Western Snowy Plover (Charadrius nivosus ssp. nivosus formerly Charadrius alexandrinus ssp. nivosus)
Western Snowy Plover (Charadrius nivosus ssp. nivosus formerly Charadrius alexandrinus ssp. nivosus)
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|---|
| Duration of Incubation or Gestation | 26.9 | incubation period | d | Both Male and Female | Embryo | 9 nests | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono |
| Time of Mating/ Laying | April 18 to July 15 | period of time from beginning to end of egg laying for one year | Female | Adult | 9 nests | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono | |
| Hatching Success | range in percent of clutches hatching at least one chick (over 4 years) | % | Not Reported | Hatchling | Not Reported | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono | |
| Fledging or Weaning Rate | 1.64 | number of chicks fledged per successful brood (for one year) | fledglings/brood | Not Reported | Fledgling | 22 nests | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono |
| Clutches or Litters per year | 2 | number of clutches laid by 30 out of 81 total nesting females | clutches/yr | Female | Adult | 81 nesting females | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono |
| Survival/ Mortality | 0.778 | minimum annual survival rates of marked individuals | Male | Adult | 18 birds | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono | |
| Survival/ Mortality | 0.743 | minimum annual survival rate of marked individuals (2 years and both sexes pooled) | Both Male and Female | Adult | 101 birds | Monterey Bay | Exposure Factor Datasets | Monterey | |
| Survival/ Mortality | 0.643 | minimum annual survival rate of marked individuals | Not Reported | Juvenile | 14 birds | Point Reyes | Exposure Factor Datasets | Marin | |
| Time of Nesting | April 18 to July 6 | period between beginning of egg laying and observation of first fledgling for one year | Both Male and Female | Adult | Not Reported | Mono Lake (elev. 1,940 m) | Exposure Factor Datasets | Mono |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties | Error |
|---|---|---|---|---|---|---|---|---|---|---|
| Hatching Success | 55.2 | percent of all eggs that hatched (over 6 years) | % | Not Reported | Hatchling | 534 eggs | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Fledging or Weaning Rate | percent of hatched chicks that fledged (over 6 years) | d | Not Reported | Fledgling | 296 chicks | Pajaro River Mouth | Exposure Factor Datasets | Monterey | ||
| Survival/ Mortality | 78.6 | percent annual survival | % | Male | Adult | 56 birds | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Survival/ Mortality | 72.6 | percent annual survival | % | Female | Adult | 73 birds | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Time of Migration or Dispersal | Mar 9 (females), Mar 24 (males) | mean dates of spring migrant arrival to breeding grounds | Both Male and Female | Adult | 44 males, 59 females | Pajaro River Mouth | Exposure Factor Datasets | Monterey | ||
| Time of Mating/ Laying | Mar 23 to Jul 13 | period between onset and end of egg laying | Female | Adult | 6-84 clutches laid/month | Pajaro River Mouth | Exposure Factor Datasets | Monterey | ||
| Territory Size | <0.5 | defended nesting territory size on salt pan habitat | ha | Both Male and Female | Adult | Not Reported | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Clutch or Litter Size | 3 | most frequent clutch size | eggs/clutch | Female | Adult | 171 nests | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Duration of Incubation or Gestation | 27.4 | average incubation period (measured from last egg laid to last egg hatched) | d | Both Male and Female | Embryo | 57 nests | Pajaro River Mouth | Exposure Factor Datasets | Monterey | 0.2 SE |
| Time of Fledging or Metamorphosis | 30.9 | fledging period, measured from hatch to first flight of at least 3 m | d | Not Reported | Fledgling | 22 birds | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Fledging or Weaning Rate | 92.7 | percent of 16 day old chicks that fledged | % | Not Reported | Juvenile | 124 birds | Pajaro River Mouth | Exposure Factor Datasets | Monterey | |
| Hatching Success | 58.2 | percent of clutches in which at least one egg hatched (over six years) | % | Not Reported | Hatchling | 189 nests | Pajaro River Mouth | Exposure Factor Datasets | Monterey |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | Countries | Error |
|---|---|---|---|---|---|---|---|---|---|---|
| Hatching Success | 1.73 | average number of chicks per successful brood | chicks/brood | Not Reported | Hatchling | 119 broods | Baja California peninsula | Exposure Factor Datasets | MEXICO | 0.78 SD |
| Clutch or Litter Size | 2.55 | mean clutch size | eggs/clutch | Female | Adult | 36 nests | Baja California peninsula | Exposure Factor Datasets | MEXICO | 0.69 SD |
| Exposure Endpoint Type | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| Population Density | number of breeding birds per km of sandy beach surveyed | birds/km | Not Reported | Not Reported | 54.5-200.2 km per survey region | mainland coast | Exposure Factor Datasets |
| Population Density | number of wintering birds per km of sandy beach surveyed | birds/km | Not Reported | Not Reported | 54.5-200.2 km per survey region | mainland coast | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|---|
| Population Density | 1.9 (fall), 3.4 (winter), 1.1 (spring) | mean population density | birds/ha | Not Reported | Not Reported | 5 seasons censused | Bolinas Lagoon, Point Reyes National Seashore | Exposure Factor Datasets | Marin |
| Population Density | 6.2 (fall), 19.2 (winter), 6.6 (spring) | mean population density | birds/ha | Not Reported | Not Reported | 10 seasons censused | Limantour Estero | Exposure Factor Datasets | Marin |
| Exposure Endpoint Type | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| Population Density | range (over 4 years) in maximum number of nests active on one day per total area of potential nesting habitat | nests/ha | Both Male and Female | Adult | 4 survey years | Howard Slough, Great Salt Lake | Exposure Factor Datasets |
| Population Density | range (over 4 years) in maximum number of nests active on one day per total area of potential nesting habitat | nests/ha | Both Male and Female | Adult | 4 survey years | West Layton Marsh, Great Salt Lake | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | Error |
|---|---|---|---|---|---|---|---|---|---|
| Time of Migration or Dispersal | late Mar to mid Jun | period of migrant arrival to breeding grounds | Female | Adult | 3 yrs data collection | Great Salt Lake, Davis County | Exposure Factor Datasets | ||
| Time of Migration or Dispersal | late Mar to May 31; Jul 1-15 | peaks of migrant arrival to breeding grounds | Male | Adult | 3 yrs data collection | Great Salt Lake, Davis County | Exposure Factor Datasets | ||
| Time of Mating/ Laying | Apr 10-Jul 18 | egg-laying period | Female | Adult | 3 yrs data collection | Great Salt Lake, Davis County | Exposure Factor Datasets | ||
| Foraging Distance | 177 | median foraging distance from nest | m | Female | Adult | 192 observations | Great Salt Lake, Davis County | Exposure Factor Datasets | 25%-75% quartiles=64-466 |
| Foraging Distance | 272 | median foraging distance from nest | m | Male | Adult | 266 observations | Great Salt Lake, Davis County | Exposure Factor Datasets | 25%-75% quartiles=110-580 |
| Clutch or Litter Size | 3 | modal clutch size | eggs/clutch | Female | Adult | 327 clutches | Great Salt Lake, Davis County | Exposure Factor Datasets | |
| Fledging or Weaning Rate | 1.87 | average number of chicks fledged per successful brood | chicks/brood | Female | Adult | 3 yrs data collection | Great Salt Lake, Davis County | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|
| Time of Migration or Dispersal | early March to April 26 | period during which most color-banded birds left the study area | Not Reported | Adult | 19 birds | Pajaro Dunes, Monterey Bay | Exposure Factor Datasets | Monterey |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| Time of Migration or Dispersal | early to late March | timing of first influx of spring migrants to interior breeding areas | Not Reported | Adult | Not Reported | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|---|
| Survival/ Mortality | 0.687 | estimated average annual adult survival probability (using Jolly-Seber model) | Both Male and Female | Adult | 361 birds captured over 3 yrs | Great Salt Lake | Exposure Factor Datasets | |
| Longevity | 2.7 | mean life expectancy for an adult plover, based on survival estimate | yr | Both Male and Female | Adult | 361 birds captured over 3 yrs | Great Salt Lake | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | Lab |
|---|---|---|---|---|---|---|---|---|---|
| Water Ingestion Rate | 20 | daily distilled water consumption as percent of body weight | % | Not Reported | Adult | Not Reported | Exposure Factor Datasets | Laboratory | |
| Body Weight - Mean | range in average body weights of treatment groups | g | Not Reported | Adult | 3-4 birds/group | Exposure Factor Datasets | Laboratory |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|---|
| Hatching Success | 37 | percent of eggs that hatched | % | Not Reported | Hatchling | 35 nests | Point Reyes | Exposure Factor Datasets | Marin |
| Fledging or Weaning Rate | 2.0 | number of young fledged per successful brood | fledglings/brood | Not Reported | Fledgling | 35 nests | Point Reyes | Exposure Factor Datasets | Marin |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|---|
| Time of Mating/ Laying | April, May | months of peak nest initiation activity, 2 years | Both Male and Female | Adult | 2-15 nests/colony/year | coast | Exposure Factor Datasets | |
| Hatching Success | 13 | proportion of nests with at least one egg hatching | % | Not Reported | Hatchling | 72 nests | coast | Exposure Factor Datasets |
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