八色鳥(Pitta nympha)在巢內放置哺乳動物糞便的行為探討

繁殖成功與否會直接影響個體的適存度與整體族群量，而鳥巢為鳥類繁殖場所，巢中的內含物是影響鳥巢的安全性的因素之一，進而影響到鳥巢繁殖的成功與否。於巢中擺放或使用動物糞便的行為在鳥類極其罕見，本研究進行前，於雀形目(Passeriformes)八色鳥科(Pittidae)的八色鳥(Pitta nympha)巢中，發現哺乳動物糞便的擺放行為，為瞭解此行為在八色鳥巢中發生的普遍性，我分別於2009及2010年5-7月在雲林縣林內鄉，以錄影、定期巡巢及拍照的方式，觀察八色鳥巢中或巢口處是否擺放哺乳動物糞便及其他的種類(合稱為Mammalian Dung-like Substance，簡稱MDS)，及MDS擺放時期、擺放量與其新鮮程度，並提出禦敵假說與供熱假說，以瞭解MDS對八色鳥巢的功用。禦敵假說推論MDS可降低巢中蛋或幼雛被天敵掠食的機率，進而提高繁殖成功率；供熱假說推測MDS可產生熱量，提高巢中的溫度，有利於孵蛋。研究期間共記錄33個八色鳥巢、76個巢期(含築巢期、下蛋期、孵蛋前期、孵蛋後期、育雛前期及育雛後期)，其中25個巢(約75.8%)有擺放MDS的行為，記錄到的MDS可分為哺乳動物糞便、土壤及其他類，其中以哺乳動物糞便的出現率為最高(67%)，糞便種類經判定有臺灣獼猴(Macaca cyclopis)及臺灣白鼻心(Paguma larvata)的糞便； MDS放置的時期則以孵蛋後期、育雛初期及育雛後期最為常見(出現率分別是87.5%，90.9%及100%)，且最常擺放的位置在距離巢口向內及向外0-5cm的區域(出現率分別為56.9%及34.5%)。我以臺灣獼猴糞便做為MDS代表，利用人工巢及市售鵪鶉蛋進行假說驗證，本研究結果僅支持禦敵假說，有放置臺灣獼猴糞便的人工巢(n=71)，巢內蛋的每日存活率(0.934±0.0013)較未擺放臺灣獼猴糞便的人工巢(n=71)為高(0.923±0.0014)，且具有極顯著差異(P<0.001)。有無放置臺灣獼猴糞便的人工巢間(n=34)，兩者巢溫並無顯著差異(P=1)，因此供熱假說在本研究未得到支持。根據本研究成果，八色鳥在巢內擺放哺乳動物糞便及似哺乳動物糞便物質為一普遍現象，且其功能應與防禦天敵有關。

關鍵字

八色鳥；台灣獼猴；糞便；巢內含物；禦敵假說

並列摘要

The rate of nesting success in birds is directly in relation to an individual’s fitness and population size. A nest is composed of materials collected by the adults, and the nesting material determines its safety and thus nesting success. It’s uncommon for birds to place or utilize animal dung in nests; however, the presence of mammalian dung was discovered in the nests of Fairy Pitta (Pitta nympha, family Passeriformes). In order to understand the generality of this behavior and the probable functions of mammalian dung and other mammalian dung-like substance (both are denominated as MDS) in Fairy Pitta nests, I used video recording, photograph taking and regular nest checking to observe nests in the Linnei Township of Yunlin County from May to July of 2009 and 2010. The types, placed period, location, quantity and quality of MDS were recorded. To ascertain the role of MDS, I examined the behavior by testing anti-predation hypothesis and heating hypothesis. The anti-predation hypothesis proposed that MDS could decrease the predation risk of eggs and chicks in nests, and thus increase the survival rate of nests, while the heating hypothesis proposed that MDS had the potential to produce heat and increase the temperature of nests. Within 33 Fairy Pitta nests, including 76 stages (which include building, egg-laying, early-incubation, late-incubation, early-nestling and late-nestling stages), 76.3% of nests (n=25) were observed with MDS using behavior. The types of MDS can be divided into three categories: mammalian dung, soil and others, with mammalian dung appearing most frequently (67%). The mammalian dung was later determined as the dung of Formosan macaque (Macaca cyclopis) and Masked Palm Civet (Paguma larvata). The placed stage of MDS was most frequent in the late-incubation, early-nestling and late-nestling stages (87.5%, 90.9%, and 100%). The location of MDS was mostly at the region which is zero to five centimeters inside the entrance of the nests (56.9%), and the second most common region was zero to five centimeters outside the entrance of the nests (34.5%). I used artificial nests and quail eggs to test the anti-predation hypothesis and the heating hypothesis, with the dung of Formosan macaque as the MDS. The daily survival rates of artificial nests supported the anti-predation hypothesis. Nests with the dung of Formosan macaque (n=71) have significantly higher daily survival rate (0.934±0.0013) than those without dung (n=71, daily survival rate= 0.923±0.0014; p<0.001). The temperature of nests with or without the dung of Formosan macaque did not show a significant difference. Results from my field observation did not support the heating hypothesis. In conclusion, the majority of breeding Fairy Pittas do in fact place mammalian dung and mammalian dung-like substance inside their nests and the function of this behavior may be related to anti-predation.

並列關鍵字

Pitta nympha ； Macaca cyclopis ； dung ； contents in nest ； anti-predation hypothesis

參考文獻

Aebischer, N. J. 1999. Multi-way comparisons and generalized linear models of nest success: Extensions of the Mayfield method. Bird Study 46: 22-31.

Birdlife International. 2010. IUCN Red List of Threatened Species. Version 2010.4. Downloaded from www.iucnredlist.org on 19/May/2011.

Clucas, B, M. P. Rowe, D. H. Owings, PC. Arrowood. 2007. Snake scent application in ground squirrels (Spermophilus spp.): A novel form of antipredator behaviour? Animal Behaviour 75: 299-307.

Eichholz, M. W., and W. D. Koenig. 1992. Gopher snake attraction to birds’ nests. The Southwestern Naturalist 37: 293-298.

Erritzoe, J. 2003. Family Pittdae (Pittas). Pages 116-123 in J. de Hoyo, A. Elliott, D. A. Christie, editors. Handbooks of the birds of the world, Vol. 8 Broadbills to Tapaculos. Lynx Edicions, Braceloan, Spain.

國際替代計量

八色鳥(Pitta nympha)在巢內放置哺乳動物糞便的行為探討

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