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Growing in the city: urban evolutionary ecology of avian growth rates.

Citation

Corsini, Michela; Schöll, Eva Maria; Szulkin, Marta (2020), Growing in the city: urban evolutionary ecology of avian growth rates., Dryad, Dataset, https://doi.org/10.5061/dryad.xgxd254dp

Abstract

Rapid environmental change driven by urbanisation offers a unique insight into the adaptive potential of wildlife as it can induce distinct selective pressures on urban dwelling organisms. Despite mounting evidence for urban-driven phenotypic differentiation across taxa, knowledge of the impact of urbanisation on vertebrate developmental rates and subsequent survival is very limited. Importantly, the role of selection on urban-driven body mass divergence in juvenile organisms remains poorly understood. We studied nestling development in a gradient of urbanisation set in Warsaw, Poland, in two nestbox breeding passerine species: great tits (Parus major) and blue tits (Cyanistes caeruleus). Each nestbox in the study system was assessed for surrounding percentage of Impervious Surface Area (ISA). Within these nestboxes, weight measurements of individual nestlings were collected during three breeding seasons and at regular intervals after hatching. Although asymptotic mass and growth rate were not directly affected by ISA in a subset of frequently measured nestlings, the age of fastest growth (inflection point) was delayed in blue tit nests surrounded by greater ISA. Across the entire dataset, nestling body mass was negatively affected by increasing ISA at days 5 and 10 after hatching for great tits, and at days 10 and 15 for blue tits, respectively. Concomitantly, offspring survival at days 5 and 10 decreased with increasing ISA for both species. An analysis of selection differentials performed for two contrasting levels of imperviousness (low and high ISA) revealed a significant positive association between mass at day 2 and survival at fledging. Importantly, the strength of selection for heavier nestlings at hatching was greater for great tits in the more transformed, high ISA environment. This study confirms the considerable impact of imperviousness -a proxy for urbanisation level- on offspring development, body mass and survival, and highlights increased selection on avian birth weight in a high ISA environment.

Methods

MATERIALS AND METHODS

2.1  Study sites

Data was collected for three field seasons between 2016 and 2018 in a gradient of urbanisation in the city of Warsaw, Poland. Five hundred Schwegler woodcrete nestboxes (type 1b with 32 mm entrance hole, suitable for great tits and blue tits) were erected in a 50 m grid in eight contrasted study sites representative of the urban mosaic: six were located within the city borders while two were exurban sites (Figure 1). The total number of nestboxes within each area varied from 21 to 110. While the monitoring of three sites (B, E and H) had already started in 2016, these and all other sites were monitored in 2017 and 2018.

2.2  Quantifying urbanisation

Urbanisation was quantified in a 100m radius around each nestbox in the study. This corresponds to literature-based estimates of parental foraging while chick feeding, assessed in blue tits to average 53.2 meters (±22.9 SD) in food poor (but natural) environments (Tremblay et al., 2004). In such food poor environments, birds were also reported to fly beyond 50 m from the nest in c. one-third of all foraging trips (Tremblay et al., 2004). An estimation of urbanisation in a 100m radius around each nestbox thus corresponds to a conservative estimate of the range of food foraging distance covered by parents of offspring developing in the nest. Within this radius, we estimated the proportion of Impervious Surface Area (ISA) in QGIS following Szulkin et al. (2020). Specifically, a 20 m-pixel resolution of ISA extrapolated via satellite imagery from 2015 (Copernicus Land Monitoring Services, https://land.copernicus.eu/sitemap) was used to define ISA around each nestbox. Such index, expressed as a percentage, included all built-up areas that replaced original natural cover or water surfaces with an artificial and usually impervious surface. These artificial surfaces include built-up areas (such as infrastructural networks and buildings) and other elements characterised by a long cover duration. For further details on the imperviousness index description, see https://land.copernicus.eu/sitemap.

2.3  Life-history data collection and nestling measurements

Starting from mid-March, nestboxes were inspected weekly to record the date of the first egg laid and clutch size. Hatching date was determined by visiting the nest one day before the expected hatching (12 days after the last egg of the clutch was laid) and around hatching date. Both laying and hatching dates were coded by setting the 1st of April as day 1. Only first broods, defined as broods that started no later than 30 days after the very first brood in a given year and site (Van Balen, 1973), were included in the analyses. Nestlings were uniquely marked by toenails clipping or by using waterproof markers on their first measurement day. In 2016, nestlings were individually weighed every 2 or 3 days from hatching (day 1) until ringing (day 15 or exceptionally, day 14 or 16, when the brood could not be accessed on day 15). In 2017 and 2018, nestlings were weighed specifically on days 2, 5, 10 and 15. Mass was recorded to the nearest 0.1 g using digital scales (KERN pocket balance CM 150-1N). At each nestbox visit, individual survival status (survived = 1, dead = 0) and brood size (number of chicks alive in the nest) were also recorded.

In 2016, up to 50 µl blood samples were collected by puncturing the brachial vein of each 15 days old nestling. Blood samples were subsequently stored in 99.0% ethanol at +4° C until molecular sexing analysis. Finally, nestboxes were checked c. 25 days after hatching to determine fledging success for each individual nestling: individuals found dead in the nest and individuals that were not present in the nestbox had a fledging success of 0 and 1, respectively.

2.4  Extrapolating data on temperature at the nestbox level

Weather data over the three-year period were provided by the Polish Institute of Meteorology and Water Management (IMGW-PIB). Average daily temperature data were computed from Warsaw Okecie and Legionowo weather stations; the nearest sampling points for the study locations situated within and outside the city borders, respectively.

To estimate temperature experienced by growing nestlings at the nestbox level, average temperature was calculated at each nestbox across the specific periods of interest: for growth curve analyses, we used averaged temperature from day 1 to day 15 of nestling growth. For body mass and survival analyses, we used averaged temperature from day 1 to day 2, from day 2 to day 5, from day 5 to day 10, from day 10 to day 15, which corresponds to the intervals between mass measurements. Finally, for fledging success, we used averaged temperature from day 15 to day 25.

Usage Notes

Data used for this publication include two main files:

1) GrowthParam2016_EvoApp2019_FlexParamCurve: contains the data used to test the effect of ISA on great tits and blue tits growth curve parameters. Statistical methods are described in detail in Section 2.6.1.

2) Survival_EvoApp2016_2017_2018: contains the data used to test the effect of ISA on great tit and blue tit nestling body mass (Section 2.6.2), survival (Section 2.6.3), and selection differentials (Section 2.6.4). 

Additional files were used to generate figures in R (ggplot):

3) CurvePlot_EvoApp_Corsini2020: data used to generate Figure 2.

4) selection_differential_coefficients_BT and selection_differential_coefficients_GT: combined data used to generate Figure 3.

 

Legend and specific information on each dataset are listed below:

 

dataset: GrowthParam2016_EvoApp2019_FlexParamCurve:

Station ID climatic station, Waw = within Warsaw city borders, Leg = outside Warsaw city borders (PAL and KPN)
NestboxID nestbox ID
Ring Ring number
DateGr Date expressed as dd/mm/yyyy
JDateGr Julian date (1st of April as 1)
Asym Asymptotic mass (in g)
k growth rate
Infl Inflaction point (in days)
M shape of the curve
Species GT= great tit, BT= blue tit
Sex F= female, M= male
HatN total number of hatched nestlings
Fledged 1= fledged, 0 = not fledged
CurveTest included for growth curve analyses, 1= yes, 0= no
EDM earliest date of measurement (at which age - expressed in days - a nestling was measured for the first time)
LayD when the first egg was laid (Julian date, 1st of April = 1)
HatDJ when the first chick hatched in a brood (Julian date, 1st of April = 1)
MeanT15 Mean temperature (in C) across the 15 or 16 days of each nestling growth
ISA impervious surface area (expressed as a percentage)
CS clutch size 
D2 body mass (in g) at day 2 (hatching date =  day 1)
D10 body mass (in g) at day 10 (hatching date =  day 1)
D15 body mass (in g) at day 15 (hatching date =  day 1)
D16 body mass (in g) at day 16 (hatching date =  day 1)

Note: only one year of data (2016 - high resoluted measurements)

 

dataset: Survival_EvoApp2016_2017_2018:

Sheet: Nestlings_EvoApp2019

Year 2016, 2017, 2018  
Site Study site abbreviation (8 sites) POL (urban park), KPN (National park - forest), UNI (Office area), MUR (Residential area I ), OLO (Residential area II), CMZ (Urban woodland I), LOL (Urban woodland II), PAL (Suburban village)
Species BT: blue tit, GT: great tit  
Sex_ch M: male, F: female nestling sex
LayD Laying date (1st of April as 1) comment: Only first broods considered
HatD Hatching date (1st of April as 1)  
ChickID NestboxID_Ring unique id per single nestling
CS Clutch size (Number of eggs)  
d2 nestling mass at day 2 (in g) comment: hatching date taken as Day 1
d5 nestling mass at day 5 (in g) comment: hatching date taken as Day 1
d10 nestling mass at day 10 (in g) comment: hatching date taken as Day 1
d15 Nestling mass at day 15 (in g) comment: chicks were ringed at Day 15
     
sur2 1: survived, 0: not survived nestling survived between Day 0 and Day 2 
sur5 1: survived, 0: not survived nestling survived between Day 2 and Day 5
sur10 1: survived, 0: not survived nestling survived between Day 5 and Day 10
sur15 1: survived, 0: not survived nestling survived between Day 10 and Day 15
Fledged 1: fledged; 0:not fledged to infer fledging success, nests were checked 25 days after hatching (D25). Hatching date taken as D1. Nestlings survived between Day 15 and Fledging (day 25)
ISA Impervious surface in % Comment: built up area in % (buldings, paved roads, etc), calculated on 100m radius at the nestbox level. TIFF file obtained from Copernicus.
Note: missing data = NA  
     
sur2old 1: survived, 0: not survived nestling survived until Day 2 
sur5old 1: survived, 0: not survived nestling survived until Day 5
sur10old 1: survived, 0: not survived nestling survived until Day 10
sur15old 1: survived, 0: not survived nestling survived until Day 15
Fledgedold 1: fledged; 0:not fledged to infer fledging success, nests were checked 25 days after hatching (D25). Hatching date taken as D1.
broodID unique brood ID unique brood ID created specifying Year_NestboxID

Sheet: Broods_EvoApp2019

Year 2016, 2017, 2018  
Site Study site abbreviation (8 sites) POL (urban park), KPN (National park - forest), UNI (Office area), MUR (Residential area I ), OLO (Residential area II), CMZ (Urban woodland I), LOL (Urban woodland II), PAL (Suburban village)
Species BT: blue tit, GT: great tit  
CS Clutch size (Number of eggs)  
HatD Hatching date (1st of April as 1)  
HatN Total number of hatched nestlings  
     
Nr_D2 Number of alive nestlings at day 2  
Nr_D5 number of alive nestlings at day 5  
Nr_D10 number of alive nestlings at day 10  
Nr_D15 number of alive nestlings at day 15  
Nr_Fledged total number of fledged chicks  
ISA Impervious surface in % Comment: built up area in % (buldings, paved roads, etc), calculated on 100m radius at the nestbox level. TIFF file obtained from Copernicus.
BroodID_unique unique brood ID unique brood ID created specifying  NestboxID, Species and Year

Note: empty cells are missing data


Daily temperature (in C) (from 2 meteorological stations: Warsaw and Legionowo. Legionowo data used for KPN and PAL).

T1_2 averaged daily temp between day 1 and day 2 (included) for body mass and survival at day 2 
T2_5 averaged daily temp between day 2 and day 5 (included) for body mass and survival at day 5
T5_10 averaged daily temp between day 5 and day 10 (included) for body mass and survival at day 10
T10_15 averaged daily temp between day 10 and day 15 (included) for body mass and survival at day 15
T15_25 averaged daily temp between day 15 and day 25 (included) for survival at fledging
T1_25 averaged daily temp between day 1 and day 25 (included) for selection analyses

Station: Climatic station (Waw = within Warsaw city borders, Leg = outside Warsaw city borders, KPN and PAL)

 

dataset: CurvePlot_EvoApp_Corsini2020

Sheet: Data

NestboxID Nestbox id.
Species GT= great tit, BT = blue tit.
Day brood age expressed in days (hatching date = day 1).
BrMass Mass average at the brood level (in g).
ISA Impervious Surface Area (in %).
newISAcat ISA category (as low or high).

Note: the plot shows growth inferred at the brood level for 1 year of data (2016) and across 3 study sites (POL, CMZ and KPN).

Funding

Narodowe Centrum Nauki, Award: 2017/25/N/NZ8/02852

Narodowe Centrum Nauki, Award: 2014/14/E/NZ8/00386

Narodowe Centrum Nauki, Award: 2016/21/B/NZ8/03082

Narodowe Centrum Nauki, Award: 2015/19/P/NZ8/02992