Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Category Archive: Ecology

  1. Bumblebee populations higher in Detroit – due to vacant lots?

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    Large amount of vacant or idle land may boost the bumblebee population by providing nesting sites and flowers for food

    Posted: 17 May 2017 08:16 AM PDT

    A new study of native bumblebee populations in southeastern Michigan cities found, surprisingly, that Detroit has more of the large-bodied bees than some surrounding, less urbanized locations.The large amount of vacant or idle land in Detroit may boost the bumblebee population by providing nesting sites and flowers for food.

    Native bees are critical sources of pollination for agriculture and wild flowering plants. Many native bees are declining in both abundance and diversity, due to various causes that likely include loss of habitat from human activities. While the effects of large-scale agriculture on native bees are relatively well understood, the effects of urban development are less clear.

    Bumbleebees belong to the bee genus Bombus. In the study, more than 500 individuals from 10 species were identified at 30 sites in southeast Michigan….Bumblebees need to nest in less-disturbed areas with bare ground, tall grass or abandoned tree stumps, making them a good candidate for testing the effects of urban land development. Handheld nets and insect traps were used to capture the bees….

    ….vacant lots are often less frequently mowed and less likely to be treated with pesticides and herbicides. Therefore, these lots can provide various flowering plants and nesting sites for bees.

    ….By analyzing males and females separately, the U-M researchers found that observed declines in overall bumblebee abundance and diversity with increasing urbanization were entirely driven by declines in female workers, while male abundance and diversity were unrelated to urbanization.

    Paul Glaum, Maria-Carolina Simao, Chatura Vaidya, Gordon Fitch, Benjamin Iulinao. Big city Bombus using natural history and land-use history to find significant environmental drivers in bumble-bee declines in urban development. Royal Society Open Science, 2017; 4 (5): 170156 DOI: 10.1098/rsos.170156

  2. Species may not be as susceptible to coextinction as once thought, new research suggests

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    May 15, 2017 Iowa State University  see full ScienceDaily article here

    …The study…focuses on mutualist networks, or webs of mutually beneficial interactions between plants and animals. Examples include fruit-eating birds that eat the fruit from trees while simultaneously helping to disperse the trees’ seeds.

    …The study… found that species with many mutualist relationships tend to be more dependent on those interactions for survival. On the other hand, species with few mutualists typically depend little on mutualistic interactions. Factoring that pattern into the equation adds a new dimension that upends much of the previous models, Fricke said…

    For instance, birds whose diets depend heavily on fruit usually eat fruit from more than one species of plant. That way, if one food source disappears, the bird has other options. “Nature seems to have some backup plans when you need them,” Rogers said….

    Evan C. Fricke, Joshua J. Tewksbury, Elizabeth M. Wandrag, Haldre S. Rogers. Mutualistic strategies minimize coextinction in plant–disperser networks. Proceedings of the Royal Society B: Biological Sciences, 2017; 284 (1854): 20162302 DOI: 10.1098/rspb.2016.2302

  3. Sooty Tern deaths linked to more intense, frequent hurricanes

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    Migratory seabird deaths linked to hurricanes

    Posted: 11 May 2017 01:53 PM PDT

    Stronger and more frequent hurricanes may pose a new threat to the sooty tern, a species of migratory seabird found throughout the Caribbean and Mid-Atlantic, a new study reveals. The study is the first to map the birds’ annual migratory path and demonstrate how its timing and trajectory place them in the direct path of hurricanes moving into the Caribbean from the Atlantic. Climate change may increase the risk….

    …”While it’s impossible to say just how many of the birds died as a direct result of the hurricanes, we saw a strong relationship between the numbers and locations of bird deaths and the numbers and locations of hurricanes,” said Stuart L. Pimm, the Doris Duke Professor of Conservation Ecology at Duke’s Nicholas School.

    “What’s really interesting is that it’s not just the big category 4 and 5 storms that can kill large numbers of birds. A series of smaller, weaker storms may have the same impact as that of a single large, strong storm,” Pimm noted…

    Ryan M. Huang, Oron L. Bass Jr, Stuart L. Pimm. Sooty tern (Onychoprion fuscatus) survival, oil spills, shrimp fisheries, and hurricanes. PeerJ, 2017; 5: e3287 DOI: 10.7717/peerj.3287

  4. Tagging songbirds with geolocators has mixed effects

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    The Ups And Downs Of Bird Tracking Devices  May 12, 2017 Science Friday

    Many songbirds migrate hundreds or thousands of miles every year, but their exact routes and flight patterns are something of a mystery. Traditional animal tracking devices based on radio transmitters are too heavy to use on such small birds, so instead researchers have turned to “geolocators”—tiny, lightweight devices that record patterns of light and darkness to estimate the birds’ latitude and longitude—to try to learn more about their migrations.  New work published in the journal The Condor indicates that even those lightweight tags may have ill effects on the birds, however. While cerulean warblers tagged with geolocators seemed to fare as well as control birds during the breeding season, fewer of the tagged birds returned the following year in the next migration cycle. Bridget Stutchbury, a researcher who uses geolocator tags but who wasn’t involved in the study, describes the possible good and bad of the tracking technology….

  5. Affluent countries contribute less to wildlife conservation than the rest of the world

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    Less affluent countries are more committed to conservation of their large animals than richer ones, a new research collaboration has found.

    May 4, 2017 University of Oxford  ScienceDaily

    …they found that in comparison to the more affluent, developed world, biodiversity is a higher priority in poorer areas such as the African nations, which contribute more to conservation than any other region….

    …the findings show that poorer countries tend to take a more active approach to biodiversity protection than richer nations. Ninety per cent of countries in North and Central America and 70 per cent of countries in Africa were classified as major or above-average in their mega-fauna conservation efforts. Megafauna Conservation Index scores for the 20 top performing countries.

    …Firstly, [countries] can ‘re-wild’ their landscapes by reintroducing mega-fauna and/or by allowing the distribution of such species to increase. They can also set aside more land as strictly protected areas. And they can invest more in conservation, either at home or abroad.”

    Lindsey, Peter A et al. Relative efforts of countries to conserve global megafauna Global Ecology and Conservation Volume 10, April 2017, Pages 243–252

    From Abstract: …we developed a Megafauna Conservation Index (MCI) that assesses the spatial, ecological and financial contributions of 152 nations towards conservation of the world’s terrestrial megafauna. We chose megafauna because they are particularly valuable in economic, ecological and societal terms, and are challenging and expensive to conserve. We categorised these 152 countries as being above- or below-average performers based on whether their contribution to megafauna conservation was higher or lower than the global mean; ‘major’ performers or underperformers were those whose contribution exceeded 1 SD over or under the mean, respectively…. Our analysis points to three approaches that countries could adopt to improve their contribution to global megafauna conservation, depending on their circumstances: (1) upgrading or expanding their domestic protected area networks, with a particular emphasis on conserving large carnivore and herbivore habitat, (2) increase funding for conservation at home or abroad, or (3) ‘rewilding’ their landscapes. Once revised and perfected, we recommend publishing regular conservation rankings in the popular media to recognise major-performers, foster healthy pride and competition among nations, and identify ways for governments to improve their performance.

  6. Scientists use satellites to count endangered birds from space

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    Posted: 04 May 2017 05:32 AM PDT  see full article here at ScienceDaily

    Albatrosses, one of the most iconic but also one of the most threatened groups of birds on the planet, are difficult to study in part because they breed on some of the world’s remotest and most inaccessible islands. Scientists have now shown that the highest resolution satellite imagery is capable of ‘seeing’ these birds from space, allowing researchers to count their numbers on remote islands directly from satellite images without ever having to go there

    Peter T. Fretwell, Paul Scofield, Richard A. Phillips. Using super-high resolution satellite imagery to census threatened albatrosses. Ibis, 2017; DOI: 10.1111/ibi.12482

  7. Measuring ecosystem services in Sonoma County

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    Using InVEST to assess ecosystem services on conserved properties in Sonoma County, CA

    Van Butsic et al California Agriculture 71(2):81-89. DOI: 10.3733/ca.2017a0008. Published online April 12, 2017
    Purchases of private land for conservation are common in California and represent an alternative to regulatory land-use policies for constraining land use. The retention or enhancement of ecosystem services may be a benefit of land conservation, but that has been difficult to document.
    The InVEST toolset provides a practical, low-cost approach to quantifying ecosystem services. Using the toolset, we investigated the provision of ecosystem services in Sonoma County, California, and addressed three related questions.
    • First, do lands protected by the Sonoma County Agricultural Preservation and Open Space District (a publicly funded land conservation program) have higher values for four ecosystem services — carbon storage, sediment retention, nutrient retention and water yield — than other properties?
    • Second, how do the correlations among these services differ across protected versus non-protected properties?
    • Third, what are the strengths and weaknesses of using the InVEST toolset to quantify ecosystem services at the county scale?
    We found that District lands have higher service values for carbon storage, sediment retention and water yield than adjacent properties and properties that have been developed to more intensive uses in the last 10 years. Correlations among the ecosystem services differed greatly across land-use categories, and these differences were driven by a combination of soil, slope and land use. While InVEST provided a low-cost, clearly documented way to evaluate ecosystem services at the county scale, there is no ready way to validate the results.


  8. Cormorant Colony Adrift as Old Bay Bridge Comes Down

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    The Old Bay Bridge Is Coming Down, Leaving a 40-Year-Old Cormorant Colony Adrift

    by Mark J. Rauzon on March 28, 2017  BayNature

    ….Back in the late 1800s before bridges spanned the Bay, several thousand double-crested cormorants nested on Lands End near Seal Rocks off the coast of San Francisco and on the Farallon Islands. The great ornithologist of the era, Robert Ridgway, described the Pacific Coast bird as a subspecies of the double-crested cormorant found throughout North America and he gave them their own moniker—the Farallon cormorant (P. a. albociliatus)….They were first documented nesting on the Bay and Richmond-San Rafael bridges in 1984, though bridge workers reportedly saw them 20 years earlier on the latter….

    I began studying those double-crested cormorants under the Richmond-San Rafael Bridge with Point Reyes Bird Observatory (PRBO, now Point Blue Conservation Science) in 1988….

    ….All this changed on October 17, 1989, when the Loma Prieta earthquake cracked the Bay Bridge right above the colony (not the birds’ fault!). Although it took years of political wrangling to settle on a new bridge design that was acceptable to all parties, the resulting plan included an agreement to provide habitat replacement for the cormorants on the new bridge.

    ….Losing the unique cormorant bridge colony in the central Bay is the end of an era. Our urban cormorants are at a crossroads. …. Double-crested cormorants have colonized urban habitats and benefited from human manipulation of San Francisco Bay. Where many species are failing to survive, the cormorant is thriving. They deserve respect for their adaptive qualities and commiseration for their commuting lifestyle.  The next time you’re stuck on the bridge, watch for cormorants flying by; understandably, you might wish you could join them.

    Mark Rauzon is a seabird biologist with extensive experience in restoration programs, detailed in his latest book Isles of Amnesia. He also teaches geography at Laney College, is a founding member of Friends of Sausal Creek, and is a Point Blue research associate

  9. Wind and rain play bigger role than temperature in breeding timing of tree swallows

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    Wind, rain play key role in breeding patterns of migratory tree swallows

    April 27 2017 ScienceDaily  CU Boulder

    Wind and precipitation play a crucial role in advancing or delaying the breeding cycles of North American tree swallows… [the study] underscores the importance of considering factors beyond temperature when examining how climate change might affect species’ biological niche.

    …when…researchers tested how swallow nesting data from two different Alaskan sites corresponded with both daily and seasonal climate indicators like the number of windy days, days with measureable precipitation and average daily temperature, they found that windiness (or lack thereof) had the most consistent correlation with swallow breeding patterns over time…

    …The results showed that a long-term decline in windiness (and to a more variable extent, rain) in central Alaska over the past decade-plus correlated with the birds’ earlier breeding much more strongly than temperature, indicating that wet, windy spring weather that may have delayed egg laying in the past is now less of an impediment for the swallows.

    Rachel D. Irons, April Harding Scurr, Alexandra P. Rose, Julie C. Hagelin, Tricia Blake, Daniel F. Doak. Wind and rain are the primary climate factors driving changing phenology of an aerial insectivore. Proceedings of the Royal Society B: Biological Sciences, 2017; 284 (1853): 20170412 DOI: 10.1098/rspb.2017.0412

  10. Exotic species aren’t all bad

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    Exotic species aren’t all bad

    Posted: 05 Apr 2017 05:40 AM PDT

    When it comes to their role in aquatic ecosystems, exotic water plants are generally no different than indigenous species. In fact, they can be an asset. That doesn’t mean all exotic species should be given free rein. But they can be managed more effectively if you focus on their properties and not their place of origin, suggests one expert.