Community Structure of Resident and Migratory Bird Species in Talabong Mangrove Forest, Bais City, Negros Oriental, Philippines

The latitudinal and elevational patterns of species richness of resident and migrant birds have been of interest to researchers over the past few decades, and various hypotheses have been proposed to explain the factors that may affect these patterns. This study aimed to shed light on the elevational distribution patterns of resident and migrant bird species richness by examining biotic and abiotic factors such as climate, and habitat heterogeneity using a piecewise structural equation model (pSEM). The overall pattern of resident species richness showed a decreasing trend with increasing elevation, whereas that of migrant species richness showed an increasing trend. The mid-peak pattern of species richness was affected by a combination of resident and migrant species and not by either resident or migrant species. Our results showed that resident species were distributed in lower elevation regions with higher mean spring temperatures, whereas migrant species were found in higher elevation regions with lower mean spring temperatures and higher overstory vegetation coverage. Although high elevation conditions might adversely affect the reproduction of migrant birds, higher overstory vegetation coverage at high elevations seemed to compensate for this by providing a better nesting and roosting environment. Despite the significance of habitat diversity and understory vegetation coverage in univariate linear regression models, multiple regression models of the interconnection of ecological processes demonstrated that mean spring temperature and overstory vegetation coverage were more explanatory than other variables.

Small tropical and sub-tropical cities frequently retain considerable and diverse green spaces. Such cities can house diverse bird assemblages but these species face conditions varying both spatially (habitats and human activity spread out unequally) and temporally (influx of migratory birds, seasonally varying weather). How do urban birds cope with such conditions? More specifically, do migratory species vary from resident ones in their requirements, and how do resident species deal with variations in conditions? To address these questions, we used an ordination technique, the Outlying Mean Index (OMI), to estimate niche characteristics (OMI, tolerance, and residual tolerance) of 74 resident and migratory bird species in the tourism-dominated Udaipur city, India, across three seasons during 2019–20 using 16 variables that incorporated human presence, land use and trees. OMIs indicated high residual tolerance suggesting that measured variables were inadequate to fully characterize urban bird niches. Contrary to predictions, birds grouped by feeding guilds had similar niche metrics both within and across seasons. Also contrary to predictions, migratory species had more generalized niches relative to resident species. Bird niches were most influenced by trees, effects due to other natural habitats (open areas, scrublands, wetlands) were weaker, and human-related variables (cattle, built-up area, people, vehicles) had the weakest influence. Seasonal niche characteristics computed for 41 resident species suggested that individual species coped with changing conditions differently. Conservation of bird assemblages in small cities will require preservation of city-wide habitat diversity alongside spatially restricting urbanization.

Prevalence and genetic diversity of avian haemosporidian parasites at an intersection point of bird migration routes: Sultan Marshes National Park, Turkey

Avian haemosporidian diversity and transmission across birds and mosquitoes in Botswana.

Integrating season-specific needs of migratory and resident birds in conservation planning

Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes delta(15)N, delta(13)C, and deltaD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001-2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes delta(15)N, delta(13)C, and deltaD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p'-DDE (100%), p,p'-DDT (57%), and total PCBs (100%). p,p'-DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues >10 microg/g wet weight in carcass. There were no significant differences in delta(13)C and delta(15)N values among species, between seasons, or between migrant and resident birds. However, deltaD values were clearly different between species and helped differentiate migrant from resident birds. deltaD values also were negatively and significantly correlated with DDE concentrations in carcass. Birds with more depleted deltaD values in feathers tended to have higher DDE concentrations than those with less depleted deltaD values, suggesting a potential latitudinal accumulation of DDE. Overall, our results suggest that during fall and spring, there is not a significant buildup of persistent OCs in migrant and resident passerine insectivorous birds in northwest Michoacán, Mexico.

Phylogenetic characterization of a reassortant H5N2 influenza A virus from a resident Mexican duck (Anas diazi)

Theobroma cacao plantings, when managed under the shade of rainforest trees, provide habitat for many resident and migratory bird species. We compared the bird diversity and community structure in organic cacao farms and nearby forest fragments throughout mainland Bocas del Toro, Panama. We used this dataset to ask the following questions: (1) How do bird communities using cacao habitat compare to communities of nearby forest fragments? (2) To what extent do Northern migratory birds use shaded cacao farms, and do communities of resident birds shift their abundances in cacao farms seasonally? (3) Do small scale changes in shade management of cacao farms affect bird diversity? Using fixed radius point counts and additional observations, we recorded 234 landbird species, with 102 species that were observed in both cacao and forest fragments, 86 species that were only observed in cacao farms, and 46 species that were restricted to forest fragments. Cacao farms were rich in canopy and edge species such as tanagers, flycatchers and migratory warblers, but understory insectivores were nearly absent from cacao farms. We observed 27 migratory species, with 18 species in cacao farms only, two species in forest only, and seven species that occurred in both habitats. In cacao farms, the diversity of birds was significantly greater where there was less intensive management of the canopy shade trees. Shade tree species richness was most important for explaining variance in bird diversity. Our study shows that shaded cacao farms in western Panama provide habitat for a wide variety of resident and migratory bird species. Considering current land use trends in the region, we suggest that action must be taken to prevent conversion away from shaded cacao farms to land uses with lower biodiversity conservation value.

AimWe compared the parasite assemblages of over‐wintering migratory birds and permanent residents on the wintering grounds. We determined whether parasite sharing between migratory and resident birds is influenced by host phylogenetic relatedness. We then inferred whether migratory birds transport haemosporidian parasite lineages between the breeding and wintering grounds.LocationSierra de Bahoruco National Park, Dominican Republic, Hispaniola.TaxaMigratory and resident birds (primarily Aves: Passeriformes) and their haemosporidian parasites (order Haemosporida, Plasmodium, Haemoproteus and Parahaemoproteus).MethodsWe used mist nets to capture birds in thorn scrub, broadleaf dry forests and pine forests during midwinter. We used molecular methods to recognize haemosporidian parasites in blood samples, and genotyped infections based on the nucleotide differences in a region of the parasite cytochrome b gene.Results and Main ConclusionWe identified 505 infections by 32 haemosporidian parasite lineages in 1,780 blood samples from 37 resident species, and in 901 blood samples from 14 overwintering migratory species, over five years at the same sites. Infection prevalence varied among migratory species from zero to 13%, whereas infection prevalence among resident species ranged up to 77%. Host relatedness did not predict parasite assemblage similarity. We discuss four hypotheses for the rarity of haemosporidian infections in migratory birds during winter, and for the infrequency of parasite sharing between migratory and resident birds: (a) relative abundance and host preferences of dipteran vectors lower parasite transmission to migratory birds; (b) parasite lineages adapted to infect endemic Caribbean hosts are unable to infect migratory species; (c) the physiology of migratory birds after migration and during winter reduces parasite survival; and (d) infected individuals suffer more pronounced mortality rates during migration. We highlight the link between host–parasite coevolution and the physiological adaptations associated with avian seasonal migration.

The coastal areas of Bangladesh are enriched with migratory avian species but the actual status of birds was unknown, particularly in the south-central coastal region of the country. A yearlong (June 2023 to May 2024) direct field observation-based study was conducted to unfold the present status of the migratory avifauna in three protected areas (Kuakata National Park, Tangragiri Wildlife Sanctuary, and Sonarchar Wildlife Sanctuary). In this study, a total of 85 migratory bird species were recorded under 10 orders and 22 families. Individuals of wetland dependent migratory birds were higher than other bird species. Sonarchar Wildlife Sanctuary (SWS) had the highest number of bird species and individuals (70 species; n = 3618 individuals) with the highest diversity index values (H’ = 3.135, Ds = 0.9257) compared to two other sites. Significant variations among migratory avian communities were found among the three study sites as indicated by the Analysis of Similarity (ANOSIM) test (R = 0.168, P < 0.001) in the non-metric multidimensional plot (NMDs). Among the migratory bird species, Charadrius dubius (14.75%), Anas crecca (14.33%), Threskiornis melanocephalus (11.69%), Actitis hypoleucos 8.47%), Vanellus cinereus (6.75%) were the most abundant. Population abundance was higher for the occurrence of the wetland dependent migratory bird species in the study area. Avian community composition of migratory species showed uneven distribution in the rank abundance curve. Across the three study sites, the majority of the migratory bird species exhibited clumped distribution patterns, followed by regular and random distribution patterns. A total of 37 (45.12%) species of migratory birds were found to use the coastline as their microhabitat. Unplanned fishing, tourism, expansion of agricultural land, hunting, and pollution were identified as major threats to the migratory bird species in the study area. This study suggests community-based conservation measures are essential for the proper conservation of the migratory birds. Dhaka Univ. J. Biol. Sci. 34(1): 155-173, 2025 (January)

Noise level and water distance drive resident and migratory bird species richness within a Neotropical megacity

West Nile virus (WNV) is a zoonotic mosquito-borne flavivirus that is harbored and amplified by wild birds via the enzootic transmission cycle. Wide range of hosts are found to be susceptible to WNV infection including mammals, amphibians and reptiles across the world. Several studies have demonstrated that WNV was present in the Malaysian Orang Asli and captive birds. However, no data are available on the WNV prevalence in wild birds found in Malaysia. Therefore this study was conducted to determine the serological and molecular prevalence of WNV in wild birds in selected areas in the West Coast of Peninsular Malaysia. Two types of wild birds were screened, namely migratory and resident birds in order to explore any possibility of WNV transmission from the migratory birds to the resident birds. Thus, a cross-sectional study was conducted at the migratory birds sanctuary located in Kuala Gula, Perak and Kapar, Selangor by catching 163 migratory birds, and 97 resident birds from Kuala Gula and Parit Buntar, Perak at different time between 2016 and 2017 (Total, n = 260). Blood and oropharyngeal swabs were collected for serological and molecular analysis, respectively. Serum were screened for WNV antibodies using a commercial competitive ELISA (c-ELISA) (ID Screen® West Nile Competition Multi-species ELISA, ID VET, Montpellier, France) and cross-reactivity towards Japanese Encephalitis virus (JEV) was also carried out using the JEV-double antigen sandwich (DAS) ELISA. Oropharyngeal swabs were subjected to one-step RT-PCR to detect WNV RNA, in which positive reactions were subsequently sequenced. WNV seropositive rate of 18.71% (29/155) at 95% CI (0.131 to 0.260) and molecular prevalence of 15.2% (16/105) at 95% CI (0.092 to 0.239) were demonstrated in migratory and resident wild birds found in West Coast Malaysia. Phylogenetic analyses of the 16 WNV isolates found in this study revealed that the local strains have 99% similarity to the strains from South Africa and were clustered under lineage 2. Evidence of WNV infection in resident and migratory birds were demonstrated in this study. As a summary, intervention between migratory birds, resident birds and mosquitoes might cause the introduction and maintenance of WNV in Malaysia, however the assumption could be further proven by studying the infection dynamics in the mosquitoes present in the studied areas.

Migratory birds are considered one of the main sources for West Nile virus (WNV) introduction into European countries. Following the WNV epidemic in the late summer of 1998 in a marshy area of Tuscany (Padule of Fucecchio), an extensive ornithological surveillance programme was carried out in the infected areas from 2006 to 2008. Several species of migratory and resident birds were trapped, sampled and serologically tested. The results of this surveillance programme gave a useful indication of potential sources of WNV re-introduction and spread into Italy. The area under study was also investigated and classified into ecological areas through satellite image processing. In August 2008, the WNV infection re-emerged in Italy in the area surrounding the Po river delta, involving three regions: Lombardy, Emilia Romagna and Veneto. Several surveillance activities were immediately put in place, including the extensive monitoring of wild birds found dead or trapped in the framework of other surveillance programmes. These activities were also prolonged in the 2009, when the virus circulation re-occurred at the border of the area already infected in 2008. The possible epidemiological role of the different species of migratory and resident birds is discussed, in relation to the different ecological patterns identified in the area and their potential ability to introduce, spread and support the endemization of WNV infection.

The Pliocene-Pleistocene transition had dual effects on North American migratory bird speciation

Migratory birds may be unable to respond to climate change at their breeding grounds in the same way as residents because they do not experience local environmental conditions until migration has been completed, or because of limited plasticity in response to environmental variation. Indeed, several studies have shown that long-distance migrants have advanced their phenology less than short-distance migrants in recent decades, suggesting a slower phenological response to ongoing climate warming. However, few studies compared the phenological response of species that live year-round within the same climatic region (including residents) with that of species migrating over longer distances. We used an extensive data set on temporal change in spring first singing date (FSD) during 1977-2006 of 56 resident and migratory bird species in Northern Germany to test whether migratory status affected 2 aspects of the phenological response: the temporal trend in FSD and the response of FSD to local temperatures. Species migrating <4° latitude (ca. 450 km) (less migratory species) showed greater temporal advancement in FSD compared to more migratory species. In addition, the variance in temporal trends was larger among less migratory species. Higher local temperatures were associated with earlier FSD, and multi-brooded species showed a stronger advancement in FSD with higher temperatures than single-brooded species. However, the tempera- ture response was unaffected by migratory status, suggesting that the difference in the temporal trend in FSD between less migratory and more migratory species was mainly due to climatic and/or environmental cues regulating departure of the latter from the wintering areas and/or temporal scheduling of migratory flights, rather than to differential responses of FSD to local temperatures. Therefore, migratory behaviour should be regarded as a life-history trait possibly constraining the phenological response to rapid climatic changes in avian species.