Saturday, January 16, 2010

The Vultures of Massai Mara

This is the third in a series of posts summarizing my experiences on our recent trip to Kenya to study East African Raptor Ecology. The first post was on African Fish Eagles and other wildlife at Lake Naivasha, Kenya. The second covered the Big Cats of Kenya. While not raptors, they were one of the many highlights of the trip. This post is focused on the vultures of Maasai Mara National Park.

Vultures play a critical role in cleaning up carcasses left in the environment. It is estimated that in Africa on average 70% of a carcass's mass is consumed by vultures. This is a critical ecosystem role which can help reduce disease among the animal populations. Some of the more powerful vultures are also known to attack sick and dying animals as well.

Old world vultures make up a diverse collection of birds. Each has carved a unique niche for its own. Their beaks are tuned to be most effective for their particular niche. Some have large powerful beaks for breaking through the tough hide of an animal and breaking bones. Some have small beaks to extract meat from tight crevasses.

We observed the following 5 vulture species in Maasai Mara

Lappet-faced Vulture.

Large powerful vulture. Expert at tearing open the carcass and breaking bones. This guy is dominant over other vultures at the carcass, which suits all as he/she can tear open the carcass for others. Common to many vultures, the head is bald to prevent feathers from getting matted with blood. In contrast to others later, this guy does not have a bald neck as it seldom inserts its whole head into the carcass. This species is threatened and vulnerable as rated by IUCN.

Lappet-faced Vulture. Maasai Mara Kenya.

African White-backed Vulture.

This was the most abundant vulture that we observed. It is smaller and thus less dominant than the Lappet-faced. We observed a single Lappet-faced move a group of White-backs off a carcass. The bald head and neck reveal its feeding style of inserting its entire head into a carcass. Conservation status was changed from least concern to near threatened in 2007.

African White-backed Vulture. Maasai Mara Kenya.

Rüppell's Griffon Vulture

Another large powerful vulture which is equipped to get dirty in a carcass. Competes most directly with the African White-backed and usually is dominant. This vulture also holds the world altitude record for a bird. A Rüppell's Griffon Vulture was sucked into a jet engine at 37,000 feet! This vulture has specialized hemoglobin in its blood enabling it to operate in low oxygen environments. While 37,000 feet might be an exception, it regularly flies to 20,000 feet. The panels on its chest flush with color when agitated. Conservation status was changed from least concern to near threatened in 2007.

Juvenile Rüppell's Griffon Vultures. Maasai Mara Kenya.

White-headed Vulture

Known as the geisha. It is a medium sized vulture that is mostly solitary. It is a scavenger like the other vultures, but is also skilled at live prey including insects, rodents, and even birds. Often arrives first at carcass and is powerful enough to tear it open. It cannot compete with other larger vultures once they arrive. In contrast to Ruppell's Griffon and the African White-backed Vultures, the White-headed is a clean feeder. The bare skin on its head flushes when agitated.Conservation status was changed from least concern to vulnerable and threatened in 2007.

Juvenile White-headed Vulture. Maasai Mara Kenya.

Hooded Vulture.

This is a small vulture with a small beak for extracting small pieces of meat. Conservation status is least concern, likely because of its adaptation to human waste. Vultures need love too!

Hooded Vultures. Maasai Mara Kenya.

A scan of the conservation status of these species spells a grim tale. Almost all have had their threatened status increased in the last ten years. For most, this increase comes from a greater than 10% decline in population within 3 generations. The usual list of issues face these species including habitat destruction, but most significantly, direct and indirect persecution. Poisoning is threatening vulture species around the world. While the largest threat in India is a veterinarian medicine called Diclofenac, the greatest threat in Africa seems to be Furadan. Furadan is a pesticide manufactured by a US company - FMC. In May of 2009 the US Environmental Protection Agency banned it use on all food products in the US. It is still manufactured in the US and exported elsewhere. Our little gift to the world (yes, we still make DDT as well). Furadan is a pesticide which is widely available in Africa over the counter. Recently it has been used by farmers and ranchers to poison predators such as lions. Furadan is placed on a carcass, the lion eats the carcass, the lion dies, the vultures arrive, they die, more vultures arrive, ... One incident in Kruger Park killed 72 vultures. In another case, vultures were targeted directly killing 50 threatened birds. It's just incomprehensible. To quote Bruce Cockburn in his song Beautiful Creatures - "The callous and vicious things humans display, The beautiful creatures are going away."

The establishment of National Parks has helped tremendously in preserving creatures, but vultures are highly nomadic. They don't recognize the park borders. Recent studies have shown they forage widely across Kenya and Tanzania in search for food.

The Storks

A distant relative of the vulture are the storks. It is interesting that western civilization associates vultures with death and storks with birth. Most carcasses with vultures also had Marabou storks nearby. While the Marabou are much larger than the vultures, the vultures were dominant at the carcass chasing the storks away. The Marabou are referred to by locals as the undertakers.

Marabou Stork. Maasai Mara Kenya.

Yellow-billed Stork over pelicans. Lake Naivasha, Kenya. Photo by Karyn.

Abdim's Stork. Maasai Mara Kenya.

Saddle-billed Stork. Nairobi National Park, Kenya.

Update Jan 19, 2010: Oops. I forgot my best vulture photos on this post. They have been added to a later post on The Vultures of Maasai Mara Revisited.

2 comments:

flowergirl said...

I was saddened to read about the vultures in Africa...was hoping they were doing better than their Indian counterparts.

Are the storks also scavengers?

wolf21m said...

Flowergirl. Some of the storks are scavengers. The Marabou specifically. I am not sure if they all are. There is a later post on my blog which shows a Marabou stork interacting with vultures on a carcass.