Foraging is the act of gathering food, for immediate consumption or future storage. Turdoides squamiceps spends much of its time digging for food in the ground or under the bark of trees. Referring to the video we can distinguish seven basic sequential components of foraging: stimulation of hunger, search for prey, hunting, localization, capture, killing and consumption. When the bird interacts with the caterpillar we see what we can define the “attack phase” that is the portion of foraging behaviour from the moment when a food item is sighted, after the bird has rasped in the ground, to the moment when a capture attempt is made. Once food is captured it may be eaten, the way that food is handled is very important because food handling time must be considered in the cost and it is a factor of studies in adaptive morphology. The bird beats its food item against hard substrate to kill and maybe to remove undesirable portions. In order to understand why it is performing the behaviour and in which way does the behaviour increase the bird fitness we can simply present animals with different food types under laboratory or field conditions. Let's assume that hitting the prey simply kills it, take two groups of Arabian babblers and give the first, live caterpillars, and the second dead caterpillars. If the hypothesis is correct, the dead ones will not be repeatedly thrown on the ground. Otherwise we could assume that the behaviour also serves to remove dangerous or simply to ingest it better. In this case we could carry out another experiment to confirm the hypothesis, that is to take a group of young birds and verify how they behave first in the absence and later in the presence of adults who already know how to eat the caterpillars. In this way we will also know if the behaviour is innate or learned. Obviously foraging affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. It remains to be understood what are the environmental or physiological causes that trigger this behaviour. The study of causation can be extended to ask how information is processed by the central nervous system, how a sequence of different stimuli influences the behavioural response of the bird, or how responses to the same cue can vary depending on previous experience and the internal state of the bird. To answer these questions we can measure a number of birds on a series of morphological (size, body condition) and behavioural (response to stimuli, exploration, aggressiveness) traits and we may also induce innovative problem-solving and induce the birds with novel foraging tasks and videotaping all innovation attempts. Situations in which decision that increase one component of fitness decrease other components are called trade-offs, and they are ubiquitous. Some foraging behaviours may expose individuals to predators, in fact, we can see how the bird continually looks around to see any of them, and also let's see how the bird ignores smaller prey that can be seen in the background, preferring a more substantial one.
References
O. Keynan, A. R. Ridley & A Lotem, Social foraging strategies and acquisition of novel foraging skills in cooperatively breeding Arabian babbler, 2001.
Yoël Jimenez, IBC1197680. Video of Arabian Babbler at Mushrif Park, United Arab Emirates. Accessible at hbw.com/ibc/1197680.
Wikipedia, The Arabian babbler.
The IUCN Red List of Threatened Species, “Turdoides squamiceps”, 2013.