A third look at our 2020-21 “superflight” irruption – red crossbills

As mentioned in my last couple blogs, finches that usually reside in Canada and the northern USA have come south this year because of a dearth of food in their usual habitats. One of the factors contributing to the shortage is the varying cycles in which cones, seeds and fruit ripen among different tree species.

Not every tree produces an equal amount of seeds or berries every year; for example, this year my red cedars didn’t have very many juniper berries and by the time the cedar waxwings arrived, the American robins (Turdus migratorius) had already cleaned out the crop. Periodically, many of the different tree species up North have low seed production at the same time, so that birds who eat different kinds of crops all need to go elsewhere for sustenance in the winter.

An interesting speculation from scientists in the Finch Research Network is that this synchronized low seed production evolved as a means of limiting food supplies for seed-eating (red) squirrels who could reproduce greatly and then wipe out all the seeds so that no new trees would grow. Jamie Cornelius, a researcher at Oregon State University, explained that “birds are mobile, and can find cone crops somewhere else,” while the sedentary squirrels then need to curtail their reproduction. In addition, some birds have evolved biological processes that make it easier for them to cope with food scarcity.

Red crossbills (Loxia curvirostra, called common crossbills in Europe) molt quite slowly, losing only a few feathers at one time, which makes it possible for them to fly elsewhere at any time in search of sustenance. They are normally not migratory but will travel for food, so in December 2020, local birders were quite excited when red crossbills were spotted at a state game lands in a neighboring county.

I was not enthusiastic about going to a hunting zone but had heard that the duck hunters were usually only busy early in the morning. So I donned my bright orange vest and ventured out on the two-mile walk to the spot where the crossbills had been seen. I waited around for a couple hours but they didn’t show, although I was looking for the reddish males and yellow females to make an appearance.

I didn’t give up. On my fourth visit to the game lands, I finally saw the crossbills (although I didn’t realize it immediately as they were so far away and my cataracts make seeing anything distinctly at a distance quite difficult. It was only after I enlarged one photo on the camera that I saw what they were! Remember, you can see a photo larger if you click on it and then back arrow to the blog).

I first thought perhaps some grosbeaks had flown in, so I focused as well as I could on the distant trees and took photos. I was thrilled to see that I had finally photographed those elusive birds – giving me a “lifer” for 2021. 😊

Sometimes it’s not easy to understand why a certain bird species has a particular common name. For example, many people would call a red-bellied woodpecker a red-headed woodpecker because the red on the head is much more noticeable than the hue on its belly. But the crossbills exemplify their common name quite accurately with their upper bills that curve down over their lower bills. A good view of their beak can be seen at the All About Birds website.

At first sight, one might think that this beak arrangement would make it difficult for them to eat, but this morphological adaptation means that they can extract seeds from conifer cones that are still closed, which other finches cannot do. Their bill structure makes it possible for them to hold onto a cone, pry it open with their beak and then take out the tightly-packed conifer seeds with their tongue.

This specialized anatomical feature does restrict the crossbills’ diet somewhat. They do eat some other seeds, berries and insects from time to time and they also ingest grit and sand from time to time as having these substances in their crop helps them to digest the conifer seeds.

What also makes these finches very unusual is that there are at least six – and perhaps as many as 11 – sub-species in North America who differ in the size and shape of their beaks and the type of calls they make. Their unique vocalizations has led to each sub-group being designated as a “call type” and each type feeds on a different conifer species. They move about in groups and call to each other while flying from tree to tree. Some scientists think they may be communicating about the feeding possibilities in each cone-laden tree they pass!

Another behavior that is distinctive for the red crossbills is that they breed at any time of the year, whenever sufficient food supplies are available. When a female and male form a breeding pair, they imitate one another’s flight calls so as to keep track of one another.

 

Unfortunately, unlike other irruption species such as evening grosbeaks and pine siskins, the red crossbills are rare visitors to bird feeders.

When I heard that crossbills had been seen at a game lands area much closer to my home, I made a couple more treks in hopes of spotting them. The first day I was incredibly lucky as I was the only person visiting the reserve and could walk at a leisurely pace in quiet fields except for the chittering of multiple bird species, including a hermit thrush.

Unfortunately, I didn’t manage to see any crossbills flying overhead. Another visit to this nearby game land was shortened considerably when I discovered it was quite noisy with two hunters accompanied by a pack of baying hounds who were yowling very loudly and frequently. I high-tailed it out of the reserve and resolved to be happy with my one and only crossbill sighting (so far). Hopefully, one day I’ll be able to see them more closely – something to which I can look forward with great anticipation!

Some beauty to offset a distressing week

This past week in the USA has been rather distressing as far as health and politics are concerned. The COVID epidemic is wreaking havoc and then humans wrought havoc during a procedure intended to be part of a peaceful transition of governmental power. So we can all use a bit of distraction to remind us there is also still beauty in the world and I’ll end my last trio of posts with one more view of hummingbirds – this time featuring the one species that visits my home every year, the ruby-throated hummingbird (Archilochus colubris).

Fortunately, my yard now has several types of plants that offer the hummers natural nectars to complement their primarily insectivorous diet.

The rose of Sharon (Hibiscus syriacus) flowers are a popular feeding site.

They are also fond of the blue-black sage (Salvia guaranitica). My original plants were a gift from birding friend, Gail; now they are growing in four areas of the yard. Sometimes a hummer doesn’t want to hover but uses a nearby prop to offer some less strenuous feeding. And then the bird can close its eyes to thoroughly enjoy the sweet sap.

Hot lips sage shrubs (Salvia microphylla ‘Hot Lips‘), which I got at a garden center, have proved to be popular feeding sites. This is quite a hardy plant.

The hummers also like going to the lantanas (Lantana) and the yellow passionflower (Passiflora lutea), which kindly came to my yard on its own.

 

Another popular plant is the butterfly bush (Buddleia davidii).  Many recommend against planting this bloomer because it can be invasive. However, some garden centers have developed varieties that scarcely seed and that must be what I luckily got as it has never appeared anywhere else in the yard in more than a decade.

It also attracts butterflies, bees, syrphid flies and hummingbird moths, so I’m quite happy with my butterfly bush.

The ruby-throats also do like their nectar, however. After visiting various flowers, they often take a seat near or on the nectar feeder so they can sip at their leisure.

 

They will also do their best to keep other hummers away from the nectar feeder — even when I have as many as three or four feeders available.

They keep an eye out for intruders.

When a rival appears, it can lead to confrontations. Mostly these involve aggressive displays and chasing one another; only very rarely have I seen them actually physically engage.

This past summer, a few laid-back moments occurred when they tolerated one another.

It’s not only the males who are aggressive; female hummers can also be quite protective of feeding grounds. This past year, it seemed that I had mostly males visiting. While a female hummer can have one or two red spots under her chin, usually that is the beginning of a young male developing his ruby-throat.

It can be fun to watch as more spots appear with passing days.

 

Eventually, the males get their fully developed gorget, which can be quite stunning.

The red hue is very dependent on how the light hits their feathers. In some cases, the red feathers almost look black.

  

The hummers take care to groom their feathers.

They take advantage of the rain to have a shower.

There are times when they look a bit scruffy, however. That is when they molt. This process of replacing old feathers with new ones usually takes place on their wintering grounds. This past summer, the hummers seemed to have lingered longer than usual and began molting before their trips further south.

White feathers appear more and more as molting proceeds. And feathers come loose before falling away.

They can look a bit scruffy during this time.

Eventually, they get back to their pretty selves. It always stays fun to watch them flying — at least for me. That is when you can see their tiny feet better.

And you get an idea of how rapidly their small wings move as they hover and soar.

They can beat their wings up to 70 times per second!

It doesn’t seem to me that I’ll ever tire of watching these tiny fliers; they always are entertaining. I hope seeing some photos of them in action have provided you with a brief respite from the worries of the world, too.

Hoppers – insects not frogs!

leafhopper IMG_7673©Maria de BruynMuch of the insect world consists of animals that we usually don’t even see or notice because: a) we don’t know they exist and therefore don’t look for them and b) they are tiny and only well visible with an enlarging lens. But once you get a good look at them, they turn out to be fascinating and sometimes quite attractive. One group of these insects is the hoppers – leaf- and planthoppers, that is, like the gray lawn leafhopper (Exitianus exitiosus) to the left.

As their name indicates, leaf- and planthoppers jump to get around, but they also move by flying, scuttling sideways like crabs, or walking slowly or quickly along plant stems and leaves. Both juveniles and adults are very aware of what is around them and if you do manage to spot one, you’ll see that they are watching you and, for example, may move underneath a leaf to get away from you.This broad-headed sharpshooter (Oncometopia orbona) stayed still for a moment.

Broad-headed sharpshooter IMG_9350©Maria de Bruyn (2)

Acanaloid hopper nymph IMG_8738©Maria de BruynLeafhoppers are only 1/16 to 5/8 of an inch (2-15 mm) long. About 20,000 different leafhoppers have been described around the world; they feed by sucking plant sap from grass, shrubs, or trees. Planthoppers, some of which look like leaves and may be a bit bigger, also feed on plants.The nymphs (juveniles) are tiny, too, as seen in this photo where you see my fingertip above the nymph of an Acanaloid planthopper .

Leafhoppers, such as the speckled sharpshooter (Paraulacizes irrorata) below generally have wide, flattened and pointy heads with large eyes.

speckled sharpshooter IMG_1059©Maria de Bruynsigned

Planthoppers come in different forms and, in tropical countries, some of them are quite unique. While many keep their wings flat against their bodies, the derbid planthopper (Mysidia mississippiensis) looks like Derbid planthopper IMG_0717©Maria de Bruyn (2)a delicate little fly while resting.

Leafhoppers’ hind legs are covered with hairs that help them spread a secretion over their body which is water repellant. Some planthopper nymphs’ back legs have gears that help them jump away in the blink of an eye.

Versute sharpshooter IMG_1179©Maria de Bruyn (2) Versute sharpshooters (Graphocephala versuta) in love

 

 

 

Broad-headed sharpshooter 772©Maria de Bruyn

The female broad- headed sharpshooter (Oncometopia orbona) develops white spots on her wings, which are egg brochosomes; these indicate she is ready to oviposit (lay eggs). These spots are made of a white waxy secretion that she places there; they dry to look like “chalky” spots. After she inserts her eggs into a plant, she uses her hind legs to scrape off the brochosomes onto the oviposition site as a way of hiding the eggs from predators.

 

Leaf- and planthopper nymphs can look as if they are completely different insects from the adult forms. As they mature, they begin to look similar to adults but are often of a different color and don’t yet have full wings. Below you see the colorful adult glassy-winged sharpshooter (Homalodisca vitripennis) and below that some nymphs of this leafhopper.

glassy-winged sharpshooter IMG_8955©Maria de BruynGlassy-winged sharpshooter IMG_8996©Maria de Bruyn

Glassy-winged sharpshooter nymph IMG_9008©Maria de BruynGlassy-winged sharpshooter nymph IMG_8910©Maria de Bruyn

As juveniles, hoppers go through a process called ecdysis. They pass through several stages to reach adulthood, molting and leaving behind their old exoskeleton in order to grow. They are called instars during these stages.

Leafhopper ecdysis IMG_9286©Maria de BruynLeafhopper ecdysis IMG_9325©Maria de Bruyn

Leafhopper ecdysis IMG_9379©Maria de BruynThe instar stages of the same hopper can look very different from one another, including color changes. Some of the nymphs, with their striped faces and big eyes, look to me as if they’d be great models for cartoon characters or Halloween masks like these coppery leafhopper juveniles (Coelidia olitoria).

Coppery leafhopper nymph IMG_9631©Maria de BruynCoppery leafhopper nymph IMG_2058©Maria de BruynCoppery leafhopper nymph IMG_2070©Maria de Bruyn (2)

Acanaloniid planthopper nymph Acanalonia bivittata IMG_8201©Maria de BruynresPlanthopper nymphs, like the two-striped planthopper (Acanalonia bivittata) and the Acanalonia servillei below, are known for producing waxy strands from their bodies which repel water. These strands also help protect them from predators, who might grab onto the showy white hairs, which break off so that the hopper can escape. The nymphs can ultimately be entirely covered in white wax.

Two-striped planthopper nymph IMG_9517©Maria de BruynAcanaloniid Planthopper nymph Acanalonia servillei IMG_8943©Maria de Bruyn

The colors and patterns on the adults can be quite beautiful, especially on the leafhoppers in the area where I live. The planthoppers tend to be white, gray or green. The colors on the coppery leafhopper are wonderful and varied.

Coppery leafhopper IMG_9646©Maria de Bruyn resCoppery leafhopper IMG_2160©Maria de Bruyn

Citrus flatid planthopper IMG_3201©Maria de BruynFlatid planthopper IMG_8772©Maria de Bruyn

Citrus flatid planthopper (Metcalfa pruinosa) and flatid planthopper (Acanalonia conica)

Sharpshooter Sibovia occatoria IMG_0126© Maria de BruynRed-banded leafhopper IMG_6376©Maria de BruynsignedLeafhopper Texananus IMG_1546©Maria de Bruyn

Sharpshooter (Sibovia occatoria), Red-banded sharpshooter (Graphocephala coccinea) and leafhopper (Texananus)

Leaf hopper Chlorotettix IMG_7677 M de BruynLeafhopper - Coelidia IMG_2649©Maria de Bruynhopper 4 IMG_8029©Maria de Bruynsigned
Leafhopper (Chlorotettix), leafhopper (Coelidia) and leafhopper (unidentified species)

As tiny as these insects are, they can be parasitized and play host to even smaller insects. This flatid planthopper (Ormenoides venusta), for example, was carrying red mites that weren’t harming it but hitching a ride. It must be annoying though.

Flatid planthopper Ormenoides venusta IMG_9737©Maria de BruynFlatid planthopper Ormenoides venusta IMG_9763©Maria de Bruyn

hopper 4 IMG_8036©Maria de BruynsignedI imagine there are many more interesting behaviors to observe with the hoppers. Maybe one day I will get a macro lens so that I can really get some good photos of these cute little insects. In the meantime, as there are several thousand species in North America, I can look forward to finding new ones – with my camera in hand as I wouldn’t be able to see anything but specks on plants without it!