The gorgeous grebes when aggrieved and grumpy!

During my great-crested grebe (Podiceps cristatus) observations at the Gouwzee in July 2018, it became apparent that they don’t mind swimming about amid groups of Eurasian coots (Fulica atra).

It turned out, however, that the grebes can also be quite aggressive and one morning these birds treated me to a stunning display as they had six years earlier. This time it was not a peaceful event like their mating dance, however, but apparently a territorial dispute. Two pairs were each tending a young one near reeds in a cove on the Gouwzee side of a dike. It appeared that one adult had ventured into space that the other pair considered their own. An epic battle ensued – I wish I’d had the presence of mind to change my camera settings to get better photos, but it was so sudden and exciting that I was just glad to be able to get some shots. The whole dispute only lasted about three minutes but seemed to last much longer!

References I found in the literature online appear to indicate that researchers believe territorial aggression mostly takes place when the grebes are building nests and tending eggs. They mention that it stops once the young are born. This was obviously not the case for the two pairs that I observed; their young appeared to be several weeks past fledging age.

The birds first caught my eye when they faced one another, lying low in the water. This is said to be a common aggressive posture.

Suddenly, they erupted upwards, calling loudly and flapping their wings strongly to intimidate one another. (You can see larger versions of photos by clicking on them.)

  

 

   

 

A couple times, they surged upwards from the water to clash their chests together.

   

One appeared to have dunked his opponent in the water, although this happened so quickly that I didn’t really see how it occurred.

They would take a few second pause, making their mutual displeasure apparent.

This would be followed by another bout of confrontation. At one point, one grebe’s mate and young one swam closer to the action.

Finally, after a couple minutes, one “combatant” was driven off by his opponent.

He was joined by his mate and offspring and peace returned. And I walked away elated at having witnessed the behavioral exhibition, glad that no injuries had been sustained. 😊

 

Gracious and gorgeous grebes nurturing newborns

After birding now for some six or seven years, I’ve come to appreciate all birds since each species can be fascinating to watch. I do have some favorites though that have captured my interest. In 2012, I fell in love with great-crested grebes (Podiceps cristatus), whom I first noticed during a trip to Switzerland. A pair was engaged in their courtship dance, which was simply delightful to see. They circled one another, stretched out their necks, ruffled their feathers and arose on the water facing one another. Their beauty enchanted me, and I felt that I had witnessed something very special.

The rust and black-tinted head plumes and ruff are gorgeous, making these birds very attractive indeed. This led to their being hunted almost to extinction during the 1800s in the United Kingdom because the feathers were desired as decorations or hats. This led to the establishment of the Royal Society for the Protection of Birds in that country and their numbers fortunately rebounded.

Fast forward six years to this past July, and I discovered that these birds are quite common in my land of birth, where I just had not noticed them before. Granted, I was not a birder while living in The Netherlands (I currently live in the USA), but I had managed to take note of house sparrows, mute swans, Eurasian coots and moorhens when walking along canals and ditches. Now, as a much more observant wildlife observer, it was thrilling to see many grebes along the dike bordering the Gouwzee (a body of water bordering Monnickendam that is part of the larger Markermeer nature area). And even better – they were all tending young ones at different stages of development.

The great-crested is Europe’s largest grebe species and the adults are stunning with their reddish-orange head plumes. (They are also found in Australia, New Zealand and African countries.) I discovered that the young look quite different – mostly light in color with black stripes on their heads and pink markings near the eyes.

Their floating nests are often found along reed beds, which were abundant along the dike and a ditch across a road from the dike. A couple mothers had chosen the ditch as their home area and the early morning light made for some nice photos in my opinion as they preened and relaxed.

  

   

The water in the lake on the other side of the dike was less calm but the young ones managed to swim well in the waves; they can already dive shortly after leaving the nest.

Their feet are set back far along their bodies and they cannot walk well. I did not ever see one on land during the week that I was observing them.

According to the literature, pairs tend 1-9 eggs, which hatch after about 27-29 days. The mothers carry newborns on their backs as they swim along, offering a safe perch for sightseeing in safety. The babies fledge after 71-79 days. I did not see any pairs with more than two young, so some were probably lost during the previous weeks.

The grebes eat fish, crustaceans, mollusks, amphibians and insects. Their fishing technique, which was more in evidence in the open water of the Gouwzee, includes skimming the water with outstretched necks and diving underwater. (The neck-to-the-water pose is also used to show aggression but in these cases no other birds were near and they would subsequently dive under to come up with some food.)

The parents demonstrate and the young imitate them, mostly coming up empty-beaked. Occasionally, a parent would fly away and return later with food. The babies eagerly grab the meals offered by both mama and papa.

After breeding, the adults gather together during a molting period, during which they do not fly. Perhaps one day, I’ll be able to watch them in winter and find out new things about them. In the meantime, if you’d like see what happens when they are feeling perturbed, check out my next blog on “The gorgeous grebes when aggrieved and grumpy!”

When those loving instincts leave you dangling

This was not a planned blog, but I recently observed something that simultaneously intrigued, amazed and astounded me, so I wanted to share it with those of you who may not have witnessed this either.

Like many gardens in my neighborhood, my yard has its fair share of leopard slugs (Limax maximus), but they don’t bother me as they do some other people who complain about them eating their vegetables. Until recently, I never thought about the slugs much and certainly didn’t wonder about their life cycle. Then my friend Mary posted a lovely photo of two intertwined leopard slugs mating and my interest and curiosity were piqued.

A few days later, a fellow nature lover, Ace, reported that he had a cool photo to show me – and there on his iPhone was a photo of mating leopard slugs. It turns out that their anatomy makes for a somewhat bizarre spectacle – at least to a human being if not a fellow slug. Now I really wanted to see this phenomenon, too, and I followed Ace’s recommendation, going out into my yard at night with a flashlight to see if I could find some amorous mollusks. Lo and behold – as I rounded the corner of my house, there were three pairs of large slugs getting ready to reproduce! They were leaving glistening slime trails on the brick wall as they slowly got into position.

The slime that the slugs exude has multiple purposes – they can leave a trail behind them as a signpost to the way home, they can numb the mouth of a potential predator with the mucus as a means of defense, and they can broadcast their interest in some reproductive behavior by emitting pheromones to attract a potential mate.

They don’t actually need to mate to reproduce – each slug is a hermaphrodite and can fertilize its own eggs with no need of outside assistance. Slugs have an organ called a spermoviduct (SO), which has two parts – one for the sperm (vas deferens, VD) and one for the ova (oviduct, OV), as seen as this drawing from the Wikipedia page.

Some slugs apparently like reproductive acrobatics, however, and seek out a partner. The mating begins with a pair of slugs following one another around and nudging and licking one another. (A couple photos look browner – I took those with a flash but most were taken with one hand holding a small camera and the other shining a flashlight near the slugs.)

 

They then begin to curl up together and suspend themselves from a long mucus rope, which is somewhat stronger than the slime that they usually exude. They form a kind of writhing ball as they intertwine their elongated bodies (see this video for an example).

Next comes the awesomely weird part – out of a gonopore on the right side of their heads (the elongated tentacles are for vision) come their translucent mating organs (penises)! This video, which is shown in a horizontal position, lets you see how this happens.

Wouldn’t this interesting anatomy and reproductive behavior make an interesting plotline for an SF novel about a genderless society?

 

      

Because the slugs are hanging upside down, gravity helps pull down their reproductive organs, which are pumped full of body fluids until they are as long as the slugs’ entire bodies! Their penises are everted (turned inside out) and the two mollusks intertwine these just like their bodies. They take a while to exchange spermatophores as the penises twirl, intertwine, elongate and pull back to look a bit like a chandelier.

  

When the creatures have been joined at the neck for some time, they begin to slowly withdraw their reproductive organs, which are now carrying genes from another parent.

              

After they separate, one of the pair usually consumes the mucus rope from which they dangled in love as it carries extra nutrients which they can use after their vigorous efforts.

          

 

 

Each slug may spend some time examining its gonopore (above) – and perhaps they are helping push back in the penis when they do this, too. After watching the process for two pairs of slugs, I decided to give the third pair some privacy during their mating tryst. On the wall beneath my screened porch, I discovered another slug with a mucus rope dangling from its tail – leaving me with a little mystery as to why this might have happened. A partner slug was not in evidence except for a much smaller slug – perhaps the big one tried to mate but the younger one was not ready. These mollusks with a life span of 2.5-3 years don’t become sexually mature until they are 2 years old.

    

I do know that at least three and perhaps six slugs will each be laying up to 200 eggs somewhere in the yard. And when I see them in the future, I will undoubtedly always be picturing them in my head doing their dangling dance with intertwined translucent blue tubes that will help promote their future generations. My discovery of their life cycle has also reinforced my support for scientist Hope Jahren’s (Lab Girl) observation: “…being able to derive happiness from discovery is a recipe for a beautiful life.”

Winter wonderland – sharing and spats at the feeders

I thought I had published this blog in early February and just discovered that I had only saved a draft. Since we had snowflakes last night (in April!), I’m going to go ahead and post this now – a break in the series about Costa Rica! When the snow began falling during our day of one-foot accumulation, the feeders were inundated by some of the dark-colored bird species who tend to come in crowds. At first, they were peacefully sharing space.

 

  

Although I sometimes have a couple dozen red-winged blackbirds (Agelaius phoeniceus) at the feeders, during the storm only one pair showed up for a brief visit and the other birds left them alone.

 

The mourning doves (Zenaida macroura) often share feeder space with other birds, including those that are smaller than they are.

The common grackles (Quiscalus quiscula) are known to other people as domineering birds at the feeder, but those in my yard have always been polite, even though they seem to have a permanent expression that expresses anger.

 

 

The brown-headed cowbirds (Molothrus ater) sometimes share space nicely and sometimes fuss at one another as they vie for a good perch. They don’t try to chase off other species though and are not apt to “yell” at other birds.

The birds who do “yell” are the European starlings (Sturnus vulgaris). Young ones yell at their parents after fledging, begging to be fed. Adults yell at each other when they are trying to all crowd together onto a feeder. And adults yell at other species to drive them away so they can have all the space for themselves.

At my feeders, however, they have found their match in the male red-bellied woodpecker (Melanerpes carolinus). One day, I watched as they managed to intimidate him for a few minutes, but he then returned to the feeder and refused to give up. Now he is no longer frightened of them and stands his ground when a starling does its best to make him move.

    

It turns out that studies have shown that the red-bellied woodpeckers are the birds most apt to resist attempts by other birds to displace them from feeders.

The red-bellied woodpecker also was not intimidated by me at one point. He doesn’t like it when he flies in and notices at the last moment that I am sitting or standing on the porch; often he will swerve away and wait for me to leave. During the snow storm, however, he decided to display his displeasure with my close presence, both from a frontal and dorsal view!

 

  

      

 

I guess that the little bird spats do make for sometimes more interesting birding observations. Seeing the tiny ruby-crowned kinglet (Regulus calendula) warning off a rival a few days before and after the snow melted did show off a gorgeous and brave little bird.

 

 

I’m looking forward to seeing what the springtime observations of animal behavior will reveal.

 

Costa Rican rambles 5B: the Talari Mountain Lodge and environs

 

After fully experiencing the “honey dew” (another name for cicada urine), we set off for the next university site, an area where students learn about planting. A statue of the Virgin Mary welcomed visitors and we admired some of the beautiful plantings and their seeds that were attracting plenty of insects.

   

 

We then left to make a quick stop at a park called Los Cusingos, that we would visit at length later; this was just a quick bathroom break before we took to the road again. My photo of the gray-headed tanager was not that great but you can see how beautiful the red passionflower (Passiflora vitifolia) at the entrance was.

As we drove to a place called Las Nubes, we passed private homes with their filled metal framework trash bins in front, a cemetery and plenty of banana plants.

 

   

One of our group members stepped in an anthill when trying to avoid puddles and traffic, which led to some stinging bites. In the meantime, others were trying to see various species of birds that were staying low in the vegetation along the road. I spotted a rather large wasp nest in a nearby tree, likely of the Synoeca septentrionalis species.

   

 

 

At some distance, there was a yellow-headed caracara (Milvago chimachima) sitting on a branch. These raptors are about 16-18 inches in length (41-46 cm) and part of their diet is carrion. They also eat reptiles, amphibians and other small birds, while avoiding birds as food. They take ticks off cattle as well, which gives them a thumbs up from me – any bird that eats ticks is a friend.

 

A gorgeous smooth-billed ani (Crotophaga ani) was sitting calmly as we milled around in the road. Some people might find this bird homely, but I think it is quite handsome despite a somewhat bulbous beak. They, too, are on my “good birds” list as they sometimes eat ticks and other parasites off of grazing animals. Another nice characteristic is their communal child-raising strategy – several pairs cooperate to build a nest together, in which several females than lay their eggs. They share the incubation and feeding of nestlings – hippies of the bird world!

 

We traveled on and the views along the road were beautiful, with the mountains and valleys in the distance and then we caught sight of some swallow-tailed kites (Elanoides forficatus) soaring over the nearest valley. We saw one land in a tree and it turned out that they were building a nest there. In the photo, you can see a small white patch on the right-hand side of the tree, which is the female kite on the nest.

As we waited patiently, a few kites began flying overhead; one with nesting material clutched in its claws.

 

They soared and swooped, giving us delightful views of their flight and then one came by with a meal that it had caught – a poor little chameleon or lizard.

 

We admired the Talamanca mountain range called La Amistad (Friendship), which separates Costa Rica from Panama. Starting in 1979, these two countries’ governments began a process to conserve the entire range, which is home to four indigenous groups of humans, 600 avian species, 215 mammal species, 250 species of amphibians and reptiles, 115 species of fish and some 10,000 flowering plants! As UNESCO has noted, this is: “one of the very few transboundary World Heritage properties, an excellent intergovernmental framework for coordinated and cooperative management and conservation.”

 

After a nice lunch, we continued visiting other sites, including one near a Canadian project. That afternoon, I saw my first trogon species – the gartered trogon (Trogon caligatus), another handsome bird to be sure.

 

      

While the rest of the group followed Steve’s instructions for sighting some birds hiding in underbrush on a slope, fellow traveler Janet and I watched some leaf-cutter ants (Atta cephalotes) at their labors. Sometimes, I was just not tall enough to see over shrubs to locate a bird and I love all wildlife anyway, so watching the ants in their industrious endeavor was fun.

On our way back to the lodge for supper, we passed small roadside stores and Steve spotted a fork-tailed flycatcher (Tyrannus savanna) for us.

 

 

Back at Talari, I did some sightseeing from the balcony of my room, spotting a lengthy and messy-looking flycatcher nest, a variegated squirrel (Sciurus variegatoides) traversing the tree canopy and a pair of palm tanagers (Thraupis palmarum), who were tending an offspring.

 

                       

At first, I thought the fledged bird was a different species as it sat under a leafy canopy, but later I saw the parents with it. Then it surprised Janet, who was staying next door – she called me over to see the fledgling who had flown into her room and was sitting in the middle of the floor.

   

She also had two nests under the roof of her balcony, one of which definitely belonged to a clay-colored thrush (Turdus grayi).

   

After admiring one of the neighbors’ cows and social flycatcher (Myiozetetes similis), I caught sight of a quiet beauty sitting on a branch in front of my room.

  

 

The Lesson’s motmot (Momotus lessonii), also known as the blue-diademed motmot, has a bright red eye and beautiful tail with what some birding sites call a “raquet tip”.

 

As we set off for the dining area, we were treated to a visit from a streaked flycatcher (Myiodynastes maculatus), quite a good-looking bird with its heavily streaked back, breast and face.

  

As we passed through some vegetation before dinner, I saw a gorgeous flowering banana as a blue-feathered and red-legged honeycreeper (Cyanerpes cyaneus) flew high overhead.

   

Even though we often were looking for birds in dark and leafy/shady areas, I avoided using a flash but when I saw the lemur anole (Norops lemurinus) on a tree, I gave in so that I coul d get a photo.

 

As dusk came on and we looked out from the dining area, we got to see some fiery-billed aracaris (Pteroglossus frantzii) in the distance.

 

 

While some others in our group got to see one close up, that was not my fate, but the next morning, the aracaris were in a little better light though still far away, allowing me to get a bit better photos.

 

   

We ended our second night at Talari Lodge with an owling outing – Steve managed to draw in a tropical screech owl (Megascops choliba) by playing its call on his phone. The owl who came had had an injury to one eye, with a pupil that would no longer dilate but s/he seemed to be flying fine and looked healthy. That bird gave us a nice long look at its beautiful self so that we retired for the night with a feeling of birding satisfaction!