Heron Research Articles

A Preliminary Survey of the Avifaunal Diversity in Pampaimadu Premise of the University of Vavuniya, Vavuniya, Sri Lanka

Vavuniya is a lowland dry zone district of the Northern Province of Sri Lanka, which is still unexplored with a natural forest cover of 1,238 km2. Even though there are many kinds of literature concerning the water birds of the Vavuniya, the diversity of tropical avifaunal species is still a gap which was the light of this study. The study area is situated 10 km from the center of Vavuniya along the A30 highway, with the dry-mixed evergreen forest as vegetation. The district is located within the dry zone which experiences a mean temperature of 28° C and annual rainfall of 1,400 mm. It also consists of 02 adjoined tanks along the boundary. The study points were used for the avifaunal survey during mid of March to end of July 2022. Habitat diversity within the study area was discussed using a prepared checklist and the community indices like the Shannon-Weiner index (H‘), Simpson‘s diversity index (D), Simpson‘s evenness (E), and Species richness (R) across various habitats ecosystem: Woodland-Paddy land (H1); Woodland-Water catchment area (H2); Forest (H3); Grassland with inundated land ecosystem (H4); and Manage Garden with Occasional trees (H5) of the study area. The checklist resulted in a total observation of 93 avifaunal species including 87 resident and 06 migrant species belonging to 47 families (including 09 endemics, and 05 nationally threatened species). Rock Pigeon (Columba livia) belongs to Family Columbidae with the highest frequency (68%, n=123) and is evenly distributed across different habitats but the family Ardeidae is found extensively dominating in H5 (39%). H1 is with the highest H‘ (3.5) and D (0.96); while H3 has the highest R (2.52) and E (0.62). The seasonally inundated habitats H2 and H4 bring water birds to the study area. It also increases the availability of avifaunal insectivores. Many anthropogenic disturbances, such as habitat alterations, intentional wildfire, and road mortality are the key threats encountered by the avifaunal species in the study area. In addition to that, the activity of stray dogs within the premises was observed to be a potential threat during the breeding season. Appropriate conservation strategies including landscape management, conservation of available forest land, and proper awareness of neighboring local communities are necessary to maintain the current ecological status. 
 Keywords: Avifauna, Checklist, Habitat variation, Species diversity, Vavuniya

Avian diversity in the paddy field ecosystem surrounding the Assam University campus in Silchar during the rainy season

Rice (Oryza sativa L.) is one of the most effective crops for absorbing carbon dioxide. Paddy is a temporary reservoir for rainwater during the rainy season, prevents soil erosion, and emits oxygen through photosynthesis. In Assam, it occupies 88.89 percent of the net cropped area. Paddy field ecosystems are also home to various cultivated and wild species of plants and animals where numerous aquatic and bird species can be found. These fields provide waste rice, a crucial food source for various bird species. The quantity of waste rice positively correlates with rice yields, and birds often feed on freshly planted rice seeds. Paddy fields constitute a semi-aquatic ecosystem that is heavily infested by insect pests. These fields also attract waterfowls, wading birds, shorebirds, and other waterbirds for migratory movements and foraging. From this pilot study conducted in the paddy field ecosystem surrounding the Assam University campus in Silchar we report 95 species of birds that belong to 37 families and 14 orders. Highly sighted avifauna included Egret, Heron, Bittern (family Ardeidae), Waterhen (family Rallidae), Kingfisher (family Alcedinidae), Drongo (family Dicruridae), and Dove (family Columbidae). Interestingly, eight 'Least Concern' bird species according to the International Union for Conservation of Nature (IUCN) – Hooded Pitta (Pitta sordida – family Pittidae), Cinnamon Bittern (Ixobrychus cinnamomeus – family Ardeidae), Watercock (Gallicrex cinerea – family Rallidae), Common Sandpiper (Actitis hypoleucos – family Scolopacidae), Emerald Dove (Chalcophaps indica – family Columbidae), White-Browed Piculet (Sasia ochracea – family Picidae), Dark-Necked Tailorbird (Orthotomus atrogularis – family Muscicapidae) and Brown Fish-Owl (Ketupa zeylonensis – family Strigidae) as well as a ‘Vulnerable’ species Lesser Adjutant Stork (Leptoptilos javanicus – family Ciconiidae) and ‘Near Threatened’ species Alexandrine Parakeet (Psittacula eupatria – family Psittacidae) were also noted. Out of a total 95 avian species, 46 species belonged to the insectivorous category, accounting for the greatest number according to the feeding guild recorded within different line transects in Visual Encounter Surveys (VES) conducted weekly from March 2023 to August 2023. Although the avifaunal studies have enormous potential in the Barak Valley, conservation measures are essential to protect the biodiversity. Public involvement in awareness campaigns and conservation activities is crucial for conserving avian diversity within the Valley. As paddy fields are used primarily by grassland and wetland bird species, there are significant information gaps in the monitoring of bird populations in paddy cultivation as well as in different stages of rice growing cycles, which makes it essential to understand the importance of paddy fields on avian populations as well as diversity.

Waterbirds in the Wetlands of Casiguran, Aurora, Philippines

The wetlands of Casiguran, Aurora, Philippines are primarily the source of livelihood for most of the coastal communities of the area. However, this also serves as a feeding ground for many of the migratory and resident waterbirds. There are waterbird species occurring in the area that need protection but only a few studies of these species exist. This study was conducted from February to March 2019 to census and identify the water birds present in the study site, determine the conservation status and index of abundance of identified waterbirds, and describe their habitat association. Based on the result, 18 waterbird species in five families were present in the area. Family Ardeidae had six representative species, Family Charadriidae had five representative species, Family Scolopacidae had five representative species while only one species represents the Family Anatidae and Family Rallidae. Two waterbird species observed (Anas luzonica and Egretta eulophotes) were listed by the International Union for Conservation of Nature (IUCN) as vulnerable and another species (Numerius madagascariensis) was listed as endangered. In terms of abundance, Intermediate Egret (Egretta intermedia) was revealed as the most abundant (94.68%) among waterbirds. Different waterbird species prefer specific habitats. Some usually frequent freshwater and saltwater habitats, including mangroves, open sea, and watercourses inside forests while some were observed in mudflats, and rice fields during the survey.

Food and Feeding Habits of Cattle Egret (Bubulcus ibis) in Thanjavur District, Tamil Nadu

The cattle egret (Bubulcus ibis) is a cosmopolitan species of heron (family Ardeidae) and they are found in the tropics, subtropics and warm temperate zones. The cattle egret and grazing cattle in close association is a classic example of commensalism. Their feeding habitats include seasonally flooded grasslands, pastures, farmlands, wetlands and rice. They often accompany cattle or other large mammals, catching insect and small vertebrate prey disturbed by these animals. This study is a first attempt in the Cauvery delta region where the abundance and distribution of cattle egrets which are common. The study was conducted in the villages such as Thugili and Kanjanur which are situated in Thiruvidaimaruthur Taluk of Thanjavur District of Tamil Nadu. The methods used for this study was direct observation involves following the birds early in the morning between 7. 00 am and 10.00 am and 4.00 pm - 6.00 pm in the evening. The observation was made on birds for feeding directly on the field. Samples of the food material eaten by the birds were collected for further observation. It fed mainly on arthropods species such as grasshoppers, cricket, catterpillers, flies, termites, ants, rarely on ticks and spiders and very rarely on plants which makes the bird to be an omnivorous. The diet of cattle egret reveals that order Orthopteran insects were the highest percentage (33.33%). This study recommends that all efforts should be taken to reduce further decline in the population of this birds so as to improve its conservation status in the environment.

Study on avifaunal diversity in Durgadahalli andMydala lakes of Tumakuru, Karnataka

The rapid avifaunal diversity assessment was carried out at two different locations Durgadahalli and Mydala lakes Tumakuru, during 2017-2019. A total of twenty (20) different birds was recorded in both lakes belonging to orders Podicipediformes, Pelecaniformes, Ciconiiformes, Falconiformes, Gruiformes, Charadriiformes and Coraciiformes. They belonging to families Podicipitidae, Phalacrocoracidae, Ardeidae, Accipitridae, Rallidae, Charadriidae, Laridae and Alcedinidae respectively. In Durgadahalli lake, 13 species from seven orders that belong to seven families except for Laridae were recorded. Among the seven families, Ardeidae had highest number of species, while in Mydala lake, 19 species belong to seven orders and eight families were recorded. Where family Ardeidae and Charadriidae, shows a highest number of species which was probably due to rich diversity of aquatic organisms.

New insights on the avian trace fossil record from NE Mexico: Evidences on the diversity of latest Maastrichtian web-footed bird tracks

In this study we describe three new web-footed bird tracks found in uppermost Maastrichtian strata of Las Encinas Formation, southeast Coahuila, NE Mexico. The described materials were collected at Rancho San Francisco locality, Ramos Arizpe County. These bird tracks can be ecomorphologically compared with those of modern members of the Order Anseriformes and the Family Ardeidae (Order Pelecaniformes). Associated invertebrate ichnotaxa include Cochlichnus and Skolithos. The co-occurrence of Leptoptilostipus isp., morphotype A and morphotype B with several invertebrate traces at Rancho San Francisco suggests that this area could represent a feeding site with abundant food sources during the latest Maastrichtian. These new bird footprints add to the previous reports of avian trace fossils for the Upper Cretaceous of the state of Coahuila and suggest that the Rancho San Francisco tracksite can be considered up to now, as the richest locality of web-footed bird tracks worldwide.

Gross pathology of herons and egrets (family Ardeidae) at a wildlife rehabilitation centre in Northern California

Gross necropsies were performed on all herons and egrets (family Ardeidae) that died or were euthanized at a wildlife rehabilitation centre in Fairfield, California, over a six-week period in the summer of 2018 (n = 145). Of the animals necropsied, 108 (74.5%) were euthanized and 37 (25.5%) died. Common reasons for euthanasia were trauma (n = 24), MBD (n = 39) and non-specific signs such as hypothermia and obtundation that persisted in the face of medical and supportive care (n = 32). MBD was found both in birds at admission (n = 9) and later in care (n = 34), despite calcium supplementation to correct calcium:phosphorus ratios of foods. Feeder fish were suspected to be deficient in vitamin D, and supplementation successfully reduced the development of this problem during the care later in the season. Nematodes of the genus Eustrongylides were found in the coelomic cavities of 43 (30%) birds. High burdens were often accompanied by coelomitis and abscessation involving internal organs. Visceral gout (n = 10) and intestinal perforation (n = 4) were both strongly associated with the administration of meloxicam. These findings suggest meloxicam should be used with caution in these species. Other less common findings included septic arthritis, intestinal perforation and hepatomegaly. This study describes common gross pathological findings of herons and egrets in a wildlife rehabilitation centre in California and demonstrates the utility of gross necropsies in determining cause of death when more advanced post-mortem diagnostics are unavailable

Great Blue Heron Forages for Fish by Bill-Vibrating

The more than 60 species in the family Ardeidae (herons, egrets, and bitterns) are known to be very creative at catching prey. Kushlan (1978) describes a total of 38 feeding behaviors for this family. Each species uses several feeding methods, but only 6 species, or about 10% of the family, are known to attract fish by vibrating their bills in water, a technique first described by Buckley and Buckley (1968). This makes bill-vibrating one of the least common feeding tactics in Ardeidae. On 10 May 2019, I observed and photographed an adult Great Blue Heron (Ardea herodias) foraging by bill-vibrating at a large pond in Dead Horse Ranch State Park, near Cottonwood, Arizona. Bill-vibrating has not previously been reported in this species.

A review of the diversity of aquatic avifauna in Mizoram, India

Aquatic avifauna are an important bio-indicator of an ecosystem changes. Mizoram, one of the north-eastern states of India, lies in one of the richest biodiversity hotspots of the world. Along its water bodies, it is home to several species of resident birds, and is also a temporary home for migrating birds in different seasons. These resident and migratory avifauna form an important component of most wetland ecosystems, as they are vital components of the food webs. While only the Tamdil and Palak Lake are recognized as wetlands, there are several rivers and smaller water bodies around which aquatic avifauna exist. However, official records comprise of about 14 species of waterbirds belonging to 6 orders and 8 families. Of these, Anatidae, Charadriidae, Scolopacidae, Anhingidae, and Podicipedidae are represented by one species each, while the Ardeidae are represented by four species. Among the 14 species reported so far, two species of the Order Pelicaniformes, namely Anhinga melanogaster (Family Anhingidae) and Ardea insignis (Family Ardeidae) are highly endangered. However, detailed studies are wanting and, while there are sporadic reports of sightings on social media, there is a need for a more comprehensive study of the diversity and seasonal variations of aquatic avifauna around the different water bodies of the state of Mizoram.

CLINICAL AND PATHOLOGIC FINDINGS OF AN OUTBREAK OF VITAMIN D3-RESPONSIVE METABOLIC BONE DISEASE IN HERON AND EGRET (FAMILY ARDEIDAE) CHICKS FED CAPELIN (MALLOTUS VILLOSUS).

An increase in cases of metabolic bone disease (MBD) in chicks of six species of heron and egret (family Ardeidae) was identified at a wildlife rehabilitation center in the spring and summer of 2018. The outbreak affected 34.3% of birds in care for four or more days during the first 3 mo of the study and was the most common reason for euthanasia during that time. Cases were characterized by lameness, increased flexibility of multiple long bones, angular deformities, and bone fractures. Gross postmortem examinations were conducted on 145 nestlings and fledglings that died or were euthanatized either because of MBD or for unrelated conditions. Histology was performed in four cases and three controls. Histologic findings were characterized by multiple lesions in the appendicular long bones, including variable elongation of the physis, retention of cartilage cores in the metaphyseal primary spongiosa, poorly mineralized osteoid seams within the primary spongiosa, thinning or lack of diaphyseal cortical bone compaction, and folding fractures typically propagating through the physis-metaphyseal interface. Folding fractures were often associated with focal metaphyseal fibroplasia. The parathyroid gland diameter of birds diagnosed postmortem with MBD in care was significantly larger than that of unaffected birds. The authors hypothesized that a dietary deficiency of vitamin D3 because of low levels in the bird's captive diet of capelin (Mallotus villosus) was the cause of the MBD. Starting in mid-July every chick's diet was supplemented with 714 IU oral vitamin D3/kg body weight per day, after which the number of birds developing MBD declined to a rate of 4.3%. This study characterizes the clinical, gross, radiographic, and histologic features of vitamin D3-responsive MBD in young herons and egrets and provides evidence to support the recommendation that captive birds on a diet of capelin be supplemented with vitamin D3, especially during growth.

Avifaunal Diversity in Urban Coastal Wetland of Colombo Sri Lanka

Sri Lanka is an island nation, exhibiting remarkable biological diversity in spite of its small size; Country has rich ecosystem diversity because of its topographic and climatic heterogeneity as well as its coastal influence. The wetland ecosystems in Sri Lanka have been internationally recognized for their outstanding biological prosperity and their conservation status. Sri Lanka’s wetlands are also diverse, comprised of 103 major rivers and associated marshes, and about 12,000 irrigation tanks harboring wetland species including inland and coastal wetland ecosystems which are even coming under Ramsar Wetland Sites. One such coastal wetland ecosystem in Sri Lanka is Crow Island coastal ecosystem. The Crow Island Beach Park is a public park located in Colombo—15 (6°58'24.1N, 79°52'09.9E). The land extent of this park is 7 ha. The beach park consists of rich avifaunal diversity since it is a coastal wetland. Sri Lanka has been recognized as a country with “important Bird areas”, a “key Asian region for threatened birds” and an “Endemic Bird Area”. The main objective of the present study was to document the avifaunal diversity of the coastal wetland of the beach park. Multiple surveys were conducted through random visits in the area for a period of two months from July to August 2020. Their status was evaluated from the National Red List. Diurnal and nocturnal observations were made through the unaided eye and using a binocular via multiple random walks and point counting method. A total of 28 bird species were recorded belonging to 14 orders and 22 families representing 5.69% of the birds recorded in Sri Lanka (492). Of the reported bird families, nine families represented Order Passeriformes while four species of birds found in the park represented family Ardeidae. This park is not only significant for biodiversity conservation but also for its value as a coastal wetland. The local community of the area is constantly interacting with the area for their living and for leisure. Consequently, these habitats are threatened by irresponsible human activities, such as garbage dumping, noise pollution, lighting fires for garbage burning, clearing of natural vegetation in and around wetlands. However, detailed survey has to be carried out to study the abundance, seasonal variation to recommend the conservation and management measures.

An Outlaw in the Family: Notes on the Dossier of Heron, Son of Phaseis

Abstract Discussion of the dossier of a Theadelphian family to which a fugitive brother can be added.

An investigation of the monitoring and management of the habitat of the family Ardeidae in Muan Yongwol-ri Breeding Sites in Korea

The purpose of this study was to investigate the variation in populations and species of the family Ardeidae through an evaluation of environmental habitat characteristics in the breeding sites of the family Ardeidae in Muan Yongwol, Korea. The study area has been protected as a Natural Monument (No. 211) in Korea and is located in Yongwol, Muan, in Korea. The monitoring of the herons was performed in October 2015 and from February to September 2016. The monitoring of vegetation, fish, benthic macroinvertebrates, and amphibian was performed in April and July of 2016, and the monitoring of land insecta was conducted in July 2016. The populations of the Ardeidae family in the Muan Yongwol-ri habitat of egrets and herons were recorded as 840, 1155, 1211, and 52 for Ardea cinerea, Egretta alba, Egretta garzetta, and Nycticorax nycticorax, respectively. Bubulcus ibis was not found. Terrestrial insects were found in 10 orders, 62 families, and 142 species. Benthic macroinvertebrates were in 11 orders, 15 families, and 18 species, and the predominant species was Chironomidae sp. Fish were found in two orders, three families, and nine species, and Carassius auratus were dominant. The proportions of fish, amphibian, reptilia, insecta, and others for food of Ardeidae were observed at 56.9%, 20.2%, 6.4%, 14.7%, and 1.8%, respectively. The area of the nest trees of Ardeidae family was approximately 8805 m2. The nest tree counts of Pinus thunbergii, Quercus serrata, and Quercus acutissima in the breeding sites were 147, 3, and 3, respectively, and all dead trees were Pinus thunbergii. The levels of salinity and available phosphate were much higher in the breeding site of the Ardeidae family than they were in control area. A management plan should be followed in this breeding area, such as understory vegetation thinning, soil improvement, or transplanting nest trees.

Sperm structure of the cattle egret (Bubulcus ibis).

It remains a major concern that sperm structure has continued to be poorly investigated and reported in avian species. To our knowledge, sperm structure in the order Pelecaniforme has not been reported. Although McFarlane (1963; Proceedings of the XIII International Ornithological Congress; Ithaca, NY; American Ornithologists' Union) reported the study of spermatozoa in two genera and two species of the family Ardeidae, he did not provide an account, or the names of the species examined. The present report on the sperm structure of the cattle egret, Bubulcus ibis, is, thus, the first in the order Pelecaniformes (this bird has been placed variably under the order Ciconiiformes, or the order Pelecaniformes). Five sexually mature and reproductively active male cattle egrets were obtained from the wild, humanely euthanized, the reproductive organs dissected out, and tissues from the ducti deferentia were prepared for transmission electron microscopy. The sperm structure of this bird is generally similar to that described for most non-passerine birds. However, the acrosome is a short, conical or bullet-shaped, blunt-ending organelle that lacks a perforatorium. The base of the acrosome is flat and makes contact with the nucleus along, a correspondingly flat plane. The nucleus, thus, ends anteriorly in a flat plane devoid of a concavity or a rostrum, and an endonuclear canal. The acrosomal and nuclear features of this bird are, therefore, main deviations from the situation in the non-passerine clade of birds.

일기와 선교편지를 통해 본 알렌과 헤론의 갈등에 관한 재 고찰

일기와 선교편지를 통해 본 알렌과 헤론의 갈등에 관한 재 고찰

Breeding Phenology and Reproductive Success of Little Blue Herons (Egretta caerulea) in an Urban Mixed-Species Colony

As human populations continue to expand into suburban and rural areas, conflicts with wildlife are likely to increase. Many populations of long-legged wading birds (Family Ardeidae) face the challenge of human disturbance both at feeding sites and breeding colonies. Little Blue Herons (Egretta caerulea) are medium-sized wading birds that often join egrets and other herons in mixed-species breeding colonies. In June and July 2018, a random sample of Little Blue Heron nests located in an urban colony were monitored from incubation to fledging. The goals of this study were to (1) characterize adult nest-activity patterns over the course of the breeding cycle, and (2) document Little Blue Heron reproductive success in an urban colony and identify sources of human disturbance. Instantaneous samples with 5-min intervals were used to record adult activity during 50 h of observation at 24 nests. An additional 77 h of continuous observation at two different nests documented fine-scale activities and changes in nesting status. Observations made at random times during morning, midday, and evening periods yielded 636 nest-hours across all breeding stages. During incubation, attending parents mostly sat (63 %) or stood (23 %) in or near their nests, spent less time in nest maintenance (5 %) and self-maintenance (scratching, preening; 5 %), and seldom (< 1 %) left the nest unprotected. By the end of the breeding cycle, nests were unattended 69 % of the time. The 26 monitored nests fledged a total 39 chicks (1.4 ± 0.3 chicks/nest attempt). The 16 successful nests (61 % of all nests) fledged 2.4 ± 0.2 chicks. Known causes of nest failure included destruction or usurpation by Cattle Egrets (Bubulbus ibis) and predation by Black-crowned Night-herons (Nycticorax nycticorax). Sources of disturbance included dogs allowed in the colony, intentional loud noises, and human presence. We compare reproductive success at this urban colony to that in less disturbed colonies reported in the literature.

Breeding Biology and Brood Reduction of Herons and Ibis in a Northern Brazilian Mangrove Swamp: Eggs Do Not Starve

Few studies on pelecaniform breeding have been conducted in tropical regions. Most species in the Order Pelecaniformes (Family Ardeidae and Threskiornithidae) are facultative brood reduction strategists, laying extra-eggs that might not fledge. In obligate brood reduction in birds, extra-eggs are insurance-eggs, but in facultative brood reduction birds, extra-eggs have historically been interpreted as additional offspring in unpredictable environments. However, this study on six species in Brazil suggests that the insurance-value might be a major factor selecting for extra-egg laying, even in facultative strategists. While Egretta thula, E. caerulea, E. tricolor, Nycticorax nycticorax, and Nyctanassa violacea showed facultative brood reduction strategies, Eudocimus ruber showed a brood survival strategy and was used to compare brood reduction parameters between strategies. Mean brood size in different species ranged from 1.94-2.52 eggs, 1.88-2.25 hatchlings, and 1.65-2.05 fledglings. Clutch sizes were between two and three in brood reduction species, and almost always two in E. ruber, which either raised the entire brood or totally failed. Individual mortality events in non-failed nests were lower in E. ruber. This difference occurred only during the egg stage, when starvation does not occur, so differences between strategies resulted from an insurance-value of extra-eggs. Nest failures were higher in E. ruber. Insurance could be the main force driving evolution of extra-egg laying in facultative species, with survival of additional offspring a collateral benefit.

Effects of anthropogenic disturbance on the species assemblages of birds in the back mangrove forests

Around the world, mangrove ecosystem has faced major threats from human activities, and birds were unexceptionally impacted. Mangrove fringe a large extent of the east and west coast of Peninsular Malaysia. The intertidal gradients along the coastline, has formed a brackish zone (back-mangrove), which exhibited different pattern of mangrove species, but received much less attention. In this study, we compare species assemblages of birds based on different level of anthropogenic pressures at different back-mangroves sites; KY; KD and KST which is measured by analysis of land use change for 15 years using ERDAS Imagine. 97 species from 36 families of birds were recorded from all sites, dominated by family Alcedinidae (kingfishers), Ardeidae (egrets, herons) and Coraciidae (dollarbirds). Anthropogenic disturbance changes the landscape structure, with reduction of mangrove cover, other than increasing horticulture, urbanization, and monoculture plantation activities. This is most apparent at KY, followed by KD and lowest at KST, which also showed reducing in species abundance and richness of birds. Species assemblages of birds also differ, as highly disturbed sites exhibited a poorer representation of mangroves-specialist, compared to less disturbed sites as illustrated by the nMDS ordination. Finally, PERMANOVA analysis showed significant effect of the bird family and their ecological niches towards the species assemblages at different back-mangrove sites. The high abundance of open country species such as mynas, crows and doves at all sites indicate the influence of anthropogenic activities. Presence of several highly protected species indicates high conservation value of the back-mangrove zone, apart from their true-mangrove counterparts.

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