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Walking in Warsaw

June 6, 2017 by Sue

We covered quite a few miles exploring Warsaw on foot and by tour bus over the past couple of days from the former Jewish ghetto in the north to the summer residence of the former king of Poland in the south, with many stops for good food in the Old City center.

Memorial to the 1943 uprising in the Warsaw ghetto

Memorial to the 1943 uprising in the Warsaw ghetto, honoring young and old, mothers and fathers who fought bravely but were tremendously outnumbered by German troops.

Memorial for the 1944 uprising in the Warsaw ghetto

Memorial to the 1944 uprising in the Warsaw ghetto, the last stand before it was purged of all life.

The old walled city was completely demolished during the war, but was rebuilt in 11 years at the conclusion of the war to resemble its former elegance.

Broad boulevards lined with flowers, and no car traffic on Sundays.

Broad boulevards lined with flowers, and no car traffic on Sundays. The streets are litter-free!

Brick wall around the Old City of Warsaw rebuilt in the 1950s.

Brick wall around the Old City of Warsaw rebuilt in the 1950s.

Plaza in Old City of Warsaw overlooking the Vistula river

Plaza in Old City of Warsaw overlooking the Vistula river with the Royal Palace on the far right

Market square, Old City, Warsaw

Market square, Old City, Warsaw

Mermaid in market square, Old City, Warsaw

Mermaid in market square, Old City, Warsaw. The mermaid is key to the story of how Warsaw got its name:  a fisherman by the name of Wars accidentally caught a mermaid by the name of Sawa, they fell in love and together their names combined Wars-Sawa, or Warsaw.

The best pierogis can be found at Zapiecek's many locations in Warsaw.

The best pierogis can be found at Zapiecek’s many locations in Warsaw. Our fantastic guide, Art, and one of the serving ladies dressed in Polish costume.

Old City, Warsaw from across the Vistula River

Old City, Warsaw from across the Vistula River

Summer palace of the king, Warsaw

Summer palace of the king, Warsaw. Unlike other royals in other countries, the Polish king preferred to summer just 5 kilometers from his winter palace, within Warsaw city limits.

Chopin memorial, son of Warsaw, in the king's summer palace grounds.

Chopin memorial, son of Warsaw, in the king’s summer palace grounds.

Posted in Uncategorized | 1 Comment »

Island rules – part II

March 6, 2014 by Sue

A second generality that has been described for assemblages of communities of island fauna derives from competition between species there.  Based on the fact that “complete competitors cannot coexist“, a species that tries to colonize an island must be, or do, something different than the ones already there.

Take doves, for example:

Doves are strong fliers, able to cross vast spaces of open water or land in search of food and water.  They snack almost exclusively on seeds and fruit (and maybe a few insects in the litter), but usually aren’t too fussy about the types of those food items they exploit.  On almost every Caribbean island, there is at least one species of dove present, and often more.  But there are rules determining which dove species will colonize islands, because, being generalist seed consumers, there is potential competition for the limited food resources of an island.

White-winged Doves are common in the southwestern deserts of the U.S. where they raise their young, even under the most extreme arid conditions. They time their nesting with the fruiting of the saguara cacti, whose fruits (and seeds) they devour. However, they migrate through Caribbean islands in the non-breeding season. They could stay there and breed, but for the competition already present.

White-winged Doves are common in the southwestern deserts of the U.S. where they raise their young, even under the most extreme arid conditions. They time their nesting with the fruiting of the saguaro cacti, whose fruits (and seeds) they devour. However, they migrate through Caribbean islands in the non-breeding season. They could stay there and breed, but for the competition already present.

Island rule #2 suggests that on small islands of limited geographic diversity, species occupying similar ecological niches will differ from each other in body weight by approximately a factor of 2.  Some argue that the size differences translate to more efficient use of the resources with less inter-species competition; others argue that size differences prevent potential species hybridization; yet another suggestion is that size variation within the “guild” of seed-eaters prevents further colonization by other, potential competitors.  Whatever the reason, the size ratio rule seems to work well for some groups of species on some islands (see Case et al. 1982 for more details)

So, let’s test the validity of this rule with the dove species I saw on Culebra.

Sure enough, there is almost an exact doubling of body size between Common Ground Dove and Zenaida Dove, and also between Zenadia Dove and Scaly-naped Pigeon.

Sure enough, there is almost an exact doubling of body weight between Common Ground Dove and Zenaida Dove, and also between Zenaida Dove and Scaly-naped Pigeon.

White-winged Doves are also found on Culebra, and on Puerto Rico as well as many other Caribbean islands, but they don’t breed there.  One reason might be their fondness for the seeds of Saguaro cactus found only in the Sonoran desert of southwestern U.S.and Mexico, but another might be the fact that they are roughly the same size as the Zenaida Dove, which has already established its presence during the nesting season on Culebra and Puerto Rico.

Hey! Get outta' here, WWD.

“Hey! Get outta’ here, WWD.  This place is already taken.”

Posted in Behavior, Birds, Nature, Tropical, Wildlife Photography | Tagged , , , , , , , | 4 Comments »

Island rules – part I

March 5, 2014 by Sue

Island visitors are often struck by how large some animals get compared to their mainland ancestors: flightless (extinct) dodos (a pigeon!) on Mauritius, giant hissing cockroaches on Madagascar, Komodo dragons on Indonesian islands, giant tortoises on the Galapagos, to name a few.  And Puerto Rico has its “giant” land iguanas, which lay around on sand or shore, unintimidated by human presence.

Head to tail, these land iguanas may stretch more than 3 feet, and they can move surprisingly fast when they want to.

Head to tail, these land iguanas may stretch more than 3 feet, and they can move surprisingly fast when they want to.

Several years ago, I remember a particular iguana that had specialized in stealing food from beach picnickers.

Several years ago, I remember a particular iguana that had specialized in stealing food from beach picnickers and terrorized my daughter into dropping her cookies.  However, this guy paid no attention to us, but was on a mission to somewhere.

But not every species that manages to find an island home grows into a giant, and thus Island Rule #1:  small-bodied species tend to get larger on islands while large-bodied species tend to get smaller (depending on the existing competition for food there and who got to the island first).

In particular, large-bodied herbivores (e.g., elephants, hippos, deer) develop into dwarfs of their mainland ancestors, and relatively quickly — within just 5,000 years in some cases. This makes sense because there simply wouldn’t be enough food on an island to support a population of large-bodied, warm-blooded, leaf eaters.

Case in point — the Key Deer in the Florida keys are about 1/2 the size of their White-tailed ancestors.  Food is limited on the key islands, and deer don’t seem to be great swimmers.

Full-grown Key Deer are about the size of a 6 month old White-tailed fawn. Photograph taken on Big Pine key, near Marathon, FL.

Full-grown Key Deer are about the size of a 6 month old White-tailed fawn. Photograph taken on Big Pine key, near Marathon, FL.

Gigantism occurs most often on islands where there are no mammalian predators, and is more frequent among smaller-bodied mammals (rodents, in particular), reptiles, and some bird species.  However, when an increased body size impacts foraging habits, like flight in birds, or hanging from ceilings in geckos, then food acquisition puts constraints on the increased body size.

Warning to those visiting tropical islands:  watch out for the giant rats!

Fictional, of course.

Fictional, of course.

Posted in Mammals, Reptiles, Tropical, Wildlife Photography | Tagged , , , , , | 8 Comments »

a mysterious decline

March 4, 2014 by Sue

When I was a graduate student (in the 1970s), American Kestrels were one of the most common avian predators I saw in upstate New York on almost a daily basis, as they perched along roadsides hoping to spot an errant grasshopper or mouse in the grass.

The smallest and most common falcon can be prey for other, larger raptors, especially sitting exposed on a bare branch or wire.

The smallest and most common falcon can be prey for other, larger raptors, especially sitting exposed on a bare branch or wire as this one did along a road in Puerto Rico.

American kestrels, or Sparrow hawks, are easily identified by their small size, black facial stripes, spotted breast feathers, and swept back wing shape in flight.

American kestrels, or Sparrow hawks, are easily identified by their small size, black facial stripes, spotted breast feathers, and swept back wing shape in flight.  Photo credit:  Steve Hillebrand.

Kestrels can be found throughout the Americas, from the most northern Alaskan tundra to the tip of South America (except the Amazon basin), including Caribbean islands, in a wide variety of habitats.  Although still considered one of the most common raptors, their populations have declined 48% since the 1960s, as the magnitude of the red areas showing population declines in the Breeding Bird census data show.

American Kestrel population status in the U.S. from Breeding Bird census data 1966-2010. Red = marked decline, orange = fluctuating population numbers; green = population growth

American Kestrel population status in the U.S. from Breeding Bird census data 1966-2010 (the Peregrine Fund). Red = marked decline, orange = fluctuating population numbers; green = population growth.

While I rarely see kestrels in MN these days, I was pleased to see them frequently while we were in Puerto Rico, and even on its small island neighbor, Culebra, where they seem to be fairly common.

A male kestrel took up a hunting perch above a sandy beach in western Puerto Rico.

A male kestrel took up a hunting perch above a sandy beach in western Puerto Rico.  Males have slate blue feathers on their wings and a darker slate blue head than the females.

Kestrels prospered in the late 18th and 19th centuries in the Americas, when forests were being cleared for agriculture.  The open grassy spaces made perfect hunting grounds for their insect, small bird and mammal diet, and forest borders provided the requisite number of tree holes for nesting.  So why the decline in more recent times, and especially in the last couple of decades?

A female kestrel perched on a power pole in a residential area in western Puerto Rico, unafraid of dogs, cats, and people below her.

A female kestrel perched and preened herself on a power pole in a residential area in western Puerto Rico, unbothered by dogs, cats, or people below her.

Are they vulnerable as prey of other raptors?  Cooper’s Hawk populations are increasing as Kestrel populations are shrinking — coincidence or causation?  A recent paper found no evidence for Cooper’s Hawk numbers or incidence of West Nile virus as a cause of Kestrel population decline, but suggested that nesting sites were a limiting factor.

Another explanation might be changes in farming practices in the U.S.:  clearing the fields of hedge rows and forest edges where the birds might find nest holes, pesticides that eradicate potential insect prey,  conversion of more pasture land to cropland, etc.

Progress for humans often take its toll on the wildlife, unfortunately.

Posted in Behavior, Birds, Landscape, Nature, Tropical, Wildlife Photography | Tagged , , , , | 14 Comments »

Pugnacious

March 2, 2014 by Sue

You wouldn’t think that a hummingbird that weighed only about 1/3 of a McDonald’s ketchup package (~ 4 grams) could be such a fighter.  However, the Antillean Crested Hummingbird readily defends its clump of flowers with tenacity and vigor, darting out to chase away other hummers, even larger-bodied ones, butterflies, large bumblebees — whatever is attracted to its private nectar supply.

In between bouts of driving away the competition, the Antillean Crested Hummingbird pauses for a sip of nectar.

In between bouts of driving away the competition, the Antillean Crested Hummingbird pauses for a sip of nectar.  

Shooting multiple frames at 1/4000 of a second, I managed to stop the wing action of this tiny 3.5 inch hummer as it came in for a drink.

the approach...

the approach…

the lean into the flower

the lean into the flower…

all that hovering is hard work; sometimes it's easier just to grab onto the flower and perch.

all that hovering is hard work; sometimes it’s easier just to grab onto the flower and perch.

This is one of 18 species of hummers in the Caribbean, and is found on most of the islands there, even the tiny little islet, Culebra.  Unlike most hummers, the male has a crest of bright, iridescent lime green that he flashes by erecting his head feathers, rather than a gaudy iridescent throat patch.  Most of the feathers on his back and sides are iridescent gold and green, making him sparkle in the sunlight.

I couldn't get him to show off his crest, so had to settle for showing off his green and gold speckled back.

I couldn’t get him to show off his crest, so had to settle for showing off his green and gold speckled back.

Antillean Crested Hummingbirds are generalists when it comes to where to live, which is probably why their populations are increasing while other hummingbird species suffer population declines with loss of their preferred habitats.  They actually prefer slightly disturbed open areas like gardens, cultivated areas, regenerating semi-open forest, anywhere from sea level to high mountains, wet or dry habitat.  Their dietary requirements are flexible as well — flower nectar when it is abundant, insects when it is not.

Ready for anything, and willing to take on all-comers — this little male was a real fighter.

Posted in Behavior, Birds, Fruit-Flowers, Gardens, Nature, Plants, Tropical, Wildlife Photography | Tagged , , , , | 4 Comments »

Not just a chicken…

March 1, 2014 by Sue

Culebra is notable for many reasons, not just its pristine and photogenic beaches.  One of its more unusual features is the number of chickens seen everywhere, but not just your ordinary run-of-the-mill domestic bird.  The wild ancestor of the domestic chicken – Red Junglefowl (Gallus gallus) –  was introduced at some time in the past, and has over-run the island.  They are everywhere — backyards, streets, underfoot in outdoor cafes, as well as natural areas.

Red Junglefowl have a cowl of chesnut neck feathers, brilliant red comb and wattles, and long, drooping blue-black tail feathers. Not your garden variety chicken!

Red Junglefowl roosters have a shawl of chestnut neck feathers, brilliant red comb and wattles, and long, drooping blue-black tail feathers. Not your garden variety chicken!  The hen in the photo, however, is most likely a domestic chicken, being far lighter in color than a true female junglefowl.

A Red Junglefowl rooster and his domestic hens search driveway gravel for seeds.

A Red Junglefowl rooster and his harem of domestic hens search driveway gravel for seeds.

Originally found in parts of southern Asia, Red Junglefowl were most likely domesticated about 5,000 years ago, giving rise to the many varieties of domestic chicken we see today. They still exist in the wild in parts of their range, but were introduced to many islands all over the world by early explorers, as future food resources for hungry sailors.  No doubt most of those Junglefowl genes have been swamped out by domestic chicken varieties, but the males still exhibit the striking plumage that differentiates them from just an ordinary rooster.

Posted in Behavior, Birds, Nature, Tropical, Wildlife Photography | Tagged , , | 7 Comments »

Islands of(f) islands

February 28, 2014 by Sue

“Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.”
(Victorian mathematician Augustus DeMorgan)

And so it seems true of islands as well … larger islands have little islands about them, ad infinitum.

Coastal and landform topography of Puerto Rico and U.S. Virgin Islands. From NCCOS http://ccma.nos.noaa.gov/ecosystems/coralreef/summit_sea/summit_sea2.aspx. Culebra and Vieques are the small islands just to the east of Puerto Rico.

Coastal and landform topography of Puerto Rico and U.S. Virgin Islands. From NCCOS. Culebra and Vieques are idyllic small islands between Puerto Rico and the U.S. Virgin Islands (St. Thomas, St. John, and St. Croix).

We got a great view of the chain of islets that span the distance between Puerto Rico and its small island neighbors to the east as we flew at 1400 feet over the ocean expanse to our destination on Culebra.

Cape Air took us from Puerto Rico to Culebra and back. I remembered to get my camera out of the luggage on the trip back!

An 8-seater Cape Air plane took us on a half-hour flight from Puerto Rico to Culebra for a mere $45. I remembered to get my camera out of the luggage on the trip back to PR!

A view of Culebra looking northeast toward St. Thomas, U.S. Virgin Islands

A view of Culebra looking east toward St. Thomas, U.S. Virgin Islands.  The coastal shores and keys surrounding Culebra are protected as part of the U.S. National Wildlife Refuge system, which results in some of the most diverse and healthy coral reefs in the Caribbean and prime habitat for nesting seabirds.

A tiny islet in the channel separating Puerto Rico and Culebra (seen in the distance).

A tiny islet in the channel separating Puerto Rico and Culebra (seen in the distance). When is a rocky outcrop in the ocean too small to be called an island?

The extreme northeastern tip of Puerto Rico, showing coral heads and sandy shoreline that surround the island.

The extreme northeastern tip of Puerto Rico, showing coral heads and sandy shoreline that surround the island.

Although birds are highly mobile and able to navigate the mileage between mainland and islands fairly easily, there is nevertheless an ever diminishing number of species on islands as the distance from the mainland increases and/or the size of the island decreases.

Birds could settle on Caribbean islands by migrating eastward from Central Mexico (1026 bird species) or southward from Florida (510 species).  To illustrate the “island effect” of distance and size:  Cuba has 368 bird species in its 43,000 square mile expanse, while nearby but much smaller Puerto Rico (3400 square miles) supports 349 bird species, and Culebra (12 square miles) has just 110 species, many of which are only passing through on migration to other sites (only 43 species actually nest on Culebra).

Over time island birds often develop unique characteristics that separate them from their mainland ancestors, becoming unique to that particular place (endemism), like the Puerto Rican Lizard Cuckoo and the diminuitive Puerto Rican Tody (from an earlier post).

Looks very much like the Cuban Lizard Cuckoo, I photographed

Looks very much like the Cuban Lizard Cuckoo, I photographed last April.

Posted in Birds, Landscape, Nature, Weeds, Wetlands, Wildlife Photography | Tagged , , , , , | 9 Comments »

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