INFREQUENCY OF PINEAL ATROPHY AMONG BIRDS AND ITS RELATION TO NOCTURNALITY W. B. QUAY Department of Zoology University of California Berkeley, California 94720 A recent resurgence of interest in the verte- any other part of the avian brain, and that it brate pineal organ or epiphysis cerebri has pro-’ is smallest in owls (Strigidae). Owing to the vided new evidence of its systematic diversity, hitherto relatively few species of adult birds as well as of its probable functional signifi- whose pineal glands have been examined, it cance in birds ( Ralph 1970). Although embry- has not been possible until recently to effec- ologically derived from the roof of a part of tively compare adult pineal development and the brain, the diencephalon, the pineal organ structure in birds with their behavioral traits has a different and unique structure and com- and daily times of activity. Although this situ- position. Microscopic and physiological studies ation has been improved, as can be ascertained have shown that, in general through the verte- from the data in table 1, it is still far from ideal. brate series, as pineal photoreceptoral activity Two major areas of deficiency in our informa- decreases, an apparent secretory capacity in- tion can be cited. There are still many families creases (Quay 1970b). Among birds only and a few orders (Gaviiformes, Gruiformes, abortive or vestigial photoreceptors have been Coliiformes, and Trogoniformes) in which identified so far in electron microscopic studies adult pineal size and structure are unknown. of the pineal organ (Oksche and Vaupel-von There are still commparativelyfew representa- Harnack 1966; Collin 1966a, b, 1967, 1968; tives of the Caprimulgiformes whose pineals Renzoni et al. 1968; Bischoff 1969; Oksche et are known. Behaviorally and physiologically, al. 1969; Oksche and Kirschstein 1969; and many of these may prove to be among the most others). Similarly, electrophysiological inves- interesting of the putatatively nocturnal or tigations have been unsuccessful in detecting a crepuscular species. The second major area of direct respoase to light by avian pineals informational deficiency is the fragmentary (Morita 1966; Ralph and Dawson 1968). and largely subjective state of evidence for Nevertheless, rapid biochemical changes occur nocturnality in most species and the varia- in avian pineal organs in close correlation with bility of supposedly nocturnal behavior in re- the daily timing of environmental illumination lation to seasonal activities, such as migration, (Ax&d et al. 1964; Quay 1966, 1970a; Ralph incubation, feeding nestlings, and others. The et al. 1967; Hedlund and Ralph 1968; Lauber present report, representing an extension of an et al. 1968; Sayler and Wolfson 1969). These earlier abstract for an oral presentation (Quay changes are thought to be most likely mediated 1968), serves primarily to outline the degree by the nervous system and the innervation of of relation between the infrequent occurrences the pineal following photoreception by the of pineal atrophy in birds and nocturnality. lateral eyes. The pineal biochemical changes have been postdated most commonly to be METHODS AND MATERIALS related to a pineal endocrine secretory activity Table 1 lists the species whose pineals have been either which may have some physiological signifi- described previously in publications or more recently cance in relation to adaptation to photoperiod, examined by the author. Excluded are species whose either on a short-term or seasonal basis. How- pineals have been studied only in developmental ever, such postulations are in need of extensive stages or by electron microscopy, since doubt may remain concerning the size or final status of the pineal additional supporting evidence ( Ralph 1970). in adults of such species. Observations and conclusions With the recent advances in our knowledge in this study are based on published descriptions of of avian pineal composition and its primary adult pineal size and structure and on microscopic correlations with light, the investigation of study of pineal specimens, some of which came from species whose pineal organs have not been studied or comparative pineal size in birds in relation to described before. Twenty-three orders, 58 families diurnality and nocturnality becomes of especial and 121 species are represented (table 1). Of these species, 89 have been examined histoloeicallv bv the interest. Krabbe ( 1952) in comparative studies ^ Y . , of the morphogenesis of the brain in birds author, usually by means of serial sections of a median slice of the entire brain and its covering membranes. found that the pineal gland or epiphysis cerebri Techniques of preparation and histological staining varies in size and shape probably more than have been noted previously (Quay and Renzoni 1963, [331 The Condor 74:33-G, 1972 34 W. B. QUAY TABLE 1. Avian species whose pineals have been de- TABLE 1. Continued. scribed in publication or (starred) examined micro- scopically by the author. SOUrCe Capella‘ gallinago Quay and Renzoni 1987 Tma SOUrCl? *Ereunetes mauri Quay 1965; Quay and Renzoni 1967 Struthionifonnes *EroZia alpina Quay and Renzoni 1967 Stmthionidae Burhinidae Struthio camelus 1955 Stack *Burhinus capensis Rheifonnes Glareolidae Rheidae *Rhinoptilus cinctus Rhea americana Starck 1955 Laridae Casualiifonnes Larus canus Wetzig 1961 Dromiceiidae *Lams occidentalis Qnay and Renzoni 1967 *Dromiceius n. hollandiae Cobb and Edinger 1962 *Sterna hirundo Alcidae Apterygifonnes *u&l aalge Apterygidae Aptelyx australis Craigie 1930; Krabbe 1959 *Aethia cristatella Quay and Renzoni 1967 Columbifonnes Tinamifonnes Columbidae Tinamidae *CoZumba Zivia Quay and Renzoni 1967 *Crypturellus cinnamomeus Columba oenas Renzoni 1970 Spheniscifonnes streptope1ia turtw Renzoni 1970 Spheniscidae Streptopelia decaocto Renzoni 1970 Breucker 1967 Aptenodytes patagonica Psittacifomes Colymbiformes Psittacidae Colvmbidae *Nymphicus hollandicus *Aechmophows occident&s *Aratinga canicularis *Podilymbus podiceps Quay and Renzoni 1967 * Melopsittacus undulatus Renzoni 1964b, 1965a, b Procellariiformes CUCdifOITIleS Diomedeidae Cuculidae *Diomedea immutabilis Cuculus canoms Renzoni 1968 Procellariidae Strigifonnes *Puffinus pacificus Tytonidae *Pterodroma leucoptera Tyto alba Renzoni 1963,1964a, 1968 Hydrobatidae Strigidae *Oceanodroma homochroa Renzoni and Quay 1963; Quay otus stops Renzoni 1963,1964a, 1968 and Renzoni 1967 *Glaucidium cuculoides Pelecanifonnes Athene noctua Renzoni 1963,1964a, 1968 Pelecanidae *Speotyto cunicuhria *Pelecanus erythrorhynchos St& aluco Breucker 1967; Renzoni 1968 *Pekcanus occidentalis Quay and Renzoni 1967 Asia otus Renzoni 1963,1964a, 1968 Sulidae *Ario flammeus ShtdniEka 1905 *sukl sula Phalacrocoracidae Caprimulgifonnes Phalacrocorax carbo Char& 1954 Camimulaidae_ I *Phalacrocorar penicillatus Renzoni and Quay 1963; Quay *Phalaenoptilus nuttallii Quay and Renzoni 1967 1965; Quay and Renzoni 1967 Caprimulgzrs europaeus Renzoni 1968 *PhaZacrocorax pelagicus Renzoni and Quay 1963; Quay Apodifonnes 1965; Quay and Renzoni 1967 Apodidae Ciconiifonnes *Strevtoor0cnezonaris Ardeidae Apus apus Renzoni 1968 Ardea cinerea Stammer 1961 Trochilidae AIlS.dfOllll~S Anthracothorar nigricollis Breucker 1967 Anatidae *cazypte co,vtae Quay and Renzoni 1967 *Anser albifrons Stammer 1961; Quay and Coraciifonnes Renzoni 1967 Coraciidae *Anas acuta Coracias garmlus Renzoni 1965a “Aythya americana Quay and Renzoni 1967 Upupidae *Melanitta deglandi Quay and Renzoni 1967 Upupa epops Renzoni 1965a Falconifmmes Picifomes Cathartidae Picidae *Cathmtes aura Quay and Renzoni 1967 Iynx torquizza Renzoni 1965a Accinitridae *cozaptes cafer *Buteo swainsoni Quay and Renzoni 1967 Picus viridis Renzoni 1965a Falconidae *Dendrocopos pubescens *F&o sparoerius Quay and Renzoni 1967 Gallifonnes Phasianidae *sayornis saya *Lophortyx californicus *Nuttallornis borealis Quay and Renzoni 1963 *Gallus StudniEka 1905; Chiodi 1940; [domestic] Alaudidae Spiroff 1958; Stammer 1961; *Eremophila alpestris Quay and Renzoni 1963 Quay 1965; Quay and Renzoni Hirundinidae 1967 *Tachycineta thalassinn Quay and Renzoni 1967 Meleagrididae Himndo wstica Renzoni 1965a Meleagris gallopaco Studnieka 1905; Stammer 1961 Motacillidae Charadriiformes *Anthus spinoletta Quay and Renzoni 1967 Haematopodidae Laniidae *Haematopus ostralegus *Larks ludovicianus Quay and Renzoni 1967 Charadriidae Troglodytidae *squataroza squatarola Quay and Renzoni 1967 *Salpinctes obsoletus Quay and Renzoni 1963, 1967 “Charadrius oociferus Quay and Renzoni 1967 Muscicapidae Scolopacidae *SiaZia mexicana Quay and Renzoni 1963,1967 *Limosa fedoa Quay and Renzoni 1967 *Myade&s townrendi Quay and Renzoni 1963, 1967 Watowtrowhorus Turdus merula Renzoni 1965a, Breucker 1967 Quay 1965; Quay and Renzoni Turdus iliacus Renzoni 1965a 1967 *Turdus migratorius Quay and Renzoni 1963 THE RELATION OF PINEAL ATROPHY TO NOCTURNALITY 35 TABLE 1. Continued. developed pineal organs, insofar as known (Quay and Renzoni 1963, 1967; Ralph and TaX3 Source Lane 1969). Thus, although the samples rep- *Regulus calendula Quay and Remoni 1963,1967 resenting particular species rarely contain Phylloscopus collybita Remzoni 1965a Aegithalidae more than two or three specimens, the pineal *PsaZtriparus minimus Ouav_ . and Renzoni 1967 Paridae status in these can probably be judged as rep- *Parus rufescens Quay and Renzoni 1963 resentative for the species. *Parus inornatus Quay and Renzoni 1967 Sittidae Detailed observations here will concern two *Sitta canadensis