I went to Santa Fe Dam for a walk on February 19, 2021. I saw this bird that looked like a crow, but it’s lovely singing sound and the dark feathers in the sun reflected a bright purple blue sheen make me doubt its identification. My instinct told me this should not be a crow. I came back and checked it and found out that this is a great-tailed grackle. They have an unusually large repertoire of vocalizations that are used year-round.
2021.02.19我去聖達菲大壩(Santa Fe Dam)走路，看到了這隻很像烏鴉的鳥，但是它動人嘹亮的叫聲以及在陽光下黝黑的羽毛反射出光鮮的深紫藍色，直覺告訴我這應該不是烏鴉，回來查了一下，才知到這是大尾擬八哥。它們有非常大的曲目庫的叫聲。
Photo Date: 2021.02.19 Location: Santa Fe Dam
I saw a male and a female great-tailed grackle together one month later. The female is darker brown color. The male is iridescent black.
一個月之後，我看到一隻公一隻母的大尾擬八哥在一起，母鳥是深棕色。 而公鳥是虹彩黑色。
Photo Date: 2021.03.19 Location: Santa Fe Dam
Notes 筆記
- The great-tailed grackle or Mexican grackle is a medium-sized, highly social passerine bird native to North and South America.
- In the southern United States, it is sometimes simply referred to as “blackbird” or (erroneously) “crow” due to its glossy black plumage although it is not a member of the crow genus Corvus.
- Males are iridescent black with a purple-blue sheen on the feathers of the head and upper body, while females are brown with darker wings and tail. Both sexes have long tails.
- Great-tailed grackles have an unusually large repertoire of vocalizations that are used year-round. The sounds range from “sweet, tinkling notes” to a “rusty gate hinge”. Because of their loud vocalizations, great-tailed grackles are considered a pest species by some.
- The great-tailed grackle mating season usually begins in early or mid-April. The nest is typically built near the top of a large or medium-sized tree. Females usually lay around 4 to 7 eggs. Incubation is usually around 14 to 13 days and their young usually leave the nest 12 to 17 days after hatching.
- Great-tailed grackles are noted for their diverse foraging habits. They extract larvae and insects from grassy areas; eat lizards, nestlings, and eggs; forage in freshly plowed land; remove parasites from cattle, and eat fruits and grains. Although they do not swim, they catch fish by flying close to the water’s surface, and are even reported to dive a few inches into the water to retrieve a fish.
- Great-tailed grackles communally roost in trees or the reeds of wetlands at night and, during the breeding season, they nest in territories using three different mating strategies:
- 1) territorial males defend their territory on which many females place their nests and raise young.
- 2) residential males live in the larger colony but do not defend a territory or have mates.
- 3) transient males stay for a few days before leaving the colony to likely move on to another colony.
- Resident and transient males sire a small number of offspring through extra-pair copulations with females on territories. Territorial males are heavier and have longer tails than non-territorial males, and both of these characteristics are associated with having more offspring.
- Great-tailed Grackles—especially females—learn to recognize individual researchers working in their breeding colonies, and will react with a chut alarm call when they see the researcher, even away from the nesting site.
- 大尾擬八哥或墨西哥擬八哥是產於北美和南美的中型，喜社交的雀形目鳥。
- 在美國南部，儘管它不是烏鴉屬的成員，但由於其有光澤的黑色羽毛，有時被簡稱為“黑鳥”或（錯誤地）為“烏鴉”。
- 雄鳥是虹彩黑色，頭部和上半身的羽毛是紫藍色，而雌性是棕色，翅膀和尾巴顏色較深。雌雄都有長尾巴。
- 大尾擬八哥有非常大的曲目庫的叫聲。聲音的範圍從“甜甜的叮噹聲”到“生鏽的門鉸鏈”。由於它們發出大聲的聲音，大尾擬八哥被某些人視為害蟲。
- 大尾擬八哥交配季節通常在4月初或中旬開始。鳥巢通常建在大或中型樹的頂部附近。雌鳥產約4至7個蛋，通常14到13天左右孵化，它們的幼蟲在孵化後12到17天離開巢。
- 大尾擬八哥因其不同的覓食習慣而聞名。它們在草地上食取幼蟲和昆蟲，吃蜥蜴、雛鳥和雞蛋，在新耕過的土地上覓食，從牛身上清除寄生蟲，並吃水果和穀物。雖然它們不游泳，但還是會飛近於水面捕撈魚，據說它們甚至會潛入水中幾英寸來獵取魚。
- 大尾擬八哥在晚上通常棲息在樹木或濕地的蘆葦上，在繁殖季節，它們使用三種不同的交配策略在領土築巢：
- 1）有領地意識的雄鳥保衛自己的地盤，許多雌鳥在其上築巢並養育幼鳥。
- 2）留鳥的雄鳥居住在較大的群體中，但不保衛地盤或沒有伴侶。
- 3）候鳥在離開群體之前可能會停留幾天，可能會遷移到另一個群體。
- 留鳥和候鳥型的雄鳥藉由與雌鳥在地盤裏的配對交配而繁殖出少量後代。有領地意識的雄鳥比非領地意識的雄鳥更重，尾巴更長，這兩個特徵都與擁有更多的後代有關。
- 大尾擬八哥（特別是雌鳥）學會識別在其繁殖群中工作的各個研究人員，當看到研究人員時，都會發出叫警報，即使在遠離築巢地點的情況下。
References 參考資料
- Wikipedia: Great-tailed grackle
- All about birds: Great-tailed Grackle
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