其實我們沒有那麼關心受脅物種?

ya jung lu
Sep 6, 2018 · 7 min read

我絕對不會說標題是集集顆痣芢建議要訂這麼嗆的

前情提要

前陣子我將HBW世界鳥類圖鑑(Handbook of the Birds of the World)裡共10725種鳥的資訊爬下來後,包括物種描述、聲音、棲地、繁殖狀況等內容.接著再用正則表達去萃取裡頭相關資訊,例如體長、體重、翼展長等。


在一筆筆確認資料的某天(是的,這是個極其無聊又需補充葉黃素的活動),突然想到一個令我好奇的事情。

一物種的受威脅等級會不會影響到我們對它的關注度?

在評定一個物種的受脅等級,會依據族群量大小、變化趨勢與分布面積增減等好幾項指標來評定這個物種的受脅等級。

受脅等級如下圖所表示,依序為滅絕、野外滅絕、極危、瀕危、易危、接近受脅、暫無危機與資料缺乏等8個等級。然而,有可能因為全球或區域評估的尺度不同,受脅等級會有些許調整,但大致分類概念是一致的。

引用IUCN Red List官網

接著,我們在看到HBW鳥類圖鑑對於不同物種的物種描述。

African Broadbill (Smithornis capensis) 受脅等級為LC (暫無危機)

內容寫得落落長,很詳細也豐富,例如我們可以知道體長範圍,雌雄兩者不同體重的區間,並有很詳盡的外型描述,如不同亞種間的外型、顏色差異。

12–14 cm; male 21–26.9 g, female 17.4–27.5 g (South Africa), unsexed 20–31 g A stocky, short-tailed bird with distinctive broad, flat bill Male has buffish forehead, black crown, greyer ear-coverts, grey lower nape; upperparts and tail rufescent brown, sometimes tinged grey, mantle and back with broad black streaks; feathers of mantle and upper back with silky white feather bases (usually concealed); median wing-coverts with distinct buffy or cream tips forming wing-bar, greater coverts with narrower tips; flight-feathers mostly dark brown, outer 4 or 5 primaries twisted; underparts white, tinged buffish on breast sides and flanks, and heavily streaked blackish except on central belly and vent; iris dark brown; upper mandible black, lower whitish; legs and feet olive to yellowish-green Differs from S sharpei in smaller size, no orange on underparts; from S rufolateralis in white or buff, rather than bright orange, breast side Female resembles male, but duller, has crown grey with black streaks Juvenile like female, but has less buff on forehead, brown crown with indistinct streaks Races vary in colour and pattern above, extent of streaking below, female crown pattern, and size: camarunensis is darker, more rufescent, above than other races, breast more broadly streaked and with strong buff wash, female crown varies from almost plain black to heavily streaked black and rufous; delacouri resembles previous, but paler, with greyer nape and top of mantle; albigularis has white-streaked grey ear-coverts, greyer upperparts than nominate, yellowish-buff wash on breast, female crown blackish with buff edgings; meinertzhageni is like previous but underparts less buffy, female crown all blackish; medianus is not so dark as previous, also less streaked above and below, with grey wash over upper mantle, ochraceous breast patches, more yellow-buff belly, longer wings, female crown blackish-grey with faint pale scaling; suahelicus differs from last in dark grey ear-coverts, more extensive black on central mantle, female has more uniform crown, buff wash below; conjunctus has buff ear-coverts, yellowish to buff-olive wash on breast and flanks; cryptoleucus is more buffy-olive above than previous, female crown olivaceous slate-grey with broad dull black streaks

OK~鋪梗鋪了這麼多,

其實就是想看一個物種的描述文字多寡與受脅等級之間的關係。

有沒有可能那些受脅等級高的物種,因為關注度高,對此物種的描述文字會越多? 或是狀況相反,因為受脅等級高,雖然關注度高,但因為族群數量少、獲取資料少,導致對此物種的描述文字偏少?

依循此概念,受脅等級低的物種,是否可能因為數量多、較不受關注,描述文字會少; 或是因為數量多,容易觀察,反而累積的描述文字多?


前提假設

1. 物種關注度來自於HBW物種描述欄位的長度
2. HBW網站對每一物種無描述欄位長度限制
3. HBW網站對於物種描述的資訊皆是全面提供
4 .編寫物種描述欄位的專家皆依據相同標準

結果如下圖


  1. 若只看中位數可以發現其描述字數無相差太多
  2. LC(暫無危機)的物種型的描述字數並未都高、反而是變動大.這部分是否可以解釋為LC物種其實的關注度還是有程度上的差別?或是可以理解成LC因為是常見種,分布範圍廣,亞種也多,所以描述有時候會爆炸
  3. 那些已滅絕的EX、EW資訊量一致性的偏少且變動不大。代表我們沒有機會再去觀察或是增加資訊量?
  4. 更有趣的問題在NR等級,NR ( Not Recognize)就是未被歸類於受脅等級分類中的物種,有的資訊量超大但卻未被歸類於任何一個受脅類群?

結語

以上就是個清資料過程中的發想,簡單做個圖來看看~

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