Attracting blue jays to North American gardens


This 22 July 2019 video from the USA says about itself:

Want to attract Blue Jays to your backyard? Try filling your bird feeder—they prefer tray feeders or hopper feeders—with some of their favorite treats: peanuts, sunflower seeds, and suet. 🥜

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Sea lamprey love life, new research


This 12 April 2018 video from Wales is called Sea lampreys (Petromyzon marinus) spawning in the upper Wye.

From Michigan State University in the USA:

Smells like love…to sea lampreys

July 9, 2019

Some people are drawn to cologne; others are attracted to perfume. When it comes to sea lampreys, however, spermine smells like love.

In new research led by Michigan State University and published in the current issue of PLoS Biology, spermine, an odorous compound found in male semen, proved to be a powerful aphrodisiac.

Spermine isn’t a new discovery. It’s been a known quantity in semen since 1678 — at least in humans. Its tractor-beam effect on spawning female sea lampreys is new, however, and it can be yet another key way to potentially control the invasive species.

“We found the male ejaculate contains spermine, a highly specific and potent pheromone, which attracts only mature females”, said Weiming Li, fisheries and wildlife professor and senior author of the study. “Mature females likely use spermine to identify males actively releasing sperm in the spawning aggregation.”

They need this help because sea lampreys migrate up to river gravel beds ¬- spawning aggregation sites — drawn by other pheromones released from spawning males. These mating cues are merely the billboards, though, along riverine highways that draw them to the sites.

Arriving at the gravel bar of love, the females see many males on nests — all mature and ready to mate. Rather than find “the perfect mate,” the females seem to act on localized cues and form promiscuous pairs with many males — in sequence and one at a time — and spawn several times per hour.

Spermine is a coup de gras [sic; coup de grâce] that helps females make their final selections, navigate the throng of males and find the best ones with which to mate. According to Li, this is the first time scientists have been able to document this behavior in sea lampreys.

“We also were able to document a specific receptor in the noses of females that picks up spermine, and it can be smelled at trace-level concentrations,” said Richard Neubig, pharmacology professor and study co-author. “This was a big job requiring nearly 12,000 tests in the MSU high-throughput screening lab to figure out the right pair of chemical and receptor.”

Ovulatory females detect this faint cologne, and they respond at levels as low as 10-14 molar, a mere whiff comparable to a single drop of perfume in a pool. It’s interesting to note that even higher levels of spermine had no effect on immature females or other males.

Li and a team of scientists identified the receptor for spermine, a trace-associated receptor, or TAAR, in females. Future work will determine if spermine can be used to manage invasive sea lamprey populations. Likewise, MSU scientists will investigate the TAAR mechanism to explore its control potential.

Controlling sea lampreys in the Great Lakes is a critical goal of fisheries scientists. The invasive species infiltrated the upper Great Lakes via the Atlantic Ocean in the 1920s through shipping canals. They feed by attaching themselves to other fish, such as salmon and trout. One sea lamprey can kill more than 40 pounds of fish, and the U.S. and Canadian governments spend approximately $20 million annually to control them in the Great Lakes.

Fish warn others chemically about dangers


This june 2013 video is called Fathead minnows in my pond.

From the University of Saskatchewan in Canada:

Fish under threat release chemicals to warn others of danger

April 18, 2019

Fish warn each other about danger by releasing chemicals into the water as a signal, research by the University of Saskatchewan (USask) has found.

The USask researchers discovered that wild fish release chemicals called ‘disturbance cues’ to signal to other fish about nearby dangers, such as predators.

The findings may have implications for fish conservation efforts across the globe.

“Disturbance cues may help to explain why some fish populations crash after they decline past a certain point,” said Kevin Bairos-Novak, a graduate student member of the research team.

While researchers have been aware that fish release chemicals into the water for 30 years, this is the first time their use has been studied.

The findings, involving researchers from the USask biology department and the Western College of Veterinary Medicine, are published in the Journal of Animal Ecology.

Fish signaled most when in the presence of familiar fish, but signaled far less or not at all when in the presence of strangers, or when on their own.

The signals provoked a ‘fright response’ in fish they knew, including freezing, dashing about and then shoaling tightly together. Fish use this behavior to defend themselves against predators.

“When minnows

The research is about fathead minnows. They live in North America.

were present alongside familiar minnows, they were much more likely to produce signals that initiated close grouping of nearby fish, a strategy used to avoid being eaten by predators,” said Bairos-Novak, who is now at James Cook University, Australia.

Disturbance cues are voluntarily released by prey after being chased, startled or stressed by predators.

One of the main constituents of the signal is urea, found in fish urine.

Fathead minnows, caught at a lake, were placed in groups with familiar fish, unfamiliar fish or as isolated individuals. The research team then simulated a predator chase. The fish responded by shoaling, freezing and dashing when they received a signal from a group they knew. But they did not take significant defensive action when receiving cues from unfamiliar fish or isolated minnows.

Disturbance cues are voluntarily released by prey after being chased, startled or stressed by predators.

“It is exciting to discover a new signaling pathway in animals,” said Maud Ferrari, Bairos-Novak’s supervisor and a behavioural ecologist in the veterinary college’s Department of Veterinary Biomedical Sciences. “We found that fish are able to manipulate the behaviour of other individuals nearby by issuing a signal.”

The research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC).

Climate change theatens North American sparrows


This 24 June 2011 video from the USA says about itself:

Seaside Sparrows in Connecticut Saltmarsh. ©JimZipp2011; following New Moon high tides that flooded out all nests.

From Oxford University Press USA:

Climate change threatens endangered sparrows

April 16, 2019

A new study in The Condor: Ornithological Applications finds that some sparrow species will go extinct within the century due to climate change.

Seaside (Ammospiza maritima) and saltmarsh (A. caudacuta) sparrows are closely related species and among only five bird species that are almost completely restricted to coastal salt marshes for their entire life. These sparrows’ nests are predominantly destroyed by predators or flooding.

Salt marshes are globally limited to about 30,000 square miles (45,000 square km), with one-third of the total on North American coasts. Of the 25 species or subspecies limited to tidal wetlands worldwide, 15 are restricted to the US Atlantic and Gulf coasts. Given rapid climate changes and other threats to salt marsh ecosystems, many of these species are in serious danger.

The global breeding range of the saltmarsh sparrow extends from Virginia to Maine, with a population estimate of 60,000 birds. Sea-level rise can negatively impact breeding seaside and saltmarsh sparrows by reducing the amount of available habitat, and by increasing nest flooding rates. Furthermore, the high human population densities of Mid-Atlantic states also make it difficult for sparrows to thrive in the region.

This study aimed to estimate population trajectories for seaside and saltmarsh sparrows within Edwin B. Forsythe National Wildlife Refuge in New Jersey, identify the primary drivers of those trajectories, and explore potential management strategies to prevent declines.

The researchers found that seaside sparrows persisted under a 1 ft (0.35 m) rise in sea level scenario and also under a sea level rise of almost 2.5 ft (0.75 m). Saltmarsh sparrows survived in neither scenario. With a 1 ft rise in sea level, the seaside sparrow population experienced a compound decline of .35% a year. Under the 2.5 ft sea level rise scenario, this decline increased to .56% a year. The saltmarsh sparrow median time to quasi-extinction was 20 years under both scenarios.

The results indicated that seaside sparrows are likely to persist, while saltmarsh sparrows are likely to become locally extinct in the next 30 years.

“Given the projected increases in sea level over the next few decades and threats from predators, we will need to implement timely and creative actions to avoid extinction of saltmarsh sparrows,” said the paper’s lead author, Samuel Griffith Roberts.

Protecting American migratory birds


This March 2017 video from the USA says about itself:

Bird Migration in North America

An overview on how and why birds migrate, including species such as the Yellow Warbler and the Woodthrush, as well as challenges migratory birds face today. This educational video was completed for ‘Birds Ecosystems and People’ at Allegheny College.

From Cornell University in the USA:

Scientists use eBird data to propose optimal bird conservation plan

The goal is to conserve habitat and protect migratory birds

April 15, 2019

A new paper published today in the journal Nature Communications shows a blueprint for conserving enough habitat to protect the populations of almost one-third of the warblers, orioles, tanagers, and other birds that migrate among the Americas throughout the year.

For the research, an international team of scientists used the Cornell Lab of Ornithology’s global citizen science database, eBird, to calculate how to sufficiently conserve habitat across the Western Hemisphere for all the habitats these birds use throughout their annual cycle of breeding, migration, and overwintering. The study provides planners with guidance on the locations and amounts of land that must be conserved for 30 percent of the global populations for each of 117 Neotropical migratory bird species.

More than a third of Neotropical migratory birds are suffering population declines, yet a 2015 global assessment found that only 9 percent of migratory bird species have adequate habitat protection across their yearly ranges to protect their populations. Conservation of migratory birds has historically been difficult, partly because they require habitat across continents and conservation efforts have been challenged by limited knowledge of their abundance and distribution over their vast ranges and throughout the year.

“We are excited to be the first to use a data-driven approach that identifies the most critical places for bird conservation across breeding, overwintering, and migratory stopover areas throughout the Western Hemisphere. In doing so, we provide guidance on where, when, and what type of habitat should be conserved to sustain populations,” said Richard Schuster, Liber Ero Postdoctoral Fellow at Carleton University, and lead author on the Nature Communications paper. “This is a vital step if conservationists are to make the best use of limited resources and address the most critical problems at a hemispheric scale.”

The team’s analysis found that conservation strategies were most efficient when they incorporated working lands, such as agriculture or forestry, rather than exclusively focusing on areas with limited human impacts (i.e., intact or undisturbed landscapes). The importance of shared-use or working landscapes to migratory birds underscores how strategic conservation can accommodate both human livelihoods and biodiversity. The research also found that efficiency was greatest — requiring 56 percent less land area — when planning across the entire year in full, rather than separately by week.

“Efforts to conserve migratory species have traditionally focused on single species and emphasized breeding grounds. Our results show that planning for multiple species across the entire year represents a far more efficient approach to land use planning,” said Scott Wilson, Environment and Climate Change Canada research scientist and co-author on the paper.

“This study illustrates how globally crowd-sourced data can facilitate strategic planning to achieve the best return on conservation investments. No other data source could have achieved anything close to this level of detail and efficiency in spatial planning over such a vast area,” said Cornell Lab senior conservation science director and co-author Amanda Rodewald.

“Prioritizing sites in which to invest our conservation dollars will dramatically improve our returns on the roughly $1 billion spent annually on the conservation of birds by government and nonprofit organizations, often in the absence of spatially explicit information on year-round abundance or geographical representation,” said Peter Arcese, co-author and FRBC Chair in Applied Conservation Biology at University of British Columbia.