Female tiger sharks migrate from Northwestern to Main Hawaiian Islands during fall pupping season
Sep06

Female tiger sharks migrate from Northwestern to Main Hawaiian Islands during fall pupping season

A partial migration of adult female tiger sharks coincides with pupping season and the months of increased incidences of shark bite in Hawaii, according to a report currently in preprint in ESA’s journal Ecology.

Read More
Declining fortunes of Yellowstone’s migratory elk
Jun26

Declining fortunes of Yellowstone’s migratory elk

Are human choices redefining the fitness of an ancient survival strategy?

Eighteen ecologists weigh in on new data in a Forum in Ecology.

Read More

Managing water with natural infrastructure: win-wins for people and wildlife

By Terence Houston, Science Policy Analyst The US Senate is moving forward with a new Water Resources Development Act, a comprehensive bill that authorizes funding for Army Corps of Engineers projects related to flood management, environmental restoration and other water resources infrastructure issues. The bipartisan legislation (S. 601) is sponsored by Senate Environment and Public Works Committee Chairwoman Barbara Boxer (D-CA) and Ranking Member David Vitter (R-LA). In light of this, the Consortium for Aquatic Science Societies recently held a congressional briefing that highlighted problems with aquatic invasive species and “natural infrastructure” solutions. David Strayer, Senior Scientist at the Cary Institute for Ecosystem Studies discussed the varied ways in which invasive species can harm ecosystems, recreation and tourism for communities living alongside major waterways. Invasive species cost the US economy $100 billion a year and cause significant lasting ecological changes, often hindering  recreation and leading to proliferation of less desirable  wildlife. Among the most costly of these is the zebra mussel, which has cost industry and business billions since its initial introduction to the United States several decades ago. The mussels damage boats, invade water treatment and power plants and clog pipes. Strayer also highlighted nutria, plant-eating rodents that can severely erode river banks,  leaving surrounding communities more vulnerable to floods; Japanese knotweed, which crowds out native plants and damages existing infrastructure; and didymo (commonly known as “rock snot”), which – in addition to its obvious aesthetic damage to otherwise scenic landscapes – alters streambeds and cuts out food sources for native aquatic species such as trout. Strayer noted that reservoirs, alteration of water flows in rivers and streams and fish stoking (which can unintentionally include contaminants and undesirable wildlife) can buttress proliferation of invasive species. He praised language in the new WRDA legislation that would establish a program to mitigate invasive species in the Columbia River Basin and manage invasive plants in the northern Rockies and urged support for an amendment recently incorporated into the bill from Sen. Kirsten Gillibrand (D-NY) that would seek to restrict invasive species from dispersing into the Great Lakes. Emma Rosi-Marshall, also with the Cary Institute on Ecosystem Services, focused her presentation on the general ecology of rivers. Many animals, including salmon and sturgeon, adapt their migration and breeding patterns on the dynamics of rivers. She also expanded on the important role of natural infrastructure such as wetlands and floodplains in mitigating floods and controlling erosion. Dams, while providing services such as water storage and power generation, can also disrupt wildlife migration and alter the manner in which sediment and nutrients are delivered along waterways. These alterations can impact fish abundance as well as...

Read More

Symposium I of ESA’s Emerging Issues Conference

This post contributed by Celia Smith, ESA Education Programs Coordinator A high standard was set by the first symposium of the Ecological Society of America’s (ESA) weeklong 2012 Emerging Issues Conference, which kicked off Monday at the U.S. Fish and Wildlife Service’s National Conservation Training Center (NCTC) in Shepherdstown, WV. The first of four sessions, Symposium I:  “Protected Areas: Fostering museums, way stations and endpoints” was held in NCTC’s main auditorium, which brimmed with top representatives from a diversity of fields in ecological research, land management and government. On Monday morning, four invited experts spoke passionately about a variety of approaches to conservation targets under global change, the overarching theme of the conference and the topic that each of the nearly 100 attendees will tackle during intensive working groups on Wednesday and Thursday. Despite the highly varied professional backgrounds and presentation topics of the speakers, it was illuminating to observe the common threads that wove through each talk and evoked connections among different ways of looking at specific conservation problems related to anthropogenic climate change. Concepts that frequently found their way into the dialogue between speaker and audience included uncertainty and connectivity, both in a spatial and temporal sense. The first two speakers dealt with the connectivity of past and present, and how rapid change inevitably forces us to compare historical ecological events and circumstances with current challenges and management options. Richard Hobbs of the University of Western Australia began the conversation with his talk, “Intervention, protection and restoration: Are we guardians or gardeners?”  He suggested that we have entered a new “Anthropocene” era in which humans are largely responsible for decisions affecting the environment. “There are many different futures out there,” Hobbs said. “We don’t have much of a clue as to what the future holds… we have an uncertain past and an increasingly uncertain future.” Hobbs argued that this is not a reason to lose hope; we must simply shift our search for solutions toward a style of management that draws both from standard conservation strategies, such as restoration and invasive species control, and new approaches reflecting the Anthropocene “new world order” that are locally focused, contingent, and anthropocentric. This “gardenification” approach would not altogether abandon the conservation strategies of the past, but adapt them to current and future changes. Hobbs stressed that this will require embracing novel ecosystems and seeing ourselves as part of the natural world rather than separate from it. The theme of historical connectivity to present and future decision-making was also addressed by Stephen Jackson in “Is history ‘just history?’ Uses of the ecological past for global-change risk assessment.” “History suggests some hope,”...

Read More

Fall migrations

This post contributed by Nadine Lymn, ESA Director of Public Affairs Now that mid-October has arrived, many of us notice the shortening days, dark mornings, and new chill in the air.  Thoughts turn to cozy indoor activities, hot beverages, and away from such outdoor hobbies such as gardening.  But while we have the luxury of moving many of our activities indoors during the upcoming winter chill, other species in North America—primarily birds and butterflies—are either preparing for long travel or are already en route to southerly destinations. As noted in a wild bird blog for nature enthusiasts, some 350 species of birds in North America migrate, the majority of them to wintering destinations that include Mexico, Central and South America, and the West Indies: “In North America there are four major migration routes, known as the Atlantic, Mississippi, Central and Pacific Flyways. A flyway can generally be described as a broad geographical area of travel consisting of hundreds of widely diverse, individual migration routes. No two species of birds will travel exactly the same route from beginning to end.” The U.S. Geological Survey provides an in-depth description of the  migration routes birds take as they leave the U.S. on their way to various wintering grounds.  Some species, such as many shorebirds, begin their fall migration as early as July, while others, like goshawks, redpolls and waxwings may not get started until winter. As many birders know, most birds migrate during the night.  According to the USGS website, the most likely hypothesis for this is that this maximizes birds’ ability to refuel and rest.  Birds traveling all night can come to rest at daybreak and begin to find food; if they flew all day and came to rest at night, they would be unlikely to garner food, which they urgently need after long exertion.   There are, however, some daytime migrants, among them loons, cranes, and pelicans as well as soaring birds which depend upon thermals for their flight. This website lets you find out what birds may be passing through your area now and in the coming months. Birds are not the only ones taking flight in the fall.  Butterflies are also on the move, with the Monarch butterfly probably the most well-known of these.  And even though many of us lose interest in gardening when summer ends, the National Wildlife Federation (NWF) points out the value of gardens that offer late blooming plants such as asters and goldenrods for fall migrants, including hummingbirds and various species of butterflies, such as the monarch, painted lady, and cloudless sulfur. Cape May, New Jersey, is a key resting spot for migrating monarchs,...

Read More

Extreme weather, campaigning honeybees and tracking whale sharks

This post contributed by Molly Taylor, ESA Science Writing Intern. Extreme weather: The rare multi-vortex that hit Joplin, Missouri on May 22 has claimed more than 100 lives and destroyed countless homes and buildings. Unfortunately, this is not the only natural disaster to devastate the U.S. this year. According to a recent Washington Post article, this storm season is turning out to be one of the most violent on record. The extreme weather, Brian Vastag and Ed O’Keefe reported in the article, is due at least in part to La Nina: “The jet stream’s river of cool air high in the atmosphere pulls warmer, more humid air from the ground upward, forming thunderstorm ‘supercells.’ Such a pattern drove the outbreak of more than 300 tornadoes that swept from Mississippi to Tennessee in late April, killing at least 365…” But according to the Post, researchers have also been exploring the potential role of climate change in recent weather patterns. Read more at “Storm season on deadly path; Obama to visit Joplin.” Campaigning honeybees: In the spring, beehives can reach capacity, basically overflowing with honey and bee larva. This overcrowding can cause the hive to literally burst in two, leaving half of the population in need of a new home. The old queen leads one half of the homeless pack to establish a new colony at a separate location, while a new queen takes charge of the existing hive. But where do the homeless bees go? Despite the royal title, the queen is not ruling a monarchy—worker bees actually vote for their favorite location. “The older, more experienced bees…fly off looking for options,” wrote NPR’s Robert Krulwich, and upon their return, they “announce their ‘finds’ by dancing.” That is the point when the “waggle dancing” begins (and yes, that is the official term), whereby the scouting bees use dancing to signal their sister bees. This encourages the sister bees to have a peek at the potential new home, and if they like what they see, they start doing the same dance. “This is how bees ‘vote,’” wrote Krulwich. “They dance themselves into a consensus.” Read more at “Nature’s Secret: Why Honey Bees Are Better Politicians Than Humans.” Tracking whale sharks: “With the help of algorithms designed to guide the Hubble telescope’s starscape surveys, conservation-minded coders have designed software that helps biologists identify whale sharks by their spots,” wrote Brandon Keim in a recent Wired Science article. “The program enlists the help of citizens with cameras, and lets researchers track Earth’s biggest fish across time and oceans.” In the past, researchers have found whale sharks to be too elusive to track as...

Read More
Hybrids in the Arctic
Mar17

Hybrids in the Arctic

Hybridization has led to some of the unique, naturally-occuring species present today, such as the Mallard duck-American Black duck hybrid. Usually this natural process takes generations to produce a new distinct species; however, it is possible for hybrids to emerge within one generation. For example, interspecies breeding could be expedited due to environmental stressors caused by climate change. Species that would not normally come in contact with one another are being pushed into the same habitats—called hybrid zones—due to the removal of physical barriers, like glaciers and ice sheets. The arctic area in particular is experiencing an increase in hybridization due to habitat changes brought about   by climate change. Everyone has seen the photographs of the polar bear clinging to a shrinking piece of ice – the shrinking ice is in fact what is encouraging the influx of non-native species into the Arctic. Polar bears broke off as their own species hundreds of thousands of years ago because they were able to adapt to the colder climate and find food. Charlotte Lindqvist of the University of Buffalo found that polar bears were able to survive the last interglacial warming period; however, Lindqvist added, because the rate of current climate change is so much faster , these Arctic animals are unable to adapt quickly enough. Polar bears are essentially being hit with a 1-2-3 punch. Not only is their habitat diminishing, so too, are their food sources, —negatively impacting their  breeding success. Research has shown that, due to lack of sustenance, female polar bears produce less healthy offspring, and the offspring that survive tend to be smaller in size. Additionally, polar bears may now have to deal with an increased number of grizzly bears. Grizzly bears do not only pose a competitive threat to polar bears but a genetic threat as well. With melting Arctic ice, more polar bears are being forced to remain on land—meanwhile, the warmer temperatures and diverse food sources are enticing grizzlies to move further north. The cross-breeding of polar and grizzly bears could eventually lead to a complete loss of the unique genes of polar bears that have enabled the bear’s survival in the Arctic for so long. Grizzly bears are better suited for the warmer temperatures of the uplands of western North America—that is, compared to Arctic temperatures. With the increase in grizzly population in the Arctic due to warmer temperatures, and the decrease in polar bear population due to habitat constraints, potential cross-breeding could be more likely to occur. While the accepted rule of thumb is that hybrid offspring are unviable—or, unlikely to survive since they are unable to reproduce—there is support in...

Read More

Rest stops for fall migration

Many animals migrate in the fall to exotic locales and warmer, more abundant southern climates. Among the more famous migrating winged species are monarch butterflies, but there are several species of birds that also migrate during the fall. Some of these birds, such as hawks, rest and “refuel” in the Gulf region of the United States as they traverse southward.

Read More