During their surveys, researchers found similar
numbers of bird species in secondary stands compared to stands comprised entirely or in part of old - growth forest.
Research from the Smithsonian Migratory Bird Centre has demonstrated that
the number of bird species found in shade coffee plantations is almost twice that found in sun grown coffee (Smithsonian 1994).
The breeding populations of
a number of bird species in Western European farmland have declined in the past decades.
Researchers in Queensland, Australia, assessed the condition of fragmented eucalyptus forests at 10 sites using conventional measures — including the size of forest patches, vegetation characteristics and
the number of bird species detected — and sound recordings.
Mastication reduced
the number of bird species by about 50 percent and reduced total numbers of birds by about 60 percent.
Typical numbers for the total
number of bird species worldwide tend to center around a range of 9,000 to 10,000, but the museum's scientists say that number is likely closer to 18,000.
Extending that ratio out to the entire bird population, the researchers suggest that there may be roughly double
the number of bird species in the sky.
The tropical Andes contains 10 % of the world's vascular plants and a high
number of bird species, such as Peru's national bird the Cock of the Rock.
Recent sightings of a black stork, a European nightjar, and a Pacific golden plover brought the total
number of bird species spotted on Kuyucuk Lake in Kars to 223 — 48 percent of all those present in Turkey.
Not exact matches
Two new studies from Europe have found that the
number of farm
birds in France has crashed by a third in just 15 years, with some
species being almost eradicated.
According to natural selection the members
of the
bird species with the smallest useless wing would be the most adaptable and most likely to survive in the largest
numbers.
In other words, the individuals
of each
species of migratory
bird are slowly diminishing in
number.
Reasons for the higher
number and
species diversity
of birds and
bird territories on organic farms include better breeding habitats and better food conditions.
Blessed with idyllic conditions on Friday evening, many
birding teams were fortunate in finding a
number of interesting
species before sunset.
The Academy has a large
number of Bailey's photographs in their Archives taken on his trips all over the United States and Canada with the intention
of recording a variety
of species of birds in their natural habitat.
The volunteer survey invites participants to list the
bird species and greatest
number of each seen at one time at their feeders and in their yards during that Saturday and Sunday.
A limited
number of mute swans would be allowed to stay in upstate under the DEC's latest management plan for the
species, released last week after years
of controversy over the huge white
birds.
That is one
of the surprising results
of the first study to systematically measure the
number of neurons in the brains
of more than two dozen
species of birds ranging in size from the tiny zebra finch to the six - foot - tall emu, which found that they consistently have more neurons packed into their small brains than are stuffed into mammalian or even primate brains
of the same mass.
The team compared the body structure
of a
number of early
birds and found that some toothed
species were more adapted for flight.
Volunteers for the aptly named AMBLE regularly walked beaches in Door County in Wisconsin, Sleeping Bear Dunes National Lakeshore in Michigan, and the Upper Peninsula
of Michigan, recording the
number of sick and dead
birds of different
species.
After two years, as expected, data showed that the
number of birds and other
species in each patch was diminishing.
An even bigger problem, he says, is that competitive displays by male
birds seeking to mate with females are «only observed in a small
number of species around the world.»
They tabulated the
number of juvenile
birds versus adults for 34
species breeding near the stations.
Some
of these regions, such as the southern Andes and certain isolated mountain ranges in the north, are also home to high
numbers of endemic and threatened
bird species, she finds.
The researchers also found that lizards» resting site choices that heightened individual camouflage were more evident on islands with higher
numbers of predatory
bird species, suggesting that this behavioral defence is more likely to evolve in riskier environments.
«There are several
species of cooperatively breeding
birds where helper
numbers or helper effort seems to have negligible effect on offspring survival, and that just didn't make any sense.»
When an alien
species enters a new ecosystem, it can alter the environment in a
number of ways: by eating native
species (in its 50 years on Guam, the Australian brown tree snake has eliminated 9
of 13 native
bird species); by spreading disease among them (introduced
birds in Hawaii thrive in part because they are far less susceptible to the avian malaria parasite, also an introduced
species, than native
birds are); or by altering the environment in such a way that favors themselves (like melaleuca, an Australian tree that is spreading through the Everglades in part by changing the frequency and intensity
of fires).
«We show that even if deforestation had completely halted in 2010, time lags ensured there would still be a carbon emissions debt equivalent to five to ten years
of global deforestation and an extinction debt
of more than 140
bird, mammal, and amphibian forest - specific
species, which, if paid, would increase the
number of 20th century extinctions in these groups by 120 percent,» says Isabel Rosa (@isamdr86)
of the Imperial College
of London.
Yet, according to a new study involving 147 cities worldwide, surprisingly high
numbers of plant and animal
species persist and even flourish in urban environments — to the tune
of hundreds
of bird species and thousands
of plant
species in a single city.
Results showed a large decrease in the
number of birds in the «sonic net» and areas just outside and found that it was particularly effective at deterring a
number of species that were at high risk
of bird strike such as starlings.
The academics attached tiny tags with a unique electronic
number onto the legs
of 452 blue tits and great tits, two
species which typically visit garden
bird feeders.
The
number of mammal and
bird species varies from place to place, but these groups
of vertebrates still span much
of the world.
Mixed forests, however, harbored more
bird species and similar overall
numbers of birds compared with cropland.
With access to museum ornithological collections from areas
of South America that Darwin had not visited, Gould corrected a
number of taxonomic errors Darwin had made (such as labeling two finch
species a «Wren» and an «Icterus») and pointed out to him that although the land
birds in the Galpagos were endemic to the islands, they were notably South American in character.
Astroviruses from a
number of species, including human, bovine,
bird, cow and dog, were detected in monkeys, This «challenges the paradigm that AstV (astrovirus) infection is
species - specific,» the authors wrote.
All
bird species showed the same response, the team reports in the 23 December issue
of Science: the
number of fledglings per breeding pair started to decline when the abundance
of forage fish dropped below one - third
of the maximum observed amount.
The researchers looked at correlations between egg shape and traits associated with the
species of bird, including nest type and location, clutch size (the
number of eggs laid at a time), diet and flight ability.
They estimate that a carefully prepared 5 % increase in conservation area would allow a dramatically improved capture
of bird and mammal biodiversity facets; an approach focused on
species numbers alone would be much less optimal, the researchers said.
Although specimens
of fishes, marine reptiles, non-avian dinosaurs,
birds, and mammals
of this age have all been recovered from this now - frozen continent, most fossils, especially those
of land - living
species, are fragmentary and poorly informative, and a
number of major vertebrate groups that likely once lived in Antarctica (e.g., amphibians, crocodilians) have yet to be discovered at all.
In the 20 to 10 million years before the mass extinction that toppled all dinosaurs except for
birds, the researchers found, therian mammals did not have a large
number of species — but there were greater differences between each
species.
However, other
bird species are running out
of disease - free habitat and the population
numbers that would allow the evolution
of resistance.
In assessing extinction intensities, scientists often talk about the
number of species going extinct within a certain genus, family, class, and so on, as I did above for
species of amphibians, reptiles,
birds, and mammals.
Logged total
numbers of birds, amphibians and corals are represented by A, B and C respectively (see Fig. 3 for maps
of the total
numbers of species).
Apparently, reisolation affects the
number of birds using fragments more than it affects
species richness.
This
number includes a minimum
of 95
bird species, as well as native and introduced
species such as the southern brown bandicoot and echidna, and house mouse, European rat, rabbits, foxes and feral cats.
November 13, 2014 • The
bird is now protected under the Endangered
Species Act, which could stop some oil and gas development in Colorado and Utah — and will likely start a
number of legal challenges.
While the majority
of dinosaur eggs were buried in hopes
of protecting their offspring, there were a
number of species that built nests and took care
of their offspring similar to how modern
birds do today.
Placing a
number of feeders in one area will create a great
bird «oasis,» where many
species will come in looking for a snack.
Many
bird enthusiasts these days are not only referring to wild
birds as «outdoor pets,» but are also recommending that people buy high - quality birdseed to draw a wider variety
of species and in greater
numbers.
What
species of birds to offer depends on a
number of factors, such as location, availability and the type
of customers who come into the store.