Aechmophorus occidentalis
Western Grebe (Aechmophorus occidentalis)
| Chemical | Endpoint Value | Endpoint Description | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| DDE (4,4'-) | 61.5 ppm DDE, 5.2 ppm DDD, wet wt | mean concentration in visceral fat | Not Reported | Adult | 18 birds | Bear River Migratory Bird Refuge | Toxicity Factor Datasets |
| DDE (4,4'-) | 0.55 ppm DDE, 0.07 ppm DDD, wet wt | mean concentration in blood | Not Reported | Adult | 16 birds | Bear River Migratory Bird Refuge | Toxicity Factor Datasets |
| DDE (4,4'-) | 6.6 ppm DDE, 1.3 ppm DDD, wet wt | mean concentration in whole eggs | Not Reported | Embryo | 40 eggs | Toxicity Factor Datasets | |
| DDE (4,4'-) | 12.8 ppm DDE, 0.8 ppm DDD, wet wt | mean concentration in breast muscle | Not Reported | Adult | 24 birds | Bear River Migratory Bird Refuge | Toxicity Factor Datasets |
| Chemical | Endpoint Value | Endpoint Description | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| DDD (4,4'-), DDE (4,4'-), DDT (4,4'-), POLYCHLORINATED BIPHENYLS | no effect | eggshell thickness compared with pre-1947 measurements | Not Reported | Embryo | 29 eggs | Tule Lake National Wildlife Refuge | Toxicity Factor Datasets |
| Chemical | Endpoint Value | Endpoint Description | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|
| MERCURY COMPOUNDS | positive correlation | Hg concentration in brain correlation with P and K concentrations in blood | Not Reported | Adult | 11 birds | Clear Lake, Tule Lake, Eagle Lake | Toxicity Factor Datasets | Lake, Lassen, Siskiyou |
| MERCURY COMPOUNDS | 0.001 (Clear Lake), 0.16 (Tule Lake) | productivity (young to adult ratios) at study locations | Not Reported | Adult | 13 birds, Clear Lake; 5 birds, Tule Lake | Clear Lake, Tule Lake | Toxicity Factor Datasets | Lake, Siskiyou |
| Chemical | Endpoint Value | Endpoint Description | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| DDD (4,4'-), DDE (4,4'-) | decreased compared with pre-1940 eggs | eggshell thickness index (Ratcliffe's Index) | Not Reported | Embryo | 93 eggs | Bear River Migratory Bird Refuge | Toxicity Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|---|
| Dietary Composition | Ascaradina (3), Gastropoda (10, Orthoptera (2), Hemiptera (2), Diptera (1), Coleoptera (4), Siluridae (4), Centrarchidae (77), plant (4) | % of total stomach content volume | % | Not Reported | Adult | 27 birds | Clear Lake | Exposure Factor Datasets | Lake |
| Food Ingestion Rate | 22.4 | estimated mass of fish consumed daily, based on stomach contents | g | Not Reported | Adult | 1 bird | Clear Lake | Exposure Factor Datasets | Lake |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | Lab |
|---|---|---|---|---|---|---|---|---|---|
| Growth Rate | -0.1321 | growth rate coefficient estimate based on Richard's growth model | Both Male and Female | Juvenile | 4 birds | Bear River Migratory Bird Refuge (collection site) | Exposure Factor Datasets | Laboratory | |
| Body Weight - Mean | estimated initial weights | g | Both Male and Female | Juvenile | 4 birds | Bear River Migratory Bird Refuge (collection site) | Exposure Factor Datasets | Laboratory | |
| Body Weight - Mean | estimates of asymptotic weights | g | Both Male and Female | Juvenile | 4 birds | Bear River Migratory Bird Refuge (collection site) | Exposure Factor Datasets | Laboratory |
| Exposure Endpoint Type | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| Body Weight - Mean | range of mean body weights | g | Male | Both Adults and Juveniles | 18 birds | Commencement Bay | Exposure Factor Datasets |
| Body Weight - Mean | range of mean body weights | g | Female | Both Adults and Juveniles | 22 birds | Commencement Bay | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|---|
| Time of Mating/ Laying | early July | peak of laying period | Female | Adult | 386 nests | Bear River Migratory Bird Refuge | Exposure Factor Datasets | |
| Duration of Incubation or Gestation | 24 | incubation period | d | Both Male and Female | Embryo | 14 clutches | Bear River Migratory Bird Refuge | Exposure Factor Datasets |
| Clutch or Litter Size | 2.6 | mean clutch size | eggs | Female | Adult | 70 nests | Bear River Migratory Bird Refuge | Exposure Factor Datasets |
| Hatching Success | 21% | percent of nests located in emergent vegetationin which at least one chick hatched | Both Male and Female | Hatchling | 221 nests | Bear River Migratory Bird Refuge | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|---|
| Population Density | 2400 | annual number of individuals censused | birds/lake | Both Male and Female | Not Reported | 1 lake | Eagle Lake, 42 km NW of Susanville | Exposure Factor Datasets | Lassen |
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