The influence of plant scents on nest box inspection by Eastern Rosella (Platycercus eximius)

Figures & data

Figure 1. Location of the Burrendong Botanic Garden and Arboretum, near Wellington, NSW, where the study on the effects of plant scent on nest box visitation by Eastern Rosellas was conducted.

Figure 2. Effects of plant scent treatments on the predicted mean number of visits per day per nest box by Eastern Rosellas. Error bars indicated 95% confidence intervals. Significance levels: p < 0.05 ‘*’.

Table 1. Results of a zero-influenced, negative binomial (nbinom 1) (log) GLMM testing whether the number of visits to each nest box per day by Eastern Rosellas was significantly influenced by a plant volatile inside boxes (eucalyptus, tree tree, distilled water), treatment order (order 1, 2 and 3 representing the first, second and last 10 days of the experiment, respectively) or treatment day within each order. The effect of eucalyptus and tea tree treatments were determined by comparing them to the effects of the distilled water. Similarly, the effects of treatment order 2 and order 3 were determined by comparing them to the effects of order 1. Significance levels: p < 0.001 ‘***’, p < 0.01 ‘**’, p < 0.05 ‘*’.

		Estimate	Std. error	z Value	p Value	Sig. level
Conditional	Intercept	0.724	0.319	2.269	0.023	*
	Eucalypt	−0.090	0.127	−0.706	0.480
	Tea tree	−0.323	0.142	−2.268	0.023	*
	Order 2	−0.247	0.201	−1.228	0.219
	Order 3	0.253	0.204	1.241	0.215
	Treatment day	−0.036	0.021	−1.769	0.077
Zero influence	(Intercept)	3.053	1.032	2.959	0.003	**
	Order 2	−5.034	3.053	−1.649	0.099
	Order 3	−5.581	2.737	−2.039	0.041	*
	Treatment day	−0.637	0.260	−2.448	0.014	*

Figure 3. Effects of plant scent treatments on (a) the predicted total time spent at each nest box, and (b) the predicted mean time spent at each nest box per visit by Eastern Rosellas. Error bars indicate 95% confidence intervals. Significance levels: p < 0.05 ‘*’.

Table 2. Results of a Gaussian GLMM testing whether the total time (ln(x + 1) transformed) spent at each nest box per visit by Eastern Rosellas was significantly influenced by a plant volatile inside boxes (eucalyptus, tree tree, distilled water), treatment order (order 1, 2 and 3 representing the first, second and last 10 days of the experiment, respectively) or treatment day within each order. Significance levels: p < 0.001 ‘***’, p < 0.01 ‘**’, p < 0.05 ‘*’.

	Estimate	Std. error	t Value	p Value	Sig. level
(Intercept)	3.950	0.259	15.235	>0.0001	***
Eucalypt	0.024	0.146	0.164	0.870
Tea tree	−0.332	0.152	−2.177	0.030	*
Order 2	−0.197	0.173	−1.138	0.256
Order 3	−0.193	0.159	−1.218	0.224
Treatment day	0.001	0.022	0.066	0.947

Table 3. Results of a Gaussian GLMM testing whether the mean time (ln(x + 1) transformed) spent at each nest box per visit by Eastern Rosellas was significantly influenced by plant volatile inside boxes (eucalyptus, tree tree, distilled water), treatment order (order 1, 2 and 3 representing the first, second and last 10 days of the experiment, respectively) or treatment day within each order. Significance levels: p < 0.001 ‘***’, p < 0.01 ‘**’, p < 0.05 ‘*’.

	Estimate	Std. error	t Value	p Value	Sig. level
(Intercept)	2.877	0.151	19.031	<0.001	***
Eucalyptus	0.065	0.093	0.702	0.483
Tea tree	−0.200	0.097	−2.060	0.040	*
Order 2	−0.165	0.110	−1.496	0.136
Order 3	−0.244	0.101	−2.416	0.016	*
Treatment day	0.001	0.014	0.099	0.922

Table 4. Results of a Gaussian GLMM testing whether the mean time (ln(x + 1) transformed) inspecting each nest box from the entrance hole per visit by Eastern Rosellas was significantly influenced by a plant volatile inside boxes (eucalyptus, tree tree, distilled water), treatment order (order 1, 2 and 3 representing the first, second and last 10 days of the experiment, respectively) or treatment day within each order. Significance levels: p < 0.001 ‘***’, p < 0.01 ‘**’, p < 0.05 ‘*’.

	Estimate	Std. error	t Value	p Value	Sig. level
(Intercept)	1.154	0.198	5.822	<0.001	***
Eucalypt	0.144	0.221	0.651	0.516
Tea tree	0.241	0.240	1.006	0.316
Order 2	−0.033	0.118	−0.277	0.782
Order 3	−0.046	0.109	−0.423	0.673
Treatment day	0.044	0.024	1.853	0.065
Eucalypt × Treatment day	−0.038	0.034	−1.132	0.259
Tea tree × Treatment day	−0.091	0.038	−2.403	0.017	*

Figure 4. Effects of plant scent treatment on predicted mean time spent inspecting boxes per visit by Eastern Rosellas depending on treatment day. The mean time spent inspecting boxes slightly increased over the 10-day period following scent placement at boxes with control and eucalypt scents, while it sharply decreased at boxes with tea tree scent. Shaded areas indicate 95% confidence intervals.

Data availability statement

Data from this study are available at https://doi.org/10.6084/m9.figshare.23930481.v1.