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Comparative studies on functionally referential alarm systems

Predator specific alarm systems are proposed to be beneficial in primates that face multiple predator types and that can respond with different survival strategies (Macedonia&Evans 1993). Other species that face similar ecological conditions should have similar alarm systems. Small songbirds have two different anti-predator strategies, either mobbing a perched predator or hiding from one in flight, and have developed two distinct alarm calls for each type of behavior (Marler 1955). These birds give a high frequency “seet” or a short “chink” in response to an airborne or perched predator respectively; this is similar to the system used by the white-faced capuchins. Another bird species, chickens ( Gallus gallus), also gives distinct aerial and terrestrial alarm calls (Evans 1993). Chickens will crouch down or run for cover in response to the aerial call, but stand up tall in a vigilant stance when responding to a terrestrial call (Evans 1993). All of these species can respond to different types of predators in distinct ways; consequently, they have evolved functionally referential alarm systems. Cooperatively breeding meerkats have developed three distinct alarm calls, in a system similar to that of vervet monkeys. The meerkats always respond to an aerial call by running to a bolthole, but scan the area and then move to a different burrow system in response to a terrestrial alarm call (Manser 2001). In response to their “recruitment” call, which seems to be used for snakes, meerkats approach the source of the call cautiously and inspect the area (Manser 2001). As with the vervet monkeys, the meerkats have evolved a specific alarm system because certain anti-predator responses are more beneficial in a specific case (Manser 2001).

Other semi-arboreal and semi-terrestrial primates, such as tamarins and the red-tailed sportive lemurs, seem to have developed predator-specific alarm systems for the same reason (Kirchhof et al, 2006; Fichtel 2007). Kirchhof observed that mustached and saddleback tamarins’ alarm calls do correspond with certain predators by measuring the time spent searching in a certain direction by the listening tamarins. He found tamarins spent a significantly longer amount of time looking up in response to the aerial alarm call but a much longer time looking down in response to the terrestrial alarm call (Kirchhof et al, 2006). Putty-nosed monkeys are another species that uses two distinct calls, pyows and hacks (Arnold et al, 2006). The monkeys combine these two calls in various ways; however, eagles always elicit hacks first and more often. The Putty-nosed monkeys use the different sequences of the distinct calls to determine whether an aerial or terrestrial predator is attacking (Arnold et al, 2008). These alarm calls are predator specific which is advantageous to species with multiple escape strategies.

Alarm calls that indicate urgency are also adaptive

In species with only one escape strategy, identifying the predator has less value. Instead, it might be more helpful to evolve a communication system that conveys the degree of risk. A primate that can only escape to the trees for safety would prefer to know whether the predator is fifty feet away or in the bush next to him, but not necessarily which type of monkey-eater he must avoid. Chacma baboons face a wide range of predators but do not have multiple escape strategies. The baboons use the same calls, which range from tonal clear barks to harsher alarm barks for all types of predators, but vary the calls to convey the degree of risk (Fischer et al, 2001; Cheney et al, 2003). The baboons respond differently based on the duration and frequency of the calls, simply ignoring any intermediate calls that are not urgent alarm calls (Fischer et al, 2001). One of the first clues that this system may be based on risk determination is the increase in alarm calls when the group is more widely dispersed (Rendall et al, 2000). This is expected; a greater area of dispersal increases the danger to each individual, representing heightened danger. In addition, chacma baboons may give a few scattered alarm barks when confronted with relatively low risk predators such as hyenas or wild dogs (Cheney et al, 2003). Lions, however, always elicit frequent harsh alarm barks from more than one baboon because they pose a greater risk (Cheney et al, 2003). The most frequent alarm calling occurs when baboons cross water infested with crocodiles. This is a high risk situation for the chacma baboons, thus it makes sense that a call system based on the degree of the threat would cause the baboons to bark most frequently in response to their riskiest predator (Cheney et al, 2003). The baboons even barked in response to harmless objects that could potentially be crocodiles, such as floating elephant dung or submerged hippos (Cheney et al, 2003). The heightened sensitivity and increase in call frequency in response to a more threatening predator confirms that their system is meant to demonstrate the relative urgency of the threat, not the particular predator (Fischer et al, 2001).

Questions & Answers

Introduction about quantum dots in nanotechnology
Praveena Reply
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Anassong Reply
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Bharti
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s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
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are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
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Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
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Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
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CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
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Do you know which machine is used to that process?
s.
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for screen printed electrodes ?
SUYASH
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s. Reply
of graphene you mean?
Ebrahim
or in general
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in general
s.
Graphene has a hexagonal structure
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Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
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