Tawny owl and mushroom


Mushroom, 6 September 2020

This a Parasola sp. mushroom which has suffered from drought. This 6 September 2020 cellphone photo is from a woodland near Joppe in the Netherlands.

That day, dozens of goldfinches and also some blue tits feeding on sunflowers along the road.

During the night, male and female tawny owl calls.

Pygmy owls threatened by climate change


This April 2018 video says about itself:

In an old forest in France, we meet a pygmy owl family and discover the feeding and young owls just going out of the niche.

I was privileged to see a pygmy owl near Turku in Finland.

From the University of Turku in Finland:

Climate change may melt the ‘freezers’ of pygmy owls and reduce their overwinter survival

August 5, 2020

Ecologists at the University of Turku, Finland, have discovered that the food hoards pygmy owls collect in nest-boxes (“freezers”) for winter rot due to high precipitation caused by heavy autumn rains and if the hoarding has been initiated early in the autumn. The results of the study show that climate change may impair predators’ foraging and thus decrease local overwinter survival. The study has been published in the internationally esteemed Global Change Biology journal.

Doctoral Candidate Giulia Masoero together with co-authors from the Department of Biology at the University of Turku analysed the unique long-term data set collected by Professor Erkki Korpimäki and his research group in 2003-2018. The aim was to study how the changing weather conditions in late autumn and winter affect the initiation of pygmy owls’ food hoarding as well as the accumulation, use and preservability of the hoarded food. The data set was collected from the Kauhava region in South Bothnia with over 500 food hoards and a research area covering 1,000 square kilometres.

Pygmy owls are small predators that feed on small mammals, especially voles which are their main prey, and birds. Pygmy owls start hoarding for winter usually in late October when the temperature drops below 0° C. They hoard a large amount of prey in tree cavities or nest boxes.

The food stores may be located in multiple nest boxes some kilometres apart. Female owls that are larger than males as well as young owls accumulate larger food stores than males and adult owls.

According to Erkki Korpimäki, the hoarded food is important for pygmy owls during winter, when small mammal prey are under snow and birds are scarce.

“This hoarding behaviour is highly susceptible to global warming because the weather during autumn and winter can affect the condition and usability of the food stores. In several northern areas, autumns have already become warmer and winters milder and rainy. Predictions show that climate change will likely continue along this path and the length of winter will strongly decrease.”

According to the study, the more rainy days there are between mid-October and mid-December, the more likely the food hoards of pygmy owls are to rotten. The owls use rotten food hoards particularly during poor vole years. However, the study showed that having rotten food hoards reduced the recapture probability of female owls in the study area, meaning female owls either die or are forced to leave the area.

“This result indicates that either the use of the rotten low-quality food and/or the energy waste linked with collecting a large food store that will not be used can lead to lower survival or dispersal from the study area,” notes Doctoral Candidate Giulia Masoero.

Pygmy owls might be partly able to adapt to climate change by delaying food hoarding but will more likely suffer due to the changes caused by the warming climate. The results of the study together with global climate predictions thus suggest that climate change has the potential to strongly impair the foraging behaviour and food intake of wintering predators, likely having negative impacts on the boreal forest food web as a whole.

How barn owlets help each other


This 2017 video is called Bringing Up Baby: How barn owls do it.

By Pratik Pawar, June 16, 2020, at 6:00 am:

Barn owlets share food with their younger siblings in exchange for grooming

Such cooperation is thought to be rare among the young of other birds

If ever there were a competition to rank sibling relationships in the animal kingdom, barn owls would be close to the top. That’s because elder barn owlets will sometimes give away their meal to their younger siblings. Such cooperative behavior has been reported in adult nonhuman primates and birds, but rarely among young (SN: 2/6/12).

“I don’t know any other species where you can find it,” says Pauline Ducouret, an evolutionary biologist at the University of Lausanne in Switzerland. But scientists weren’t sure what prompted the food sharing. Now, observations of nests show that elder barn owlets offer their food to their younger siblings in exchange for grooming, Ducouret and her colleagues report in the July issue of the American Naturalist.

Barn owls (Tyto alba) raise six chicks at once, on average, and sometimes as many as nine (SN: 9/19/17). But not all chicks hatch at the same time, which means that elder chicks are usually healthier and larger than their younger brothers and sisters.

That’s because all chicks are entirely dependent on the parents for food, and food, in this case, is usually a small rodent, like a vole or a shrew, that can’t be easily split. So at any given visit, mom or dad can feed only one chick at a time. In many bird species, the eldest siblings would simply outcompete the rest, but not barn owls.

To understand the seeming generosity of the elder birds, Ducouret and her team observed 27 broods of barn owls across the Switzerland countryside. The scientists videotaped each brood for two consecutive days and nights to understand how the owlets interacted and attached a tiny microphone backpack to each chick to help identify individual calls.

The team found that older chicks preferentially shared food with the younger siblings that extensively groomed them. And younger owlets, in general, groomed elder siblings more often than the older ones groomed the youngsters, “perhaps to maximize the probability of being fed in return,” the researchers write. In some cases, an elder chick would also offer food to the neediest sibling, which called out incessantly, irrespective of whether it groomed or not.

But food sharing occurred only when the researchers provided extra food to the owlets. So it wasn’t a case of the older chicks risking their survival to feed the youngsters. But when there was enough food to go around, the elder siblings chose to share instead of hoard.

“[It’s an] interesting study with a large sample size and technically nice observation techniques,” says Ronald Noë, a retired behavioral ecologist from the Netherlands who was not part of the research. “One usually reads about competition among siblings and even siblicide,” he says.

Ducouret says that this food-sharing behavior could have evolved because the elder siblings enjoy both indirect and direct benefits. Being groomed offers such immediate boons as protection against parasites like lice or fleas. Grooming could also reduce conflict and social stress among the owlets. And, by helping their genetically related younger kin survive, the elder siblings ensure that more of their genes stay in the gene pool, thus indirectly benefitting themselves in the long, evolutionary run.

Screech owl fledglings in the USA


This 10 June 2020 video from the USA says about itself:

The three Screech Owl kids are alive and well and all paid a special visit to the Backyard with their Dad the other evening. I was fortunate to be able to get in on video in the fading light so you all could see them, especially those who watched the live feed of the development. Most of the quality time was spent with the eldest and largest “Riker ” but at the end, the little one “Finito” made a brief appearance. All is well!

How to photograph little owls


This 31 May 2020 video from Britain says about itself:

Wide Angle Little Owl Photography | How I Took This Shot

One of the wonderful things about wildlife photography is the unexpected which can lead to one of those memorable moments and images.

In this video, I take you along to my little owl site – a bird I simply love to photograph, and explain the wide-angle techniques I use to create dramatic images with a very different perspective than that you get when using a long telephoto lens.

I hope you enjoy it, take care and continue to stay safe.

Rare eagle-owls nest in flowerpot


This 18 May 2020 video, recorded in Belgium, says about itself:

Man shares apartment with family of huge owls | Vroege Vogels

We could hardly believe it when we got a message from Jos Baart telling us that Europe’s biggest owl, the Eurasian eagle-owl, had made a nest in a planter in front of his window. Not only that, she had also hatched three giant chicks! Now, when he watches television, three huge chicks watch television with him.

Vroege Vogels is a Dutch radio and television show about nature, environment, climate and animal welfare.