Niche Analysis and Conservation of Bird Species Using Urban Core Areas

Round 1

Reviewer 1 Report

This is a sound piece of work and written up in a logic way. It is also an original way of comparing urban habitats. If have only minor comments. 

1. Only two study areas were selected and they do not represent an average of Europe, being at quite extreme positions within the continent. This means that some typical birds of cities like the Black Redstart are lacking in the survey. I do not see this as a shortcoming. But for sure, the study would have more impact if just one more location in Central Europe would have been selected in addition.
2. If we look at the Google earth maps of both cities (figure 1), my first impression was a possible mismatch in scales. I remeasured the scales in Google Maps and indeed it's fully correct. The reason for the seemingly wrong scale is a much finer pattern of the gardens in Greece. In some way this is not fully clear from the description.
3. At several places the importance of urban habitats for birds is mentioned, like in:  line 67: In addition, urban areas are important for the conservation of birds, as they host many threatened species because they often occupy biodiversity hotspots 68 [28,29]. In my view (from West-Europe) this is somewhat too strong and I would suggest to add "locally" or something similar, if the authors can agree.
4. Data a listed in the supplementory should be rounded up: presentation of tree coverage of 30.39 ± 17.58 in Finland data fo 5.00-60.00 in Greece look more consistent if presented as 30.4 and 60.0.  
5. The english names of birds should be written consistently with or without capitals, see for instance the following part of the ms (lines around lines 280): Eurasian blackbird (Turdus merula), Sardinian warbler (Sylvia melano-
   cephala), willow warbler (Phylloscopus trochilus), common nightingale (Luscinia megarhynchos), great tit (Parus major), Eurasian blue tit (Cyanistes caeruleus), Eurasian jay (Garrulus glandarius), common chaffinch (Fringilla coelebs), European greenfinch (Chloris chloris), European serin (Serinus serinus)]. The feral pigeon (Columba livia), collared dove (Streptopelia decaocto), northern house martin, Eurasian magpie (Pica pica), western jackdaw (Corvus 281
   monedula), hooded crow (Corvus cornix), common starling (Sturnus vulgaris) and European goldfinch (Carduelis carduelis)

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Line 52: encourage use of "greatly" rather than "heavily"

Line 61: suggest insert "either" between "usually" and "exploiters"; otherwise, it is not clear that the categories of exploiters and adapters are being defined/compared here, until three lines later.

Line 93: I question the use of the word "antipodal" here. Usually it means literally at the opposite side of the world: e.g., New Zealand and the U.K. are (roughly) antipodal to each other – they are as far away from each other as is possible on the planet. The latitudes are numerically equal, but one is north and the other south.. This does not apply here (the antipodes of both places are somewhere in the South Pacific Ocean), so I wonder why the word is used and suggest it should simply be deleted.  I think you mean they were on roughly the same longitude, but that's not what "antipodal" means.

Ll 125-6: Most residents living in the city core, is not I think necessarily typical of  many cities, world-wide; in many cities, residents live mostly in suburbs, not the city core. I mention this only as a caution against over-generalising the applicability of the results.

Line 146: why 19 sites?! This is a very strange number (i.e., not "round").

Figure 1. These are excellent images. But they suggest that sampling in the two sites was not really comparable; in Rovaniemi, there are lots of quite large green spaces and many of the sampling points are in or adjacent to them. Kavala seems to be much more densely built-up and sample points don't seem to have other green spaces near them. Green spaces appear much smaller and separated by much more densely built-up spaces. Since there is a scale on only one of the images, I assume it applies to both, in which case the two sites are ecologically very different.  I see no reflection of this in the environmental variables measured, which focus solely on the point-count circle, not the matrix. This problem is not mentioned in the Discussion.

Data analysis:  I am not familiar with OMI or some of the other statistical treatments used here. But I am wary about quantifying niche marginality/tolerance of species of different frequency of encounter; the rarer species will surely have lower tolerance just because they may not be numerous enough to fill up the space available. Also, I would look for correlations among variables; I would expect, for example, that gray space and bare ground would be negatively correlated with measures of vegetation cover, but they are treated as independent variables. This is not appropriate. Some discussion of both these points is necessary.

Ll. 325-6; if there are national species-status evaluations for the Finnish city but not the Greek one, use European status for both!

Line 329. Says that Red Book status of urban birds has not been evaluated for Kavala, yet now names two species as of "first conservation status". What is the source of that statement?

Author Response

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Reviewer 3 Report

The manuscript was well-written and the study is valuable. I have only one comment/suggestion about the results (section 3.3: exploiter and adapter). There is no definitions about the exploiter and adapter until the first paragraph of Discussion. Therefore, I suggest to move the sentence about the classification of exploiter and adapter from Discussion section to Introduction section and highlight them as one of your study purpose in the last paragraph of Introduction.

Author Response

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Round 2

Reviewer 2 Report

line 436 - 'heeded' should be 'headed'

Author Response

line 436 - 'heeded' should be 'headed'

Response: Corrected.