Chytrid signs in the Wet Tropics: evidence to guide park management

Analysis of amphibian surveys across 15 national parks to detect patterns in visible chytrid signs to inform mitigation and monitioring priorities.

Waterfall frog (*Litoria nannotis*).
Photo: David White via the Atlas of Living Australia .

Common mistfrog (*Litoria rheocola*).
Photo: Jodi Rowley via FrogID .

## Background

[Research context, photographs and significance]

At a glance

Primary finding: [draft after checking the model results].
Secondary finding: [draft after checking the model results].
Management implication: [what the evidence supports].
Important caution: visible signs were recorded, not laboratory confirmed infection.

Why chytrid matters

[Draft: insert reading, background & context. ~150 words.]

Research questions

1: Is the proportion of sampled amphibians with visible chytrid signs associated with park-level atmospheric dryness, measured as mean annual vapour pressure deficit (VPD)? (climate/microclimate hypothesis)
1. Is that proportion associated with annual visitation and nearby walking-track density, after accounting for the other included factors? (disturbance/pathogen-movement hypothesis)
1. Is the proportion associated with host density, and are there differences among the three sampled species after accounting for the other included predictors? (host-community/habitat interaction and context hypothesis)

Methods

Data and sampling design

Summer 2023/24 surveys.
15 parks, five creeks per park and three species per creek.
225 creek–species records—not 225 individual amphibians.
Variable numbers of individuals sampled.
Counts with visible signs out of the number sampled.
Which predictors are measured at park, creek and species-within-creek levels.

Justification of models and variables

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Statistical analysis and diagnostic checks

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Results

[Results text, figures and any relevant tables together]

Figures

[Succinct intro paragraph]

[Figure 1: Succinct clear caption]

Limitations

[draft ~150 words] - Visible signs rather than laboratory-confirmed infection. - One summer survey rather than repeated seasonal monitoring. - Park-average VPD rather than creek-level microclimate measurements. - Five sampled creeks not necessarily representing an entire park. - The unresolved track-density diagnostic warning. - Observational associations rather than demonstrated intervention effects.

Management recommendations

Proposed action: A specific monitoring or management action
Evidence supporting it: Your relevant model result plus literature
Qualification or evaluation needed: What the observational study cannot establish

References

A list of 10-15 references go here

Appendix

Table X. First six rows of the prepared analysis dataset.
NP	creek_id	track_density	pop_density	species	n_frogs_sampled	n_infected	VPD	NP_area_1000_ha	visit_rate_1000_per_yr	frog_spp_richness	plant_spp_richness	creek_uid	n_uninfected	infected_prop	infection_percent
NP_A	NP_A_1	6.63	1.66	Litoria nannotis	11	0	1.847131	4.095840	8.336	18	179	NP_A.NP_A_1	11	0.00	0
NP_A	NP_A_2	3.62	1.57	Litoria nannotis	21	0	1.847131	4.095840	8.336	18	179	NP_A.NP_A_2	21	0.00	0
NP_A	NP_A_3	4.17	2.44	Litoria nannotis	18	0	1.847131	4.095840	8.336	18	179	NP_A.NP_A_3	18	0.00	0
NP_A	NP_A_4	11.55	2.68	Litoria nannotis	21	0	1.847131	4.095840	8.336	18	179	NP_A.NP_A_4	21	0.00	0
NP_A	NP_A_5	8.85	1.52	Litoria nannotis	20	1	1.847131	4.095840	8.336	18	179	NP_A.NP_A_5	19	0.05	5
NP_B	NP_B_1	4.56	3.32	Litoria nannotis	21	0	2.608888	8.407718	2.380	21	309	NP_B.NP_B_1	21	0.00	0