Pycnonotus Jocosus Research Articles

<b>A reassessment of the avian species diversity in the Eastern Ghats of Tamil Nadu, after the Vernay Survey</b>

The Eastern Ghats of Tamil Nadu have been poorly surveyed for birds. The best known bird survey in the Eastern Ghats of Tamil Nadu (EGTN) was by V.S. LaPersonne who carried out the the Surveys in Tamilnadu Eastern Ghats between 08th April, 1929 and 25th July 1929. This was reported by WHistler & Kinnear. Thereafter information about birds in EGTN has come only from checklists published from time to time, by researchers, whose primary focus was not birds. Hence, to fill this lacuna, a comprehensive survey of birds was undertaken in the EGTN from March 2012-–--February 2015. The objectives of the study were to document the avian richness and abundance in EGTN, put them in perspective to the Vernay Survey conducted more than 80 years back, and identify priority sites for bird conservation. The study covered the hills and forests of Tamil Nadu spanning nine districts. In total, 262 species of birds were recorded during the survey. Eight species of birds fall under the threatened category. Species such as Square-tailed Bulbul Hypsipetes (lecocephalus) ganeesa, Rufous Woodpecker Micropternus brachyurus, Asian Fairy Bluebird Irena puella, and Malabar Whistling Thrush Myophonus horsfieldii still persist in the same old sites reported in the Vernay Survey. The top five abundant species were the Red-vented Bulbul Pycnonotus cafer, White-browed Bulbul Pycnonotus luteolus, Red-whiskered Bulbul Pycnonotus jocosus, Common Iora Aegithina tiphia, and Purple-rumped Sunbird Leptocoma zeylonica. The Vaniyar riparian tract in the Shevroys, from its origins in the hills to the Vaniyar dam downstream, is a potential bird conservation site in the Eastern Ghats of Tamil Nadu.

Invasion history and demographic processes associated with rapid morphological changes in the Red-whiskered bulbul established on tropical islands.

The Red-whiskered bulbul is a very successful invasive bird species. Morphological differences have been reported among individuals inhabiting the humid and dry coasts of Reunion Island, in a 30-year-old population. This suggests a capacity for rapid local adaptation which could explain the general invasive success of this species. However, the origin and invasion history of this population is unknown. It is therefore not possible to establish with certainty the cause of these morphological differences. Here, we investigated the invasion history of populations of Red-whiskered bulbul established on Reunion Island, Mauritius and Oahu (three geographically similar tropical islands) to assess the link between invasion history and morphological changes in these populations. We first assessed the source(s) of the invasive populations. We then compared the morphology of the individuals between the invasive and native populations and between the dry and humid coasts of invaded islands. Finally, we inferred the invasion history of the invasive populations to investigate the role of neutral processes (e.g. founder effect and drift) on morphology. We found that the invasive populations have a similar origin and that the morphology of the individuals in these populations has diverged in a similar way from the native range, suggesting a convergent adaptation to tropical islands. Like on Reunion, we found differences in morphology between the dry and humid coasts on Mauritius. These morphological differences can be explained by invasion history on Reunion but not on Mauritius. Both neutral evolution and adaptation thus shape the morphology of invasive Red-whiskered bulbuls.

Avifaunal diversity in Assam University Campus, Silchar, India

<p>We conducted a bird survey in the Assam University campus, Silchar from February 2011 to June 2011. A total of 73 species of birds belonging to 56 genera, 32 families and 13 orders was recorded. Significantly, the highest number of bird species restricted to only one particular habitat (17 species) was recorded in the forest area called ‘eco-forest’ (χ<sup>2</sup>=18, df=3, P<0.01). The highest similarity of bird species was found between degraded area and secondary growth area, and the lowest was found between eco-forest and degraded area. Species richness and dominance of species were more in the eco-forest area. The diversity of species was more in the secondary growth area. Red-vented Bulbul, Spotted Dove and Red-whiskered Bulbul were the most abundant and frequent bird species found in campus. The avifaunal diversity in the study area shows the importance of the University campus as an ideal bird habitat. </p>

The relationship between defecation and feeding in nestling birds: observational and experimental evidence.

BackgroundAdult birds clean the nest by consuming or transporting feces, which is thought to be important in order to lower the levels of parasites, pathogens and predation at the nest. If nestlings were to defecate when parents were absent, however, feces could accumulate in the nest.ResultsTo understand the mechanism by which nest sanitation is maintained, we studied the timing of defecation in nestling birds of common passerine species in southwest China. In 159 nests of 8 species at the nestling stage during 779 randomly timed observations, we never found fecal sacs present. Video recordings, totaling 455 h at five Pycnonotus jocosus nests in the field, showed almost all defecation after feedings, and only nestlings that were fed defecated. Six translocated P. jocosus nests were taken into captivity in order to manipulate the frequency of feeding. These nestlings defecated only after feeding, even when feeding intervals were extended to 60 and 120 min. The fecal sac weight also increased with extended feeding intervals, demonstrating a remarkable plasticity for nestlings to wait for feedings.ConclusionThe evidence allows two major conclusions: 1) defecation in the nest occurs at a time that ensures nest sanitation, stimulated by feeding, rather than there being a set time of gut processing between feeding and excretion; 2) the strong plasticity in the timing of defecation and the possibility of negative repercussions (if defecation occurs when parents are absent) are important mechanisms underlying the efficiency of the feeding-defecation system.

The Red-whiskered Bulbul Pycnonotus jocosus in Australia – a global perspective, history of introduction, current status and potential impacts

The Red-whiskered Bulbul Pycnonotus jocosus naturally occurs from the Indian subcontinent to the northern Malay Peninsula. Its anthropogenic spread also encompasses Australia, Japan, the southern Malay Peninsula, Singapore, Florida, California, 11 islands in the Indian Ocean, and Oahu, Hawaii. The earliest known introduction occurred in Sydney in 1865, with subsequent releases in the 1900's leading to establishment. It was first released in Melbourne, Victoria in 1915, with a population establishing in the late 1950's. Sightings have been reported in Coffs Harbour since 1972, forming a population in the Northern Rivers region. There has also been a small population in Mackay, Queensland since 1983. Red-whiskered Bulbuls had been recorded in South Australia between the 1940's and 1980's, but did not proliferate and are no longer present. The main ecological impact identified is the dispersal of exotic weeds, although evidence in Australia remains anecdotal. There has also been preliminary evidence of inter...

The breeding biology of Red-Whiskered Bulbul (Pycnonotus jocosus) in Xishuangbanna, southwest China.

To fill the gap in breeding biology information about the Red-Whiskered Bulbul (Pycnonotus jocosus), in 2013, we studied the breeding biology of this species in Xishuangbanna, southwest China. The breeding began from February and continued until early August. The breeding strategy of P. jocosus was more flexible and their nests were only built in cultivated landscapes, whereas, no nest building in native tropical rain forest was found. Small open cup nests were built on 50 different plant species, and at heights ranging from 2.1±0.6 m above the ground (n=102). The mean clutch size was 2.53±0.51 eggs (n=40) and the mean egg mass was 2.81±0.25 g (n=60). The average incubation period was 11.1±0.5 days (n=14), and the average nestling period was 11.0±0.8 days (n=31). The overall nest success was 34.22%.The hatching and fledging showed either asynchrony or synchrony. Invertebrate food decreased with nestling age, whereas, plant food increased with nestling age. Moreover, distinct parental roles of the parents in nestling period were found. Compared with other passerine species, P. jocosus spent less time in incubating (58%). The clutch size, incubation and nestling period of the P. jocosus in southwest China were different from those of the P. jocosus in India.

Contaminants of legacy and emerging concern in terrestrial passerines from a nature reserve in South China: Residue levels and inter-species differences in the accumulation

Knowledge is limited about the bioaccumulation of persistent halogenated compounds (PHCs) in terrestrial wildlife. Several PHCs, including dichlorodiphenyltrichloroethane (DDT) and its metabolites (designated as DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenylethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and stable isotopes (δ15N and δ13C) were analyzed in the muscle of four terrestrial passerines, Parus major, Copsychus saularis, Pycnonotus sinensis and Pycnonotus jocosus, from a nature reserve in South China. P. major had the highest PHC concentrations, with median values of 1060, 401, 92, 25 and 0.3 ng/g lipid weight for DDTs, PCBs, PBDEs, DBDPE and BTBPE, respectively. Fractions of DDT in P. jocosus and PCBs 153, 118 and 180 in C. saularis were higher compared with the other species. The inter-species differences in PHC concentrations and profiles could be attributed to the differences in trophic level, diet, living habits and metabolic capacity among the birds.

Host compatibility interacts with seed dispersal to determine small-scale distribution of a mistletoe in Xishuangbanna, Southwest China

Aimsn Mistletoe infection between intra-and interspecific hosts can be restricted by seed dispersal, host-mistletoe compatibility and other factors, yet few studies have linked seed dispersal and seedling establishment together for understanding mistletoe plant distribution and demography together in different anthropogenic disturbance forest types at a local scale. The objectives of this study were to examine how three factors-seed disperser behavior, post-dispersal host compatibility and canopy cover-affect the spatial distribution of a generalist mistletoe Dendrophthoe pentandra (Loranthaceae) in plantation and rainforest within Xishuangbanna, Southwest China.n Methodsn We observed mistletoe D. pentandra infection patterns at the scale of individual trees and sixteen 400-m(2) forest plots in adjacent plantation and rainforest within Xishuangbanna. To elucidate what determines infection patterns at different scales and in different forest types, we observed the behavior of major avian seed dispersers and carried out a seed inoculation experiment to examine how post-dispersal compatibility and light incidence affect the infection of different hosts.n Important Findingsn Dendrophthoe pentandra displayed an aggregated distribution and infected 10 species in our study site, with a significantly higher infection prevalence and intensity in the plantation than in the tropical forest. Different seed dispersers provided contrasting initial mistletoe templates: the specialist frugivore Dicaeum concolor (plain flowerpecker) preferred to fly between mistletoes in infected trees in the plantation and likely intensified existing infections. In contrast, the dietary generalist Pycnonotus jocosus (red-whiskered bulbul) was more likely to visit uninfected trees, thereby establishing new infections. Thus, seed dispersal appears to be an important determinant of the mistletoes distribution, with deposition patterns providing an initial distribution template and determining small-scale patterns. However, post-dispersal and abiotic factors revealed that different host compatibilities and levels of light incidence in different habitats affected the survival of D. pentandra seedlings. Hence, our findings suggest that seed dispersal interacts with host compatibility and canopy cover to determine establishment success, survival and the observed distribution patterns.

Accumulation of Dechlorane Plus flame retardant in terrestrial passerines from a nature reserve in South China: The influences of biological and chemical variables

Although a number of studies have addressed the bioaccumulation of Dechlorane Plus (DP) flame retardant in wildlife, few data are available on terrestrial organisms. This study examined the presence of DP isomers in the muscle tissue of seven terrestrial resident passerine species, i.e., the great tit (Parus major), the oriental magpie-robin (Copsychus saularis), the red-whiskered bulbul (Pycnonotus jocosus), the light-vented bulbul (Pycnonotus sinensis), the streak-breasted scimitar babbler (Pomatorhinus ruficollis), the long-tailed shrike (Lanius schach), and the orange-headed thrush (Zoothera citrina), from a national nature reserve located in South China. The ∑DP (sum of syn-DP and anti-DP) concentrations ranged from 1.2 to 104ng/g lipid weight, with significantly higher levels in insectivorous birds than in omnivorous birds. The overall exposure to DP isomers of the current passerines may be attributed to the intensive release of this pollutant from electronic waste recycling sites and industrial zones in the vicinity of the nature reserve. Species-specific DP isomeric profiles were also found, with significantly greater fanti values (the isomer fractions of anti-DP) in the red-whiskered bulbul and the oriental magpie-robin. Additionally, the fanti values were significantly negatively correlated to ∑DP concentrations for the individual bird samples, suggesting the influence of DP concentrations on the isomeric profiles.

Do avian communities vary with season in highly urbanized Hong Kong?

Abstract Urban habitat has become more and more important for birds because of rapid urban development and reduction of natural areas, and the responses of birds to season in urban habitats is important to research in urban avian ecology. We examined whether bird communities varied with season in terms of community attributes, composition of species and species groups, and nestedness in highly urbanized Hong Kong, which is positioned on one of the main migratory routes, and thus has great conservation value for birds. We studied 30 urban parks, and had 3,815 observations of 31 species in the breeding season (May–Aug 2010), compared to 3,972 observations of 53 species in the nonbreeding season (Nov 2010–Feb 2011). Eurasian Tree Sparrows (Passer montanus), Red-whiskered Bulbuls (Pycnonotus jocosus), and Japanese White-eyes (Zosterops japonicus) were the most abundant species in both seasons. Bird species richness and diversity in the nonbreeding season were significantly higher than in the breeding season. ...

An updated checklist of birds of Sariska Tiger Reserve, Rajasthan, India

Surveys were carried out at 10 sites in the buffer and core zones of Sariska Tiger Reserve during 2007-2011. MacKinnon species listing method was used to compile a checklist of birds. A total of 224 bird species was recorded including 36 new records. Ashy Drongo Dicrurus leucophaeus, Marshall Iora Aegithina nigrolutea, Eurasian Eagle Owl Bubo bubo, Brown-headed Barbet Megalaima zeylanica, Indian Nightjar Caprimulgus asiaticus, Long-legged Buzzard Buteo rufinus, Northern Goshawk Accipiter gentilis, Red-necked Falcon Falco chicquera, Pheasant-tailed Jacana Hydrophasianus chirurgus, Red-whiskered Bulbul Pycnonotus jocosus, White-capped Water Redstart Chaimarrornis leucocephalus were some new records. Some important observations are given in detail.

Seed dispersal in Hong Kong, China: past, present and possible futures

In the present article, published and unpublished information regarding seed dispersal in the degraded landscape of Hong Kong, China, is reviewed. Information was available for 1681 native plant species, of which 1165 were assigned to probable seed dispersal modes. Endozoochory accounted for one-third (34.4%) of all species evaluated, half (54.4%) of those from forests, and more than two-thirds (69.2%) of all trees and tall shrubs. Wind dispersal (25.9%) and dispersal by an unknown agent (30.7%) accounted for most of the rest, with the unknown species mostly small-seeded herbs. Although the frugivore fauna of the Hong Kong region has been truncated since the late Pleistocene, there are few clear examples of failed mutualisms. The most striking is the absence of scatter-hoarding rodents from Hong Kong, despite the presence of forest trees that appear to require them for effective dispersal. There are also some large Lauraceae fruits that appear to be targeted at larger-gaped birds than currently present. Most endozoochorous species are dispersed by 3 small passerine birds (Pycnonotus jocosus, P. sinensis, and Zosterops japonicus), with larger birds, fruit bats (Cynopterus sphinx, Rousettus leschenaulti), rhesus macaques (Macaca mulatta), civets (Paguma larvata, Viverricula indica), and muntjacs (Muntiacus muntjac) accounting for the remainder. The low plant diversity in frugivore droppings, seed traps, and secondary vegetation suggests plant succession may be dispersal limited, although this has not been investigated experimentally. Planting underdispersed species is the simplest solution but, in the longer term, the (re)introduction of a scatter-hoarding rodent should be considered as well as that of other locally and regionally extinct frugivores.

Population characteristics of Phthiraptera occurring on Red Whiskered Bulbul (Pycnonotus jocosus)

Two phthirapteran species, Menacanthus eurysternus (Amblycera) and Brueelia sp. (Ischnocera) were recovered from 100 Red Whiskered Bulbuls (Pycnonotus jocosus) during March to December 2006. The occurrence of both the phthirapteran species on the aforesaid host are new host records. The prevalence, intensity of infestation, range of infestation, variance to mean ratio, sex ratio, adult nymph ratio, index of discrepancy (D) and exponent of negative binomial (k) were computed. The frequency distribution pattern of M. eurysternus conforms to negative binomial model. The frequency distribution pattern of Brueelia sp. was skewed but not described by the negative binomial.

Stable isotope analysis to examine possible diet-morphology relationships among Red-whiskered Bulbuls introduced on Réunion Island

A recent study on the introduced Red-whiskered Bulbul Pycnonotus jocosus on Réunion Island has highlighted the existence of rapid morphological divergence in bill size between the leeward and windward sides of the island. The hypothesis that diet could explain such geographical variation was explored by means of stable isotope analysis (C and N) on bird tissues. We found no evidence of geographical differences in δ15N and δ13C in muscle and feather tissues of birds collected on both sides of the island, despite morphological differences. Correlations between wing length, tail length and δ15N in tissues suggested that bigger birds could benefit from greater feeding opportunities on insects. However, stable isotope ratios in bird tissues marginally explained variation in bill size, indicating that diet specialisation may not be the major cause for morphological divergence among Red-whiskered Bulbuls on Réunion Island.

Gut passage effect of the introduced red‐whiskered bulbul (Pycnonotus jocosus) on germination of invasive plant species in Mauritius

AbstractIn Mauritius, many of the worst invasive plant species have fleshy fruits and rely on animals for dispersal. The introduced red‐whiskered bulbul (Pycnonotus jocosus) feeds on many fleshy‐fruited species, and often moves from invaded and degraded habitats into higher quality native forests, thus potentially acting as a mediator of continued plant invasion into these areas. Furthermore, gut passage may influence seed germination. To investigate this, we fed fleshy fruits of two invasive plant species, Ligustrum robustum and Clidemia hirta, to red‐whiskered bulbuls. Gut passage times of seeds were recorded. Gut‐passed seeds were sown and their germination rate and germination success compared with that of hand‐cleaned seeds, as well as that of seeds in whole fruits. Gut passage and hand‐cleaning had significant positive effects on germination of both species. Gut‐passed seeds of both C. hirta and L. robustum germinated faster than hand‐cleaned seeds. However, for L. robustum, this was only true when compared with hand‐cleaned seeds with intact endocarp; when compared with hand‐cleaned seeds without endocarp, there was no difference. For overall germination success, there was a positive effect of gut passage for C. hirta, but not for L. robustum. For both C. hirta and L. robustum, no seeds in intact fruits geminated, suggesting that removal of pulp is essential for germination. Our results suggest that, first, the initial invasion of native forests in Mauritius may not have happened so rapidly without efficient avian seed dispersers like the red‐whiskered bulbul. Second, the bulbul is likely to be a major factor in the continued re‐invasion of C. hirta and L. robustum into weeded and restored conservation management areas.

Rapid morphological divergence of introduced Red‐whiskered BulbulsPycnonotus jocosusin contrasting environments

New environmental conditions may impact on behaviour and morphology, and consequently affect population dynamics. Rapid response to new conditions is likely to be a key factor in species introduction success. The Red‐whiskered BulbulPycnonotus jocosusis an Asian species which, following accidental introduction only 30 years ago, has colonized the two climatically and ecologically contrasting sides of the island of Réunion in the Indian Ocean. We assessed the degree of morphological divergence of mature birds in 11 non‐seasonal and three seasonal characters, in windward and leeward sites. Our study showed (1) that sexual dimorphism existed, (2) that when sexual dimorphism is controlled, nine non‐seasonal characters differed significantly between windward and leeward sites, (3) that these non‐seasonal characters define groups of geographically proximal sites, especially in males, and (4) that classification according to the most indicative character, the bill, also clearly separated birds from windward and leeward sites. These results indicate very rapid morphological divergence, particularly in bill size, in an introduced bird species in fewer than ten generations. We suggest that differences in diet could partly explain this variability.

Relationships between alien plants and an alien bird species on Reunion Island

Many studies have shown that plant or bird invasions can be facilitated by native species, but few have demonstrated the possibility of a positive interaction between introduced species. We analysed the relationships between four invasive alien fleshy-fruited plants, Clidemia hirta, Rubus alceifolius, Lantana camara, Schinus terebinthifolius, and an invasive alien bird, the red-whiskered bulbul Pycnonotus jocosus introduced to Reunion Island (Indian Ocean). We compared the distribution of food items in the bulbul diet according to seasons and to abundance classes of this bird. Pycnonotus jocosus is mostly frugivorous and frequently eats the main alien plants (more than 80% frequency of food items). Sites with alien species, such as Clidemia hirta, providing fruits throughout the year supported more birds than sites providing fruits, such as Schinus terebinthifolius, seasonally. The birds facilitated seed germination by removing the pulp of fruit: the final per cent germination (FG) of cleaned seeds was higher than those within the fruit for three of the four plant species and in some cases passage through birds significantly increased FG (Schinus terebinthifolius) or Coefficient of Velocity (CV) (Lantana camara).

Fast Colonization of an Introduced Bird: the Case of Pycnonotus jocosus on the Mascarene Islands1

Fast Colonization of an Introduced Bird: the Case of Pycnonotus jocosus on the Mascarene Islands¹

Pollination in a degraded tropical landscape: a Hong Kong case study

Although the pollination biology of many individual plant species has been investigated in the Oriental region, there have been very few community-level studies. The two most comprehensive of these were in the primary mixed dipterocarp forest of Lambir Hills National Park, Sarawak (4°20′N: Momose et al. 1998, Sakai et al. 1999) and in the warm temperate evergreen broad-leaved forest and cool temperate mixed forest on Yakushima Island (30°N: Yumoto 1987, 1988). Hong Kong (22°17′N) lies midway between these sites, at the northern margin of the tropics, where winter temperatures fall below 10 °C at sea-level for a few days every year and there are occasional frosts above 400 m (Dudgeon & Corlett 1994). Latitudinal effects, however, are compounded in comparisons with other well-studied East Asian sites, by centuries of massive human impact, leaving a degraded landscape of steep, eroded hillsides, covered in fire-maintained grassland, secondary shrublands and, locally, secondary forests (Zhuang & Corlett 1997). This history has left a relatively impoverished fauna but a surprisingly diverse flora, including 400 native tree species (Corlett & Turner 1997). In these circumstances, failures of pollination and dispersal mutualisms might be expected to accelerate the loss of plant species from the landscape (Bond 1994, Kearns & Inouye 1997). Previous studies have shown that most woody vegetation in Hong Kong is dominated by species whose seeds can be dispersed by the commonest avian frugivores, the light-vented and red-whiskered bulbuls (Pycnonotus sinensis (Gmelin) and P. jocosus (Linn.)) and the Japanese white-eye (Zosterops japonicus Swinhoe) (Corlett 1996, 1998), but there is no equivalent information available on pollination biology.

Fast Colonization of an Introduced Bird: the Case of Pycnonotus jocosus on the Mascarene Islands1

Fast Colonization of an Introduced Bird: the Case of Pycnonotus jocosus on the Mascarene Islands1