Conservation

Distribution and habitat use of the endemic Yungas Guan Penelope bridgesi in the Southern Yungas of Argentina

Posted on September 18, 2023

Identifying the factors that determine the spatial distribution and habitat use of species of conservation importance is essential to developing effective conservation and management strategies. As seed dispersers, guans play a key role in the regeneration of forests in South America and are threatened mainly by habitat loss and hunting pressure. The Yungas Guan Penelope bridgesi, an endemic species restricted to the Southern Yungas of Argentina and Bolivia, has been recently recognized as a separate species. To determine the conservation status of Yungas Guan, information on its distribution and habitat use is urgently needed. The objectives of our work were to 1) determine the potential distribution of the Yungas Guan in the Southern Yungas of Argentina and 2) assess the influence of environmental and anthropogenic covariables on habitat use of the species. We used records of Yungas Guan to model the potential distribution of the species with MaxEnt software and developed occupancy models to determine habitat use and influential elements of the landscape (puestos, urban areas, roads, rivers, and elevation). We obtained data on the presence of Yungas Guan with camera traps, with an effort of 6,990 camera trap-days. The total potential distribution of the species was 21,256 km2.We found that the habitat use by Yungas Guan increased with proximity to rivers and streams. The probability of habitat use was 0.27, with a range of 0.02–0.42.Of the total potential distribution area, 15,781 km2 (81%) had a probability of habitat use greater than 0.2. This study is the first in determining the potential distribution of Yungas Guan in the Southern Yungas of Salta and Jujuy provinces in Argentina and highlights the importance of conducting analyses with occupancy models to assess the influence of environmental and anthropogenic variables and threats to cracid species.

File: Tejerina-et-al-2022-BCI.pdf

Arctic waterfowl migration through Eurasian steppe: how to catch short-term environmental conditions and identify key migratory habitats using satellite images

Posted on August 28, 2023

Long-distance migrations are an important part of the life cycle for most Arctic waterfowl. The birds spend several months each year between their breeding and wintering places, with most of this time staying at their stopover sites to rest and feed. Habitat quality at the stopovers determine subsequent survival during migrations and reproductive success. Two questions present themselves: where are the key waterfowl habitats along their migratory routes, and what landscape features make these places vitally important? Understanding this is crucial for bird protection and population management.

Satellite images are used widely for landscape research; however, their application to bird migration studies is challenging. First, environmental conditions within a large area are not the same during migration period, so there is no single time window suitable to select satellite images for the entire area. Second, favorable conditions at each stopover site are short-term, as birds spend only a few weeks at each site. The needed satellite images may be unavailable for those exact periods due to weather conditions (clouds etc.), making it difficult to obtain sufficient data for a single migratory season. Third, environmental conditions and migration time could vary by several weeks depending on weather of a given year, which, in turn, impedes combining images from different years.

Natalia studied how to use satellite images for delineating key migratory habitats using the example of spring migration of Bewick’s Swan in Eurasian steppe (fig. 1). To overcome the limitation related to satellite image availability, Natalia used snow melt as a synchronizing point. In practice, specific dates on which the swans appear at one or another area do not really matter because the birds will move farther north as soon as ice-free water and food become available there. In other words, they arrive soon after snow melt and stay a couple of weeks until more northern areas become snow-free.

Natalia used daily MODIS data to identify where snow melted each year in different parts of the swan’s migratory flyways and then filtered Landsat images using that information. This allowed her to combine Landsat images for all migration areas from different years at the same phenological phase. This approach made it possible to produce accurate and detailed landscape maps demonstrating what environmental conditions prevailed at stopovers at exactly the time when the swans were present. With these maps species distribution modeling can delineate key swan’s habitats.

The maps have revealed the critical landscape feature important to the birds: numerous local depressions scattered across croplands (fig. 2). In summer these appear as a part of the agricultural landscape (only the smallest, lowermost places may not be ploughed and get overgrown with wildflowers) and are hardly detectable (fig. 3, e) on satellite images. In spring, however, they accumulate melted water to become shallow temporary water bodies (fig. 3, a-c). These flooded depressions provide migratory birds with food and refuge so that the waterfowl do not need to move between roosting and feeding sites. They are also available 10-15 days before ice-out on lakes, allowing birds to migrate and potentially reach breeding grounds earlier.

Fig.3 Changes in open water in the steppe during spring. RGB: SWIR 1, NIR, Red bands. Red circle –flooded fields, yellow square -permanent lake. Bright blue color indicates snow/ice, black color indicates open water. — Fig.3 Changes in open water in the steppe during spring. RGB: SWIR 1, NIR, Red bands.
Red circle –flooded fields, yellow square -permanent lake.
Bright blue color indicates snow/ice, black color indicates open water.

More generally, Natalia’s research provides a useful approach to understanding the key short-term conditions that birds rely on during migrations. Natalia’s results have important implications for conservation efforts, such as the creation of protected areas and free hunting zones and adjusting land management in agricultural lands.

Comparing Approaches to Identify Protected Areas for Wildlife across the U.S.

Posted on August 23, 2023

By schlorian 13 May 2019
https://www.schlorian.ch/cartoon-der-woche-2019/

Species and populations are declining rapidly, with over 3 billion birds lost in the past 50 years. Astoundingly, the US is on track to lose 50% of its remaining individual birds in 50 more years without intervention (stateofthebirds.org/2022/). Birds, unfortunately, are not alone, as 40% of all species are projected to face extinction by the end of this century. Despite these alarming numbers, conservation spending in the US has remained relatively stable over the past years – roughly $6-7 billion with few exceptions. Therefore, one of the most challenging questions for scientists is where will conservation action – and protected areas in particular – do the most to protect species of conservation concern.

https://www.ers.usda.gov/data-products/chart-gallery/gallery/chart-detail/?chartId=99510

Kathleen Carroll’s current work in the SILVIS Lab compares various biodiversity metrics, each with unique assumptions, to my previous maps of threatened/endangered and decreasing species (see my previous webstory for more on that project). I can use these comparisons to evaluate how well these additional metrics, which are usually treated as direct surrogates for biodiversity, capture the conservation patterns necessary to protect threatened or endangered species. I also will evaluate which, if any, combinations of these metrics work best to inform conservation planning on regional and national scales. To do this, I will model all metrics for the US and then compare them directly to my threatened/endangered species data. I will do so using Marxan, a conservation planning problem support tool, to create nationwide maps that identify conservation priority areas. These maps, one for each metric, will include a certainty estimate based on pixel importance across data layers and identify gaps in protected areas. By comparing different metrics, we will be provided maps of high-certainty high-priority areas where land managers and agencies can focus on endangered species conservatio through designation of new protected areas.

How has half a century of land cover changes altered habitats of ungulates in the biologically diverse Caucasus?

Posted on August 22, 2023

Landscapes are undergoing continuous transformation, with both natural and human factors causing the destruction of some habitats and the formation of others. While wildlife can adapt to natural changes, the current scale of human-made landscape alterations is much greater than nature’s ability to adapt. Some species can thrive in human-made landscapes, but others are at risk of extinction due to habitat loss.

Azerbaijan, a country in the Caucasus region with rich biodiversity and a long history of human-driven land cover changes. For conservation and sustainable management there, it is critical to understand the impacts of landscape changes on wildlife habitats. The changes in the Caucasus eco-region have accelerated in the 20th century due to population growth and Soviet nature-transformation efforts. A new study by Afag Rizayeva aims to understand the impact of these changes on the habitats of eight ungulate species, including common animals like wild boar and roe deer, as well as a rare species of gazelle. With landscapes constantly changing due to natural and human causes, it is increasingly important to understand how these changes are affecting wildlife populations.

East Caucasian tur – Capra cylindricornis by Azerchin Muradov

Afag has developed the Caucasus land cover maps for the 1960s using former spy satellite images (Corona) and has analyzed the long-term changes in these landscapes using recent land cover maps derived from Landsat images. Her research begins by using the presence data of eight ungulate species, conducting species distribution modeling to evaluate their current ranges and the landscape features that are most important to each species.

Red deer – Cervus elaphus by Azerchin Muradov

Next, Afag will analyze the changes in land cover within each species’ range, determining stable areas, habitat gains and losses, and assessing the positive or negative effects of these changes on the species’ habitats. This will enable her to determine if the species can continue to use the same areas despite human activities, or if they require urgent land management solutions to protect them. The results of Afag’s study will help guide wildlife conservation planning and will be used by local NGOs and government agencies. As human impact on nature is a global issue, the methodological approach she develops in her research will have applications in other regions facing similar issues.

Chamois – Rupicapra rupicapra by Azerchin Muradov

In conclusion, understanding the impact of long-term land cover changes on wildlife habitats is crucial for conservation and sustainable management. The research being conducted by Afag Rizayeva will provide valuable insights into this issue and help guide efforts to protect the wild species in Azerbaijan and beyond. Stay tuned!

Forest phenoclusters for Argentina based on vegetation phenology and climate

Posted on August 22, 2023

Classifying forests at tree species level from remotely sensed data over large areas is challenging, especially when ground-data do not exist. Since the opening of the Landsat archive in 2008, opportunities to improve forest type mapping and classification have increased, making it possible to explore phenological properties across different forest types. The seasonal dynamics of vegetation indices (e.g., enhanced vegetation index, EVI) are well correlated with the seasonal dynamics in photosynthetically active leaf area and are a good proxy for phenological stages. In addition to being helpful for individual forest type and tree species classification, phenology is linked to landscape resources because vegetation phenology determines food availability for a wide range of forest species.

To improve broad-scale forest mapping and landscape characterization, we developed an approach that can categorize forests based on both land surface phenology and climate characteristics, the forest phenoclusters. We calculated land surface phenology metrics based on EVI Sentinel-2 and EVI Landsat 8 combined annual time series. We also derived land surface temperature (LST) from Band 10 of the thermal infrared sensor (TIRS) of Landsat 8 and used precipitation from the WorldClim dataset. We then performed stratified X-means classification followed by hierarchical clustering. We applied the methodology in Argentina (2.8 million km2), which has a wide variety of forests, from rainforests to cold-temperate forests. We characterized the forest phenoclusters based on land surface phenology and climate characteristics, as well as based on strong regional expert knowledge.

We identified 54 forest phenoclusters across Argentina (Figure 1), each with unique combinations of vegetation phenology and climate characteristics. The resulting map is a valuable source of novel and ecologically relevant information applicable to management and conservation of biodiversity, for example, for stratifying biodiversity assessments, supporting wildlife habitat mapping and to improve landscape planning, including development of new reserves strategies. Additionally, using our method, it is possible to estimate phenoclusters at a variety of scales, which makes them useful for a variety of modeling applications. Specifically, forest phenoclusters could be an input data set to benefit species distribution modeling greatly over large areas with low data availability, such as for tapirs (Tapirus terrestris) and jaguars (Panthera onca) that occupy several ecoregions in Argentina.

Figure 1. The 54 classes of forest phenoclusters across Argentina and some examples in five regions. ESP, Espinal; HDC, Humid and Dry Chaco; HM, High Monte; MAF, Misiones Atlantic; PAT, Continental Patagonian forests; PFS, Parana flooded savanna; SAY, Southern Andean Yungas; TDF, Patagonian forests of Tierra del Fuego.

Spatio-temporal remotely sensed indices identify hotspots of biodiversity conservation concern in Argentina

Posted on August 22, 2023

Climate variability affects the phenology of vegetation and the seasonality of temperature, which can lead to mismatches between species and resources. When species are not able to track phenology and seasonal temperate changes, populations decline, posing a threat to biodiversity. Many plants and animals synchronize the timing of their life events with vegetation phenology. Mismatches in the timing of such events, can entail, for example, food limitations when the peak of bird nestling growth is not timed to occur during the annual peak in caterpillar abundance, which may affect reproductive success. In contrast, high spatial variability enhances ecological resilience to biodiversity loss from high inter-annual variability. Biodiversity should benefit from high spatial variability in vegetation greenness and land surface temperature within intact habitats, because such spatial variability is indicative of a variety of resources in close proximity and increases the likelihood that suitable conditions are available during times of extremes. Eduarda Silveira, a postdoctoral research in the SILVIS lab, recently published a study with her colleagues describing their efforts to identify hotspots of biodiversity conservation concern due to threats from high inter-annual variability (Figure 1).

Figure 1. Potential integrations of inter-annual and spatial variability in vegetation greenness and land surface temperature, and the level of conservation concern for each integration.

They generated inter-annual and spatial remotely sensed indices based on time series analysis and image texture, respectively, and integrated these indices to identify areas of high, medium and low conservation concern (Figure 2).

Figure 2. Areas of high and low conservation concern based on (1) vegetation greenness and (2) land surface temperature: (a) inter-annual variability in phenology, (b) spatial variability, (c) integration between inter-annual and spatial variability, and (d) hotspots maps.

They applied their method in Argentina. They identified hotspots of conservation concern in parts of northeastern and southern Argentina. These are sites where management efforts could be valuable (Figure 3). Eliminating existing pressures (i.e., dam construction, land use change) and improving spatial variability by increasing the abundance and diversity of natural landcover in these highly modified regions are promising approaches to increase resilience to climate extremes for native wildlife species. In contrast, areas in the northwest and central-west have high spatial variability, which may confer resilience to climate extremes, due to the variety of conditions and resources within close proximity (Figure 3). Adding protected areas in these naturally resilient regions may be effective in both protecting current patterns of biodiversity and maintaining their adaptive capacity to climate change. Eduarda Silveira hopes that her results will help Argentina’s conservation leaders to be strategic in their protection decision and to prioritize conservation management actions.

Figure 3. Hotspots of highest and lowest conservation concern in Argentina.

The Benefits of Satellite Data for Wildlife Species Distribution Models Across the US

Posted on August 21, 2023

For centuries, humans have recognized that our collective actions modify and shape the world around us. These actions also have direct and lasting impacts on the plants and animals that many communities rely on for their livelihoods ─ often referred to as ecosystem services. For example, in the Rocky Mountain West, local communities rely on provisioning from local wildlife (e.g., hunting), safe water and air from local plants and snowmelt, ecosystem cultural services for tribal communities, natural soil creation for agriculture, pastures for grazing livestock, and income from tourists seeking to fish, hike, hunt, ski, and view local wildlife. Similarly, the Great Lakes wetlands provide fisheries habitat that supports wildlife and people, space for recreational activities and tourism, hydro and wind power, shoreline protection, sediment trapping, and storage for nutrients and carbon. The ecosystem services provided by any one region, such as the Rocky Mountain West or the Great Lakes, are intrinsically tied to the health of the species and people in that community. Without plants and animals, many of these services could suffer. Therefore, one of the most challenging questions for scientists is how to ensure that our science advances conservation and subsequently bolsters ecosystem services that support local communities.

A small sample of the diversity of birds in the lower 48. There are an estimated > 1,100 species of birds in the United States. Photo source: Creative Commons.

In the SILVIS Lab, Kathleen Carroll identifies and averts biodiversity loss by developing complex models to predict and examine biodiversity patterns across the US. Biodiversity, which measures the variety of life in an area, is essential to conservation. If biodiversity declines, there is a risk to both species and ecosystem services. By modeling and predicting biodiversity over broad areas, we can determine where the biggest threat to species is. While this approach is simple in theory, extensive information about where species are and what they select habitat based on is key. Researchers have been limited by access to data. The SILVIS lab has developed new satellite indices, which provide detailed datasets that I am using in complex models. My preliminary results show higher predictive power from relatively new machine learning models, called randomForest models, compared to other approaches. Access to the new satellite datasets and complex models helps me to 1) further evaluate the value of fine-scale satellite data for biodiversity mapping, 2) develop predictive biodiversity models, and 3) provide maps to land trusts and communities to help them protect species and ecosystem services.

Preliminary map of bird species richness – a biodiversity metric. Photo credit: Dave Helmers.

Mapping the human footprint in the forests of Argentina

Posted on August 11, 2023

The human footprint in the forests of Argentina, along with examples of different forests present in the country (Yungas and Andean-Patagonian Forests; photos by N. Politi and Y. Rosas).

Wild forests – forests where human influence levels are low or null – provide important habitat for plants and animal, and therefore are a top priority for conservation. Yet forests around the world are being lost and degraded at high rates, and with this the remaining wildest forests. This is the case for Argentina, in southern South America, which supports diverse forest ecosystems but also high rates of forest loss (Figure 1).

Figure 1. Argentina supports different forest regions that are a result of large latitudinal and elevational gradients. Photos by N. Polity and G. Martínez Pastur

With an international team of US (Silvis Lab) and Argentinian researchers (National Scientific and Technical Research Council, and National Parks Administration), and with funding from NASA, I mapped the human footprint in Argentina’s forested areas to help conservation planning at regional and country levels.

The human footprint is a mapping approach that combines data on roads, human settlements, power lines, and other anthropogenic threats, into a single index. The assumption is that forests that are far away from these human features are likely to have low or null human influence, and thus represent potential wild forests (Figure 2). However, until now, such information was unavailable for conservation planners in Argentina, or was too coarse to be useful.

Figure 2. Roads, human settlements, and agriculture are major threats to forests in Argentina. Their ecological impact expands hundreds of meters inside the forest. Image source: Google Earth.

Our human footprint map shows that a substantial portion (43%) of Argentina’s forests remain wild, which suggests there are unique opportunities for conservation. However, we found that the level of human influence varied across the county, and Atlantic and Chaco forests, both in northern Argentina, have the highest levels of human influence (Figure 3).

Figure 3. Human footprint index in the native forest areas of Argentina developed by this stufy. 1. Yungas/Chaco, 2. Atlantic, 3. Espinal, and 4. Andean-Patagonian Forests

Our study revealed that Argentina’s wildest forests are under threat. In Argentina, land use in forested areas is regulated by law, which dictates which areas can be deforested, which areas should be protected, and which can be used for activities thought to be sustainable (like silvopasture). Unfortunately, we found that most (78%) of the wild forests are in places where allowed activities can threaten the ecological integrity of these forests, diminishing their biodiversity conservation value.

Our study provides new datasets for forest conservation planning in Argentina, and highlights the urgent need to strengthen protection of the remaining wildest forests. The human footprint map developed in this study can be used for a variety of purposes related to forest conservation, such as refining the types of activities allowed in forest areas, planning for new protected areas (national parks or provincial reserves), identification of ecological corridors, and promotion of payments for private owners to maintain the intactness of wild areas, among others.

The extent of buildings in wildland vegetation of the conterminous U.S. and the potential for conservation in and near National Forest private inholdings

Posted on July 17, 2023

Development in natural areas is a leading threat to biodiversity. Global conservationists have called for the expansion of protected areas to preserve wildlands that are free from buildings, and in the U.S., the ‘America the Beautiful’ initiative aims to protect 30% of land and water areas by 2030 (known as the ‘30x30’ target). Here, we determined opportunities and limitations for conservation in the conterminous U.S. by assessing the extent of buildings in wildland vegetation. We focused specifically on National Forest lands, as these contain numerous private inholdings where development may occur. Using a newly available building footprint dataset, we determined 1) whether buildings were present and 2) numbers of buildings within three distances of wildland vegetation (100, 250, and 500 m), representing varying magnitudes of ecological impact. Our findings revealed that 29% of wildland vegetation nationwide was within 500 m of a building, 15% was within 250 m, and 5% was within 100 m. National Forest lands were less affected by building disturbance, but a substantial proportion (12%) of wildland vegetation area was within 500 m of a building. Of National Forest lands that were within 500 m of an inholding, 76% was not yet in proximity to a building; consequently, ~10% of National Forest lands (143,474 km2) are susceptible to impacts from future development on inholdings. We conclude that National Forest inholdings are therefore important opportunity areas for 30x30 conservation goals. Our assessments can inform where conservation efforts can limit impacts from present and future development on biodiversity.

File: Carlson-et-al_2023_The-extent-of-buildings-in-wildland-vegetation-of-conterminous-US_Landscape-and-Urban-Planning.pdf

Low Kirtland’s Warbler fledgling survival in Wisconsin plantations relative to Michigan plantations

Posted on April 10, 2023

The Kirtland’s Warbler (Setophaga kirtlandii) is a formerly endangered habitat specialist that breeds mainly in young jack pine (Pinus banksiana) forests in northern Lower Michigan, USA. The species is conservation-reliant and depends on habitat management. Management actions have primarily focused on creating jack pine plantations, but the species also breeds in red pine (Pinus resinosa) plantations in central Wisconsin, USA. However, the plantations were not intended as breeding habitat and have suboptimal pine densities. While nesting success is similar between low-density red pine plantations and optimal jack pine habitat, it is not clear if low-density red pine plantations support high fledging survival. If high-quality nesting and post-fledging habitat are not synonymous, fledgling survival and breeding population recruitment may be low. We characterized survival, habitat use, and movement patterns of dependent Kirtland’s Warbler fledglings in Wisconsin red pine plantations and compared fledgling survival between Wisconsin and Michigan. Mayfield cumulative survival estimates at 30 days post-fledging were 0.20 for Wisconsin fledglings and 0.43–0.78 for Michigan fledglings. Logistic exposure cumulative survival estimates for Wisconsin fledglings were 0.23–0.34 at 30 days post-fledging. Fledglings in Wisconsin used areas where vegetation cover and density of red and jack pine were high relative to available areas but not at greater proportions than what was available. Our findings demonstrate that red pine plantations with low pine densities were not equally suitable as nesting and post-fledging habitat, as fledgling survival rates were low. We hypothesize that reduced habitat structure, and not particular pine species, likely contributed to reduced fledgling survival in Wisconsin. Thus, we recommend including red pine as a component in managed Kirtland’s Warbler habitat only if tree densities approach optimal levels.

File: Olahetal_2023_KirtlandsWarblerFledglingSurvivalWisconsinOrnithologicalApplications.pdf