Birds

In the tiny tropical nation of Costa Rica, there are 850 species of birds alone -- or about 1/10 of all known birds in the world!  With such a large number of avian species in one country, all of the birds of Costa Rica have developed specialized adaptations to take advantage of every available opportunity.  Many of these adaptations involve beaks -- the unique size and shape of a birds beak directly correlates to its specialized use.

  
photos M. Noonan

The Scarlet Macaw

One of the jewels of the Costa Rican rainforest is the scarlet macaw.  There is hardly a more beautiful sight to be seen than a group of macaws flying past at up to 35 miles per hour.  These beautiful birds use their strong beaks to feed on the toughest fruits and nuts that other rainforest species cannot open.

 

Occasionally, scarlet macaws are seen consuming clay found along riverbanks.  Scientists now think that the clay may help the birds to digest harsh chemicals such as tannins that are ingested when they eat unripe fruit.

 

Scarlet macaws, like many birds, form a close monogamous pair bond for life.  The pair are dutiful parents, both male and female help to care for the chicks once they hatch.  The young macaws remain with their parents for about two years, until they are mature enough to fledge, or set out on their own.  Only when the young macaws fledge will their parents then raise another group of chicks. 

 

Unfortunately, scarlet macaws are threatened by loss of habitat and by the illegal pet trade.  In fact, macaws draw huge sums from traders -- an individual bird may be sold for up to $1000

          

 

           photo M. Noonan

Toucans


photo M. Noonan    

Toucans are visually distinct birds that can be found throughout the tropics of Central America. Different species of toucans can be distinguished based on beak size, body size, and body coloration. The behavior of the species in the toucan family, on the other hand, is very similar.

 

 

The function of the unique bill of toucans is not fully understood, but it is suspected that it allows the bird to pluck fruit from branches that cannot hold its weight. The strong beak is also used in “bill clashes” when defending a tree. A great deal of the diet consists of fruit that can be taken in by the tipping back of the head and a gulp. Toucans are not entirely frugivorous. They also prey upon birds, snakes, insects, frogs, and lizards that provide a good protein source.

Threats to the toucan include hunting for meat and capture for the pet trade.

 


 

 

 

 

                            photo M. Noonan

Hummingbirds

 

One of the most dynamic groups of birds in Costa Rica are the hummingbirds.  These tiny birds beat their wings at 100 beats per second, moving their wings so rapidly that the human eye cannot detect them moving at all.  The rapidly-moving wings of the hummingbird do indeed make a humming sound, which has earned the birds their name. 


 

Hummingbirds are the smallest birds in the Costa Rican jungle, their eggs are no larger than coffee beans and their nests may only be the size of a thimble.  But, it takes a lot of energy for hummingbirds to fly.  In fact, these tiny birds have the highest metabolic rate per unit of body weight in avian world.  To maintain this energetically-expensive lifestyle, hummingbirds consume up to 850% of their own weight in food and water each day. 

Hummingbirds feed on nectar from flowers using their extremely long tongues. In the Costa Rican rainforest, hummingbirds have bill shapes that are perfectly adapted to feeding on various forest flowers.  This is an example of a mutualistic relationship, for while the birds get food, the plants get pollinated as the bird rubs against them.  The specialized predation by hummingbirds on certain flower species that fit their special bill shape ensures specialized pollination for the patchily-distributed flowers.  Thus, this ingenious relationship ensures that the hummingbirds pollinate the correct flowers.

 

 

 

 

photos M. Noonan

 

CAC is a program of the Institute for the Study of Human-Animal Relations at Canisius College in Buffalo, NY.