Seasonality in predation risk: varying activity periods in lemurs and other primates

The Evolution of Cathemerality in Primates and Other Mammals: A Comparative and Chronoecological Approach

“…Predation and cathemerality in primates has been reviewed and discussed in detail by Colquhoun [2006], who concludes that although cathemerality allows lemurs to avoid diurnal predation by raptors in Madagascar, this activity cycle is more likely to be inherently linked to predation by and/or avoidance of the arboreal cathemeral viverrid, Cryptoprocta ferox [see also Curtis and Rasmussen, 2002;Rasmussen, 2005]. In fact, Colquhoun [2006] proposes a co-evolutionary relationship between this formidable predator and cathemeral lemurs on Madagascar, with the nocturnal ancestor of Cryptoprocta adopting a cathemeral activity cycle as an adaptation to the presence of cathemeral lemurs.…”

“…While it is unlikely that any cathemeral species can eliminate predation risk entirely through the shifting of activity between daylight and night-time hours, even slight adjustments in activity across the 24-hour day may be extremely effective when combined with other antipredator behaviours and when the ecology of predator species and other potential prey species is taken into account. During the wet season in northwest Madagascar mongoose lemurs can minimize diurnal predation risk from raptors and the viverrid carnivore, C. ferox , by pursuing a 'cryptic small group' strategy [Janson, 1998] and taking advantage of dense canopy cover while foraging and travelling [Rasmussen, 2005]. However, their small group size and cryptic habits offer less protection from aerial predators during daylight hours in the dry season when canopy cover is greatly reduced.…”

“…The fi rst fi eld reports of night-time activity in taxa presumed to be diurnal or crepuscular [Petter, 1962;Albignac, 1981] derived from northwest Madagascar and the Comoran archipelago and were linked to feeding ecology and thermoregulation [Tattersall and Sussman, 1975;Sussman and Tattersall, 1976;Tattersall, 1978]. As more long-term studies of wild lemurs were carried out in the late 1980s and 1990s it became clear that cathemerality was a distinctive hallmark of the Lemuridae or true lemurs [Overdorff, 1988[Overdorff, , 1991Wilson et al, 1989;Andrews and Birkinshaw, 1998;Colquhoun, 1998;Mutschler 1998;Curtis et al, 1999;Rasmussen, 1999Rasmussen, , 2005Donati et al, 1999;Gerson, 2000;Donati and Borgognini-Tarli, 2006;Kappeler and Erkert, 2003]. Cathemerality was also reported for populations of owl monkeys inhabiting highly seasonal forests in Paraguay [Wright, 1989] and Argentina [Fernandez-Duque, 2003].…”

Predator avoidance and dietary fibre predict diurnality in the cathemeral folivore Hapalemur meridionalis

“…It is often suggested that a switch to nocturnal foraging represents a predator-avoidance mechanism, reducing risk from diurnal predators (Cowan and Peckarsky 1994;Metcalfe et al 1999;Reebs 2002;Lang et al 2006;Orpwood et al 2006). Considering this strategy, predation has been tentatively linked to lemurid cathemerality as an ultimate determinant (Overdorff 1988;Curtis et al 1999;Donati et al 1999;Rasmussen 1999Rasmussen , 2005Colquhoun 2006Colquhoun , 2007.…”

Lemurs Active in Day and Night: Investigation into Phylogenetic Origin, Proximate Mechanism, and Adaptive Significance of Cathemerality

“…霊長類学における活動パターン研究の意義 現生の霊長類の活動パターンを分類群ごとに整理し ていくと，キツネザル下目を除く曲鼻猿亜目，すなわ ちロリス下目は夜行性であり，直鼻猿亜目はメガネザ ル下目と広鼻猿下目のヨザル属(Aotus)以外は昼行性 である (Griffin et al, 2012;Santini et al, 2015) 。霊長類 の共通祖先は夜行性であり，霊長類全体における進化 の流れとしては，夜行性から昼行性へと移行してきた と 考 え ら れ て い る (Griffin et al, 2012;Santini et al, 2015) 。霊長類における昼行性化は，群れや複雑な社会 性の進化を伴い (Shultz et al, 2011) ，視覚や脳の発達に もつながる一大イベントであったと考えられる (Barton, 1998) 。よって，霊長類における活動パターンの進化は 霊 長 類 学 の メ イ ン ト ピ ッ ク の ひ と つ に な っ て き た (Heesy & Ross, 2001;Martin, 1990;Martin et al, 2003) (Tattersall, 1979) 。やはり夜行性とも昼行 性とも適用しがたかったために，Tattersall(1987はギ リシャ語の"Kata(= Through) " と"Hemera(= Day) " を用いて"Cathemerality"という言葉を考案し，今日ま で使用されている。日本語では小山・高畑 ( 33：3 − 20, 2017(doi：10.2354 / psj.33.003) (Tattersall, 1987) Fernandez-Duque, 2003;A. trivirgatus Wright, 1989) 。曲鼻 猿亜目では既述の 3 属だけでなく，近年ではジェント ルキツネザル属に近縁なオオジェントルキツネザル属 (Prolemur)が周日行性に位置づけられた (Curtis, 2006;Curtis & Rasmussen, 2006) 。さらに，厳格な昼行性であ ると定義されていたワオキツネザル(Lemur catta)でも 夜間活動が確認されおり (Donati et al, 2013;LaFleur et al, 2014;Parga, 2011) Curtis et al, 1999;Rasmussen, 1999Rasmussen, , 2005Tattersall, 1987) (Rasmussen, 1999(Rasmussen, , 2005Tarnaud, 2006) 。雨季と乾季が明瞭な熱帯乾燥林に みられる。 C タイプ：1 年を通して昼も夜も活動する恒常的な周日 行性を示す (Colquhoun, 1998;Donati & Borgognini-Tarli, 2006;Schwitzer et al, 2007a) 。季節が不明瞭な熱帯雨林 にみられる。 これらの共通点や差異を生じさせる至近要因と究極 要因については，後ほど触れていく。 2. 周日行性は昼行性化の途中か？ 霊長類の共通祖先が夜行性であることは長らく主張 されており，近年の研究においても強く支持されてい る (Griffin et al, 2012;Santini et al, 2015) 。我々ヒトを 含め，直鼻猿亜目のほとんどは昼行性であることから， 霊長類は夜行性から昼行性に進化してきたといえる (Santini et al, 2015) 。一方，原始的...…”