Tag Archives: irruption

A “superflight” irruption for North Carolina – the pine siskins

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As mentioned in my previous blog, North Carolina’s Piedmont region is experiencing a spectacular winter irruption of multiple finch species. So many birds have migrated south from the northern USA and Canada that scientists are calling this a “superflight” year. The first to arrive in my yard during this irruption were the pine siskins (Spinus pinus).

Scientists don’t yet know as much about siskin migration as they would like to know. From 1960 to 2011, almost 675,000 siskins were banded but only 2000 of them were ever spotted again.

However, it is known that the siskins enjoy eating many types of seeds. The finches’ usual diets up North center around the fruit and seeds of spruce, pine, hemlocks, maples, and beech trees, among others. Some species favor certain trees, while others enjoy eating a large variety of seeds.

In “mast years,” the forests provide large amounts of seeds that both feed animals (e.g., birds, squirrels) and provide the germination material for new vegetation. In other years, the forests produce very few crops because of fires, drought, and outbreaks of spruce budworms that eat the needles of spruce and balsam firs, which can kill the trees. In 2020, it was noteworthy that authorities in Quebec were unable to completely treat the forest trees for budworms because of the COVID epidemic.

 

Some trees also have slow biological cycles. For example, the Eastern white pine (Pinus strobus), known to the Iroquois as the “tree of peace,” has cone production that peaks every 3 to 5 years.

When mast years have taken place and there are large budworm infestations, the finches have plenty to eat and their numbers increase substantially. When the following seed- and cone-poor years occur, the large populations then need to travel further away to find sufficient food supplies and that is what has now brought them to our area.

The pine siskins arrived in my yard in late autumn. They came in a large crowd, with some 30 birds flocking to the feeders at a time. Most of these little brown and beige birds have a trace of yellow on their wings.

About 1% of the siskins – all males – have more yellow or yellow-green coloring on their backs, heads and under-tail coverts. These so-called “green morphs” also have less streaking on their chests. The siskins above may be in this group. Interestingly, whereas female birds of many species prefer brightly colored males as their mates, female siskins appear to choose males with less yellow to distinguish them.

 

What really distinguishes the siskins for me – in addition to their penchant for visiting in large groups – is their feistiness. They seem to be very troubled by the idea that there may not be enough seeds to satisfy their appetites if many other birds are around.

Below you see them challenging a house finch, a downy woodpecker and cardinals.

 

And this includes not only birds of other species but also their species mates with whom they arrive! They first will open their seed-filled mouths to “yell” at the incoming diners.

Next, they may open their wings in a challenging display.

 

Sometimes they seem to be taking food from another’s mouths! (But perhaps this is not aggressive but a sign of care between family members?)

Finally, they will fly at their food rivals in an effort to drive them off.

Unlike other members of the finch family, the siskins not only eat a very large variety of seeds from conifers, deciduous trees, grasses, weeds and flowers. They also forage for insects and have been seen to drink from sapsucker sapwells in trees.

A group of siskins can clean out a feeder with mixed seeds in my yard in very short order indeed. They have developed body mechanisms to help them survive cold nights: increasing their metabolic rates and gaining body fat for the winter.

 

This is accomplished by eating more seeds than they can process right away; they can store seeds weighing up to 10% of their body mass in their crop (part of the esophagus) for a short period so that they have access to more energy during the night!

 

Some local birders who were delighted to see them at the beginning of the season are now occasionally voicing “regrets” since large groups continue to visit their feeders. They could refrain from putting out seed and hope the flocks move away so they don’t spend so much on bird seed, but many birders would then miss seeing the other species and don’t want to forego that pleasure.

 

 

Fortunately, the siskins have been eating seeds from crepe myrtles and other trees in my yard so their visits to my feeders have been somewhat sporadic when the weather is mild. When it rains or gets very cold, they return in feisty groups!

“My” yard siskins have also refrained from pecking at the cement of my brick house. Other birders have seen them chipping away at chimney and brick cement – they do this get at minerals contained in the cement.

 

While the siskins migrate in very large groups (e.g., flocks numbering up to a few thousand individuals!), they are still considered to be a common bird that is showing a steep decline in numbers. They are vulnerable to predators as well as contagious diseases spread at feeders such as salmonella.

Although we are still in the throes of winter in North Carolina, spring is fast approaching and it’s uncertain how long these irruption birds will stay. I’ll miss these lively little visitors when travel back up North!

A gathering of gorgeous grosbeaks

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If you know birders, you’ve undoubtedly heard that this 2020-21 winter season marks an “irruption” year – a period when large numbers of certain bird species migrate to places where they’re usually not seen. This year is especially notable because it is one of the largest mass migrations that has taken place in about 25 years.

The scientists who study irruptions are calling this season a “superflight,” because all the species in the finch family that breed in the boreal forests of the northern USA and Canada have been moving south. Here in the Piedmont, we’ve been lucky to see several of these species.

The finches that have drawn the most attention from local birders are the evening grosbeaks (Coccothraustes vespertinus) with their eye-catching colors and plumage. They tend to move about in flocks and when they land at feeders, they appear more than willing to share with other birds, like a red-bellied woodpecker (above) or pine siskins (below).

When they land on a feeder, however, they may crowd out others due to their size.

While the evening grosbeaks don’t seem quarrelsome like some other birds, they may still have territorial defense encounters when they are vying for food. Perhaps that is what happened to this female with what appears to be a slight injury below her eye. It is unlikely that it would have come from escaping another type of assault as it has been reported that they have no known predators!

The females are subtly colored in shades of gray-beige with touches of green and yellow on their flanks, neck and near their throat. Their wings are marked with black and white patches.

 

Their coloring may look a bit different depending on the quality of the light and how overcast the day is.

The males are eye-catching due to their vibrant yellow and black plumage, featuring a notable dark yellow stripe over the eyes and a bright white patch on black wings.

Both females and males have the very thick, conical bills characteristic of their species.

Watching them at breeding time would be interesting as it does not involve song but instead features the males dancing for their prospective mates.

In the summer, the evening grosbeaks eat insects, including the spruce budworm, which is a tiny caterpillar. Their winter diet includes large seeds, berries and tree buds; maple samaras (papery winged seeds) and sunflower seeds are favorites (especially the gray-striped kind).

In 2018, a few individual evening grosbeaks were spotted in the Triangle but not many people had the chance to see them. I was fortunate to have three visit my feeders for an afternoon when it was snowy.

This year, none have visited me, but they have been very present in our area, especially at the feeders of bird enthusiasts Bert Fisher and Leto Copeley. This lovely couple welcomed birders to visit their yard by appointment (with limited numbers of visitors wearing masks in the large area).

 

Bert kindly updated everyone on the birds’ comings and goings. Their number increased over time to a high count of over 60 birds seen at one time. They often sit high in the trees of the wooded property and then suddenly descend to sit in groups on platform feeders and to pick up fallen seed on the ground.

Over time, the evening grosbeaks have expanded their “territory” over the Northeastern USA, partly in response to increased planting of boxelders (Acer negundo, a type of maple) as shade trees. The seeds of the box elder are available throughout the winter and are a preferred food for these large finches.

Like numerous other bird species, evening grosbeak populations have declined steeply over time. Between 1966 and 2015, their numbers on the East Coast declined by 97%. Continued logging of forests in northern North America, avian diseases, aerial spraying of insects and climate change may all contribute to further reductions of this group of birds.

Researchers are now collaborating in an Evening Grosbeak Project that aims to compare flight calls, genetics and breeding behaviors of five distinctive sub-groups in this species. They are distinguished by the types of calls that they make and birders are asked to help out by submitting recordings to the eBird website.

It appears that Type 3 (Coccothraustes vespertinus vespertinus, the most irruptive of all five sub-groups) is the call type which has traveled to our area. It has a call that is similar to that of a house sparrow.

Some northeastern grosbeaks are now being tracked by the Project. An avian ecologist with the Pennsylvania Natural Heritage Program recently was able to band 47 birds so that sightings of them elsewhere can be reported. He also put a new model of solar radio tracking tags on 29 of the birds, which can help monitor their movements throughout their lifetime.

Evening grosbeaks can live well into their teens; the oldest banded individual was found when he was 16 years and 3 months. Perhaps some of those visiting us this year have been here before during food-poor periods up North. It will be interesting to see when they next decide to visit our area in the future and hopefully a few will visit me.

 

I’ve added some of the trees that tend to attract them, such as winterberries, maples and crabapples, to complement the junipers, pines and elms in my yard, so the welcome mat will be out!

My special bird in autumn 2018

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Well, having had time to finally process photos as the year end approaches, I’m “on a roll” with posting blogs in contrast to other months in 2018. I have two more to post on mammals this year. This one is to commemorate a real birding treat that came to me during the snowstorm that was featured in my last two blogs.

 

There had been reports on birding sites and listservs that some bird species which usually don’t come too far south during the winter were on the move this year to warmer climes. They included birds that sometimes arrive in North Carolina (NC) in winter, but who don’t always come in large numbers (an “irruption”) such as pine siskins (Spinus pinus, above) and purple finches (Haemorhous purpureus, below).

  

I’ve also been lucky to see red-breasted nuthatches (Sitta canadensis), another irruption species, either in my yard or on nature walks.

 

So why are they coming here in numbers?  It turns out that trees in the northern boreal forests are not producing enough food sources that these birds need to survive winter weather such as conifer seeds and berries (from trees such as hemlock, spruce, firs, alders and larch).

What was really exciting for birders in NC, however, was that some other bird species are also seeking new winter foraging areas. They include redpolls, crossbills and the gorgeous evening grosbeaks (Coccothraustes vespertinus) who are seen here only rarely.

I had only ever seen a photo of these grosbeaks and thought it would be fun to see one in person. Members of a listserv mentioned that these grosbeaks had been spotted in Virginia, just above the NC border, so we should be prepared to perhaps see them.

On my visits to the Brumley Nature Preserve, I spent time in the spruce areas in the hope of spotting one, but I had no such luck. And then as the snow was falling heavily on the first morning of our snowstorm, I caught sight of a bright yellow and black bird on a feeder as I looked out my window. Lo and behold, when I grabbed my camera I discovered a male evening grosbeak on a feeder!

What was even more exciting was that he was accompanied by two female birds, both of whom were very lovely as well. I took lots of photos.

They finally flew off and I counted myself very lucky indeed. A while later, when the snow had stopped for a while, I was watching the feeders again and the threesome returned to my delight. They fed and then rested on feeder poles.

I tried to go outside quietly so I could photograph them without a window between us but they were quite skittish and left quickly as soon as I appeared. They flew to the tops of nearby tall pines and then disappeared off into the distance. They were not shy when I stood in front of the living room window, however.

The trio reappeared a third time and I stayed behind the window to admire them. It was interesting to see how they could look different, depending on their posture. The bird above looked “tall” as it fed next to the Eastern bluebird. And then the other looked fat and fluffy on the feeder pole – even looking as if it had an outsized head when it leaned forward a bit!

 

They left in the afternoon and did not return, even when it snowed again the next day. A fellow birder who lives northwest of me spotted a male evening grosbeak on one of her feeders that day – the birds were obviously en route to another destination. I hope they found a good food source area for the rest of the winter. And my photos will remind me of their wonderful visit, which made this snowstorm one to remember. 😊

Back to blogging with the golden crowns!

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Litter boxes scrubbed, bird feeders filled, other chores waiting but I’ve decided to end my blogging hiatus on this rainy and somewhat gloomy Sunday morning. This and my next blog will feature two of my favorite birds and then I hope to treat you with a nesting saga as spring is well underway.

With a lovely ruby-crowned kinglet visiting my yard every year for the past four years, I’ve developed a particular fondness for this tiny avian species. This past autumn and winter, my partiality expanded to include their jeweled cousins, the golden-crowned kinglets (Regulus satrapa), who seemed to have favored our geographical area with an irruption (an ecological term for a sudden increase in an animal population). Whereas in previous years, I felt lucky to catch a glimpse of a golden crown during their months-long stay in North Carolina, they appeared to be everywhere this past winter and in full view to boot.

 

The golden-crowned kinglets are about the same size as the ruby crowns and similar in overall body color except that they also have a black eyebrow stripe.

While the ruby-crowned males only flash their red crests when mating or upset, however, the golden crowns have a permanent yellow stripe atop their heads.

 

         

The male golden crowns can sometimes be distinguished by the fact that there will be a hint of red in their golden crest.

         

Like the ruby crowns, these little insect foragers are in constant movement as they scour branches, shrubs and plants for a meal. Their varied diet includes beetles, flies, crickets, butterflies, spiders, and bees and wasps. In the winter, they will also eat some seeds.

     

Searching for the insects often means they hang upside down from branches as they look at the underside and in crevices for their next bite to eat.

 

They also hover mid-air to snatch an insect or fly.

The golden crowns sometimes sit still a bit longer than ruby crowns so that you have a chance to get off a few photographic shots before they resume their dietary searching. And this year, one of those photos placed me among the winners in a small local competition.

These birds are not much bigger than hummingbirds, but like the hummers, they also undertake a long migration twice yearly. Their winters are spent throughout North America but for breeding they travel to the far North and mountainous Northwestern areas of this hemisphere.

This year, many places had mild winters but if they arrive in the North before spring-like temperatures arrive, they are able to survive nights as cold as –40 degrees; sometimes, they huddle together to keep a bit of warmth. Their lifespan is several years, with the oldest recorded golden crown being a banded male who was at least 6 years and 4 months when he was recaptured in Minnesota in 1976.

       

 

This species prefers life in coniferous forests but it seems if a few spruce and pines are around, they will settle in. I saw them in a small and somewhat sparsely vegetated area near a senior center, an arboretum, along the Haw River, and in the woods and bogs of various nature reserves.

 

 

In the United States, the number of golden-crowned kinglets declined 75% between 1966 and 2014. Habitat loss has contributed to this. However, spruce reforestation in the Eastern USA may have contributed to a more recently seen increase in numbers of kinglets. I’m very glad that they are not (yet) an endangered species and I hope we get to see them a lot next winter, too!