Coal Oil Point Reserve

The Coal Oil Point Reserve Annual Newsletter highlights the conservation, restoration, and research projects at the reserve in 2015.

The Coal Oil Point Reserve Annual Newsletter highlights the conservation, restoration, and research projects at the reserve in 2023.

The Coal Oil Point Reserve Annual Newsletter highlights the conservation, restoration, and research projects at the reserve in 2022.

In 2008 we continued with the management of the WSP population at Coal Oil Point Reserve as in previous years. We were able to estimate chicks until fledged age. We experimented with replacing plover eggs with wood eggs and then returning the hatching egg to the plover nest. This was s successful way to improve hatchability during a high skunk predation time but it was very laborious.

In 2007 we continued with the management of the WSP population at Coal Oil Point Reserve as in previous year. We were not able to track chicks until fledged age as in previous years. I attribute this to the more complex beach profile that prevented a clear view of the beach and the large number of simultaneous broods that hatched in the beginning and again at the end of the breeding season. We experimented with replacing plover eggs with wood eggs and then returning the hatching egg to the plover nest. This was s successful way to improve hatchability during a high skunk predation time but it was very laborious.

In 2021, we continued with the monitoring of the Western Snowy Plover (WSP) population at Coal OilPoint Reserve as in previous years. The number of breeding adults this year (56) was higher than theaverage (37) for our site. The wintering population size (175) was just over the average (167). This year,predation was the primary cause of nest failure. There were three cases of take by people on Sands Beach. The eggs from 3 nests were removed and in 2 of the nests that had exclosures, the exclosure wasremoved and vandalized. Implementation of Australian crow traps this year prevented crow predation.However, one quarter of all nests were predated by skunks and an additional 8% were lost to unknownpredators. In response to the high levels of predation by skunks, all nests present on or laid after July 13thwere collected, incubated until near the hatching date, and then returned to the parents. The real eggswere replaced with wooden eggs so that the parents would continue incubating. COPR had a lower thanaverage hatching rate (35%) and a high fledging rate (72%) (this analysis excludes the 8 out of 8 neststhat hatched with the egg replacement technique). The number of fledged chicks per male (1.5) was belowaverage for our site but exceeded our site's recovery goal of 1.0 fledged chicks per male. 99% of nests(92) were initiated on the beach, and 1% (1) were initiated on the mudflats of the slough (delta).

During the May 2015 Refugio Beach oil spill, federally threatened western snowy plovers (Charadrius nivosus nivosus) were feeding with their recently hatched chicks on southern California beaches. They primarily forage on invertebrates in the wrack and wave-washed swash zone and were directly threatened by both the oil and the actions of the clean-up crews. During the spill, the extent and location of oiling observed on western snowy plovers at Coal Oil Point Reserve, in Santa Barbara, were documented. In addition, annual monitoring of reproductive success was conducted (i.e., number of nests, number of eggs laid, number of chicks fledged, etc.), contributing to data collected on this population since 2001. Although no direct mortality of western snowy plovers was observed during the spill, a spike in the percentage of infertile eggs was observed in the year following the spill. As part of the Natural Resource Damage Assessment, estimated oil ingestion rates were compared to exposures associated with reproductive harm in other avian oil toxicity studies. A plausible connection between oil ingestion via preening and feeding and the increase in egg infertility in western snowy plovers at Coal Oil Point Reserve was demonstrated.