Bird: California scrub jay (Aphelocoma californica) 西叢鴉

“California Scrub-Jays are great to watch because they’re animated, vocal, and playful.” according to All About Birds. They are beautiful but snarky. They have been known to steal acorns from Acorn Woodpeckers and other jays. From the Wikipedia, I learn that they are among the most intelligent of animals. Their intelligence is very impressive.
根據《關於鳥類的一切》的介紹“西叢鴉是值得觀看的鳥,因為它們活潑,聲音動人並且調皮有趣。” 。 它們很漂亮,但是很狡猾。 眾所周知,它們會從橡子啄木鳥和其他松鴉偷走橡子。我從維基百科了解到它們是最聰明的動物之一。它們的才智令人驚嘆。

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Photo Date: Various Location: Los Angeles County
Photo Date: 2019.05.02 Location: The Huntington Library
Photo Date: 2021.01.19 Location: LA Arboretum
Photo Date: 2021.05.10 Location: Peck Road Park

Notes 筆記

  • While many refer to scrub jays as “blue jays”, the blue jay is a different species of bird entirely.
  • The generic name Aphelocoma derives from Latinized Ancient Greek apheles- (from ἀφελής-) “simple” + Latin coma (from Greek kome κόμη) “hair”, in reference to the lack of striped or banded feathers in this genus, compared to other jays. californica, Latin: “from California”.
  • The California scrub jay is a medium-sized bird, approximately 27–31 cm (11–12 in) in length (including its tail), with a 39 cm (15 in) wingspan.
  • The California scrub jay inhabits areas of low scrub, preferring pinon-juniper forests, oak woods, and edges of mixed evergreen forests. It also inhabits suburban gardens.
  • California scrub jays usually forage in pairs, family groups, or small non-kin groups, outside of the breeding season. They feed on small animals, such as frogs and lizards, eggs and young of other birds, insects, and (particularly in winter) grains, nuts, and berries. They will also eat fruit and vegetables growing in backyards. They can be hand-fed by humans.
  • California scrub jays, like many other corvids, exploit ephemeral surpluses by storing food in scattered caches within their territories. They rely on highly accurate and complex memories to recover the hidden caches, often after long periods of time. They have shown an ability to plan ahead in choosing cache sites to provide adequate food volume and variety for the future. They are also able to rely on their accurate observational spatial memories to steal food from caches made by conspecifics.
  • Recent research has suggested that western scrub jays are among the most intelligent of animals. The brain-to-body mass ratio of adult scrub jays rivals that of chimpanzees and cetaceans, and is dwarfed only by that of humans. Scrub jays are also the only non-primate or non-dolphin shown to plan ahead for the future which was previously thought of as a uniquely human trait. Other studies have shown that they can remember locations of over 200 food caches, as well as the food item in each cache and its rate of decay. California scrub jays also summon others to screech over the body of a dead jay, according to new research from the University of California, Davis. The birds’ cacophonous “funerals” can last for up to half an hour.
  • Nests are built low in trees or bushes, 1–10 m (3.3–32.8 ft) above the ground, primarily by the female, while the male guards her efforts. Four to six eggs are laid from March through July, with some regional variations. The female incubates the eggs for about 16 days. The young leave the nest about 18 days after hatching.
  • 儘管許多人將叢鴉稱為“冠藍鴉”,但冠藍鴉完全是另一種鳥類。
  • 欉鴉屬(Aphelocoma)的名稱源自拉丁古希臘文 apheles-(源自ἀφελής-)“簡單”+拉丁文 coma(源自希臘語komeκόμη)“頭髮”。與其他松鴉相比,這個屬沒有條紋或帶狀羽毛 。 拉丁文 californica:“源自加利福尼亞”。
  • 西叢鴉是中型鳥類,長約27-31公分(11-12英寸)(包括尾巴),翼展39公分(15英寸)。
  • 西叢鴉棲息於低灌木叢地區,偏愛松柏杜松林,橡樹林和在常綠混交林的邊緣之地。它也棲息於郊區花園中。
  • 在繁殖季節之外,西叢鴉通常會一對對,家庭羣組或非親屬小羣組一起覓食。它們以青蛙、蜥蜴、蛋和其他幼鳥、昆蟲以及(尤其是冬季)穀物、堅果和漿果等為食。它們也會吃後院種植的水果和蔬菜。人也可手餵它們。
  • 像許多其他鴉科的鳥一樣,西叢鴉會將它地盤內零散的貯藏物儲存起來,有効利用轉瞬即逝的剩餘食物。它們能藉極其準確和復雜的記憶力來找到藏了很久的貯藏物。它們也以選擇儲存地點、為將來提供足夠的食物數量和種類來展露出它們有提前計劃的能力。它們還能夠依靠自己準確的觀測空間記憶,竊取同種藏匿的食物。
  • 最近的研究發現西叢鴉是最聰明的動物之一。成年叢鴉的大腦與身體的質量比,可以與黑猩猩和鯨類的動物相媲美,只比人類遜色。叢鴉也是非靈長類動物或非海豚中唯一被顯示會為未來計劃的動物。會為未來計劃,在以前被認為是人類獨特的特徵。其他研究顯示它們可以記住200多個食物儲藏的位置,以及每個儲藏地方的食物及其腐爛率。加州大學戴維斯分校的一項新研究顯示,西叢鴉還可以召喚其他鳥在死鳥的屍體上尖叫。它們刺耳的“葬禮”可以持續長達半小時。
  • 它們主要是由雌鴉巢築,巢築在樹或灌木叢低處,離地面1-10公尺(3.3-32.8英尺),而雄鴉則負責保衛雌鴉。從三月到七月可產四到六個蛋,但會有一些區域上的差異。雌鴉用約16天將蛋孵化。幼鳥在孵化後大約18天離開巢穴。

References 參考資料

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