Bird Behavior

[stan kostka]

Came across this article on the web recently, don't know if it's true or a hoax, but it sure is an interesting read. I know the situation does not reflect consequences of feeding martins, but one could conceivably argue that eastern martins no longer have the knowledge of how to find a nest in a tree cavity.

THE PELICAN CHALLENGE ON THE WEST COAST
The near-threatened Great White Pelican (Pelecanus onocrotalus) is arguably
the largest fish-eating seabird endemic to the South African West Coast. It
can be recognised in flight by its huge wingspan, S-shaped neck, long beak,
its penchant for soaring in thermals and for flying in formation. Some call
it the Jumbo Jet of the birds.
A number of years ago, a pig farm near Cape Town started feeding their pigs
chicken carcasses. These were gutted before feeding and the offal was thrown
into a hole in a remote corner of the farm. Before long, various scavenging
birds, amongst them the Great White Pelican, started eating this regularly
supplied and nutritious food. Unfortunately, as we all know, most chickens
battery-reared today are fed growth hormones, and it is suspected that this
has had an effect on these pelicans.

It is postulated that this plentiful supply of hormone-enriched feed caused
the pelicans to breed better than is usual, and their offspring went to eat
where their parents took them - to the pig farm. Furthermore, it was
believed that they never learned that their waterproof feathers, long beak
and gular pouch were so ideally suited to bulk fishing in the sea, for here
were easy pickings on land. Today, a whole generation of pelicans has grown
up with no knowledge of fishing techniques, or even what a fish is, or looks
like.
When the authorities finally realised what was happening on the pig farm,
they intervened and closed up the offal hole, effectively cutting off this
bountiful food supply. After some initial confusion during which some of
these birds died from starvation, the remaining pelicans started looking for
alternative food sources, by seeking in an ever-widening search pattern.

After some time, they found that some unpopulated, predator free islands in
the mouth of the Langebaan lagoon just outside Saldanha Bay had thousands of
defenceless gannet, cormorant, penguin, oystercatcher and gull nests, ripe
for easy pickings. These hungry pelicans waddled through the breeding
colonies, scared the resident parent birds away with their daunting size,
and swallowed every egg and chick they could find, in many cases, decimating
local populations of our endemic sea birds. The Jumbo Jet of the birds had
become the Jumbo Vacuum Cleaner. The 2006/7 breeding season yielded a
virtually zero production of hatchlings to complement the West Coast seabird
population.

These pelicans cannot be shot as the species is listed as "near-threatened"
in the Red Data Book, and besides, there is no way one can identify an
ex-pig farm bird from a normal one at a distance. They cannot be poisoned
without serious risk to other life forms. In the meantime, these birds are
breeding, and passing on their bad feeding habits in turn to their
fledglings, thereby exacerbating the problem. As the islands are part of the
proclaimed West Coast National Park, the SANParks Honorary Rangers (HRs)
have teamed up with Park permanent staff under the watchful eye of avian
scientists at the University of Cape Town. The idea was to create a rotating
presence on these exposed and wind-swept islands during this year's seabird
breeding season (October to January), in order to scare off pelicans
whenever they land. This is a lonely, risky and labour-intensive operation
entailing much scrambling over rocks and climbing to high ground to watch,
and down again to chase, followed by more climbing. The teams operate in
5-day shifts on the two bigger islands, Jutten and Malgas. Their day starts
at first light (05h00) when the pelicans arrive and ends at sunset (20h30)
when they leave to roost on the mainland.

The idea is that each island is divided in two, with one half being left to
the pelicans to carry on with their bad habits, while the other half is
considered as a "pelican-free" zone and the birds are actively chased from
these parts of the islands. This effectively provides comparative zones on
each island, where one is a control zone showing what happens if we do
nothing, while the other indicates the results of the chasing operation. A
weekly, and in some cases, daily breeding success count is maintained by the
HRs on the islands, as well as other possible sources of predation such as
Cape (Kelp) Gulls and Cape Fur Seals, so that the bird scientists can assess
the impact that chasing has had on the pelican predation and then use this
data to make a decision on the way forward for next year's breeding season.

Once again, man's thoughtless actions have initiated a complex web of change
that is not easily unravelled. We already know that an unthinking motorist
throwing an apple to a baboon at a lay-by to impress his child is signing
the death warrant of that animal, for the day will most certainly come when
that animal will be shot by other folk who are sick and tired of the
marauding baboons who have become used to free food as supplied by other
thoughtless humans. A life lesson for the reader is not to ever feed a wild
animal, no matter how "sorry" we feel for it or how cute it is. We don't
realise the longer-term implications of such acts, and in many cases, what
starts out as an innocent attempt to supply a perceived shortage of food,
results in an unforeseen catastrophe later.

So what is the long-term answer? Everyone is feverishly working on a
solution, and the island teams are chasing pelicans from the pelican-free
zones and gathering important field data during their shifts on the islands,
but in the meantime, our coastal bird populations are under serious threat.
Bird scientists are hoping that the pelicans will get the message to stay
off the islands, and scientists are happy to report that some pelicans
chased from the islands have been spotted catching fish in the sea.
However, it remains to be seen if they can all switch to this sole method of
sustenance and desist from pillaging the seabird populations on the islands
into the future.

Mike Lodge
Honorary Ranger: West Coast National Park

[Gary-La]

Wierd story. Even wierder that those pelicans could distinguish chicken guts with eggs/hatchlings as food. And they were worried that they didn't know what a fish was

Makes one wonder how much involvement we humans should have on martins as well. We supply them with housing, nesting material, B&B trays of food, egg shell, and even more nesting material, kill their parasites for them, protect them from predators, what else? have I missed something?

[Donnie Hurdt MN]

Somthing else to think about, when was the last time most of us saw a Bluebird pair nesting in a natural cavity? In my openion, they are fast becoming like the martins, totally dependant on man supplied housing.
Is this bad? I dont know for sure.
The list goes on, Tree Swallows, Wrens, Chickadees, Barn Swallows, etc. Granted these birds are not as much dependant on us for housing as the martins are but just how dependant will they become?
We have been modifying the martins nesting behavior ever since the first Native American hung out a gourd for them, I feel that we are doing the same for other birds as well.
Is this bad? I dont know for sure.

[KathyF]

What an interesting article, Stan. I know the "damage has been done" with the martins' nesting habits; starting with the import of the english sparrow & starling, then the gourds that were put up by the indians.

The question then becomes how much further do we go and make these birds dependent on us? We all love them dearly and hate to see their demise, but it's like the doctor's hypocratic oath; "First, do no harm". I built a small nest last year to help attract martins to my new setup. This year, I will probably throw in a few pine needles here & there in each box of my new house, but not build a substantial nest. I think, other than mite control, I really have to question myself about how far I should go.

*We*, meaning humans, have perpetuated the mite problems by setting up the types of houses (closely placed nestboxes), so I think we should probably contribute somewhat to their control. Control being the operative word - maybe not be concerned about complete erradication.

Then the question of feeding and its impact. It's only temporary to get them through any inclement weather, right? However, what if they "remember" that next year and come back even earlier because of that early season food availability? Are we disrupting their natural migration instincts which may be based on availability of food, weather, etc.? I don't know, but it does worry me.

Something else to consider; what happens when we're gone? Have we "trained" someone to take over our colonies and if not, how will they survive at a new colony that doesn't pamper them like we do?

I hope I don't get flamed by posting this - I am not criticizing or judging anyone. I've built the nests and killed the mites and changed out nests myself because I couldn't stand to see not one of them die - but my heart does foolish things sometimes that my head says I probably shouldn't . I think it's a deeply troubling topic that deserves attention and a lot of soul-searching and thought and I've tried to express that here.

[KathyF]

To dhurdtMN: I do think some of this has been caused by the import of the ratbirds & starlings, unfortunately. Here in Missouri, I do see a lot of bluebirds, but they are definitely in need of housing. But since they catch insects on the ground, they have plenty of food in supply.

Just today, I already have 3 male bluebirds fighting over 1 of my 2 nestboxes, even though we have lots & lots of trees on the back half of our 23 acres and some of them have large holes from old woodpecker nests.

[litedave]

Hey Plain Dealing Gary,
You missed toys. Ha
Would these birds be here if we did not supply housing and all the other things for all these years?
Where would they be?