https://wildlife.blog/tags/black-oystercatcher/Recent content in Black-Oystercatcher on Wildlife.blogHugoen-usMon, 24 Aug 2026 01:43:10 +0000https://wildlife.blog/posts/black-oystercatcher-at-china-beach-san-francisco/Mon, 24 Aug 2026 01:43:10 +0000https://wildlife.blog/posts/black-oystercatcher-at-china-beach-san-francisco/<hr> <p><strong>Black Oystercatcher</strong> <em>(Haematopus bachmani)</em></p> <p>A big, all-black shorebird of rocky Pacific coastlines, with a blazing red-orange bill it uses to pry mussels and limpets off the rocks.</p> <p>Year-round along the SF coast — look for them on rocky points and breakwaters rather than sandy beaches.</p> <figure class="range-map-figure"> <div class="range-map" data-geojson="/posts/black-oystercatcher-at-china-beach-san-francisco/range.geojson" data-taxon="4838" aria-label="Map of the modeled range of this species"></div> <figcaption>Modeled range · <a href="https://www.inaturalist.org/taxa/4838" target="_blank" rel="noopener">iNaturalist</a> · CC BY 4.0</figcaption> </figure> <script src="https://wildlife.blog/js/leaflet.db49d009c841f5ca34a888c96511ae936fd9f5533e90d8b2c4d57596f4e5641a.js"></script> <script> (function () { var CORE_PCT = 0.05; var GAP_MIN = 20; var KEEP_FRAC = 0.75; function quantile(sortedAsc, q) { if (!sortedAsc.length) return undefined; var pos = (sortedAsc.length - 1) * q; var lo = Math.floor(pos), hi = Math.ceil(pos); if (lo === hi) return sortedAsc[lo]; return sortedAsc[lo] + (sortedAsc[hi] - sortedAsc[lo]) * (pos - lo); } function rangeBounds(geo, layer) { var pts = []; (function walk(c) { if (!c) return; if (typeof c[0] === 'number' && typeof c[1] === 'number') { pts.push([c[0], c[1]]); return; } for (var i = 0; i < c.length; i++) walk(c[i]); })((function collect(g) { if (g.type === 'FeatureCollection') return g.features.map(function (f) { return f.geometry && f.geometry.coordinates; }); if (g.type === 'Feature') return g.geometry && g.geometry.coordinates; return g.coordinates; })(geo)); if (!pts.length) return layer.getBounds(); pts.sort(function (a, b) { return a[0] - b[0]; }); var n = pts.length; var wrapGap = (pts[0][0] + 360) - pts[n - 1][0]; var maxGap = wrapGap, splitIdx = 0; for (var i = 1; i < n; i++) { var g = pts[i][0] - pts[i - 1][0]; if (g > maxGap) { maxGap = g; splitIdx = i; } } if (maxGap < GAP_MIN) return layer.getBounds(); var ordered = []; for (var k = 0; k < n; k++) { var p = pts[(splitIdx + k) % n]; var lon = p[0]; if (k > 0 && lon < ordered[k - 1][0]) lon += 360; ordered.push([lon, p[1]]); } var clusters = [], cur = [ordered[0]]; for (var j = 1; j < ordered.length; j++) { if (ordered[j][0] - ordered[j - 1][0] >= GAP_MIN) { clusters.push(cur); cur = []; } cur.push(ordered[j]); } clusters.push(cur); clusters.sort(function (a, b) { return b.length - a.length; }); var kept = [], have = 0, need = Math.ceil(n * KEEP_FRAC); for (var c = 0; c < clusters.length; c++) { kept = kept.concat(clusters[c]); have += clusters[c].length; if (have >= need) break; } var lonSorted = kept.map(function (p) { return p[0]; }).sort(function (a, b) { return a - b; }); var latSorted = kept.map(function (p) { return p[1]; }).sort(function (a, b) { return a - b; }); var w = quantile(lonSorted, CORE_PCT); var e = quantile(lonSorted, 1 - CORE_PCT); var s = quantile(latSorted, CORE_PCT); var nn = quantile(latSorted, 1 - CORE_PCT); if (!(e > w)) { w = lonSorted[0]; e = lonSorted[lonSorted.length - 1]; } if (!(nn > s)) { s = latSorted[0]; nn = latSorted[latSorted.length - 1]; } return L.latLngBounds([[s, w], [nn, e]]); } function shiftGeo(geo, dLon) { function shiftCoords(c) { if (typeof c[0] === 'number' && typeof c[1] === 'number') { return [c[0] + dLon, c[1]]; } return c.map(shiftCoords); } function shiftGeom(g) { if (!g) return g; return { type: g.type, coordinates: shiftCoords(g.coordinates) }; } if (geo.type === 'FeatureCollection') { return { type: 'FeatureCollection', features: geo.features.map(function (f) { return { type: 'Feature', properties: f.properties, geometry: shiftGeom(f.geometry) }; }) }; } if (geo.type === 'Feature') { return { type: 'Feature', properties: geo.properties, geometry: shiftGeom(geo.geometry) }; } return shiftGeom(geo); } function initRangeMaps() { if (typeof L === 'undefined') return; document.querySelectorAll('.range-map').forEach(function (el) { if (el._rangeMap) return; var map = L.map(el, { scrollWheelZoom: false, worldCopyJump: true }); el._rangeMap = map; var taxon = el.getAttribute('data-taxon'); var credit = taxon ? '<a href="https://www.inaturalist.org/taxa/' + taxon + '">iNaturalist</a>' : 'iNaturalist'; L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', { maxZoom: 12, attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> · Range: ' + credit + ' (CC BY 4.0)' }).addTo(map); map.setView([0, 0], 1); fetch(el.getAttribute('data-geojson')) .then(function (r) { return r.json(); }) .then(function (geo) { var style = { color: '#2e7d32', weight: 1, fillColor: '#2e7d32', fillOpacity: 0.35 }; var layer = L.geoJSON(geo, { style: style }).addTo(map); [-360, 360].forEach(function (dLon) { L.geoJSON(shiftGeo(geo, dLon), { style: style, interactive: false }).addTo(map); }); try { map.fitBounds(rangeBounds(geo, layer), { padding: [12, 12], maxZoom: 8 }); } catch (e) {} }) .catch(function () { }); }); } if (document.readyState === 'loading') { document.addEventListener('DOMContentLoaded', initRangeMaps); } else { initRangeMaps(); } })(); </script> <p><a href="https://en.wikipedia.org/wiki/Black_oystercatcher">Wikipedia</a> | <a href="https://www.inaturalist.org/taxa/4838">iNaturalist</a> | <a href="https://www.inaturalist.org/taxa/4838/map">Range map</a> | <a href="https://ebird.org/species/bloys2">eBird</a></p>