Haemosporidians in Non-Passerine Birds of Colombia: An Overview of the Last 20 Years of Research

Round 1

Reviewer 1 Report

In this manuscript Lotta-Arevalo and colleagues, explore the haemosporidian fauna of non-passerine birds of Colombia and present an archival collection of more than 1200 samples of neotropical non-passerines as an important resource for future studies. The study is a valueble contribution to the existing profiles of the involved organisms, while it also neatly summarizes all knowledge about the parasites of the inspected host groups gathered in the Neotropics over the past 40 years. The study is fully descripive, uses standard methods and is very detailed on the analysed parasite and host species, showing their morphological features and phylogenetic relationships. Several new host-parasite associations are described and almost complete mitogenomes presented.

 

A drawback which should be more clearly outlined in the discussion part is that only microscopically positive samples have been molecularly analysed, which is a small fraction of all samples. This surely leaves unidentified a great fraction of the low-intensity infected samples and a large portion of the parasite diversity hidden. Thus the negative samples and prevalence presented per genus in Table 1 are hard to accept as representative and should be probably abandoned. Molecuarly scanning all samples of the collection is something which future studies should definitely engage in.

 

Related to this, my main concern is that given the number of actaully analysed samples belonging to diverse host taxa, the found diversity of parasites actually appears quite low, even if the molecularly analysed ones are far fewer (86). This seems unrepresentative. Even in Europe, being the continent with most intensively studied avian haemosporidian fauna, the diversity among that many host species would be higher and in a sample of hundreds of individuals, especially of non-trivial host species there are typically many unknown haemosporidian lineages in each new study. This seems to be missing here. Among the possible reasons I can identify subsampling (of only microscopically postive ones), methodological (limiting primers are discussed in the manuscripts and surely play a role, but that big?) or biological? I would rather bet on the former two reasons. This means that the prospects for future research of the collection should be more prominently flagged in the discussion. Especially the found diversity of Leucocytozoon is strikingly low. In this context there should be a greater accent that, given how many species and biomes, are involved in the collection, despite its impressive size it is insufficient to cover all in detail  – deeper sampling will be needed to understand parasite diversity and dynamics for any one of them.

 

Further remarks:

 

L41-42 avian species?

 

L53, 57, 156, 160, 293-310, genus and species names in italic?

 

L120 this of course underestimates the actual prevalence

 

L166 and 186 – Are the models the same because the notation is slightly different. It would not make sense for them to be different.

 

L199 avian orders

 

L200 Infected individuals

 

L202 – these prevalences appear to be very low compared to other biomes and potentially related species there. Are they supposed to be representative of the parasite genus and/or species? I guess not, but this should be spelled out already in the methods and or results and discussion sections.

 

Table 1 does not give information on number of tested individuals and thus is not really informative about prevalence. Only a list after the table is given for ll negative samples. It would be useful for all species with positive samples to also add the examined sample size.

 

Fig S1 – location from the map are referred to in Table 1. Thus the figure would be better placed in the main text.

 

L234-236 Formatting inconsistent

 

L338 nisi

 

L553, 566 – Such species/lineages? Rather - this species/these lineages

 

L623 parasite membrane?

 

L683 is there a specific reason for the capitals in barcode here?

 

L691-692 I find this sentence hard to understand

 

L694 aid instead of aided? Otherwise the grammar would not fit, consequently understandability

 

L698 for the Neotropics. Also only host orders involved in this study or all?

 

L712 second to what/which order? Most prevalent genus

 

L713 prevalence in doves was high – not the doves were prevalent

 

L720 these parasites

 

L725 in all these biomes (to avoid repetition of places)

 

L735 competent vectors – not singular

 

L738 these parasites – a genus is not a single parasite

 

L740-745 even mistnets with a wide mesh and reaching more than 3 m would already increase the diversity substantially \

 

L760 individual parasites / stages?

 

L763 gametocytes can be easily misunderstood as the typical infection stage and thus as synonimous to infection. I suggest rewording to “to detect specific haemosporidian developmental stages such as gametocytes”. These methods however would be RNA-based and less applicable for casual sampling and standard cheap lab methods.  

 

L735-773 Thus a main follow up to the current study should be molecularly scanning all samples, not just the obviously microscopically positive ones.

 

L786-790 While all that is written is correct it would be good to mention if for the new partial mitochondrial genomes there are discrepancies in phylogenetic placement based on the cyt b and almost complete 6kb mitochondrial sequence.

 

L793 have been explored

 

Figure 7 – what is the meaning of the big yellow circle? Akiba instead of Akita for caulleryi

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The authors have done a lot of work based on plenty of data, however the writing is not attractive enough to address the importance of this work, making it barely a data report.  The inreoduction and discussion need to be rewrite before it can be accepted.

Besides, a few minor comments:

Lines 118-119: Why two different methods were used? In which case the kit was used?

Line 120: If only smear-positive samples were checked, it may lead to a underestimate of prevalence, as it is presumed that PCR is more sensitive.

Lines 152-163: The contents in these paragraph are similar, it can be transfered to a table.

Result part: Species names should be in italic form.

Author Response

Please see the attachment

Author Response File: Author Response.pdf