Birds of prey migrating in the Netherlands


This video is about raptor migration in Panama.

The Dutch SOVON ornithologists report about migration of birds of prey.

Yesterday, 27 August 2017, was a good day for raptor migration.

451 honey buzzards were counted. And 278 marsh harriers; though most individuals of this species migrate in September.

There were 38 ospreys. And four Montagu’s harriers; one hen harrier, and a pallid harrier (claimed; experts still have to find out whether it was really that rare species).

Yellow-billed cotinga online


Yellow-billed cotingas

From Neotropical Birds Online:

New on Neotropical Birds Online: completed account for the endangered Yellow-billed Cotinga (Carpodectes antoniae). This account features what may be the first-ever images of a juvenile of this beautiful, ghostly, and declining species.

Yellow-billed cotingas live only in southern Costa Rica and adjacent southwestern Panama.

Costa Rican birds, bye-bye!


This video is called Amazing hummingbirdsCosta Rica.

31 March 2014.

After yesterday, today departure from Costa Rica.

To Panama and beyond.

Early in the morning on the bird table: clay-coloured thrush and blue-grey tanager.

Also buff-throated saltator and rufous-collared sparrow.

This video from Colombia is called Buff-throated Saltator, Silver-throated & Lemon-rumped Tanagers.

On our way to the airport: great-tailed grackles.

15:00, Panamanian time: a great-tailed grackle flies past a window at Panama City airport. Like when this journey began; closing the circle.

Howler monkeys and least grebes in Costa Rica


This video from Panama is called The Mantled Howler Monkey of Central America.

23 March 2014 in Costa Rica.

After yesterday, still near the Rio Tempisque.

A mantled howler monkey family with a youngster in the trees, early in the morning.

Four black-necked stilts near the lakelet. They drink.

Two least grebes swim.

A bare-throated tiger heron.

A flock of black vultures.

Near the next lakelet, a green heron on a tree.

A yellow-naped parrot.

Two great kiskadees, busy with nesting material in their bills.

A black-headed trogon in a tree.

A Hoffmann’s woodpecker.

A solitary sandpiper on a lake bank.

A blue-black grassquit in a tree.

A white-collared seedeater.

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To the wildlife in Costa Rica, 13 March


This music video from the USA is called Dionne WarwickDo You Know The Way To San Jose?

However, this blog post is about a different San Jose; the capital of Costa Rica.

Costa Rica is only 0,04% of the surface of planet Earth. However, 5% of all wildlife species can be seen there.

So, I went there on 13 March 2014.

Our plane departed; first, to Panama.

At the international airport of Panama, I saw my first Central American birds. Great-tailed grackles flying around.

This video is about a great-tailed grackle singing near an airport in California, USA.

Further away at Panama airport, birds of prey circling. Too far away to see what species exactly.

There, we transferred to Costa Rica.

This video is called Bird Photography Workshop – Costa Rica (With Wildlife Photographer Glenn Bartley).

Costa Rica 2014 presidential elections: here.

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Bat research in Panama


This video says about itself:

30 May 2010

“Bat Women of Panama” showcases a small group of female scientists who use reason, technology and even creativity to reveal the many mysteries of Central America’s amazing bats.

Set on the small island of Barro Colorado, in the Panama Canal, this film follows five research biologists through wet tropical forests as they encounter a variety of bat species with surprising physical and behavioral adaptations. Stunning scenes, fascinating biological wonders and the playful wit of the film narrator will keep students engaged as they learn about one of nature’s most misunderstood creatures.

From Smithsonian.com in the USA:

A Night in the Forest Capturing Bats

Our intrepid reporter joins tropical bat researchers in the field one night and gains some appreciation for their fangs

By Paul Bisceglio

January 30, 2014 2:00PM

Stefan Brändel lives on a big island in the middle of the Panama Canal and spends his nights catching bats. Part of a small group of German scientists studying disease transmission in tropical forests, he hikes deep into the island’s thick vegetation three to four evenings each week to collect data by snaring the creatures in long nets secured between trees. The work lasts until early morning, but Brändel, a doctoral student at the University of Ulm, is indefatigable—he really likes bats.

“I love diversity, and bats are a super diverse group of mammals, with a few thousand species worldwide, and 74 here on this island in the neotropics,” he told me a few months ago, when I visited the island, named Barro Colorado, to see one of the Smithsonian Tropical Research Center‘s research outposts, a cluster of labs and dorms on the forest’s edge where he stays with other scientists throughout the year to study the island’s protected flora and fauna.

“And they are cool animals,” he added. “That’s the most convincing part.” …

The data collection took about two hours. After processesing each bat, Brändel unpinched their wings to let them go. The final one he studied was a rare catch: Phylloderma stenops, known as the “pale-faced bat.” Its tan fur and pointed, ridgy ears were indeed attractive. Tschapka joined Brändel and Hiller to say goodbye to the creature, and they gently passed it around, each holding its puggish face close to his own for one last inspection. When they released it, the bat disappeared shrieking into the forest.

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Frogs mating, and the bats danger


This video says about itself:

Risky Ripples

23 Jan 2014

When a male túngara frog serenades female frogs from a pond, he creates watery ripples that make him easier to target by rivals and predators such as bats. A túngara frog will stop calling if it sees a bat overhead, but ripples continue moving for several seconds after the call ceases. In the study, published Jan. 23, 2014 in the journal Science, researchers found evidence that bats use echolocation — a natural form of sonar — to detect these ripples and home in on a frog. The discovery sheds light on an ongoing evolutionary arms race between frogs and bats. Video by Wouter Halfwerk.

From The Why Files:

Menacing mating game: Frogs fear bats!

23 January 2014

Like any foolish fellow, the túngara frog lives and loves dangerously. To those in the tropical-bio-biz, it’s old news that this resident of shallow ponds ranging from Venezuela to Central Mexico is prey to frog-eating bats.

That croaking mating call makes a great target for the flying mammals with an appetite for frogs’ legs. But now we hear another reason why life is hard for the feckless frog.

In a study released today, scientists revealed that the croaking frog sends two separate signals to the bats: First, the mating call, which deters competing males while attracting females — and those hungry bats.

But the frogs power their croak by inflating and deflating an enormous air sac, which forms ripples on the pond that survive even after the frog chokes off its croaks after seeing a bat against the night sky

To test the interaction between the bats and frogs, first author Wouter Halfwerk of Leiden University in The Netherlands set up an experiment in Panama, using artificial frogs to simulate the appropriate sound, with or without ripples

Halfwerk and co-author Michael Ryan, professor of zoology at the University of Texas, found that bats would attack in response to the mating call alone, but the attacks increased 36 percent when ripples accompanied the soundtrack.

Frogs croak, and then croak!

This makes life difficult for the frogs, Ryan notes. To reproduce, they must call. “The males can stop calling, but they can’t take these ripples back, so the danger of calling extends for a few seconds. It’s amazing that bats are able to figure this out.”

The tests were held in darkness, so the bats must have been using their sonar — echolocation — to find the pattern of ripples.

The mating call is primarily to attract females, but it also shouts “Keep away!” to other males, and the competition doubled their “I’m here too!” responses when ripples followed the croaks. “If you look when they are calling, the frogs are spaced out,” Ryan says. “If another male is too close, they start to make aggressive calls, and sometimes they fight; I have seen them kill each other.”

Ryan, who first noticed the frog-bat system as a graduate student in the 1980s studying with bat biologist Merlin Tuttle, notes, “We have known for a long time that the bats can find the frogs.” The new study, however, is the first to show how waves created when the frog sounds off affects bats — and other frogs.

Now that they know that competing males are more responsive when ripples are present, the researchers plan to see how females act with and without ripples.

Live to love, but love to live!

If the bats have “cracked the code” of the frogs behavior, turning a mating move into a death dance, that could be shaping frog behavior. “We know frogs prefer calling under cover, compared to out in the open,” says Ryan. Not only do bats have trouble flying to the sheltered frogs, but they may also have difficulty detecting ripples with echolocation in the brush.

We mused: the frogs, like certain guys we could name, allow mating to trump everything, even mortal danger. “Through the entire animal kingdom — there are exceptions — but most of the attributes that make an animal sexy or beautiful can be very costly. Men die before women in part because testosterone has a negative effect on the immune system.”

Every time an animal communicates, it creates a disturbance in the environment, and that’s especially true for the “look-at-me” mating messages. “The question I have,” Ryan adds, “is how many of these incidental things that we animals do become fodder for another animal that is looking to parasitize, to lay eggs” or grab dinner?

Do some showboating, and a biological big brother may be bugging your channel, Ryan says. “Males have to make themselves more conspicuous to females; to call louder, to wear brighter colors, do fancy dances. But all of this also makes them more conspicuous to predators.”

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