Carolina Chickadee (Aves, Paridae, Poecile carolinensis) Vocalization Rates: Effects of Body Mass and Food Availability under Aviary Conditions

We evaluated the effect of body mass and several environmental factors on vocalization rates of Carolina chickadees ( Poecile carolinensis ) housed in an aviary. Two different nonsong vocalizations (tseet and chick-a-dee) and song (fee-bee fee-bay) were recorded. Food was delivered from a feeder and three different levels of food access were presented to each bird: 10, 40 and 55 min/d. Two scales of body mass were measured: 'dawn mass' and 'focal mass' (mass during a focal observation divided by dawn mass). Across all birds, there was a significant negative correlation between both nonsong vocalization rates and body mass (both dawn and focal mass) and the effect of mass on call rate was greatest for days when food was relatively abundant. Nonsong vocalizations were also given at higher rates when food was limited (10 min/d) than when food was more abundant (40 and 55 min/d). No changes in call rates with time of day were observed. Overall, song rates were substantially lower than nonsong rates. Unlike nonsong rates, song rates were highest in birds that had relatively high dawn mass. No significant correlation between song rates and focal mass was observed, and no significant correlation between song rates and time of day was observed. Finally, vocalizations from nonfocal birds had little effect on vocalization rates of focal birds. Our results suggest that nonsong communicative signals are more important for birds facing energetic stress, while song is more important for birds that are not energetically stressed.     

Auditory Same/Different Concept Learning and Generalization in Black-Capped Chickadees (Poecile atricapillus)

Abstract concept learning was thought to be uniquely human, but has since been observed in many other species. Discriminating same from different is one abstract relation that has been studied frequently. In the current experiment, using operant conditioning, we tested whether black-capped chickadees (Poecile atricapillus) could discriminate sets of auditory stimuli based on whether all the sounds within a sequence were the same or different from one another. The chickadees were successful at solving this same/different relational task, and transferred their learning to same/different sequences involving novel combinations of training notes and novel notes within the range of pitches experienced during training. The chickadees showed limited transfer to pitches that was not used in training, suggesting that the processing of absolute pitch may constrain their relational performance. Our results indicate, for the first time, that black-capped chickadees readily form relational auditory same and different categories, adding to the list of perceptual, behavioural, and cognitive abilities that make this species an important comparative model for human language and cognition.     

Achromatic Plumage Reflectance, Social Dominance and Female Mate Preference in Black-Capped Chickadees (Poecile atricapillus)

Individual variation in achromatic plumage reflectance of male Black‐capped Chickadees (Poecile atricapillus) is correlated with social rank and reproductive success, suggesting it may play an important role in sexual signaling. We asked whether female chickadees could assess male quality based on plumage, in the absence of information about relative social dominance. Sexually mature but inexperienced females captured during the pair formation period in late fall and early winter were presented with a choice of two unfamiliar, sexually experienced males in separate compartments of an outdoor mate choice arena. Following each preference trial, we released the males into a single compartment and scored their pairwise dominance interactions. In 10 of 11 trials, females spent significantly more time with the male subsequently identified as dominant, despite not witnessing the males interact. Spectral analysis of male plumage reflectance revealed that UV‐chroma of dark body regions (bib, cap and mantle) was significantly greater in dominant, preferred males and that dominant, preferred males had significantly brighter white cheek patches. There were no differences in vocalization rates of preferred and non‐preferred males. These results show that female chickadees can rapidly assess unfamiliar males based on visual cues, and suggest that variation in achromatic plumage functions in sexual signaling.     

Historical biogeography of tits (Aves: Paridae, Remizidae)

Tits (Aves: Paroidea) are distributed all over the northern hemisphere and tropical Africa, with highest species numbers in China and the Afrotropic. In order to find out if these areas are also the centers of origin, ancestral areas were reconstructed based on a molecular phylogeny. The Bayesian phylogenetic reconstruction was based on sequences for three mitochondrial genes and one nuclear gene. This phylogeny confirmed most of the results of previous studies, but also indicated that the Remizidae are not monophyletic and that, in particular, Cephalopyrus flammiceps is sister to the Paridae. Four approaches, parsimony- and likelihood-based ones, were applied to derive the areas occupied by ancestors of 75?% of the extant species for which sequence data were available. The common ancestor of the Paridae and the Remizidae inhabited tropical Africa and China. The Paridae, as well as most of its (sub)genera, originated in China, but Baeolophus originated in the Nearctic and Cyanistes in the Western Palearctic. Almost all biogeographic reconstruction methods produced similar results, but those which consider the likelihood of the transition from one area to another should be preferred.     

Patterns of Vocalization Use by Female Red-winged Blackbirds (Aves: Emberizidae,Icterinae): Variation and Context

Variation within communication systems can be examined at several levels: variation among individual notes, variation in the arrangement of notes, and variation in delivery. Here, variation in the arrangement and delivery of notes used in female red-winged-blackbird vocalizations is described, and this variation is examined for correlations with the context in which the vocalizations were given. Within a vocalization, notes were normally arranged in a series of similar notes. Of the 75 different note arrangements recorded from the population, 12 arrangements accounted for 84 % of vocalizations. Provisional results indicate that the arrangement of notes was influence by the following contexts: 1. The stage of the breeding season; 2. The individual female; 3. The breeding status of the female; 4. Certain female behaviour patterns; 5. Other red-winged-blackbird vocalizations; and 6. The presence or absence of a female's mate in the territory. Variation in delivery was measured by the number of notes within a vocalization; delivery was influenced by the stage of the breeding season, the individual female, and the breeding status of a female. Most note arrangements were used in a wide variety of contexts and did not appear to be functionally distinct.     

Seasonal and diurnal patterns of black-capped chickadee (Poecile atricapillus) vocal production

Changes in vocal behaviour observed in temperate songbirds have been linked to changes in photoperiod. Research has focused on the fluctuation of hormones that lead to photosensitivity, photostimulation and photorefractoriness, as well as the 'dawn chorus' observed in numerous species. However, photoperiod in the natural environment is a complex event that occurs as seasons change. To determine the natural relationships between photoperiod and vocal behaviour we sampled vocal production of black-capped chickadees for three major vocal classes over one year at dawn, meridian and sunset. Fee-bee song production increased twice, once in the winter and once in the spring, and occurred almost exclusively at dawn. Chick-a-dee call production was highest in autumn and winter generally at the meridian. Gargle production did not differ significantly by season; however, the most gargle production occurred during the winter at the meridian.     

地山雀线粒体基因组全序列的测定和分析

基于长距PCR扩增及保守引物步移法测定并注释了地山雀(Pseudopodoces humilis)的线粒体基因组全序列.结果表明,地山雀线粒体基因组全长1.6 809万bp,A+T含量为52.9%,37个基因排列顺序与红原鸡一致.蛋白质基因的起始密码子中,除COI基因为GTG外,其余均为ATG.NDⅠ和ND5基因终止密码子为AGA:COⅡ基凶为AGG:COⅢ和ND4基因为不完全终止密码子T;其余基因均为典型的TAA或TAG.预测了22个tRNA基闪的二级结构,发现tRNAScr(AGN)缺少DHU臂,tRNAPhe的TψC臂存在一单核苷酸插入.预测的地山雀12S和16S rRNA二级结构分别包括3个结构域47个茎环和6个结构域60个茎环. 控制区位于tRNAGlu和tRNAPhe之间,长度1240 bp.控制区结构为高变Ⅰ区、中央保守Ⅱ区和保守序列Ⅲ区3个结构域.     

Food hoarding behaviour of black-capped chickadees (Poecile atricapillus ) in relation to forest edges

In temperate forests, small birds avoid the use of forest edges in adverse winter weather suggesting high foraging costs in terms of energetic requirements. Since hoarding species will often retrieve caches during adverse winter weather, they may perceive forest edges, especially exposed ones, as low quality hoarding sites. We tested whether black-capped chickadees ( Poecile atricapillus) inhabiting fragmented forests modify and reduce hoarding activity near forest edges. We also tested whether hoarding behaviour will be most affected in sites with forest edges more exposed to extreme weather. Black-capped chickadees taking food from a feeder 30 m from the nearest forest edges hoarded items mostly towards the forest interior, whereas no preference in hoarding location was observed with birds taking food from a feeder placed >100 m from the edge. Furthermore, birds avoided direct flights towards forest edges and, at sites exposed to prevailing winds, hoarding trips were shorter than at other locations. These results suggest that individuals avoid hoarding near forest edges and there, they lower their investment in terms of hoarding effort. The observed difference in hoarding behaviour was more evident near forest edges delimiting wide unforested areas than in edges delimiting narrower unforested areas. Edge exposure to prevailing winds influenced hoarding behaviour much less. We suggest that hoarding birds may partially overcome the ecological costs of habitat loss and fragmentation due to abiotic edge effects. By hoarding food away from forest edges in good weather, they may use forest interiors as low-cost retrieval sites under adverse weather.     

Evidence of accelerated beak growth associated with avian keratin disorder in black-capped chickadees (Poecile atricapillus)

We recently documented an epizootic of beak deformities in more than 2,000 Blackcapped Chickadees (Poecile atricapillus) and other wild bird species in North America. This emerging avian disease, which has been termed avian keratin disorder, results in gross overgrowth of the rhamphotheca, the outer, keratinized layer of the beak. To test the hypothesis that the beak deformities characteristic of this disorder are associated with accelerated keratin production, we measured rates of beak growth and wear in affected Black-capped Chickadees (n=16) and a control sample of unaffected chickadees (n=14) collected from south-central (61°09'-61°38'N, 149°11' -149°48'W) and interior Alaska (64°51' -64°53'N, 147°49' -147°59'W). Rates of absolute growth were 50-100% higher in affected birds than they were in control birds and exceeded records from other passerine species. These results suggest that abnormally rapid epidermal growth is the primary physical mechanism by which beak deformities develop and are maintained in affected chickadees. Although beak overgrowth typically worsened over time, differential patterns of wear influenced the severity and morphology of deformities. In some cases, the effects of accelerated keratin growth were partially mitigated by frequent breakage of rhamphothecal tips. However, mortalities occurred in 9 of 16 birds (56%) with beak deformities during the study, suggesting that avian keratin disorder results in severe health consequences for affected birds. Additional study of factors that control beak keratin production is needed to understand the pathogenesis of this debilitating disease in wild birds.     

Failure to detect seasonal changes in the song system nuclei of the black-capped chickadee (Poecile atricapillus)

Most temperate songbird species sing seasonally, and the brain areas involved in producing song (the song system) vary in size alongside the changes in behavior. Black-capped chickadees (Poecile atricapillus) also sing seasonally, and we find that there are changes in the stereotypy and the length of the fee-bee song from the nonbreeding to the breeding season. Yet despite these changes, we fail to find any evidence of seasonal changes in the song system. The song system of males is larger than that of females, as is typical in songbirds, but the ratio between the sexes is small compared to other species. We suggest three hypotheses to explain our failure to find seasonal variation in the chickadee song system.     

Ecological and morphological variation of Canary Island blue tits, Parus caeruleus (Aves: Paridae)

Canary Island blue tits have differentiated within the last million years. Compared with mainland populations they have short wings, large beaks and tarsi, and tend to be less variable in these parameters. Within the archipelago the eastern populations have the shortest wings and tarsi but the widest and deepest beaks. The eastern populations may have been derived from central island ones, following extinction of the original eastern populations during a warm period in the last Ice Age. New measurements have been used to test contrasting predictions of hypotheses that explain inter-island morphological variation in terms of either climatic or ecological influences. Neither hypothesis is sufficient to explain the variation. A model which combines mem is proposed as follows. Mild winter temperatures have selected for small body size and wing length, especially on the hot, dry, eastern islands. On the other pine-forested, islands, selection has favoured relatively long tarsi and long, slender, beaks for efficient foraging among pine foliage. The absence of die pine-dwelling coal tit from the islands has facilitated mis evolutionary shift. It is shown that blue tits in pines forage more in the needles and cones on the Canary Islands than they do on die North African mainland.     

Microevolution of eastern palaearctic Grey tits as indicated by their vocalizations (Parus [Poecile]: Paridae,Aves) I. Parus montanus: Contributions to the Fauna of the Far East,No. 2

Within the Palaearctic Region, the Willow tit (Parus montanus) displays four vicariant forms of territorial song. 1. “Alpine” form (pure single-frequency whistles, Fig. 5: 1) in the Alps and adjacent mountains to the East. 2. “Lowland” or “Normal” form (frequency change from high to low within one note, Fig. 5: 2) in the other parts of NW, Central and SE Europe. 3. In populations of N and E Europe as well as of W and E Siberia every individual bird uses - so far as known - both song types; this “Siberian” form (Figs. 1, 2) includes intergrades (Fig. 3). The comparatively type-rich Siberian repertoire is found in a vast area from N and E Europe to the Amur River and Ussuriland in Siberia. 4. In song types of S Palaearctic Asia whistled notes dominate, as in the Alpine form, but the single notes contrast by marked differences in pitch (frequency jumps); this is the “Sino-Japanese” form (Altai, China, Japan, Fig. 4). These acoustically defined groups of Eurasia comprise several morphological subspecies. Subspecies groups with the same song type are closely related. We hypothesize that the Alpine and Lowland song types developed in Pleistocene refuge areas in the southern Alps and in the Balkan Peninsula, respectively, both originating from the complex Siberian song type. According to this hypothesis, both extant Central European song types lost one note type of the Siberian song type (Lowland or Alpine, respectively). In contact zones and hybrid belts of Alpine and Lowland song, the Secondary Siberian song type occurs, which combines the Lowland and Alpine types. Marked song types, which cover vast areas, also characterize the closest relatives in the Nearctic Region, the Chickadees P. atricapillus, P. carolinensis and P. sclateri (Mexico), the most southerly representative of Chickadees in America. P. carolinensis uses Sino-Japanese song, P. atricapillus a derived form with only minor frequency jumps. The Willow tit probably evolved in the E Palaearctic Region, perhaps in the area of E China, Amur/Ussuri and NE Siberia, rich in diverse local taxa at present (songarus sector; parts of montanus sector; kamtschatkensis sector, respectively, Fig. 5). The Sino-Japanese song type was also developed here. Starting from this area, montanus settled the W Palaearctic Region, where the song types were modified as follows: loss of frequency jumps of the old Sino-Japanese form, threefold geographical splitting into areas of Alpine, Lowland and Siberian song. Also starting from NE Asia, the Nearctic Region was colonized by at least two immigration waves. The first one resulted in the present P. carolinensis, which introduced Sino-Japanese song into the Nearctic Region. Considered not closely related to P. carolinensis on genetic grounds, the present P. atricapillus may represent another immigrant from E Asia with already modified Sino-Japanese song (minor frequency jumps). In the Nearctic Region, Alpine song occurs in Alaska, where it resembles much Alpine song in Siberia and the rare Alpine form in Japan. Territorial song supports the currently rejected assumption of conspecifity of palaearctic and nearctic Willow tits under the name P. atricapillus. Despite allozyme differences, P. atricapillus and P. carolinensis behave largely as a common biological species. In accordance with its peculiar song, the allopatric P. sclateri is attributed species status. Song structure in both the montanus and atricapillus / carolinenis complexes of the Holarctic Region is highly conservative and gives even better insight into evolutionary history than morphological characters.     

Structural Variation in the Call of the Cory's Shearwater (Calonectris diomedea,Aves, Procellariidae)

The duet call, the principal vocalization of Cory's shearwaters, was structurally variable with different classes of call being apparent, corresponding to different individuals, sexes and populations. In playback tests, birds responded more frequently to the call of their mate than to other birds, birds of a given sex responded more frequently to playback calls of their own sex and birds of a given locality responded more frequently to birds of their own locality. We suggest some biological functions with respect to mating strategy, individual recognition, territorial behaviour, and population isolation.     

Plumage and Size Variation in Swedish Common Buzzards Buteo buteo L. (Aves, Accipitriformes)

Plumage colouration, using quantitative methods, and size of 320 museum specimens of Buteo buteo from Sweden were measured. The frequency of extremely pale birds was significantly higher in south Sweden than elsewhere. The amount of reddish colour in the plumage was minimal in central Sweden, rising northwards probably because of connexion with more easterly populations, and southwards probably because reddish pigments to a disproportionate degree persist even after an advanced general depigmentation. Size decreases clinally from south to north and a significant negative correlation was established between size and redness. No trace was found of any demarcation line between two distinguishable subpopulations, nor was there any bimodality in the data collected, and therefore nomenclatorial separation of the north Swedish population seems unjustified. Thus, the western limit of Buteo b. vulpinus must be located east of the Baltic. Finally, various factors possibly contributing to the complex pattern of variation in the Swedish population of Buteo buteo are discussed.     

Microgeographic diversity in the neotropical knife-fish Eigenmannia macrops (Gymnotiformes,Sternopygidae)

Synopsis Examination of 681 individuals of electric knife-fishes, Eigenmannia macrops, from the Orinoco River, Venezuela, revealed a pattern of morphological diversity which covaried with habitat. Fishes from the caños (small stream tributaries) are on average smaller than those from offshore habitats and lagoons. Even at the same body size the tails of caño fishes are relatively shorter, their bodies are deeper, and their heads are relatively wider than those from other habitats. Caño fishes are more different from fishes of the deep channels than from those of the shallow channels, beaches, or lagoons. Several factors are examined for their possible relationship to the origin of the observed diversity including electrophysiology, locomotory adaptation, growth rate and ecology. The problems of genetic versus physiological bases of morphological variation are addressed.     

Allozyme Variation within and between Populations of Coreopsis latifolia (Asteraceae)

Abstract Enzyme electrophoresis was used to measure genetic variation in five populations of the rare diploid species Coreopsis latifolia which appears to be a relict taxon endemic to a small area of the southeastern United States. Gene diversity within the species as a whole is low compared to other species with similar ecological and life history traits. Also, gene diversity in C. latifolia is lower than nearly all other species of Coreopsis that have been examined. Larger populations contain significantly more variation at isozyme loci than do smaller populations. Populations of C. latifolia are deficient in heterozygotes relative to expected equilibrium values.     

Significance of Agonistic Vocalization in the Croaking Gourami (Trichopsis vittatus,Teleostei)

Trichopsis vittatus emits high amplitude sounds during agonistic encounters with conspecifics. The sound producing organ is derived from the structural components of the pectoral fins. The study involved muting a sample of subjects by removing two pectoral fin tendons without any further restriction in movements and behaviour. Mute and unaltered males were then placed together in pairs and the following agonistic behavioural elements were determined: attacks, lateral displays, sound production and frontal displays. Soniferous males had a higher probability of winning contests when size differences were small. In pairs with big size ratios, the larger males were more often successful. Besides visual and acoustical signals, lateral line stimuli seem to play no role in threatening displays. These results demonstrate that vocalization during agonistic encounters is important for becoming dominant in specific circumstances. Because of correlation between main frequencies and size, sound emission might be a very effective method of assessing the physical strength of an opponent.