Pycnonotus Jocosus Research Articles

Revealing the key signals in nestling begging behavior perceived by parent birds during parent-offspring conflict.

The parent-offspring conflict in avian species encompasses resource allocation and a balance necessary for survival for both parties. Parental investment is modulated according to various factors, among which begging is important. Endogenous hormones, particularly corticosterone (CORT), play a role in modulating begging behavior. However, most studies on hormonal regulation of begging behavior induced elevated hormone levels in the offspring through feeding or injections, thus, limiting our knowledge of the evolution of the parent-offspring conflict under natural conditions. In this study, we aimed to identify the key signals that parents respond to during interactions with their nestlings in the wild, considering factors such as endogenous hormone CORT, nestling age, and brood size, which may affect nestling begging behavior. Begging performance was evaluated by measuring the begging frequency and score of the red-whiskered bulbul (Pycnonotus jocosus), along with assessing CORT levels in feathers. CORT levels were significantly correlated with both the begging frequency and score of nestlings, while variables such as body mass and tarsus length did not influence parental feeding frequency. Additionally, factors such as the number of nestlings (brood size), age, and begging frequency were predictors of parental feeding frequency. Our findings indicate that begging frequency, nestling age, and brood size are signals that help navigate the intricacies of the parent-offspring conflict and that parents may rely on these key signals from the range of begging cues exhibited by nestlings to adjust their feeding strategies.

Assessment of diversity, abundance, and seasonal variations of bird species in Bengaluru District, India during COVID-19 lockdown

The study investigates bird population dynamics in Bengaluru, India, post-lockdown, focusing on occurrence, seasonal abundance, species diversity, richness, dominance, and evenness. It covers 55 bird species across 52 genera, grouped into 32 families within 13 orders, with a notable peak in winter. Various indices, including Shannon Wiener, Margalef’s, Pielou’s, and Simpson’s, reveal significant seasonal differences in bird population characteristics. The Rock Pigeon Columba livia dominates, while the Black-headed Ibis Threskiornis melanocephalus is less prevalent. The study identifies Near Threatened species like Black-headed Ibis and Oriental Darter Anhinga melanogaster, along with Least Concern species per the IUCN Red List. Common species include Rock Pigeon, Large-billed Crow Corvus macrorhynchos, House Crow Corvus splendens, Black Drongo Dicrurus macrocercus, Brown Shrike Lanius cristatus, Common Myna Acridotheres tristis, Jungle Myna Acridotheres fuscus, Red-whiskered Bulbul Pycnonotus jocosus, and Streak-throated Swallow Petrochelidon fluvicola. The study aims to inform improved management and conservation strategies for Bengaluru’s diverse bird species.

First Record of Breeding Behavior of Red-Whiskered Bulbul (Pycnonotus jocosus) in the Himalayan Foothills of India (Western Himalayas)

First Record of Breeding Behavior of Red-Whiskered Bulbul (Pycnonotus jocosus) in the Himalayan Foothills of India (Western Himalayas)

Optimization and application of loop-mediated isothermal amplification technique for sex identification in red-whiskered bulbul (Pycnonotus jocosus).

The red‐whiskered bulbul (Pycnonotus jocosus) is a popular avian species in Thailand and many other countries. The red‐whiskered bulbul has a high economic value, but breeding is challenging since sex identification is difficult. The PCR method is now used for sex identification. However, PCR amplification and post‐PCR analysis necessitate the use of a laboratory equipped with specialized scientific instruments, which is inconvenient for field operations. This research describes a method for amplification of DNA samples using the loop‐mediated isothermal amplification (LAMP) approach, which is a molecular biology methodology for isothermal amplification that is extremely sensitive, fast, and easy for post‐LAMP product visualization. Herein, total of 23 blood samples were collected and DNA was extracted. Two sets of LAMP primers were designed for CHD‐Z and CHD‐W genes. The colorimetric assay was used to investigate the best conditions for LAMP reactions and post‐LAMP product visualization. LAMP reactions for sex identification were compared to traditional PCR in terms of sensitivity and specificity. LAMP reactions were found to be 10‐fold more sensitive than PCR at 1 ng of DNA. When compared to electrophoresis analysis, the visualization with colorimetric assay using GelRed® and SYTO™ 9 was 100% accurate. The optimal LAMP condition tested simple DNA extracted from bird feathers using the HotSHOT technique. The result showed that the optimal condition could distinguish the sex of red‐whiskered bulbuls totally and accurately. A powerful method for red‐whiskered bulbul sex identification is demonstrated in this study, which can be used in field studies because it is quick and easy to perform, has high sensitivity, and does not require advanced scientific equipment.

Population increase of the invasive red–whiskered bulbul Pycnonotus jocosus in Valencia, Spain

The red–whiskered bulbul Pycnonotus jocosus is a medium–sized passerine that has been classified as an invasive species because of its impact on native ecosystems. It was first reported in the Canary Islands of Spain in 1997. In March 2003, it was sighted in the province of Valencia, in eastern Spain, in a residential area called ‘La Cañada’. From 2015 to 2020 we monitored its population in a suburban area close to La Cañada using point counts every spring. Since 2015, the population has shown a trend towards a significant increase in this area, with an estimate of (2,428 < 2,878 < 3,412) individuals in 2020. Its frequency of occurrence has also increased, and it appears to have a continuous distribution in the study area. In the last 17 years the red–whiskered bulbul has spread as far as 20 km from La Cañada, and it is expected to continue spreading and increasing in numbers, with consequences as yet unknown.

Investigating how different classes of nest predators respond to the playback of the begging calls of nestling birds

Begging brings benefits and costs for nestling birds: it can indicate their needs to their parents, but it can also be a cue used by predators to find the nest. The costs, like many variables related to nest predation, can be specific to what kinds of predators are present and their auditory capabilities. These costs and benefits could also be affected by human noise, as noise could disrupt communication to parents and eavesdropping by predators, although human-produced noise might be easily ignored if predators can hear high-frequency components of the begging. We studied nest predation on a generalist bird, the Red-whiskered Bulbul (Pycnonotus jocosus), in a tropical forest in which there are many kinds of nest predators, including birds, mammals and reptiles. In 20 natural nests in which artificial eggs were placed, and subsequently in 140 artificial nests, we broadcast recordings of begging nestlings, with and without traffic noise, at two volume levels. We hypothesized that playback would increase predation relative to a silent control, and that mixing in traffic noise with the begging would decrease predation, as the begging signal was masked. However, we hypothesized that some predators, particularly small mammals with sensitive high-frequency hearing, might ignore the traffic noise. We found that predation was lowest for the control treatment, and lower for treatments mixed with traffic noise than for those without it. Small mammals, however, showed an unexpected pattern, displaying less nest predation in the treatments with traffic noise. Our results demonstrate the human-associated noise can disturb nest predators and influence which kinds of predators use begging to locate nests.

Persistent fine-tuning of egg rejection based on parasitic timing in a cuckoo host even after relaxation of parasitism pressure

Egg rejection is one of the most effective defenses to avoid avian brood parasites by hosts, and reflects avian cognition during parasite-host coevolution. However, egg rejection varies with different populations and species, or under different contexts. Here we studied the egg recognition behavior in a non-parasitized population of the red-whiskered bulbul (Pycnonotus jocosus), which has been recorded as a host of the banded bay cuckoo (Cacomantis sonneratii). By comparing its egg rejection frequency and latency between egg-laying and egg-incubation stages with a variety of nest ages, which represent different costs of cuckoo parasitism, the results show that the hosts rejected parasite eggs more frequently in the egg-laying stage than in the egg-incubation stage without a difference in latency, and accepted parasite eggs with an increase of nest age. These findings indicated that the hosts are able to adjust the intensity of their anti-parasitic responses according to the parasitic timing. A relaxation of parasitism risk and the tradeoff between parasitism risk and egg rejection cost may contribute to explaining our results.

A Review: Caring Practices of Songbird, Red-Whiskered Bulbul (Pycnonotus jocosus)

Pycnonotus jocosus is known as red-whiskered bulbul or known by local Malaysian as songbird or burung candik. Burung candik is one of the favourite pet birds’. Generally, it comes from Bangladesh, southern China, India, Nepal, north Peninsular Malaysia, Thailand and Vietnam (Animal Pest Alert: Red-whiskered Bulbul). Burung candik is favoured because of their ability in singing in east-coast region of Malaysia specifically. In this research, the caring practices are observed. All the result were recorded and documented through interview and experiment research. The caring practices concerned are housing and cage, bathing and grooming, singing feature and diet and feeding. The results showed that one cage equipped with one bird for comfort and to avoid fighting. The birds were needed to be bathed once in a week at least according to the bird’s willingness. General singing functions are to attract the mate and territorial defense. Feed given were insects, fruits and pellet.

Multiple constraints on urban bird communication: both abiotic and biotic noise shape songs in cities.

Ambient noise can cause birds to adjust their songs to avoid masking. Most studies investigate responses to a single noise source (e.g., low-frequency traffic noise, or high-frequency insect noise). Here, we investigated the effects of both anthropogenic and insect noise on vocalizations of four common bird species in Hong Kong. Common Tailorbirds (Orthotomus sutorius) and Eurasian Tree Sparrows (Passer montanus) both sang at a higher frequency in urban areas compared to peri-urban areas. Red-whiskered Bulbuls (Pycnonotus jocosus) in urban areas shifted the only first note of their song upwards. Swinhoe’s White-eye (Zosterops simplex) vocalization changes were correlated with noise level, but did not differ between the peri-urban and urban populations. Insect noise caused the Eurasian Tree Sparrow to reduce both maximum, peak frequency, and overall bandwidth of vocalizations. Insect noise also led to a reduction in maximum frequency in Red-whiskered bulbuls. The presence of both urban noise and insect noise affected the sound of the Common Tailorbirds and Eurasian Tree Sparrows; in urban areas, they no longer increased their minimum song frequency when insect sounds were also present. These results highlight the complexity of the soundscape in urban areas. The presence of both high- and low-frequency ambient noise may make it difficult for urban birds to avoid signal masking while still maintaining their fitness in noisy cities.

Impact of nest sanitation behavior on hosts' egg rejection: an empirical study and meta-analyses.

Egg rejection in birds is a specific adaptation toward avian brood parasitism, whereas nest sanitation is a general behavior for cleaning the nest and avoiding predation. However, both behaviors refer to the action of ejecting objects out of the nest, and nest sanitation has been proposed as a pre-adaptation for egg rejection. Here, we tested the eliciting effect of nest sanitation on egg rejection in the red-whiskered bulbul Pycnonotus jocosus, a potential host species that are sympatric with parasitic cuckoos. We conducted meta-analyses of previous studies on both nest sanitation and egg rejection, in order to evaluate the consistency of our conclusions. Our results showed that nest sanitation did not elicit egg rejection in P. jocosus. The conclusions concerning such an eliciting effect from previous studies were mixed, whereas the methodologies were inconsistent, making the studies unsuitable for comparisons. However, the ejection frequency of nest sanitation was consistently higher than the frequency of egg rejection across different host species or populations. These results suggest that nest sanitation, which is an ancient behavior, is more fundamental than egg rejection, but the effect of the former on the latter is complex and needs further study. Standardized methodologies and the integration of behavior, physiology, and modeling may provide better opportunities to explore the relationship between nest sanitation and egg rejection.

Breeding Biology of the Red-Whiskered Bulbul, Pycnonotus Jocosus (Linnaeus, 1758) In Madhupur National Park, Bangladesh

Breeding biology of the Red-whiskered Bulbul, Pycnonotus jocosus (Linnaeus, 1758) in Madhupur National Park (MNP), Bangladesh, was carried out from January to June in 2009. The breeding season lasted from February to May. Both the parents built a hollow cup-shaped nest, the weight, length, and depth of which were respectively, 9.9-12 g (10.98±0.78 g), 8-10 cm (8.98±0.67 cm), and 4.1-5 cm (4.62±0.312 cm). The outer and inner diameter of the nest opening was 8-9.7 cm (8.92±0.54 cm) and 6-7.5 cm (6.72±0.49 cm), respectively. The height of the nest from the ground ranged from 0.6-2.1 m (1.41±0.55 m). They took 14-16 days (15±0.85 days) in nest building and laid 2-4 (2.74±0.81) whitish with brown blotched eggs. The egg size was 2.10×1.45 cm. The hatchlings hatched out after 12-15 days (13.14±1.17 days) of incubation period and fledged between 13-18 days (14.85±1.77 days) after hatching. The breeding success was 81.82% in relation to nestlings hatched and 51.92% in relation to eggs laid. Infertility (47.36%) was the leading cause of egg loss and stolen (66.67%) for nestlings.
 Asiat. Soc. Bangladesh, Sci. 46(2): 179-189, December 2020

Age-Related Testosterone Changes and Corresponding Song Patterns in Red-whiskered Bulbul (Pycnonotus jocosus Linnaeus, 1758)

We monitored total testosterone profiles and song patterns of 12 males and 2 females Red-whiskered Bulbuls (Pycnonotus jocosus), aged 5-10 months. Each bird was maintained in a cage sized of 38 × 38 × 50 cm and raised in a 22 °C-controlled room-sized of 6 × 10 × 3.5 m. The song prototype was played during 0700-11.00 h, with an amplifier-connected loudspeaker placed at the center and the song was recorded during both 1100-1200 and 1300-1500 h, and then their sonograms were analyzed with Avisoft SAS Lab Pro, version 4.3. Feces were collected monthly and immediately following recording their songs to determine male and female total testosterone levels by radioimmunoassay. The results demonstrated that an average of a frequency that the male and the female birds produced was 4.27 ± 0.13 kHz with a frequency range of 1.50 - 5.18 kHz. The males aged 8-10 months old produced songs with an average of 25.83 syllables/10 s, similar to those found in the song prototype while the females produced those with an average of 18.33 syllables/10 s. The males produced songs consisting of more syllables and fewer intervals than those of the females. The coefficient of correlations between the mean total testosterone levels with the syllables/10 s and intervals/10 s were +0.68 and -0.69, respectively. Additionally, the male Red-whiskered Bulbuls created the complicated and various song types that corresponded well with the marked increases in the total testosterone levels at the age of 8 to 10 months old.

Food for Feeding Red-Whiskered Bulbul (Pycnonotus jocosus Pattani)

Food of an economic bird, Red-whiskered bulbul (Pycnonotus jocosus pattani), was investigated since November 2017 – August 2018 in yala province, Thailand. They were studied by applying survey method. The samples were the red-whiskered bulbul caretakers selected by convenience sampling. Deep Interview and rating scale questionnaires were used as research tools to find the kind of food for most likely tendency by average and percentages. The results showed that 98 percent of samples were male, their education level were undergraduate and lower. The average income was between 10,000 - 30,000 baht. The majority of food which the caretakers used for feeding their pet birds at different ages were the same. They were derived from plants 18 families, including 24 species. The main plants were Kluai Hin (Musa acuminata × balbisiana (ABB Group) ‘Saba’), Kluai Nahm Wa (Musa sapientum Linn.), papaya (Carica papaya L.), water melon (Citrullus lanatus (Thunb.) Matsum. & Nakai), tomato (Solanum lycopersicum L.), cucumber (Cucumis sativus L.), chinese squash (Luffa acutangula (L.) Roxb.) and Tam Lueng (Coccinia grandis (L.) J.Voigt,). Some insect such as mealworm (Tenebrio molitor L.), crickets (Gryllus bimaculatus), some species of grasshopper, and ant eggs were also provided. However, some caretakers mixed some supplements such as vitamins and chili curry into their food for feeding the mature pet bird. Meanwhile, honey and ready-made meals were only used into rearing their chicks.

Phenological patterns, fruit predation, and seed dispersal in two Endangered trees (Elaeocarpus spp.) of Southern Western Ghats, India

The observation on phenological patterns, fruit predation, and seed dispersal behavior of Elaeocarpus gaussenii and Elaeocarpus recurvatus was carried out at Megamalai wildlife sanctuary and Kodaikanal wildlife sanctuary, Southern Western Ghats of Tamil Nadu, India. The phenoevents of vegetative and reproductive phases of both trees were mainly depended on climatic factors such as temperature and rainfall. The leaf flushing period of two species of Elaeocarpus was observed during presummer season and the leaf initiation was recorded from the end of November or December. The observation on flowering phenology of two species of Elaeocarpus indicated that mass flowering has observed as regular phenoevents, whereas flowering intensity has varied from year to year. However, in both species, flowering period was influenced by temperature of study site. The fleshy fruits have been attracted by different predators such as the Malabar giant squirrel, lion-tailed macaque, bonnet macaque, Indian crested porcupine, red-whiskered bulbul, green barbet, Indian white-eye. The size and weight of the fruit were also play an important role toward the attraction of predators. The study has find out the problems in the mature individuals of both tree species in the study areas and to develop a solution to raise the additional individuals in the forest areas.

In All the Futures

In All the Futures Emily Jungmin Yoon (bio) You are still on the island we love,you are in a bathtub, twice framed by water, and let’s say in this scenario,the red-whiskered bulbul that was born outside our door, nesting by the desiccated toad,is now seventy years old. Say we believed enough timeswith thorough sincerity the promises that we will happen to dieon the same day. For all these years, we let the old wavesfold over our ordinary heads never hurting us,generous, full, [End Page 427] shining with ancient livessoftening in the kind of aloneno earthly darkness can know. Every day, I labor to hope that the ocean stays unskinnedof its ice and you always have water to spare. Now let’s imagine that I wenthappy, sure of this. Selfish, I know. I always have been. In all the futures I am capable of prayer for,you are not alone — you are alive. [End Page 428] Emily Jungmin Yoon Emily Jungmin Yoon is the author of A Cruelty Special to Our Species (Ecco 2018), winner of the 2019 Devil’s Kitchen Reading Award and finalist for the 2020 Kate Tufts Discovery Award. She is the poetry editor for The Margins and a PhD candidate in Korean Literature at the University of Chicago. Copyright © 2021 The University of the South

Levels and distribution pattern of organochlorine pesticide residues in eggs of 22 terrestrial birds from Tamil Nadu, India.

Long-term monitoring is essential to assess the patterns and distribution of the residues of organochlorine pesticides (OCPs) in biota. Bird eggs have several advantages than other environmental matrixes, which have been used extensively to portray the accumulation and distribution of OCPs. The present study investigated the organochlorine pesticide (OCP) residues in eggs of 22 species of terrestrial birds collected from Tamil Nadu, India. Eggs found abandoned were collected during nest monitoring between 2001 and 2008 and analyzed for the presence of organochlorine pesticide residues. The results showed that the mean concentrations of total hexachlorohexane (∑HCHs), total dichlorodiphenyltrichloroethane (∑DDTs), heptachlor epoxide, and dieldrin ranged from non-detectable (nd) to 2800ng/g, nd to1000 ng/g, nd to 700ng/g, and nd to 240ng/g on a wet mass (wm) basis, respectively. The variation in magnitude of contamination among the species and feeding guilds were not significantly different (p > 0.05). Among the OCPs analyzed, the residues of β-HCH and p,p'-DDE were found to be the abundant in concentration. Similarly, among various bird species studied, the highest concentrations of ∑OCPs (> 5000ng/g wm) were recorded in the eggs of gray junglefowl, scaly-breasted munia, and red-whiskered bulbul. This may be due to their widespread occurrence of their habitat at proximity to the agricultural fields, where organochlorines were in use until recently. Among the various contaminants analyzed, concentrations of p,p'-DDE and heptachlor epoxide exceeded the threshold levels of toxicity for wild birds in > 5% of the egg samples. Hence, this study indicates the need for continued monitoring and further systematic ecotoxicological investigation of these compounds not only in eggs but also in other environmental media.

Comparison of DNA Extraction Methods and Selection of Primer Sets for Sex Identification of the Red-Whiskered Bulbul (Pycnonotus jocosus)

Comparison of DNA Extraction Methods and Selection of Primer Sets for Sex Identification of the Red-Whiskered Bulbul (Pycnonotus jocosus)

Patterns in spatial segregation between the endemic Nicobar Bulbul (Ixos nicobariensis) and the introduced Red-whiskered Bulbul (Pycnonotus jocosus) on two islands of central Nicobar

ABSTRACT Introduced and invasive species are emerging as a significant threat to biodiversity, especially to endemic species, worldwide. One of the ways in which introduced species might impact nat...

Nest predation on an abundant generalist bird in tropical China

Nest predation is the main reason for breeding failure of small passerines. Theory states that predation in the incubation stage should be mostly due to predators finding poor-quality sites, whereas predation in the nestling stage may be driven by parental activity. Yet field evidence for this theory is mixed, and there are few studies from tropical Asia. Red-whiskered Bulbul (Pycnonotus jocosus; RWB) is an abundant generalist species in tropical Asia, often found in human-modified environments. Between 2012 and 2017 in the Xishuangbanna Tropical Botanical Garden, Yunnan, China, we monitored 775 RWB nests, including 287 nests with infrared-triggered cameras, 20 nests with digital video cameras, and 10 with temperature data loggers. The richness of nest predators was high, with at least 11 species, including mammalian, avian, reptilian, and invertebrate species; northern tree shrew (Tupaia belangeri) and Greater Coucal (Centropus sinensis) were the predator species most detected and identified. There was no significant difference in daily predation rate (DPR, as assessed by the Mayfield method) between incubation (DPR = 0.046, n = 682) and nestling (DPR = 0.049, n = 525) stages, even though parental visits in the nestling stage were almost 3 times the number in the incubation stage. Yet during the nestling period there was a strong positive relationship between the parental visitation on a particular day post-hatching (from day 1 to day 10; visitation measured with digital video cameras) and the nest predation rate of that day (measured on all nests). To determine the effect of nest sites on predation, we placed clay eggs in 127 previously used RWB nests. Sites that had been depredated at the incubation stage had marginally higher DPR (0.076, n = 43) when reused than sites that had been successful (DPR = 0.043, n = 50), although this difference was not significant when Bonferroni-corrected. This result thus provides weak evidence for an effect of nest site selection on nest predation. In total, this study emphasizes the strong forces of selection during the nesting period, particularly for birds in human-modified tropical habitats where the diversity of nest predators is high.

Bird play: raising red-whiskered bulbuls and (re)inventing urban ‘nature’ in contemporary Vietnam

ABSTRACT A socially recognisable signifier for wealth and class in Southeast Asian consciousness, ornamental birdkeeping often focuses on exotic avian species to enhance the status symbolism of this practice. For the past five years, contemporary Vietnamese urbanites have renewed interest in and refocused birdkeeping on a non-exotic avian native to the region: the red-whiskered bulbuls, widely considered a ‘bird of the people’ (chim bình dân) in the words of participants. Popular media have recognised the return of ornamental birdkeeping as a healthy cultural practice that encourages mental stimulation, yet the favouring of a native, non-exotic species quite amenable to a variety of living and economic situations (dễ nuôi), I argue, is remarkable in its reimagination of the high society associations of this tradition. Further, this article will demonstrate that the increased popularity of raising red-whiskered bulbuls reflects a rapidly urbanising Vietnam wherein holistic ideals of nature, characteristic of and integral to Vietnamese consciousness, underline human-nonhuman interactions from city to country, and are caught amid a transition from industrial modernity, with its nature-culture binarism, to a postmodern period fraught with uncertainties.