Great tits look for food


This 18 February 2017 video is about great tits looking for insect food among fallen leaves in the Amsterdamse Waterleidingduinen in the Netherlands.

Pine siskins at Canadian feeders


This video from Canada says about itself:

Pine Siskins Make an Uncommon Visit to Ontario FeederWatch Cam – Feb. 22, 2017

Two or Three Pine Siskins spent some time on the feeder tray of the Ontario FeederWatch Cam this afternoon. These small, brown, streaky finches have subtle yellow edgings on wings and tails. Pine Siskins can be easily confused with the Common Redpolls on cam, but they have a slender, more sharply pointed bill and are much streakier on the breast. They also lack the red forehead spot of the Common Redpolls.

Thanks to our eagle-eyed cam host for the spot!

Thanks to Perky-Pet for helping to make the Ontario FeederWatch Cam possible!

The FeederWatch cam is located in a residential neighborhood in Manitouwadge, Ontario.

Featuring pine grosbeaks as well.

British barn owls still in trouble


This video from England says about itself:

20 March 2015

Barn Owls, Tyto alba. In slow motion.

Near Hundred End Lancashire, March 2015.

With a Panasonic Lumix GH4

From BirdLife:

22 Feb 2017

British Barn Owls still struggling to adapt to modern life

The most recent nest site survey indicates that the factors that wiped out 70% of Barn Owls in the 20th century still impact the beloved species today

By Alex Dale

One of the most widespread birds of prey in the world, the Common Barn Owl Tyto alba has proven so successful at adapting to life alongside humans that even its very name reflects the symbiotic relationship that has been shared by farmers and this charismatic bird over the course of thousands of years.

Common Barn Owls prefer to roost and nest in sheltered areas that protect them from the elements, and when settlers first began building on Britain’s countryside, crafty barn owls quickly swooped on the opportunity, swapping rock crevices and holes in trees for comfy crevices in the attics of barns and churches. In return, Barn Owls would repay their unwitting landlords by preying on the mice and voles that ventured onto their land.

However by the mid-20th Century, changes to the dynamic of this human-bird relationship rapidly sent British Barn Owl numbers into a tailspin. According to the Barn Owl Trust – a UK-based charity who works to protect the species – Barn Owls in the country declined by as much as 70% between 1932 and 1985.

The Barn Owl declined by 70% during the 20th Century, as intensive farming practices took their toll on the much-loved countryside bird

These declines are largely the result of improvements in the way farmers cultivate their land. The rise of the combine harvester, which is extremely efficient at harvesting grain, and the development of sealed grain silos, means grain is no longer stored in enclosures on farmland, meaning less food for rodents during the long, cold winters, and subsequently less prey for owls.

Today’s farmers are also able to cultivate land that was previously beyond their tools’ means, allowing them to plough right to the edges, resulting in the loss of the Barn Owl’s favoured hunting habitat: rough grassland verges.

The 20th Century has also brought with it other dangers that have taken their toll: road fatalities, potent rat poisons and the loss of nesting spots as traditional barns are pulled down and replaced with less inviting buildings.

There is evidence that numbers of barn owls in the UK have stabilised since the mid-1990s, but clearly these factors are still impacting the species today. While numbers of the UK population of this reclusive, nocturnal species are poorly understood, we can determine the health of the country’s Barn Owl population through the Barn Owl Trust’s annual nest site survey, in which 32 independent local groups from across the country – from Cornwall to Norfolk to Northern Island – pool together to visit nest sites and record the brood size of successful breeding pairs.

The results tell the story of another poor year overall for the Barn Owl – the number of nesting pairs in 2016 was down 6% on the all-year average, and the number of young in the nest was down 7%. While disappointing, the numbers are at least an improvement on 2013 and 2015, two exceptionally poor years where cold weather saw nesting occupancies down 70% and 25% against the all-year average.

Low productivity is clearly becoming a trend, which the Barn Owl Trust attributes to a lack of available prey, and an overall low population density exacerbated by a lack of juvenile barn owls to replace the adults.

The report, which can be read here, recommends several measures to help sustain Barn Owl numbers, including habitat improvement, the installation of low-flight prevention screens around trunk roads to avoid collisions, and replacing existing nest boxes to reduce chick mortality by ensuring the replacements are no less than 460mm deep.

How endangered Southwestern Willow Flycatchers survive in California, USA


This video from the USA says about itself:

25 April 2016

We need your help to defeat an effort by developers and others to remove protected status for the Southwestern Willow Flycatcher. Please visit audubon.org/takeaction to speak up for this great bird.

From The Condor, magazine of the American Ornithological Society, in February 2017:

Female-biased sex ratio, polygyny, and persistence in the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus)

Barbara E. Kus*, Scarlett L. Howell, and Dustin A. Wood

ABSTRACT

Demographic changes in populations, such as skewed sex ratios, are of concern to conservationists, especially in small populations in which stochastic and other events can produce declines leading to extirpation. We documented a decline in one of the few remaining populations of Southwestern Willow Flycatcher (Empidonax traillii extimus) in southern California, USA, which dropped from 40 to 5 adults between 2000 and 2015. Declines were unequal between sexes (94% for males, 82% for females). Adult sex ratios were female-biased in 10 of 16 yr.

The proportion of paired males that were polygynous ranged from 0% to 100%, depending on the ratio of females to males in the adult population. Some males paired with up to 5 females simultaneously.

We investigated the role of nestling sex ratio in the female-biased adult sex ratio by using genetic techniques to determine sex from blood samples collected from 162 nestlings in 72 nests from 2002 to 2009. Both population-level and within-brood nestling sex ratios were female-biased, and were not influenced by nest order (first or subsequent), parental mating type (monogamous or polygynous), or year. Disproportionately more females than males were recruited into the breeding population, mirroring nestling and fledgling sex ratios. It thus appears that a skewed nestling sex ratio has contributed to a female-biased adult population, which in turn has influenced mating behavior.

We propose that the capacity for polygyny, which generally occurs at low levels in Southwestern Willow Flycatchers, has allowed this population to persist through a decline that might otherwise have resulted in extinction.

Sea snails and hermit crabs video


This video says about itself:

Giant Horse Conch & Burglar Hermit Crabs – Blue Planet – BBC Earth

20 February 2017

An amazing Giant Sea Snail makes a meal of a smaller Tulip Snail and it is not long before a group of eager Hermit Crabs seize the opportunity to grab a new home.