Last updated: October 1, 2019
Article
Unusually Long 2019 Snowy Plover Breeding Season Ends on a High Note
NPS / Matt Lau
September 2019 - The western snowy plover breeding season in Point Reyes National Seashore officially ended on September 11th this year, with the last plover chick fledging on Limantour Beach. Breeding activity persisted unusually late into the season, with a couple active nests not hatching until mid August (and subsequently, chicks not fledging until early to mid September). The minimum estimated breeding population size was 23 individuals (10 females, 13 males), which is appreciably lower than the 2018 breeding population of 38 individuals (18 females, 20 males); the population decreased approximately 39.5%.
Biologists found and monitored a total of 35 nests this year: 6 on Limantour Beach, 7 on Kehoe Beach, 13 between Abbotts Lagoon and North Beach, 3 in the Abbotts Lagoon Restoration Area, 5 on North Beach, and 1 on South Beach/Lighthouse Beach. The single South Beach nest is the first known record of breeding activity on this site since the 1980’s!
Of the total nests, 13 hatched (37.1%) and 22 failed (62.9%). Nest success was much lower than the 24-year average (mean=62.2%, sd=16.6) partially due to the record number of nest predation events by common ravens (n = 15 nests). Despite the decline in breeding individuals and low nest success, the plover chicks that hatched survived at a higher rate than in recent years. Plovers successfully fledged 15 hatchlings (45.5% success rate) this year, compared to 14 chicks in 2018 (26.9%) and 23 in 2017 (41.1%). In an unusual twist, two of those successfully fledged chicks were separated from their father shortly after hatching, and initially presumed dead. To their surprise, biologists found them weeks later being raised by another plover father, who successfully raised and fledged his own two chicks at the same time.
Check out the Point Reyes snowy plover webpage to learn more, or contact Matt Lau with any questions about the breeding season.