Osa Birder


Mother Nature really did it this time

Liz Jones

Liz and husband Abraham Gallo own and operate Bosque del Rio Tigre, a lodge in Dos Brazos that specializes in birding.  You may reach her at liz@osaadventures.com


Boat-billed Herons with nestlings

November 15 2016 was a day I will not forget for many years to come. It was the day the deluge began. For many, it meant over two weeks of being cut off from the rest of the Osa by raging rivers. Bridges, roads, homes and water systems were destroyed, and sadly, at least one life was lost to one of the many landslides. In Dos Brazos, we had 10 days of heavy, non-stop rain even before the 3 or 4 days of rain from the hurricane. I truly wondered if someone should start building an ark.

Thankfully the sun is now shining. Most of us on the Osa survived and have managed to get back to our normal lives. Homes, roads, bridges and water systems are being repaired, or have been repaired. For many it took days to dry out and clean our flooded homes and businesses.

What was the impact on our natural world? We can only imagine. The forest floors were washed clean impacting many of the various, less mobile, forms of insect and amphibian. Eggs, larvae, and tadpoles, for sure, were washed away. Many of the stream valleys, which have distinct ecosystems, were scoured by landslides. And the prolonged high waters left little seed or plant roots behind in the river and stream beds. I expect it will be quite awhile for these riparian systems to return to their normal state. Trees just starting to flower lost their flowers or failed to be pollinated, which obviously means no fruit this time around. And many plants did not flower for lack of sun.

The animals were unable to forage and were desperate for food. We had a squirrel that was so cold, wet and hungry he came into the open house for shelter various times during the rains. And for the first time in 20 years, one squirrel was brave enough to attack the screening on our food cabinets during daytime hours.

Our troop of squirrel monkeys was split in half, on opposing sides of the river, when high waters took out the natural monkey bridge. They spent much time on the edge of the river calling to one another . . . and trying to get all the bananas and fruit we were providing for the birds. Normally they would not bother with our feeders.

As the waters receded, we found several dead snakes along the banks and even one large Caecilian (a large worm-like, soil-dwelling amphibian).

The birds¬¬, although fairly mobile, had a hard time as well. Not only was it difficult for them to forage in the rain, but quantities of their food resources had been washed away. We have no way of knowing if, any, or how many may have died due to the excessive rains and related stress and starvation. We did observe extreme signs of famine, more pronounced than we had seen in the past 20+ years. The greatest indication of famine was the lack of the bird’s discretion at the feeders. In the past our birds have been snobs about food even in hard times, only eating bananas and ignoring other fruits. They would refuse papaya, plantains, mango and cuadrados (a square banana originally cultivated for pigs). But early on, during the entrapping rains, we ran out of bananas and started putting whatever we had on the feeders. All forms of fruit, even the pineapples and strawberries, disappeared in short order.

Some species, not regularly feeder birds at the lodge, such as Orange-billed Sparrow, Gray-headed Tanager, Bay-headed Tanager, and Gray-chested Dove, were partaking of the fruit. Over the years, I have noticed that when famine strikes the nicely ordered and polite feeder behavior disappears. Under normal circumstances each species or individual will feed separately, while others wait patiently in line. But during the rains, there would be many species on the feeders at one time, often not even attempting to chase each other off the platform. There were a few exceptions, though. The larger species such as the Yellow-throated Toucan (in the past known as the Black-mandibled Toucan) and Lesson’s Motmot (previously called Blue-crowned Motmot) scared away the smaller birds when they approached the feeders and they often sat at the platform guarding the fruit even after eating their fill.

A first for me was watching a male Green Honeycreeper that regularly came to the feeders. He would feed with others, but kept them at a distance, protecting his piece of the fruit. He was amazingly, and successfully, aggressive for a bird of his size. His bill, longer than the various tanagers tending the feeders, brought a lot of respect and he managed to reign while in attendance.

During the annual Audubon Christmas Bird Count we noticed an absence of some species’ vocalizations. Many avian vocalizations are associated with breeding season, generally late December-July on the Osa. The bird count is largely done by ear, and though many species normally are not yet vocalizing in December, there were less this year. Notably absent was the repetitive call of the Green Shrike-Vireo, a bird virtually impossible to see, but very vocal. We have done 10 annual Christmas bird counts and have always had several of this species on the count. Not one was counted on December 17th 2016.

Bay-headed Tanager is rarely seen on our feeders but was seen there during the recent deluge

Now, a month later, in mid-January, we are still observing the impacts of the rains on the avian populations in our area. It appears that for many species, the breeding season is delayed, perhaps due to the reduction of protein-rich foods in the forests, such as insects, amphibians, small reptiles and larvae. Protein-rich foods are essential to rapid development of the nestlings. In an average year, the breeding season morning song of The Black-cheeked Ant-Tanager, a species endemic to the Golfo Dulce, would be heard for the first time before the end of December. We have yet to hear it. There have been few observations of birds with nesting materials. The male Orange-collared Manakins have, just today, January 18th, started to display on the lek. A lek is a spot where male birds of the same species gather to attract females. The Red-capped Manakin has not yet started to lek.

The good news is we do have several nests, some with young, of the Boat-billed Heron. Over a week ago we observed the Marbled Wood-Quail checking out a nesting spot in a deep crevice at the base of a tree. Two weeks ago, a Long-billed Gnat wren flew back and forth from one spot to another for a half hour, carrying nesting material to a nest site.

Nature is resilient and despite the hardships of the past months, the birds WILL start breeding once again—- reproduction being the primary “goal” of all species.

In closing I want to thank all who participated in the December 7th annual Audubon CBC on the Osa. I know it was a special effort, especially after the struggles and hardships of the previous weeks of rain.

Enjoy the sunshine.

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