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Grooming Solicitation & Hierarchy
in Cercopithecus petaurista

By: Ryan Domitz | Mentor: Frank Logiudice


Figure 2

The most proportionate allogrooming was exhibited by Tumani, subject C (Figure 2), while Timbi, subject B, exhibited the lowest proportionate allogrooming (Figure 2), which is typical of males (Chiarelli 1980). Consistent with the literature (Chiarelli 1980), most of the grooming associations were between the females, A & C (Figure 2).

Table 1. Test for Influence of Grooming Solicitation, ID, and Retintroduction on Allogrooming

The ANCOVA test for influence of monkey identity, the reintroduction event, and grooming solicitation on rates of allogrooming indicate that only monkey identity as a variable influenced allogrooming (Table 1). Neither the reintroduction event nor solicitation of grooming influenced group allogrooming rates, reinforcing the idea that allogrooming and grooming solicitation are not casually related.

Figure 3

Table 2. Test for Influence of Reintroduction, ID, and Time on Grooming Solicitation

Figure 4. Pre- (X22 = 32.53, p<.05) Post- (X22 = 6.42, p<.05)

The second ANCOVA test for influence of monkey identity, the reintroduction event, and the time observed, on grooming solicitations indicate that Mama's reintroduction as well as monkey identity influenced grooming solicitation rates (Figure 3, Table 2).

Timbi's (B) power of displacing other individuals within the enclosure (Chiarelli 1980) in concert with his highest proportional counts of aggression (Figure 4) are both indicative of his position as alpha male within the group. This result was expected as Timbi is the sole male of the captive group. The non-parametric Wilcoxon test analyzed rates of aggression before and after the reintroduction event and measured a notable increase in aggression from Timbi and Tumani (Figure 4). Thus, the reintroduction event marked a notable increase in aggression as well as grooming solicitation, supporting the idea that grooming solicitation rates are positively correlated to aggression. This result was not what I expected as I believed that the grooming elicited, rather than solicited, would be a valuable metric to measure hierarchy by.

Figure 5

Overall, Timbi (B) reflected a more stable behavior pattern and had the lowest behavioral variance in his activity budget (Figure 5).

Figure 6

Another feature of communication between hierarchal individuals involves the presentation of the anogenital region to another individual, most commonly expressed by individuals of higher rank (Morris, 2006). My data, however, did not support this conclusion because Mama elicited anogenital cues in higher frequencies than Timbi or Tumani (Figure 6).

Figure 7

As expected, a higher status individual Timbi (B) elicited the least proportional grooming solicitation, whereas Mama (A) elicited the most (Figure 7).