Bird Habitat Research Articles

Social and ecological drivers of illegal bird hunting in the Indawgyi wetland ecosystem in Myanmar

AbstractHunting and illegal bird killing are major concerns for avian conservation globally. Unsustainable bird hunting in wetland habitats, particularly those located along important flyways, has contributed to avifauna defaunation and species endangerment. Since wetlands are primary habitats for migratory birds and are associated with anthropogenic landscapes, a comprehensive understanding of bird harvesting, and its drivers is fundamental to reduce threats to current avifauna. In this study, we examined the distribution of illegal bird hunting and its socioecological drivers in the Indawgyi wetland ecosystem in Myanmar by integrating data from bird surveys, household surveys, and market surveys. We found that illegal bird hunting using nets, traps, and poisonous substances is prevalent in areas close to water and during the migration season. People who had negative attitudes toward avian species were more likely to engage in bird hunting, primarily because of the conflicts between bird conservation and crop production. Socioeconomic needs were not the major driving factors of bird killing. We therefore suggest sustainable management interventions promoting coexistence by integrating bird conservation and agricultural production, accompanied by increasing awareness to improve avian conservation in an internationally important wetland in Myanmar.

Avidant: A Descriptive-Analytical Tool for Urban Bird Monitoring in the Province of Negros Occidental

Urban bird diversity is a sound environmental indicator of the overall biodiversity. However, despite extensive bird monitoring efforts, there still needs to be more tools for efficiently recording and analyzing bird data. This data is vital for making informed decisions about biodiversity conservation. To address this issue, this study aimed to develop a reliable and user-friendly analytical tool for urban bird monitoring in the Province of Negros Occidental. The descriptive analytics functionality of the device was designed to identify bird species, track changes in bird populations over time, identify areas where bird species are at risk, and prioritize conservation efforts accordingly. The study used the Agile Scrum method and Constructive Research design to develop the mobile application and web system. The system utilizes the Shannon Diversity and Evenness Index and Simpson’s Dominance Index algorithms to analyze bird data. Only identified land bird species found within Negros Occidental were included for urban bird monitoring, excluding sea birds. The study's findings revealed that the system is, indeed, user-friendly, and reliable for gathering data on bird species distribution and abundance in urban areas of Negros Occidental, effectively assisting conservationists in identifying significant bird habitats and assessing the overall state of urban biodiversity. Bacolod City was selected as the pilot location for this study. The study was developed in the School Year 2022-2023.

The role of glaciations in the evolutionary history of a widely distributed Neotropical open habitat bird

AbstractAimThe Neotropics constitute the most biodiverse region of the world, yet its patterns of diversification and speciation differ among Neotropical areas and are not equally well understood. Particularly, avian evolutionary processes are understudied in the open habitats of temperate South America, where the role of glacial cycles is not clear. We analysed the evolutionary history of a Neotropical widespread bird species as a case study to evaluate its continental‐scale patterns and processes of diversification, with a focus on Patagonia.LocationOpen habitats of the Neotropics.TaxonVanellus chilensis (Aves, Charadriiformes).MethodsWe obtained reduced representation genomic and mitochondrial data from the four subspecies of V. chilensis to perform a phylogenetic/phylogeographical analysis and study the evolutionary history of the species. We complemented these analyses with the study of vocalizations, a reproductive signal in birds.ResultsThe initial diversification event within V. chilensis, approximately 600,000 years ago, split a Patagonian lineage from one containing individuals from the rest of the Neotropics. We found considerable gene flow between these two lineages and a contact zone in northern Patagonia, and showed that genomic admixture extends to northwestern Argentina. Shallower divergence was detected between the two non‐Patagonian subspecies, which are separated by the Amazon River. Vocalizations were significantly different between the two main lineages and were intermediate in their temporal and frequency characteristics in the contact zone.Main ConclusionsPatagonian populations of V. chilensis are clearly differentiated from those of the rest of the Neotropics, possibly as a consequence of Pleistocene glaciations. A secondary contact zone in northern Patagonia with extensive gene flow among lineages appears to be the consequence of post‐glacial, northward expansion of the Patagonian populations. Future analyses focused on the dynamics of the contact zone will allow us to establish whether the species continues to diverge or is homogenizing.

Infrastructure and the ethnographic-cartographic production of urban bird species richness

The qualitative bio-geographies of human geographers and the quantitative mappings of biogeographers share a goal: how to understand living with non-human life. Yet they rarely bridge the conceptual and methodological gap between them. This article theorizes how the concept of infrastructure can bridge this ethnographic-cartographic divide. Infrastructure is not just inert shell. It is also a system of relation, a dynamic patterning of socionatural form emerging out of experiences and affective moments of its constituents. As proof of concept, we quantified and compared urban bird species richness and frequency for Tallahassee, Florida over a 17-year period (2000–2017) for two co-occurring observational infrastructures, eBird and a wildlife rehabilitation center that serves the city. Species common to both infrastructures comprised 94% of all eBird observations and 99% of all rehab records. Their differences reflected contrasts in how the motivations for experiencing birds intersected with bird habitat preferences, behavior, and contingencies of urban history and development. eBird observations had a higher species richness (295 spp) and reflected the growing popularity among birds and a small number of active birders for visiting stormwater retention lakes recently modified to improve bird habitat. Rehabilitation records had a lower richness (194 spp) and exhibited a much more even distribution of bird encounters among individual residents as well as community institutions like schools, universities, law enforcement, and other government organizations. Infrastructural perspectives convey how affective and individualistic encounters with the non-human can link to emergent biogeographic mappings and how urban biodiversity is relationally and heterogeneously produced rather than simply contained in cities.

Review of terrestrial temporarily conserved areas in Canada, the United States, and Mexico.

The establishment of protected areas is a cornerstone of conservation, but permanent protection could be inefficient or even impossible in some situations. We synthesized the literature on temporarily conserved areas (TCAs) across Canada, the United States, and Mexico. We used a comprehensive search string to retrieve peer-reviewed articles published from 2000 to 2021 from the Web of Science. We identified 27 relevant peer-reviewed articles that examined the potential benefits of TCAs in the study area, indicating TCA is a relatively understudied area of research in the peer-reviewed literature. The TCA studies were highly clustered; 77% of studies focused on protecting a single life stage of migratory species and 61% of studies related to temporary conservation of breeding or staging habitats for migratory birds. Ninety-three percent of studies focused on preventing human-driven threats, mainly on public lands of coastal areas, the Great Plains, and the Mississippi Valley in the central United States. Short-term and experimental studies were the dominant study types. TCAs have the potential to complement permanently protected areas and provide protection when permanent protection is difficult. Some included studies examined their conservation value, but the ecological, social, and economic outcomes of TCAs are unclear. More TCA research is needed to determine the role they could play in conservation worldwide. Embracing the concept of TCAs as conservation tool could lead to more comprehensive and consistent reporting of the outcomes of temporary area-based conservation measures. However, a global review and analysis of effectiveness of TCAs will be required if they are to play a formal role in meeting international targets for biodiversity conservation.

Twenty‐five years of change in forest structure and nesting behavior of Hawaiʻi ʻelepaio

Long‐term ecological studies are invaluable for detecting changes over time. Forest restoration has been a conservation priority in Hawaiʻi, where invasive species have negatively impacted native bird habitat. During 1993–1994, a study was conducted of Hawaiʻi ʻelepaio (Chasiempis sandwichensis) nest site selection and forest composition in mesic montane forest along Mauna Loa Road in Hawaiʻi Volcanoes National Park. We returned to the site and repeated the methods used in the earlier study to record Hawaiʻi ʻelepaio nest site selection (tree species, tree and nest height, and tree girth [diameter at breast height, DBH]) from 2015 to 2017, and measured forest composition (tree density, relative abundance, height, and DBH) in 2019. Three times as many nests were found in ʻaʻaliʻi (Dodonaea viscosa) as in koa (Acacia koa) in both time periods. Heights of koa and ʻaʻaliʻi did not change, but their DBH increased over time. The relative height of nests in ʻaʻaliʻi trees did not change, but nests in koa were placed higher in the crown during the later study. Overall tree density increased from 1,619 (95% confidence interval [CI] = 1,499–1,740) trees/ha to 2,583 (95% CI = 2,176–3,096) trees/ha. Koa relative abundance was 53% of total trees earlier and 45% later, ʻaʻaliʻi remained at 47%, and māmane (Sophora chrysophylla) increased from 0 to 8% over time. Our results indicate that changes in forest composition affect nesting behavior, but in ways that are not necessarily simple or consistent.

Historical racial redlining and contemporary patterns of income inequality negatively affect birds, their habitat, and people in Los Angeles, California

Abstract The Home Owners’ Loan Corporation (HOLC) was a U.S. government-sponsored program initiated in the 1930s to evaluate mortgage lending risk. The program resulted in hand-drawn “security risk” maps intended to grade sections of cities where investment should be focused (greenlined areas) or limited (redlined zones). The security maps have since been widely criticized as being inherently racist and have been associated with high levels of segregation and lower levels of green amenities in cities across the country. Our goal was to explore the potential legacy effects of the HOLC grading practice on birds, their habitat, and the people who may experience them throughout a metropolis where the security risk maps were widely applied, Greater Los Angeles, California (L.A.). We used ground-collected, remotely sensed, and census data and descriptive and predictive modeling approaches to address our goal. Patterns of bird habitat and avian communities strongly aligned with the luxury-effect phenomenon, where green amenities were more robust, and bird communities were more diverse and abundant in the wealthiest parts of L.A. Our analysis also revealed potential legacy effects from the HOLC grading practice. Associations between bird habitat features and avian communities in redlined and greenlined zones were generally stronger than in areas of L.A. that did not experience the HOLC grading, in part because redlined zones, which included some of the poorest locations of L.A., had the highest levels of dense urban conditions (e.g., impervious surface cover), whereas greenlined zones, which included some of the wealthiest areas of the city, had the highest levels of green amenities (e.g., tree canopy cover). The White population of L.A., which constitutes the highest percentage of a racial or ethnic group in greenlined areas, was aligned with a considerably greater abundance of birds affiliated with natural habitat features (e.g., trees and shrubs). Conversely, the Hispanic or Latino population, which is dominant in redlined zones, was positively related to a significantly greater abundance of synanthropic birds, which are species associated with dense urban conditions. Our results suggest that historical redlining and contemporary patterns of income inequality are associated with distinct avifaunal communities and their habitat, which potentially influence the human experience of these components of biodiversity throughout L.A. Redlined zones and low-income residential areas that were not graded by the HOLC can particularly benefit from deliberate urban greening and habitat enhancement projects, which would likely carry over to benefit birds and humans.

Performing arts of embodied refusal amid anthropogenic climate change: the Salim Ali Biodiversity Park and Bird Sanctuary, Pune, India

Birds twitter, flap their wings or wade in the gurgling water of the Mula-Mutha river in a special place, named after Salim Ali, the world famous, award-winning ornithologist and ‘Birdman of India’ (1896–1987). Yet, bird habitat, migratory routes, species diversity and songs are affected by the slow violence of global warming and environmental pollution. Urban citizens or Punekars including artists, women, children and ornithologists refuse the brutality of this slow violence by enacting forms of activism that centre birdlife and affirm thriving more-than-human worlds. This co-authored piece focuses on the embodied performances of refusal at the Salim Ali Biodiversity Park and Bird Sanctuary, Pune, a rapidly growing city in the western state of Maharashtra, India. Activism takes the form of poetry, city walks, participatory mural art and other forms of resistance by the Save Salim Ali Sanctuary Action Group (SSASAG). Our co-authorship collective consists of an activist/ornithologist of the SSASAG, an internationally acclaimed mural artist, and an Australian geographer of Indian heritage who went on daily ‘nature walks’ while visiting family in Pune. We craft this piece as a continuation of our activist refusals of anthropogenic climate change and toxic environmental pollution, and to illuminate solidarity with the brilliance of human and more-than-human worlds in and beyond Pune.

Field practice of Scirpus mariqueter restoration in the bird habitats of Chongming Dongtan Wetland, China

The coastal saltmarshes in China have been seriously degraded and artificial restoration strategies have become one of the primary measures to protect the coastal habitats. In this study, we investigated efficient restoration techniques for native saltmarsh plants in vacant habitats within the project area of the Ecological Control of Spartina alterniflora and Improvement of Birds Habitats in the Shanghai Chongming Dongtan Bird National Nature Reserve in the Yangtze Estuary. Through field and pilot experiments, we analyzed the effects of propagule types and transplanting methods on the restoration efficiency of Scirpus mariqueter, a dominant saltmarsh species in the Yangtze Estuary. We further evaluated the cost and efficiency of various restoration strategies. Our results indicated that: 1) The corm seedlings of S. mariqueter had higher flood tolerance, and were suitable for use in the habitats with higher environmental heterogeneity. 2) Across the four treatments for S. mariqueter restoration, the most economically efficient treatment was to transplant low-density corm seedlings without sediment, with an investment cost of approximately ￥10100 per hectare. The costs were ￥41100, ￥30000, and ￥120100 per hectare for high-density without sediment, low-density with sediment, and high-density with sediment restoration, respectively. 3) After nearly 5-yr efforts, the S. mariqueter community of Plot C3 in project area had achieved a coverage of over 60%, marking a relatively successful large-scale field restoration. This study could provide the foundation and support for large-scale coastal saltmarsh restoration projects.

Evolution of bird habitat quality driving mechanisms and ecological network weights

Evolution of bird habitat quality driving mechanisms and ecological network weights

A dataset of bird checklist and community characteristics during breeding and wintering seasons in typical forest ecosystems of Dinghushan (2015–2018)

Bird diversity and its community structure are important indicators for the long-term monitoring of biodiversity in ecosystems. Three typical forest vegetation types have been well preserved in Dinghushan National Nature Reserve, including the monsoon evergreen broad-leaved forest, the mixed Pinus massoniana/broad-leaved forest and the Pinus massoniana coniferous forest. In particularly, the monsoon evergreen broad-leaved forest has a conservation history of more than 400 years without any human disturbance. The dataset consists of organized data on the long-term monitoring of bird communities during breeding and wintering seasons from 2015 to 2018 in all three forest types. Field surveys recorded information such as bird species, number, time, distance, ground height, habitat type, activity substrate and behavior. Moreover, we carried out various data analyses of diversity index, evenness index, dominance index, similarity coefficient of bird community and occurrence frequency, individual number, as well as average density of bird species in different survey periods. The dataset includes a total of 89 species from 9 orders and 35 families. This dataset provides valuable information for future studies on bird communities, and for better understanding inter-species interaction between multiple groups of plants and animals. It is further expected to support the protection and management of forest ecosystems in this region.

Ecological characterization of 175 low-pathogenicity avian influenza viruses isolated from wild birds in Mongolia, 2009-2013 and 2016-2018.

Since 2005, highly pathogenic avian influenza A H5N1 viruses have spread from Asia worldwide, infecting poultry, humans and wild birds. Subsequently, global interest in avian influenza (AI) surveillance increased. Mongolia presents an opportunity to study viruses in wild birds because the country has very low densities of domestic poultry and supports large concentrations of migratory water birds. We conducted AI surveillance in Mongolia over two time periods, 2009-2013 and 2016-2018, utilizing environmental fecal sampling. Fresh fecal samples were collected from water bird congregation sites. Hemagglutinin (HA) and neuraminidase (NA) subtypes of positive samples were identified through viral isolation or molecular assays, with pathogenicity determined by HA subtype or sequencing the HA cleavage site. A total of 10,222 samples were collected. Of these, 7,025 fecal samples were collected from 2009 to 2013, and 3,197 fecal samples were collected from 2016 to 2018. Testing revealed 175 (1.7%) positive samples for low-pathogenicity influenza A, including 118 samples from 2009 to 2013 (1.7%) and 57 samples from 2016 to 2018 (1.8%). HA and NA subtyping of all positives identified 11 subtypes of HA and nine subtypes of NA in 29 different combinations. Within periods, viruses were detected more frequently during the fall season than in the early summer. Mongolia's critical wild bird habitat is positioned as a crossroad of multiple migratory flyways. Our work demonstrates the feasibility of using an affordable environmental fecal sampling approach for AI surveillance and contributes to understanding the prevalence and ecology of low-pathogenicity avian influenza viruses in this important location, where birds from multiple flyways mix.

Bird population and bird hunting in the rural ecosystem of Cijambu, Sumedang, West Java, Indonesia

Abstract. Suroso, Iskandar J, Withaningsih S, Nurjaman D, Iskandar BS. 2023. Bird population and bird hunting in the rural ecosystem of Cijambu, Sumedang, West Java, Indonesia. Biodiversitas 24: 4470-4484. Some rural West Java ecosystems have a high bird species diversity because they have forests, bamboo talun, mixed gardens, rice fields, and homegardens. Rapid population expansion, illicit bird shooting, forest degradation and conversion, and pesticide pollution have reduced rural bird species diversity. This study examined bird diversity in natural forests, coffee agroforestry, vegetable gardens, and bird hunting. Quantitative and qualitative research were used. The point count approach investigates bird species and populations, whereas detailed interviews with knowledgeable informants are used to study bird hunting. In natural forests, vegetable gardens, and coffee agroforestry, 67 species from 39 bird groups were found. The bird species diversity index in three habitats: vegetable garden (H'=2.59), coffee agroforestry (H'=2.97), and natural forest (H'=2.96). Based on the Sorensen Similarity Index, bird species in in vegetable garden and coffee agroforestry, vegetable garden and natural forest, and coffee agroforestry and natural forest had a similarity index of 31.03%, 22.22%, and 52.05%, respectively. These findings suggest that bird species may prefer coffee agroforestry over vegetable gardens. The coffee agroforestry system can generate complex vegetation canopy stratification with a multi-layered vegetation canopy, resembling natural forest stratification. Illegal hunting of bird species for trade is one of the causes of the decline in bird populations in rural ecosystems of West Java, including in Cijambu Village. The coffee agroforestry provides a habitat for rural birds.

Conservation status of birds in habitats along a successional gradient from bare ground to forest

Conservation status of birds in habitats along a successional gradient from bare ground to forest

Avian species functional diversity and habitat use: The role of forest structural attributes and tree diversity in the Midlands Mistbelt Forests of KwaZulu-Natal, South Africa.

Forest transformation has major impacts on biodiversity and ecosystem functioning. Identifying the influence of forest habitat structure and composition on avian functional communities is important for conserving and managing forest systems. This study investigated the effect of forest structure and composition characteristics on bird species community structure, habitat use and functional diversity in 14 Mistbelt Forest patches of the Midlands of KwaZulu-Natal in South Africa. We surveyed bird communities using point counts. We quantified bird functional diversity for each forest patch using three diversity indices: functional richness, functional evenness and functional divergence. We further assessed species-specific responses by focussing on three avian forest specialists, orange ground-thrush Geokichla gurneyi, forest canary Crithagra scotops and Cape parrot Poicephalus robustus. We found that bird community and forest-specialist species responses to forest structure and tree species diversity differed. Also, forest structural complexity, canopy cover and tree species richness were the main forest characteristics better at explaining microhabitat influence on bird functional diversity. Forest patches with relatively high structural complexity and tree species richness had higher functional richness. Different structural characteristics influenced habitat use by the three forest specialists. Tree species diversity influenced C. scotops and G. gurneyi positively, while P. robustus responded negatively to forest patches with high tree species richness. Our study showed that site-scale forest structure and composition characteristics are important for bird species richness and functional richness. Forest patches with high tree species diversity and structural complexity should be maintained to conserve forest specialists, bird species richness and functional richness.

Avifaunal diversity of Tsirang District with a new country record for Bhutan

Birds play a vital role in ecosystems. Studying avifaunal diversity therefore has a noteworthy role in indicating nature’s ecological balance in the environment. A total of 749 bird species have so far been recorded in Bhutan. We present a comprehensive checklist of birds of Tsirang, District which largely lies outside Bhutan’s protected area system. The data was collected through opportunistic encounters and with regular field visits to a range of locations in different seasons. One-fourth of the country’s total avifauna and a new species recorded for Bhutan, The Plum-headed Parakeet Psittacula cyanocephala was recorded as part of this study. In all, 285 avian species belonging to 18 orders and 65 families including one globally ‘Critically Endangered’, three ‘Vulnerable’, and a ‘Near Threatened’ species were recorded during the survey. The high species richness of birds in the study area reveals that it includes good habitats for birds in Bhutan. Similar studies are suggested in other areas contiguous to the protected areas in Bhutan including the current study area. This should aid in understanding of the factors driving the differences in bird diversity within and outside the protected areas so as to facilitate informed conservation actions in future.

Distribusi Ruang Vertikal Burung di Hutan UB Forest Malang Jawa Timur

The sustainability of birds is also influenced by the dynamics that occur in nature. Conditions like this can be studied by looking at various patterns and habits such as distribution patterns, activities, and other habits. In a habitat type, the same species can fill different vertical spaces. This is also related to the components that support bird life, starting from shelter, cover, feed, and other habitat components. UB Forest as a bird habitat is managed by Universitas Brawijaya. There is a conservation program in its management to maintain the sustainability of the resources in it. The physical form of UB Forest has various Forest strata, so that the vertical distribution of birds can determine the sustainability and health of the Forest. This study aims to analyse the vertical use of space for birds in UB Forest to see the proportion of bird preservation in the Forest area. The research was conducted in three types of habitats, namely Coffee Pine, Coffee Mahogany, and Natural Forest. The results of the observations found 59 species of birds from 27 families spread over the three types of habitats. Then the vertical distribution of the most common bird species is in strata B and C. The value of bird conservation when viewed from the conservation status, UB Forest's Forest has a fairly high value. There are two species that have NT status, one VU, and one EN based on the IUCN red list. Six are included in CITES Appendix II, and seven species are protected by the government. The uniqueness possessed by birds can be offered as one of the ecotourism packages.
 Keywords: Forest birds, insectivore, ecotourism, sustainable management

Cavity‐nesting birds are limited by nesting habitat in Neotropical agricultural landscapes

AbstractMost studies comparing biodiversity between natural and human‐modified landscapes focus on patterns in species occurrence or abundance, but do not consider how different habitat types meet species' breeding requirements. Organisms that use or nest in tree cavities may be especially threatened by habitat conversion due to the loss of their nesting sites. Although cavity‐nesting bird diversity is highest in the tropics, little is known about how tropical birds use cavities, how agriculture affects their reproductive biology, and how effective nest boxes could be as a conservation strategy in tropical agriculture. Here, we explored how habitat conversion from tropical forests to pasture affects the abundance, nesting habitat availability, and nest success of cavity‐nesting birds in Northwest Ecuador. We conducted bird surveys and measured natural cavity availability and use in forest and agriculture. We also added artificial nest boxes to forest and agriculture to see whether cavity limitation in agriculture would elicit higher use of artificial nest boxes. We found evidence of cavity limitation in agriculture—there were many more natural cavities in forest than in agriculture, as well as more avian use of nest boxes placed in agriculture as compared to forest. Our results suggest that it is important to retain remnant trees in tropical agriculture to provide critical nesting habitat for birds. In addition, adding nest boxes to tropical agricultural systems could be a good conservation strategy for certain species, including insectivores that could provide pest‐control services to farmers.Abstract in Spanish is available with online material.

Identification of Bird Habitat Restoration Priorities in a Central Area of a Megacity

Rapid global urbanization has caused habitat degradation and fragmentation, resulting in biodiversity loss and the homogenization of urban species. Birds play a crucial role as biodiversity indicators in urban environments, providing multiple ecosystem services and demonstrating sensitivity to changes in habitat. However, construction activities often disrupt urban bird habitats, leading to a decline in habitat quality. This paper proposes a framework for prioritizing habitat restoration by pinpointing bird hotspots that demand attention and considering the matching relationship between bird richness and habitat quality. Shanghai represents a typical example of the high-density megacities in China, posing a significant challenge for biodiversity conservation efforts. Utilizing the random forest (RF) model, bird richness patterns in central Shanghai were mapped, and bird hotspots were identified by calculating local spatial autocorrelation indices. From this, the habitat quality of hotspot areas was evaluated, and the restoration priority of bird habitats was determined by matching bird richness with habitat quality through z-score standardization. The results were as follows: (1) Outer-ring green spaces, large urban parks, and green areas along coasts or rivers were found to be the most important habitats for bird richness. Notably, forests emerged as a crucial habitat, with approximately 50.68% of the forested areas identified as hotspots. (2) Four habitat restoration types were identified. The high-bird-richness–low-habitat-quality area (HBR-LHQ), mainly consisting of grassland and urban construction land, was identified as a key priority for restoration due to its vulnerability to human activities. (3) The Landscape Shannon’s Diversity Index (SHDI) and Normalized Difference Vegetation Index (NDVI) are considered the most significant factors influencing the bird distribution. Our findings provide a scientifically effective framework for identifying habitat restoration priorities in high-density urban areas.

A bird’s eye view of ecosystem conversion: Examining the resilience of piñon-juniper woodlands and their avian communities in the face of fire regime change

Climate change and land-use legacies have caused a shift in wildfires and post-fire growing conditions. These changes have strong potential to diminish the resilience of many ecosystems, with cascading effects and feedbacks across taxa. Piñon-juniper (PJ) woodlands are a diverse and widespread forest type in the western US and are home to many obligate and semi-obligate bird species. As such, this system is ideal for understanding wildfire resilience, or lack thereof, in terms of both vegetation and wildlife associations. This study evaluated post-fire vegetation structure and associated avian communities following three wildfires; one that burned one year prior to sampling (recent fire), and two that burned approximately 25 years previously (old fires). Vegetation characteristics and the habitat use of PJ-associated bird species were compared across severely burned patches, unburned refugia, and unburned sites outside of the burn perimeter. We expected wildfire to alter vegetation and bird usage for the first few years post-fire, which we observed in our recent burns. However, even 25-years post-fire, little recovery to PJ woodland had occurred and the associated bird communities had not returned, compared to unburned areas. No piñon regeneration was observed in any burned areas and no juniper regeneration in the recent fire. Piñon seedling densities in unburned sites and refugia averaged 80 ha−1 and 151 ha−1, respectively, while juniper seedling densities were 220 ha−1 in both habitat types. Habitat use for thirteen PJ-associated species were modeled, three of which (Woodhouse’s Scrub Jay, Ash-throated Flycatcher, and Virginia’s Warbler) used all habitats. Four species (American Robin, Gray Vireo, Black-throated Gray Warbler, and Gray Flycatcher) were essentially absent from the old burn habitat, reflecting species-specific need for mature piñon or juniper trees and/or greater canopy cover. Conversely, birds that were present in the old burn habitat (including Virginia’s Warbler, Blue-gray Gnatcatcher, Woodhouse’s Scrub-jay, Ash-throated Flycatcher, and Spotted Towhee) are typically associated with habitat edges, high shrub cover, or cavity nests. Altered vegetation structure and bird habitat use in burned areas 25 years post-fire are evidence for enduring conversion to non-forest vegetation types. However, unburned refugia embedded in burned areas maintain forest attributes and support obligate bird communities, supporting ecological function and biological diversity.