Sequential analysis reveals use of mutual assessment in contests between wild New Zealand giraffe weevils

Figures & data

Table 1. Ethogram of agonistic behaviours employed during male-male interactions.

Behaviour	Description	Scoring method
Low Intensity
Walk/Approach	Directed movement towards opponent.	Duration
Orientate/Investigate	Turning to face opponent and/or touching opponent antennae and rostrum.	Duration
Lift rostrum	Holding rostrum above parallel with the body when encountering opponent, rostrum may also be swung sideways.	Duration
Crouch	Lowering body down either over a female they are guarding, or on tree surface, and gripping firmly while becoming unresponsive to opponent.	Duration
Climb on	Climbing and standing on top of opponent.	Duration
Line up	Standing head-on and parallel to opponent with rostrum overlapping opponent’s body.	Duration
Antenna beat*	Flicking movement of antennae, typically from being held perpendicular to rostrum and moved completely back or forwards and parallel to rostrum and back.	Frequency
High Intensity
Paw	Rapidly moving front or middle legs in a pawing action, contacting with opponent (Figure 1A).	Duration
Push	Vigorously pushing using rostrum, often across their opponent’s entire body.	Duration
Grapple	Rostrum held along opponent’s body and hooked under opponent’s middle leg (Figure 1B).	Duration
Pick-up/Toss	Gripping opponent with mandibles and holding them off the tree, followed by tossing them a distance away.	Duration
Rake	Movement of rostrum in a pulling lever-style action in attempt to dislodge opponent (Figure 1C).	Frequency
Kick*	Kicking of one or both back legs towards opponent.	Frequency
Bite*	Gripping opponent with mandibles (Figure 1D).	Frequency
Conflict Ending
Retreat	Rapidly moving (or attempting to move) away from opponent. Also includes being picked up by their opponent and tossed.	Instant event
Pursue	Orientating towards and moving after opponent as they retreat.	Instant event
End	Loss of contact with opponent with no further conflict behaviours displayed.	Instant event

*Not included in transition matrices.

Figure 1. Examples of some competitive behaviours used by male giraffe weevils during contests. A, Paw: A male (centre) guarding a female (left) has both front legs raised and moving in a vigorous pawing action, contacting with the intruder male (right); B, Grapple: Two males line up with their rostrums held along the length of the other’s body and hooked under the middle leg; C, Rake: A male (right) uses his rostrum in a pulling action both downward and towards himself against a competitor male (left); D, Bite: A male (right) bites the middle leg of a male (centre) who is guarding a female (left).

Figure 2. Kinematic diagram describing a first order Markov chain analysis of competitive interactions for winner and loser giraffe weevil males (N = 63 individuals, 100 contests) for all transitions that occurred 10% or more of the time. Arrow thickness relates to transition frequency between behaviours (see legend). Box size is proportional to the frequency that each behaviour occurred. Light grey boxes represent low intensity behaviours, dark grey boxes, high intensity behaviours, and white boxes, conflict resolution behaviours.

Figure 3. Kinematic diagrams describing a first order Markov chain analysis of interactions between male giraffe weevils shown for contest A, losers and B, winners for all transitions between behaviours that occurred 10% or more of the time. Arrow thickness relates to transition frequency between behaviours (see legend). Box size is proportional to the frequency with which each behaviour occurred. Light grey boxes represent low intensity behaviours, dark grey boxes, high intensity behaviours, and white boxes, conflict resolution behaviours.

Table 2. Comparison of competitive behaviours used by contest winners and losers.

Behaviour	Units	Status	%	Mean ± SD	Max	Min	CV
Investigate/Orientate	Seconds	Winner	80	2.37 ± 1.77	8.4	0.3	0.75
		Loser	66	1.99 ± 1.53	6.7	0.3	0.77
Climb on	Seconds	Winner	14	8.33 ± 3.85	28.8	0.9	0.46
		Loser	0	–	–	–	–
Crouch	Seconds	Winner	1	1.80 ± –	1.8	1.8	–
		Loser	26	10.98 ± 7.84	42.0	0.6	0.71
Lift rostrum	Seconds	Winner	47	1.79 ± 1.38	5.8	0.4	0.77
		Loser	53	2.67 ± 2.41	15.5	0.2	0.90
Line-up	Seconds	Winner	43	1.20 ± 1.36	12.7	0.2	1.13
		Loser	44	1.34 ± 1.42	12.6	0.3	1.06
Paw	Seconds	Winner	19	3.03 ± 1.65	10.5	0.8	0.54
		Loser	5	1.54 ± 0.38	2.4	0.3	0.25
Push	Seconds	Winner	51	4.50 ± 4.59	34.6	0.4	1.02
		Loser	6	5.00 ± 1.54	10.7	1	0.31
Grapple	Seconds	Winner	23	3.80 ± 2.20	12	0.5	0.58
		Loser	22	3.80 ± 2.19	12	0.5	0.58
Pick-up	Seconds	Winner	3	8.83 ± 1.80	14.7	1.4	0.20
		Loser	0	–	–	–
Antenna beat	Number	Winner	82	8.01 ± 9.08	57	1	1.13
		Loser	56	4.49 ± 4.32	25	1	0.96
Kick	Number	Winner	19	4.37 ± 2.25	12	1	0.51
		Loser	26	4.54 ± 2.91	17	1	0.64
Rake	Number	Winner	41	4.31 ± 4.21	27	1	0.98
		Loser	2	1.00 ± 0.14	1	1	0.14
Bite	Number	Winner	26	2.73 ± 1.81	14	1	0.66
		Loser	5	2.00 ± 0.48	3	1	0.24
Number of behaviours	Number	Winner		4.55 ± 2.28	10	1	0.50
		Loser		3.18 ± 1.82	8	1	0.57

NB: % =  percentage of individuals that displayed each behaviour, CV = coefficient of variation.

Table 3. GLMs comparing investment in competitive behaviours between winners and losers, and overall number of behaviours executed.

Behaviour	χ^2	P	Odds Ratio	95% CI
Investigate/Orientate (sec)	0.44	0.51	0.77	0.35,1.64
Lift rostrum (sec)	0.15	0.70	0.88	0.44,1.72
Line-up (sec)	2.00	0.16	0.40	0.10,1.32
Grapple (sec)	0.02	0.88	0.91	0.26,3.13
Antenna beat (number)	0.031	0.86	1.07	0.50,2.38
Kick (number)	0.04	0.84	0.86	0.17,4.09
Number behaviours	1.9	0.17	1.89	0.79,4.84

NB: CI = confidence intervals.

Data availability

Data associated with this study is deposited at 10.6084/m9.figshare.22207954

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