Birds mobbing snakes

posted in: Interspecific | 6

Birders are familiar with the mobbing behaviour of birds, especially when it is directed at raptors and owls (1, 2, 3, 4, 5). However, they are less familiar with birds mobbing non-avian predators.

There are enough reports in the avian literature to show that this is not an uncommon phenomenon. One reason for this lack of awareness can be because the snake being mobbed would most probably be among the vegetation and not easily visible. And birders may mistake the ruckus as mobbing of a raptor. The other reason would be the obvious one, that local birders are unaware that mobbing can extend to predators other than birds.

With the present posting, it is hoped that birders will be more aware of this phenomenon and be more vigilant when in the field.

bbb2.jpg

On October 2006 KC Tsang was observing an Oriental Whip Snake (Ahaetulla prasina) stalking a Crimson Sunbird (Aethopyga siparaja). Just when the snake was about to strike, Ping, who is Amy Tsang’s cousin, saved the bird by grabbing it (above right). A close up image of the snale is shown on the left and KC has specifically pointed out that the person handling the Oriental Whip Snake is not Ping, considering the hairy nature of the arm.

Yes, snakes commonly catch birds, their fledglings and their eggs but there have been few, if any, documentation of such activities. And it would be natural for the parent birds to raise an alarm when a snake is about to raid their nest.

But mobbing by a number of species and working together?

Some two years ago, Amy and KC Tsang saw a huge Red-tailed Ratsnake (Gonyosoma oxycephalum) being mobbed by birds in the Central Catchment area (left). (These snakes can grow up to 240 cm in length.) The birds involved in the mobbing included Striped Tit Babblers (Macronous gularis), two Greater Racket-tailed Drongos (Dicrurus paradisus), bulbuls and some others which KC was not able to identify. The forest was just alive with screaming birds, hopping from branch to branch just out of reach of the snake. Squirrels were also there chattering away.

Another incident that KC encountered was with an Oriental Whip Snake, also a fairly big one, gliding from branch to branch that had attracted the attention of the forest birds.

Matheus et al. (1996) reported seeing a snake grabbing the fledging of a pair of adult Golden-hooded Tanagers (Tangara larvata) in Eucador. The alarm calls the parent birds made attracted the attention of other bird species that flew in to mob and dive-attack the snake. Although the snake swallowed the fledgling within 5 minutes, the mobbing continued for half an hour. A total of 14 bird species joined in the mobbing, scolding and attacking the snake.

Input by KC Tsang, images by KC except the hairy arm by ?YC.

Reference:
Matheus, J.C., Wittmann, U., Olaf, J., Leutfeld, M., & Schuchmann, K-L. (1996). Reactions of birds to nestling predation by a snake. Ornithologia Neotropical 7:163-4.

3+

6 Responses

  1. I feel as nature lovers we should not intervene in the daily rituals of survival. Yes we do have emotions attached to some of these species we admire, but denying a snake of a meal ( probably one after a long time) is not very kind to the reptile. I think we should just watch,admire from afar and let nature takes her course. Just like how we avoid disturbing birds feeding their chicks in a nest while we try to snap a picture or watch them.My two cents..

    Haniman

    0
  2. I am in total agreement with Haniman. The best would be to watch a natural predation event and observe how the prey is subdued, or how the potential prey actually fends off the predator. It is through such field encounters that we learn about animal behaviour and ecology. Hence the account by Matheus et al. (1996). If it is cruel for a bird to be eaten by a snake, would it also not be cruel to deny a snake of a meal?

    0
  3. Wow i tot I would be the only one to voice the same feelings. I agree with haniman and benjamin. non-intervention and silent observer is the best stance any true nature lover can take. unless there is a purpose beyond that of saving one’s preferred species..

    0
  4. My daughter and I just observed this phenomena today and cheered the birds on to victory! The snake can feast on vermin and leave the birds alone.

    0
  5. Linda Nicholson

    I had this mobbing happen once in my maple tree. All different kinds of birds. There was a snake in the tree. They harassed it till it left the yard. The next day there was only one baby left in the nest I could see from the window. Today something similar was happening in the mulberry tree but I could not see what was alarming them the sound is so frantic it makes you feel slightly alarmed yourself.

    0
  6. Thanks for your input Linda. It must have been exciting with all that noise… if not alarming?

    0

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.