Mammals on the move

As spring progresses, we’re seeing ever more mammals on the move. They’re mating and having young and in search of extra sustenance for these activities. The animals whom we unfortunately see dead alongside — or on — roads often include members of the rodent group: groundhogs, squirrels and chipmunks.

Would you be surprised to discover that about 40% of all mammal species are rodents? When people hear that term, many immediately think of rats and mice (i.e., “vermin”) but the group is more diverse. What they all have in common is a pair of incisor teeth in their upper and lower jaws which never stop growing.

groundhog P3203437© Maria de Bruyn (2) res    groundhog P2249052© Maria de Bruyn sgd res

The woodchucks (another name for groundhogs, Marmota monax) whom I’ve seen the past couple months have been seeking food at two local reserves. The name woodchuck does not indicate one of their activities, however. It comes from the Native American name “wuchak,” which means “digger”.

groundhog P3203312© Maria de Bruyn (2) res

These rodents are fairly solitary but live near family members. They greet one another, with one individual touching the other’s mouth with his or her nose. Their ever-growing teeth are bright white, unlike the dingier teeth of other rodents.

groundhog P3203339 © Maria de Bruyn (2) res  groundhog P2249047© Maria de Bruyn (2 res)

They have both summer and winter dens in well-drained areas. The summer abode is near food sources and the winter one is situated near areas with protective cover. Their ear canals are kept clean while they burrow because their round ears can cover the auditory opening, so no dirt or debris gets in. They usually have more than one entrance to dens with multiple tunnels and spaces, including an escape hole!

groundhog P3203375© Maria de Bruyn (2 res)

groundhog P2248981© Maria de Bruyn res

If there is danger, they call out a warning by giving a high-pitched whistle, which has led to them also being called “whistle pigs.” They also use other vocalizations and scent glands to communicate with one another. To escape predators, these hefty mammals can climb trees.

groundhog P3203306© Maria de Bruyn (2) res  groundhog P3203338 (2) (2) res

groundhog P2249010 © Maria de Bruyn res

We may not see the groundhogs too often — unless you have a garden. They enjoy eating alfalfa, dandelions and clover, but I can attest to their penchant for savoring tasty vegetables like tomatoes. One came up onto my porch to sample the wares in my container garden! In my experience, however, they tend not to stay around too long.

Eastern gray squirrel P2090522© Maria de Bruyn (2 res)

Eastern gray squirrel P2218598© Maria de Bruyn (2 res)A rodent that we may see much more often in yards, parks, public gardens and along trails are the Eastern gray squirrels (Sciurus carolinensis). Some people find them amusing to watch, while others wish they would just go away — especially birders who end up spending more on bird food than they planned because these clever rodents find innumerable ways to get up onto bird feeders. Facebook groups for birders regularly have postings by people asking for suggestions on how to thwart squirrels from gaining access to their feeders.

Eastern gray squirrel IMG_0418© Maria de Bruyn (2) resI, too, continue with ongoing efforts to outwit these feeder marauders. They are not shy, coming up on the front porch to look in on my indoor cats.

They jump from trees onto the roof and then perch at the edge, calculating whether they could accomplish a far enough jump to reach some feeders.

Eastern gray squirrel P6170627© Maria de Bruyn (2) res      Eastern gray squirrel P6170625© Maria de Bruyn (2 ) res

I’ve moved my feeder poles away from trees, roofs, tall bushes and shrubs numerous times since squirrels can successfully launch themselves to a feeder 10 feet away.

Eastern gray squirrel P5255669© Maria de Bruyn (2 res) In my yard, they have gnawed at the bottom of a baffle designed to keep them off poles as they try to pull it down. Their ability to chew through plastic and metal may be one reason that they manage to keep their dentition to “normal” lengths since their teeth grow about 6 inches per year.

Eastern gray squirrel P5255651© Maria de Bruyn (2) res

Eastern gray squirrel P5255633© Maria de Bruyn (2) res

In the past week, one especially athletic individual has figured out how to jump over the baffle from the ground to get to feeders.

Eastern gray squirrel P2197722© Maria de Bruyn (2) res

Eastern gray squirrel P2197741© Maria de Bruyn (2 res)

I raised the baffle and put chicken wire on it in an experiment to see if this would deter this determined rodent. It didn’t. I finally put a second sloping baffle above the tube baffle and the squirrel slid off in its latest attempt to get to the fruit and nuts.

Eastern gray squirrel PA241931© Maria de Bruyn res (2)Many nature observers do admire squirrels’ cleverness. For example, squirrels spend a lot of time hiding food in caches dug in the ground. To outwit other squirrels and rodents who might be watching, they will prepare a hole, pretend to deposit food, and cover it up. Then they will go somewhere else where they don’t see a rival watching and hide the food in another place.

An anatomical peculiarity these animals share with other rodents is that they are unable to burp, have heartburn or vomit. (How this was discovered is probably something I don’t want to know.) They also can suffer from insects, carrying ticks and having botflies lay eggs under the skin as happened to this individual whom I spotted in a city park.

Eastern gray squirrel PA170160© Maria de Bruyn ed (2) res

Scientists have determined that gray squirrels’ spatial memory is excellent as they later are able to retrieve about 80% of food stored in their numerous (up to several thousand!) caches. One university study showed that almost two years after some squirrels learned to solve a tricky problem to gain access to a desire food, they were still able to recall the solution to the problem.

Eastern gray squirrel P6267310© Maria de Bruyn res (2)

The squirrels are quite vocal and have a variety of calls, including chattering, squeaking, raspy noises and one particular call that I have come to recognize as a warning that a hawk is near the yard. And they not only avoid predators but have been shown to be able to remember whether people are their friends or enemies!

In our area, the number of gray squirrels is quite high, even when they are often hunted and caught by local predators. It would surprise some of my friends and neighbors, I’m sure, if they learned that, in July 1856, a crowd went to New York City’s (NYC) Central Park to see what was then considered a rare gray squirrel! Other cities also had low numbers; in 1847, Philadelphia initiated one of the first squirrel reintroduction projects, followed by NYC, Boston and other municipalities.

Eastern chipmunk PC292310© Maria de Bruyn (2) resA rodent that many people tend to like more than groundhogs and squirrels is the diminutive Eastern chipmunk (Tamias striatus). The “cuteness” factor undoubtedly plays a role as these active little animals do tend to look a bit endearing.

   

They also look amusing to many people when they are filling their cheek pouches to carry food home. These pouches can stretch to three times the size of their heads so that they can build up a sizeable store of saved food for winter.

Eastern chipmunk IMG_0243© Maria de Bruyn (2 res)

Because they have two litters a year, encounter so much competition for seed and nuts, and because they must work hard to gather supplies, I have on occasion given them a little dish of food for them to gather with ease. Since I just love watching them, I get something out of it, too.

Eastern chipmunk IMG_0273 © Maria de Bruyn (2 res)

Eastern chipmunk P6094693© Maria de Bruyn (2 res)

These rodents live in burrows dug about 3 feet underground. The multiple “rooms” (one used for nesting and others for food storage) can be connected by alleyways up to 30 feet or so in length. They can also climb; one individual in my yard has been imitating the squirrels who run up my bird feeder poles.

Eastern chipmunk PB283524© Maria de Bruyn res   Eastern chipmunk PB283523© Maria de Bruyn res (2)

Eastern chipmunk P2010412© Maria de Bruyn (2 res

My observations have convinced me that these little creatures are very brave. When I’ve spread some bird seed on the ground, they will join the towhees, robins, sparrows and other birds to feed. When squirrels move in and try to chase them off, they will retreat but only for a minute or so and then they return to continue gathering seed.

Eastern chipmunk P3022838© Maria de Bruyn ed (2) res

One day, some white-tailed deer moved in to also eat some of the seed on the ground. A chipmunk was there, and one deer very tenderly nuzzled it a bit in a non-aggressive way. The brave little rodent, confronted with a touch from a being hundreds of times its size, just kept filling its pouch! It was a touching moment (poorly photographed through the screened porch but nevertheless showing the event).

Eastern chipmunk P1304359 © Maria de Bruyn ed res

Because chipmunks don’t tend to eat vegetable garden plants or figure out ways to deplete bird food sources, they may be the rodent that people like best among the garden and field visitors.

Eastern chipmunk P1304354© Maria de Bruyn res (2)

Eastern chipmunk P3022806 © Maria de Bruyn (2 res)

If you take the time to just observe these three commonly seen mammals, however, you might find that they all have behaviors you find interesting and/or amusing. So please try not to hit them on the road. Tolerating their presence, especially given how much of their wild habitat has been destroyed, means that we are at least helping promote biodiversity in our environment.

Eastern chipmunk P3044769 © Maria de Bruyn (2) res

A star performance!

 

Who is this above? Read on below for a few looks at a usually highly elusive bird.

But first, let me say that in the Piedmont region of North Carolina (NC) spring is an especially nice season with abundant flowers and many birds filling the air with lovely courtship calls and songs. Sometimes, you get a little confused when walking in a reserve — thinking there are several species of birds in the vicinity to judge by all the different vocalizations, but then you discover you are hearing a concert by one of the avian mimics — Northern mockingbirds, brown thrashers and gray catbirds are both talented imitators of other birds’ calls.

While the mockingbirds repeat other birds’ notes three times each, brown thrashers (Toxostoma rufum) sing out two repetitions of other species’ songs, interspersed with a large variety of their own calls. A thrasher has been serenading lately near one of a local nature reserves’ ponds. On this occasion, s/he had an Eastern towhee audience (Pipilo erythrophthalmus).

       

A bird that does not have a lovely call, the American bittern (Botaurus lentiginosus), sometimes sounds a bit like a bull bellowing, which led to one of its nicknames — “thunder pumper.” Despite its lack of melodious calls and songs, however, birders get excited when one is spotted because this medium-sized heron (2-3 feet tall) usually is only visible hiding among dense grasses and reeds. In contrast to great blue herons or great egrets, American bitterns lead mainly solitary lives, so birders can’t count on seeing a group of them either.

One local nature reserve became a real hot spot recently when a local birder alerted other bird lovers to the presence of a bittern at one of the ponds. Unexpectedly, this bittern was not shy at all.

 

Even when s/he was being watched by half a dozen people, the bird emerged from the grasses and reeds to forage for food at the water’s edge or stopped for a grooming session in front of an audience. And this went on for over a week as the bird gave us a star performance.

 

 

When approached, the bittern’s usual “concealment” pose is to stand tall with its neck stretched upward and its bill pointing at the sky. They don’t move until they feel it is safe to resume stalking their food.

           

When they stand this way, some people say they look like they have “googly eyes”. The bitterns can focus downwards even when pointing their heads upward; it is surmised that this ability helps them spot and catch the creatures on which they feed.

   

I can see where the googly-eyes terminology was applied to them, but I recently saw a common grackle (Quiscalus quiscula) that had much more of that look in my opinion!

In one of their typical hunting modes, bitterns bend over and stand almost motionless, slowly lowering their long bills down so that they can plunge their heads quickly into water to grab their prey, which they bite or shake to death.

 

When they lift their heads, you may notice their third eyelid in position, indicating that they shielded their eyes while submerged. They also engage the nictitating membrane when they scratch their heads, getting close to their eyes – the bittern’s very large feet make that a very good decision on their part!

   

After catching their prey, the bittern subsequently repositions its prey — a tadpole, crayfish, frog, snake, rodent, fish — inside its bill so that it can be swallowed head first. Parts of the eaten animal that they can’t digest are later regurgitated as a pellet.

 

American bitterns are considered a species of high concern by Waterbird Conservation of the Americas. It is the loss of wetlands habitat that is contributing to their decline; in the last decades more than half of the original wetlands in North America have been destroyed or degraded. Let this past Earth Day be a reminder of the very urgent need to make haste in protecting the natural areas that remain and restoring areas that can be rescued.

 

Weird weather but spring is coming!

Our extremely wet winter in the Piedmont region of North Carolina (NC) continues with rain days tomorrow and the day after tomorrow, but then we have a forecast of a whole week of sunny days! Daffodils and lenten rose are blooming, crocuses are coming up and beautiful little speedwell flowers (Veronica persica) are emerging. Spring is on its way!

While one of our common birds, the gently cooing mourning doves (Zenaida macroura), are a little unusual in that they can mate at any time during the year, they mostly prefer to start their nesting period in the spring. And one pair in my yard were so kind as to allow me to watch them canoodling on a feeder pole this week. As many of these doves mate for life, perhaps they had lost any feelings of shyness. 🥰

They first alighted together and looked around (perhaps scanning for the sharp-shinned and Cooper’s hawks that hunt around here). With the coast clear, they faced one another with an open-eyed look.

And then their tryst began – I got to watch a romantic scene without having to turn on the TV! Mutual grooming and neck preening ensued, as did quiet moments of quiet repose. They even engaged in billing — the male opening his beak and the female inserting her beak into his — a signal she is interested.

 

Life is the flower for which love is the honey. — Victor Hugo

Everything I do, I do it for you. — Bryan Adams

True love stories never have endings. — Richard Bach

           

There’s nothing that I wouldn’t do to make you feel my love. — Bob Dylan

Love was made for me and you. — Nat King Cole

 

In all the world, there is no love for you like mine. — Maya Angelou

All you need is love — The Beatles

Well, that and a bit of peace and quiet. When they finally descended to the ground and the male began his mating dance, another dove flew in and Ms Dove decided she didn’t want to deal with more than one suitor. The session ended.

But there will be another day! 😃 🍀

 

The birdy breeding cycle 2020 – 1: courtship and mating

Although we in the Northern hemisphere are already a little more than a month into summer, many species among our avian friends have not yet completed their breeding cycle. In my yard, many parents are still feeding begging (sometimes almost adult) children. Others are feeding young ones in the nest and some appear to be busy constructing new nests for a second or third brood. So, after a long hiatus in blogging, I decided to feature some of my bird friends, including the American goldfinch pair below (Spinus tristis) as they have worked on their new family lives in 2020.

American goldfinch P7130178 © Maria de Bruyn resSome of these photos go back to early spring. A series of misfortunes (including a crash of my laptop hard drive, a broken camera, loss of Internet) meant that I had a backlog of photos to process and then suddenly a large gap in photos taken. But I managed to recuperate some of the work and hope you enjoy the coming series of posts about the birds’ breeding and family life!

belted kingfisher

Breeding season is heralded by increasing bird song in the meadows, forests, fields and our yards. Males especially sing to attract mates and establish territories, but females treat us to songs and calls, too. This makes it easier to spot birds as the tree foliage gets thicker, especially if you have good hearing!

pine warbler P4175086© Maria de Bruyn                     white-eyed vireo P4123164 © Maria de Bruyn res

Pine warbler (Setophaga pinus)            White-eyed vireo (Vireo griseus)

Eastern meadowlark P4279816© Maria de Bruyn res            Orchard oriole P4279889© Maria de Bruyn res

Eastern meadowlark (Sturnella magna)     Orchard oriole (Icterus spurius)

Carolina wren P3316544 © Maria de Bruyn res                 blue grosbeak P4291500© Maria de Bruyn res

Carolina wren (Thryothorus ludovicianus)      Blue grosbeak (Passerina caerulea)

summer tanager P4291520© Maria de Bruyn res

Summer tanager (Piranga rubra)

Indigo bunting P6308502© Maria de Bruyn

Indigo bunting (Passerina cyanea)

Courtship is usually a sweet behavior to watch in my view. The male Northern cardinals (Cardinalis cardinalis) are especially devoted suitors, seeking out nice morsels to present to their intended mates, while among the American crows (Corvus brachyrhynchos), it’s the females who loudly call to their mates for some tasty bites.

Northern cardinal P4164873© Maria de Bruyn res

American crow P4080661 © Maria de Bruyn res

A fact that perhaps many bird lovers do not know is that few male birds have a penis. Like the female birds, most species’ males have a cloaca, a cavity externally located just under the bird’s tail and internally at the end of the digestive tract. Feces, urine, sperm and ova are all deposited in the cloaca. Birds who reproduce with this organ briefly rub their cloacae together (an activity called the “cloacal kiss”) whereby sperm from the male bird’s testes are transferred into the female’s cavity to unite with her eggs. During breeding season, the cloaca is slightly swollen and protrudes a bit from the bird’s body, facilitating the transfer. In the photo of this Carolina wren, you can see a slightly darker area under the tail indicating where the cloaca is found.

Carolina wren P7059955 © Maria de Bruyn res

red-headed woodpecker P4217162© Maria de Bruyn res

When ready for mating, the red-headed woodpeckers (Melanerpes erythrocephalus) seem to focus mainly on chasing away rivals and then snatching a quick mating session. The female woodpecker then takes a break from the chase to rest and have a bite to eat.

Some cliff swallow males (Petrochelidon pyrrhonota) seem to take advantage of females who are preoccupied with gathering mud for their nests for a quick tryst.

cliff swallows 2G0A3283© Maria de Bruyn res

The brown-headed cowbirds (Molothrus ater) seem to take their time for mating. This pair was occupied for at least 5-10 minutes in preparing for the upcoming production of eggs. At times, it seemed like the male was giving the female instructions on what to do once “the deed” was done!

brown-headed cowbird P5097676 © Maria de Bruyn res   brown-headed cowbird P5097677 © Maria de Bruyn res

Many birders do not like the cowbirds because they are parasitic nesters, i.e., they lay an egg in another bird’s nest so that the other bird will raise the young. Since the cowbird baby usually hatches before the other eggs, they either monopolize the food that the foster parents bring or they may even destroy the eggs laid by their foster mother.

brown-headed cowbird P5097682 © Maria de Bruyn res      brown-headed cowbird P5097686© Maria de Bruyn res

It’s been posited that the cowbirds evolved to use this strategy because they followed the bison in migration and therefore couldn’t stay in one place to raise their young. Others believe, however, that the birds developed the practice because dispersing their eggs over several nests gave their young a better chance of reaching adulthood.

brown-headed cowbird P5097689© Maria de Bruyn res

chipping sparrow P6256620© Maria de Bruyn sgd resThe quickest mating scenario I’ve witnessed came from a pair of sweet little chipping sparrows (Spizella passerina). I’d seen the two fluttering together at the feeders and had noted one sparrow chasing another away – which I now think was the victorious suitor driving away a rival. Then one July afternoon, the two flew to a dying cedar and sat close to one another on a branch. Suddenly, Mr. Victory mounted his mate but for what only seemed a few seconds – really very quick work indeed! She sat there with her rear end elevated for a bit and then the two went back to feeding – and soon after I saw them collecting nesting materials.

chipping sparrow P6256622© Maria de Bruyn res    chipping sparrow P6256623© Maria de Bruyn res

The birds in which the males do have a penis include some duck and swan species, ostriches, cassowaries, kiwi and geese. They differ from other birds in that development of the penis is NOT stopped in the male bird embryos during development (the case in cloacal birds).

The mallard males (Anas platyrhynchos), like some other ducks, unfortunately do not treat their partners well. They may mount the female very roughly. During a mating, she may be dunked underwater repeatedly and at length; occasionally, this results in her drowning. This behavior has been the subject of various studies and some newspaper articles with sensationalistic headlines (e.g., “The horrible thing you never knew about ducks)”.

Mallard duck P1232837 © Maria de Bruyn

Mallard duck P1232839 © Maria de Bruyn     Mallard duck P1232840© Maria de Bruyn

Once the actual mating is over, the birds devote most of their energy toward building a nest. While female ruby-throated hummingbirds (Archilochus colubris) must construct her nest and tend her babies alone, many other birds cooperate in the venture, like the Eastern bluebirds. Their efforts are featured in the next blog. (And if you’d like to see a previous post on courtship, it is here.)

ruby-throated hummingbird 2G0A4084© Maria de Bruyn res

Hopping into springtime

I’ve been planning new blogs for quite some time; then I keep taking new photos that will fit into them and the blog writing gets delayed. But two days ago, I saw such a cool natural event that I resolved to produce a blog quickly and here it is!

One welcome feature of springtime is that many insects emerge from their over-wintering spots. Some are bugs we dislike (mosquitoes, ticks and chiggers), but others are fascinating and wonderful members of our natural systems. Pollinators like this spicebush swallowtail (Papilio troilus) keep our gorgeous plants and important food crops going and many bugs provide other wildlife with meals.

On my trip to Costa Rica last year, our guide not only pointed out birds but also some mammals and insects. He had developed an interest in treehoppers, a group of insects with about 3200 species worldwide that specialize in eating plant sap. He was unable to find any to show me, but I resolved to keep an eye open for them when I returned home. I had forgotten that I had seen my first one the year before, a pretty green Ceresini species.

As I stared at plants during nature walks, I was lucky and managed to find my first treehoppers when I was actually looking for them. These were of a dark-colored species (Acutalis tartarea) that favors the sap of black locust trees, sunflowers, goldenrod and ragweeds.

The treehoppers, which are related to leafhoppers and cicadas, are popular with some entomologists because many species have elaborate “helmets” at the top of their heads. I got to see my first example of this type on my recent walk when I happened to find a young oak tree with numerous nymphs and recently eclosed (emerged) adult oak treehoppers (Platycostis vittata).

The mother treehopper is known for staying close to the nymphs to protect them against wasps and other predators.

The hoppers get plant sap by piercing plant stems with their beaks. The nymphs have extensible anal ducts that deposit the sap away from their bodies. This is important because the concentrated excess sap, called honeydew, can get moldy.

 

                              

The honeydew attracts ants, which like the sugar-rich liquid, so the hoppers and ants have a mutually beneficial relationship.

Just how the helmet develops into an unusual shape has been a source of investigation. One team of entomologists theorized that the helmet was formed by body parts that were actually modified wings. Another researcher countered that this was impossible and that the helmet was an unusual pronotum — the foremost dorsal section of the thorax. More recently, a third group of evolutionary biologists postulated that the helmet is indeed a section of pronotum but one that developed with the aid of genes that code for wings.

In various species, the pronotum has developed into a quite unusual and oddly shaped appendage; examples can be seen in this article. When the helmet resembles a plant thorn, it is thought to aid in camouflage.

When I discovered the group of oak treehoppers, one was just in the process of emerging from its nymph form. A friend who saw the photo remarked that it reminded her of the film Alien but this process was slow and deliberate and not a heart-thumping explosive emergence as shown in the movie.

As you can see, the oak treehopper is quite a beautiful insect with its pristine white body decorated with pink/red stripes and hints of yellow. They made me think of mints and Candy Stripers (a sign of our times when almost anything makes me think of health and health-related concerns. For younger readers: young female volunteers who work under nurses’ supervision in hospitals used to wear pink and white striped smocks and thus got the name Candy Striper).

Not all the adults had the horned pronotum; some had rounded heads.

This close-up of a hopper’s face could evoke all kinds of thoughts. I thought it looked as if it had a pig’s snout. Another friend thought it looked like a grumpy old man. What do you think when you see this visage?

Or about this one, with its head upside down? (It looks a bit more “innocent”, don’t you think?)

In any event, I found these insects just adorable and I felt very privileged to have had the chance to see them emerge into adulthood. It turns out that in this species, older individuals may change color, turning a dull brown or green color. Some mottled forms may be blue with yellowish spots. It would be interesting to see those forms as well one day – or perhaps one of the other treehoppers with a different fabulous helmet!I hope you, too, are able to get out in nature during these social distancing times so that you can connect with the wonderful wildlife around us!