1,721,101 research outputs found
Effects of climate change and invasive plants on autumn phenology in Massachusetts, USA
Full text linkThe timing of biological events in autumn, or autumn phenology, is an important factor in many ecosystem processes. Leaf senescence terminates the growing season, fruiting is important for seed dispersal and frugivorous wildlife, bird migration concludes the breeding season and is a high-mortality event, and insect diapause ends the active season for insects. Climate change and the spread of invasive species have the potential to shift autumn events and ecological processes. However, autumn has been neglected in the phenology literature, and there are many gaps in our knowledge of basic phenological patterns in this season, as well as how they are affected by anthropogenic changes. To address these gaps, I first synthesized the literature on how climate change affects autumn phenology. I found that shifts in autumn phenology can alter reproductive capacities, exacerbate invasions, increase disease transmission rates, reshuffle enemy-prey dynamics, and alter interactions between species. With a focus on autumn interactions between birds and fleshy-fruited plants, my colleagues and I then observed patterns of fruit phenology, using herbarium specimens of 55 species collected across New England, and over 400 species in the living collections of 5 international botanical gardens. Last, I monitored fleshy fruit phenology and abundance at Manomet, a migratory stopover site in coastal Massachusetts, and compared those patterns to seeds identified from landbird fecal samples collected across the autumn season. I found that the sequence of fruiting is moderately consistent from year to year and place to place, and has a significant phylogenetic signal. In wild plants, invasive species fruit, on average, nearly one month later than native species. Considering many landbirds are migrating through New England later over time and in warm years, this suggests birds are increasingly likely to encounter invasive fruits during late-autumn migration. However, bird diets do not reflect the increased availability of invasive fruits in late-autumn; rather, birds show a preference for native fleshy fruits throughout the autumn season. These findings add to our knowledge of how climate change and species invasions affect autumn synchrony, and highlight the importance of native, rather than invasive, fruits as a food source for migratory landbirds.2019-11-07T00:00:00
Effects of climate, habitat, and conservation management on an aerial insectivore, the tree swallow, and its insect prey in Massachusetts, USA
Full text linkHuman-driven climate, habitat, and land use changes often co-occur in ecological communities. We must consider the multiple components of global change acting on individual species and assemblages to document biological responses to environmental change and determine the mechanisms underlying these responses. Here, I examine climate, habitat, and land management impacts on a model aerial insectivore, the Tree Swallow (Tachycineta bicolor), and its insect prey. Both groups are undergoing population decline and phenological shifts in many parts of the world; however, the magnitude and mechanisms of these shifts are not well understood. I first document the impacts of temperature and precipitation on fall flight times of 20 butterfly species with varied life histories in Massachusetts. I find many butterfly species are flying later into the fall now than they were over 20 years ago; however, the response of butterflies to fall climate is complex and often mediated by life history characteristics, like number of broods per season. I then examine the effects of climate, habitat, and insect prey abundance on Tree Swallow reproduction to determine if anthropogenic changes in the breeding habitat result in declines in reproductive performance that contribute to population decline. I find that climate and foraging habitat impact egg laying phenology, clutch size, hatching success and fledging success of Tree Swallows. For example, reproductive phenology is delayed in rainy springs and fledging success is increased in nests with open water in their foraging radius. However, I find no evidence to indicate a change in insect abundance or anthropogenic changes, including climate and land management, are driving decreases in reproductive success of Tree Swallows over time. Lastly, I examine the effects of artificial nest management on Tree Swallow reproduction across Mass Audubon conservation areas. I find habitat, density, and predation of artificial nests to be strong and often overlooked determinants of Tree Swallows reproductive performance; for example, fledging is increased in nests placed in open habitat, far from forests and developed areas. This work provides novel evidence for the impacts of local-scale nest habitat and management on Massachusetts Tree Swallows, a threatened population of aerial insectivores
7. Pollution, Overharvesting, Invasive Species, and Disease
No full textA pair of southern white rhinoceros (Ceratotherium simum simum, NT) in Tshukudu Private Game Reserve, adjacent to South Africa’s Kruger National Park. Once nearly extinct due to uncontrolled hunting, this species rebounded to over 20,000 individuals. Now, poaching is taking a toll again, even in premier protected areas such Kruger, where at least 662 rhinos were lost in 2016. Rangers have cut off the horn of one of the rhinos in the photo in a desperate attempt to prevent poaching.Photograph ..
3. What is Biodiversity?
No full textA “silverback” mountain gorilla (Gorilla beringei beringei, EN) in Mgahinga Gorilla National Park, Uganda. Once thought to be one species, genetic analyses have shown that there are two gorilla species, each with two subspecies. Thanks to the efforts of dedicated conservationists and local communities in the Albertine Rift, the IUCN downlisted the mountain gorilla from Critically Endangered to Endangered in 2018. The three other subspecies are still considered Critically Endangered.Photograph..
6. Our Warming World
No full textUN secretary general Ban Ki-moon introduces the Momentum for Change initiative at the UN Climate Change Conference, also known as COP17, held in Durban, South Africa in 2011.Photograph by UNFCCC, https://www.flickr.com/photos/unfccc/6470741719, CC BY 2.0. Life-threatening heatwaves, drowning coastal towns, tens of thousands of displaced refugees… These words may very well describe a scene from the latest horror movie. But they also describe the nightmare scenario facing us humans in just a fe..
13. The Importance of Protected Areas
No full textSea anemones and cold-water corals are among the species that enjoy protection in the 1000 km2 Table Mountain National Park Marine Protected Area (MPA), South Africa. The MPA is divided into several no-take zones which act as breeding and nursery areas for marine life, as well as zones where harvesting is allowed under certain conditions.Photograph by Andrew Beard, https://www.flickr.com/photos/andrewbeard/13268749044, CC BY 2.0. With its rich biological diversity, Africa plays a critical rol..
Appendix C
No full textObtaining Conservation Funding Funding limitations often hamper conservation activities. Because conservation funding is limited, there is much competition for the few options available. Below are 15 tips to make the writing of funding proposals less tedious, time-consuming, and depressing. The list is not meant to be exhaustive, and by no means a guarantee for funding—no tip can ever do that. But these generalities should give early-career conservationists a better chance for success. 1. Sta..
10. Conserving Ecosystems
No full textRising 500 m above the Sahelian plains of Mali, the sandstone cliffs of the Bandiagara Escarpment are home to the Dogon people, whose unique homes are carved into the cliff’s walls. The Escarpment is a World Heritage Site, known for its outstanding cultural and natural value. However, both nature and humans are suffering from environmental degradation due to climate change and unsustainable land use.Photograph by Timm Guenther, https://commons.wikimedia.org/wiki/File:Les_Falaises_de_Bandiagar..
Conservation Biology in Sub-Saharan Africa
No full textThis book comprehensively explores the challenges and potential solutions to key conservation issues in Sub-Saharan Africa. Easy to read, this lucid and accessible textbook includes fifteen chapters that cover a full range of conservation topics, including threats to biodiversity, environmental laws, and protected areas management, as well as related topics such as sustainability, poverty, and human-wildlife conflict. This rich resource also includes a background discussion of what conservation biology is, a wide range of theoretical approaches to the subject, and concrete examples of conservation practice in specific African contexts. Strategies are outlined to protect biodiversity whilst promoting economic development, and scientists who live and work throughout the region are featured in each chapter
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