June 13, 2019
American Oystercatchers Hatching on the beach
So on this windy very windy day I just noticed the Oystercatchers clutch has hatched!
Breeding Author: Tom Virzi (TV), Dept. Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ. Pair Formation Pair formation begins when both birds arrive on territory. In Georgia and Texas, resident pairs begin to defend territories in January (B. Winn, S. Heath, unpublished). In South Carolina resident pairs seen on territory every month of the year except October (Sanders et al. 2004). In Virginia, females arrive on territory of previous year as much as 3 wk before males, last week of Feb to first week of Mar (Baker and Cadman 1980). In New Jersey, individuals arrive early-Mar and pairs form by late-Mar (TV). In New York, birds arrive mid-Mar (B. Lauro, unpublished). In Massachusetts, most birds arrive paired, last week of Mar to first week of Apr (RH). Lone females defend territories until mates return or they pair with new mate (Baker and Cadman 1980, RH). On islands near Puerto Rico, nesting in May and Jun (Raffaele 1989). On Galapagos Islands, nesting in late December, early Jan (EN). Nest Building See Behavior. Nest-scraping begins as part of courtship, often several weeks before egg laying, performed by both sexes, most often by male. In Georgia, may defend territory as much as 3 mo before eggs are laid (Tomkins 1954); in Virginia, more typically 6 wk (EN), New Jersey and Massachusetts 1 mo (TV, RH). First/Only Brood Per Season Figure 5. Typically lay repeat clutches when nests are destroyed or young depredated early; in South Carolina, 67% had 2 nest attempts and 35% had 3–4 nests (Thibault 2008); up to 6 nest attempts reported in New Jersey (TV). Earliest full clutch reported in Texas Jan 22 (Hockey and Freeman 2003). First clutches in Virginia, first week of Apr, peak mid-Apr. Second peak depends on timing of spring tides, as these can inundate and destroy all first clutches, and hence most renests occur at approximately the same time. Cold wet weather can result in less synchronous nesting in populations (Nol et al. 1984). In New Jersey, earliest nest reported on 6 Apr (TV) and peak nest initiation late-Apr to May (Virzi 2010a). First nest in New York by 1 Apr (B. Lauro, unpublished). In Massachusetts, earliest nest 25 Mar; mean initiation date 29 Apr (Murphy 2010). Further south, first clutches initiated earlier; South Carolina, first nest 3 Mar (Sanders et al. 2008); Georgia peak nest initiation 4 Apr (B. Winn, unpublished); Florida mean nest initiation 10 Apr (Toland 1999). Peak hatch usually 27 d later. Chicks tended and fed until fledged, approximately 35 d; begin feeding on their own, but still predominantly dependent on adults for food for some time; adults observed feeding young near breeding sites in late-Aug in New Jersey, and in Dec after migrating to Florida (TV). Microhabitat/Site Characteristics Non-randomly select nest sites with more substrate, less vegetation, farther from water, and higher elevation (Lauro and Burger 1989, RH). In New York, New Jersey and Maryland, birds rarely nest in sand dunes, favoring marsh islands (Zaradusky 1985, Lauro and Burger 1989, Virzi 2008). In North Carolina and New Jersey, commonly nest on high, sandy sites (Bent 1929, Lauro and Burger 1989); also often use tide wrack deposits for nesting in New Jersey salt marshes, sandy sites preferred, and vegetated sites on dredge-spoil islands (Virzi 2008). In Georgia and South Carolina, oyster shell mounds in back-bay areas used extensively (Winn 2000, Sanders et al. 2008). In Virginia, nest in dunes and salt marsh (Cadman 1979), dredge spoils, sometimes very close to high tide if nothing else available (Wilke et al. 2005). In Massachusetts, nest in low, flat sandy areas, upland dune, and marsh islands, the latter most frequently (RH). Vegetative cover varies from non-existent or sparse in lower sandy areas, to moderate in marsh islands and dense in upland dunes vegetated with Spartina, Ammophila, Lathyrus, and Solidago. Nests typically on slightly elevated site with at least 180° visibility, rarely on side-slopes with obstructed view (Bancroft 1927, Bent 1929, RH).Elevation very important to nest success (Lauro and Burger 1989, Virzi 2008). Distance to water: high sites, average 7.5–12.7 m from water in New York and slightly further (21–32 m) in North Carolina and Massachusetts (Lauro and Burger 1989, RH). Vegetation averages 23–50% around nest sites, but highly variable (Lauro and Burger 1989, RH). Distance to nearest conspecific nest depends on habitat; in South Carolina, mean distance 334 m ± 27 (SE) all habitats; 200 m ± 29 (SE) barrier islands; 65 m ± 10 (SE) estuarine islands; 577 m ± 51 (SE) edge shell mounds (Sanders et al. 2008). Elsewhere, average distance ranges from 124 to 190 m (RH); may be much lower (< 10 m) on small back-bay islands with high pair density in New Jersey (TV). Elevation above mean high tide: in New York, about 1 m above sea level, and significantly higher than random points (Lauro and Burger 1989). In Massachusetts, elevation depends on habitat, but all < about 0.3 m above sea level (RH). Nest Construction Nests scraped during daylight hours. Actual scraping takes little time; bird settles on sand and scrapes shallow depression with feet. May make and abandon multiple scrapes (Tomkins 1954). Once a pair has selected a scrape, lining is prepared by side-throwing in the vicinity and side-ways building at the site. Nest Structure And Composition Nests typically a shallow depression scraped out of sandy substrate, sometimes lined with shells or shell fragments, pebbles, bits of tide wrack, or other debris. In New York and New Jersey, sand substrate preferred; however, tide wrack also used extensively in marsh habitat (Lauro and Burger 1989, Virzi 2008). In Virginia and South Carolina, shell rake used predominantly in seaside marshes (Wilke et al. 2005, Sanders et al. 2008); shell rake used extensively in Georgia and Texas as well (Winn 2000, S. Heath, unpublished).
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