eggs were collected from Texas in 1970 (King et al., 1978). There was a significant 11% decrease in shell thickness between eggs collected in 1970 and the thickness of 43 eggs collected prior to 1947.

11.

Eggs collected from Texas in 1970 (N=11) and 1974 (N=5) were 10% and 8% thinner than historical values (King and Flickinger, 1977).

12.

Eggshell thickness in coastal Texas from 1970 through 1981 was at a maximum in 1977 (4% thinner than historical values) and a minimum in 1978-79 (14% thinner) (King et al., 1985).

13.

In 1971 and 1972, eggs collected from unsuccessful nests at the Cape Romain National Wildlife Refuge had significantly higher levels of DDE, dieldrin, and DDD than successful nests (Blus et al., 1974b). PCBs were also higher in unsuccessful nests though not significantly

14.

Eggshell thickness of Louisiana brown pelicans was 7% lower than pre-1947 eggs in 1971 and 12% lower in 1972 and 1973 (Blus et al., 1975).

15.

A total of 147 brown pelican eggs collected from Louisiana between 1971 and 1976 showed a decrease of 6.7 to 13.5% in shell thickness when compared to pre-1947 eggs (Blus et al., 1979a).

16.

Data from South Carolina, Louisiana, and Florida were analyzed to examine the relationship between organochlorine levels and nest success (Blus, 1982). Successful nests (those nests which had at least one downy young leave the nest) tended to have lower organochlorine values (DDT, DDD, DDE, dieldrin and PCBs) than unsuccessful nests.

17.

From 1980-82 and 1992-93, brown pelican eggs (N=46) were collected from one site in Puerto Rico (Montalva Bay), and three sites in the U.S. Virgin Islands (Congo Cay, Ducthcap Cay, and Conejo Cay) (Collazo et al., 1998).  Overall eggshell thickness increased from 0.496 mm in 1980-82 to 0.526 mm in 1992-93.  Both values were within the 95% confidence intervals of pre-1947 eggs (0.510 mm). 

B.

Biochemical and Morphological Responses

1.

An adult female pelican found in Georgia between 1971 and 1973 with organochlorine levels of 5.50 g/g DDE, 5.30 g/g dieldrin and 10.0 g/g PCBs, was suspected to have died from myocardial necrosis and dieldrin poisoning (Blus et al., 1977).

2.

The distribution of DDT was examined in birds that were fed versus those which were starved (Thompson et al., 1977b). After 1 week, a significant increase in the concentration of DDE was seen in the fat of starved birds as compared to those that were fed. After 2 weeks a significant increase of DDE was also seen in the brain of starved birds, and continued to occur in the fat.

3.

In 1974, 300 of the 465 brown pelicans transplanted from Florida to Louisiana were believed to have died from exposure to endrin and other chlorinated hydrocarbons (Winn, 1975).

4.

Blood samples were taken from pelicans reared at a dredge spoil island and a control site off the South Carolina coast in 1994 (Wickliffe and Bickham, 1998).  Mean half-peak coefficient of variation (HPCV) in erythrocyte DNA content, high values of which indicate genetic damage, was approximately 4.0 at the control site and 3.1 at the spoil site.  No correlation was observed between HPCV of DNA content and TCDD-EQ.

5.

Excreta were collected from 3 species of seabirds at 3 sites in Chile (Casini et al., 2001). Elevated levels of porphyrins occurred near Talcahuano, Chile. Excreta samples were collected from 3 brown pelicans. Porphyrin levels in nmols/g estimated from graph were 1.00 copro-, 0.25 uro-, 2.75 proto-, and 4.00 total porphyrins.

II.

Cholinesterase-Inhibiting Pesticides

 

No response data available

III.

Trace Elements, Metals and Metalloids

1.

Blood samples were taken from pelicans reared at a dredge spoil island and a control site off the South Carolina coast in 1994 (Wickliffe and Bickham, 1998).  Mean half-peak coefficient of variation (HPCV) in erythrocyte DNA content, high values of which indicate genetic damage, was approximately 4.0 at the control site and 3.1 at the spoil site.  No correlation was observed between HPCV of DNA content and As, Se, or Hg.

2.

In 1996, liver and kidneys from 9 brown and 10 white pelicans terminally ill from type C botulism were collected from Salton Sea National Wildlife Refuge (n=19).  Reference samples were collected from healthy brown pelicans at Sea World of California, San Diego (n=4) (Bruehler and de Peyster 1999).   Eleven of nineteen birds from Salton Sea had Se levels above 16 μg/g dry weight, the level known to cause immune suppression in other birds.  The authors suggest the elevated levels of Se may have been a contributing factor in the botulism infection.

IV.

Petroleum

1.

A heavily oiled brown pelican was found in November 1976 and died within 24 hours (King et al., 1979). This was an incidence of a bird dying weeks after a known oil spill.

2.

In 1982, after a diesel oil spill of approximately 80,000 gallons in the Cape Fear River of North Carolina, the repercussion of this spill on brown pelicans was measured (Parnell et al., 1984). In all, of 98 nests studied, 24 were found to have at least some oil contamination. Of these 24, 15 were 'lightly oiled', 7 'moderately oiled' and only 1 'heavily oiled.' Hatching success in oiled eggs was significantly less than in unoiled eggs.

3.

Brown pelicans rehabilitated and released after exposure to oil spills in the Southern California Bight in 1990 did not return to normal breeding and survival conditions in 1991 (Anderson et al., 1996). Compared to controls, rehabilitated birds disappeared at a higher rate, had a lower survival rate, and showed no breeding activity, including even presence or association with breeding colonies. 


References for Brown Pelican

Anderson, D.W., J.R. Jehl, Jr., R.W. Risebrough, L.A. Woods Jr., L.R. Deweese, and W.G. Edgecomb. 1975. Brown pelicans: Improved reproduction off the southern California coast. Science 190:806-808

Anderson, D.W., F. Gress, and D.M. Fry. 1996. Survival and dispersal of oiled brown pelicans after rehabilitation and release. Marine Pollut. Bull. 32:711-718.

Anderson, D.W. and F. Gress. 1983. Status of a northern population of California brown pelicans. Condor 85:79-88.

Bischoff A.I., Azevedo, J.A., and L.A. Woods. 1970. Pesticides investigations: Current fish and wildlife problems. Cal. Dept. of Fish and Game. 3pp.

Blus, L. 1970. Measurements of brown pelican eggshell from Florida and South Carolina. Bioscience 20:867-869.

Blus, L.J. 1982. Further interpretation of the relation of organochlorine residues in brown pelican eggs to reproductive success. Environ. Pollut. (Series A): 28:15-33.

Blus, L.J., A.A. Belisle, and R.M. Prouty. 1974a. Relations of the brown pelican to certain environmental pollutants. Pestic. Monit. J. 7:181-194.

Blus, L.J., Burkett S. Neely, Jr., A.A. Belisle., and R.M. Prouty. 1974b. Organochlorine residues in brown pelican eggs: Relation to reproductive success. Environ. Pollut. 7:81-91.

Blus, L.J., A.A. Belisle, and R.M. Prouty. 1975. The brown pelican and certain environmental pollutants in Louisiana. Bull. Environ. Contam. Toxicol. 13:646-655.

Blus, L.J., B.S. Neely Jr., T.G. Lamont, and B. Mulhern. 1977. Residues of organochlorines and heavy metals in tissues and eggs of brown pelicans, 1969-73. Pestic. Monit. J. 11:40-53.

Blus, L., E. Cromartie, L. McNease, and T. Joanen. 1979a. Brown pelican: Population status, reproductive success, and organochlorine residues in Louisiana, 1971-1976. Bull. Environ. Contam. Toxicol. 22:128-135.

Blus, L. J., T. G. Lamont., and B S. Neely, Jr. 1979b. Effects of organochlorine residues on eggshell thickness, reproduction, and population status of brown pelicans (Pelecanus occidentalis) in South Carolina and Florida, 1969-76. Pestic. Monit. J. 12:172-184.

Bruehler, G., and A. de Peyster.  1999.  Selenium and other trace metals in pelicans dying at the Salton Sea.  Bull. Environ. Contam. Toxicol.  63:590-597. 

Bull, J. and J. Farrand, Jr. 1977. The Audubon Society Field Guide to North American Birds. Alfred A. Knopf, New York. 784 pp.

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Clapp, R.B., R.C. Banks, D. Morgan-Jacobs, and W.A. Hoffman. 1982. Marine birds of the southeastern United States and Gulf of Mexico. Part I: Gaviiformes through Pelecaniformes. U.S. Fish and Wildlife Service, Office of Biological Services, Washington, D.C. FWS/OBS-82/01. 637 pp.

Collazo, J.A., T. Agardy, E.E. Klaas, J.E. Saliva, and J. Pierce.  1998.  An interdecadal comparison of population parameters of brown pelicans in Puerto Rico and the U.S. Virgin Islands.  Colon. Waterbirds 21:61-65.

Dunning, Jr., J.B., ed. 1993. CRC Handbook of Avian Body Masses. CRC Press, Ann Arbor. 371 pp.

Ehrlich, P.R., D.S. Dobkin, and D. Wheye. 1988. The Birders Handbook. Simon & Schuster, New York. 785 pp.

Jehl Jr., J.R. 1973. Studies of a declining population of brown pelicans in northwestern Baja California. Condor 75:69-79.

Keith, J.O. 1978. Synergistic effects of DDE and food stress on reproduction in brown pelicans and ringdoves. Ph.D. dissertation, Ohio State University.

King, K.A., and Edward L. Flickinger. 1977. The decline of brown pelicans on the Louisiana and Texas Gulf coast. Southwest Naturalist 21:417-431.

King, K.A., E.L. Flickinger., and H.H. Hildebrand. 1978. Shell thinning and pesticide residues in Texas aquatic bird eggs, 1970. Pestic. Monitor. J. 12:16-21.

King, K.A., S. Macko, P.L. Parker, and E. Payne. 1979. Resuspension of oil: Probable cause of brown pelican fatality. Bull. Environ. Contam. Toxicol. 23:800-805.

King, K.A., D.R. Blankinship, E. Payne, A.J. Krynitsky, and G.L. Hensler. 1985. Brown pelican populations and pollutants in Texas 1975-1981. Wilson Bull. 97:201-214.

Lamont, T.G., G.E. Bagley., and W.L. Reichel. 1970. Residues of o,p-DDD and o,p-DDT in brown pelican eggs and mallard ducks. Bull. Environ. Contam. Toxicol. 5:231-236.

Lincer, J.L. and D. Salkind. 1973. A preliminary note on organochlorine residues in the eggs of fish-eating birds of the west coast of Florida. Florida Field-Nat. 1:19-22.

Mendenhall, V.M., R.M. Prouty. 1978. Recovery of breeding success in a population of brown pelicans. Proc. Colon. Waterbird Group pp. 65-70.

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NACWCP.  2001.  Review Draft IINorth American Waterbird Conservation Plan. Volume One: Seabirds and Colonial Waterbirds, 23 October 2001, Waterbird Conservation Steering Committee, Washington DC (www.nacwcp.org/).

Nesbitt, S.A., R.E. Cowan, P.W. Rankin, N.P. Thompson, and L.E. Williams Jr. 1981. Chlorinated hydrocarbon residues in Florida brown pelicans. Colon. Waterbirds 4:77-84.

Ohlendorf, H.M., D.W. Anderson, D.E. Boellstorff, and B.M. Mulhern. 1985. Tissue distribution of trace elements and DDE in brown pelicans. Bull. Environ. Contam. Toxicol. 35:183-192.

Palmer, R.S., ed. 1976. Handbook of North American Birds. Vol. I. Yale University Press, New Haven. 567 pp.

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Schreiber, R.W. 1977. Shell thickness in brown pelican eggs from Tampa Bay, Florida. Florida Field Nat. 5:31-34.

Schreiber, R.W. and R.W. Risebrough. 1972. Studies of the brown pelican. I. Status of the brown pelican populations in the United States. Wilson Bull. 84:119-135.

Thompson, N.P., P.W. Rankin, P.E. Cowan, L.E. Williams, Jr., and S.A. Nesbitt. 1977a. Chlorinated hydrocarbon residues in the diet and eggs of the Florida brown pelican. Bull. Environ. Contam. Toxicol. 18:331-339.

Thompson, N.P., C.H. Courtney, D.J. Forrester, and F.H. White. 1977b. Starvation-pesticide interactions in juvenile brown pelicans. Bull. Environ. Contam. Toxicol. 17:485-490.

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Wickliffe, J.K. and J.W. Bickham.  1998.  Flow cytometric analysis of hematocytes from brown pelicans (Pelecanus occidentalis) exposed to planar halogenated hydrocarbons and heavy metals. Bull. Environ. Contam. Toxicol. 61:239-246.

Williams, L.E., Jr., ed. 1980. Recovery plan for the Eastern brown pelican. Eastern Brown Pelican Recovery Team, U.S. Fish and Wildlife Service, Washington, D.C.

Wilkinson, P.M., S.A. Nesbitt, and J.F. Parnell. 1994. Recent history and status of the Eastern brown pelican. Wildl. Soc. Bull. 22:420-430.

Winn, B. 1977. Pesticides decimate transplanted pelicans. Audubon 77:127-129.

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