This study reports on the patterns of species occurrence, abundance and richness of a wintering water-related bird assemblage in an ‘archipelago’ of 70 small artificial urban ponds (AUPs) embedded in a metropolitan landscape (Rome, central Italy). A total of 20 species in 26 AUPs were sampled. Only the largest AUPs (>0.1 ha) contained all these species, except for Gallinula chloropus. The highest total mean species abundance was observed in the largest ponds, with statistically significant differences evident among size classes. Two significant spatial thresholds in species abundance and richness were observed (between 0.01 and 0.1 ha; between 0.1 and 1 ha in size). The abundance of single species was correlated with their frequency of occurrence. Ponds in urban areas must be larger than 0.1 ha to host a rich winter assemblage of birds, with a further increase in richness noted with a surface area larger than 1 ha. The highest number of species was observed in the larger ponds (>1 ha). The species richness of each AUP is directly correlated to their size (log-transformed species–area relationship: log S = 3.515 + 0.497 log A; R2 = 0.76). Further research should be conducted to confirm these patterns and to implement information useful for planning and management of artificial ponds in urban areas for this purpose.

1. Water-related bird assemblages in an urban pond
‘archipelago’: Winter patterns of bird species occurrence,
abundance and richness
Maria Paola Di Santo,1
Giuseppe M. Carpaneto2
and Corrado Battisti3
*
1
Xemina - emozioni in natura Cultural and Environmental Association, 2
Dipartimento di Biologia Ambientale,
Universita “Roma Tre”, and 3
“Torre Flavia” LTER (Long Term Ecological Research) Station, Environmental Service,
Province of Rome, Rome, Italy
Abstract
This study reports on the patterns of species occurrence, abundance and richness of a wintering water-related bird
assemblage in an ‘archipelago’ of 70 small artificial urban ponds (AUPs) embedded in a metropolitan landscape (Rome,
central Italy). A total of 20 species in 26 AUPs were sampled. Only the largest AUPs (0.1 ha) contained all these spe-
cies, except for Gallinula chloropus. The highest total mean species abundance was observed in the largest ponds, with
statistically significant differences evident among size classes. Two significant spatial thresholds in species abundance
and richness were observed (between 0.01 and 0.1 ha; between 0.1 and 1 ha in size). The abundance of single species
was correlated with their frequency of occurrence. Ponds in urban areas must be larger than 0.1 ha to host a rich winter
assemblage of birds, with a further increase in richness noted with a surface area larger than 1 ha. The highest number
of species was observed in the larger ponds (1 ha). The species richness of each AUP is directly correlated to their size
(log-transformed species–area relationship: log S = 3.515 + 0.497 log A; R2
= 0.76). Further research should be con-
ducted to confirm these patterns and to implement information useful for planning and management of artificial ponds in
urban areas for this purpose.
Key words
abundance, frequency of occurrence, pond management, richness, species–area relationships.
INTRODUCTION
Urban landscapes can host a unique biodiversity. Species
assemblages in these remnant fragments and altered
anthropogenic habitats (e.g. wooded parks, green areas,
ponds) include many species of conservation concern, as
well as many synanthropic, generalist or alien taxa (Beis-
singer Osborne 1982; Rebele 1994; van Heezik et al.
2008).
The artificial or semi-natural water bodies (fountains,
ponds, small lakes) occurring in urban landscapes are
suitable in many cases for hosting many vagrant or resi-
dent bird species (Tyser 1982). These habitats exhibit
characteristics (food availability, artificial lighting, scar-
city of predators, etc.) that may be attractive for some
‘urban exploiters’ (Marzluff 2001; Savard Falls 2001;
McKinney 2002; Faeth et al. 2005; Chace Walsh
2006).
Several studies have demonstrated a key role played
by natural or artificial ponds for water-related birds (e.g.
waterfowls, waders) not only as wintering or breeding
sites, but also as stopover areas during migration (Chov-
anec 1994). In heavily human-transformed landscapes,
such as metropolitan areas, these ponds may represent a
multifunctional resource of vital importance to the conser-
vation of many species (Gledhill et al. 2004; Zacchei et al.
2011).
The role of area in defining the number and abun-
dance of species has been largely highlighted in both
natural and anthropogenic wet habitats (Celada Bo-
gliani 1993; Benassi et al. 2007; Magurran McGill
2011). As a general model, larger water bodies host a
higher number of species and individuals, compared to
smaller ponds. This is due to a higher availability of
*Corresponding author. Email: c.battisti@provincia.roma.it
Accepted for publication 28 December 2014.
Lakes and Reservoirs: Research and Management 2015 20: 33–41
© 2015 Wiley Publishing Asia Pty LtdDoi: 10.1111/lre.12086

2. niches and resources (Wiens 1976, 1989). The species
abundance and richness of birds in natural wetlands is
directly related to the area as a proxy of the environ-
mental heterogeneity (Brown Dinsmore 1986; Acuna
et al. 1994; Hoyer Canfield 1994; Suter 1994; Fron-
eman et al. 2001; Newbold Eadie 2004). In particular,
large-area sites are preferred by water-related birds,
being used as roosts, trophic and refuge sites, espe-
cially in winter (Tuite et al. 1984). Nevertheless, the
effect of area on the abundance of birds in urban
ponds has not been extensively studied (Tyser 1982,
1983; Hoyer Canfield 1994; Suter 1994; Naugle et al.
1999; Froneman et al. 2001; Hattori Mae 2001; Riffell
et al. 2001; Guadagnin Maltchik 2007; Pearce et al.
2007; Guadagnin et al. 2009), especially in the Mediter-
ranean area (Benassi et al. 2009).
The present study analyses the structure of wintering
bird assemblages occurring in a large number of small
water bodies located in the metropolitan area of Rome,
to assess the patterns of the occurrence, abundance and
richness of species. It is hypothesized that: (i) the num-
ber of wintering species increases with increasing size,
following the species–area relationship applied to main-
land fragment archipelagos (MacArthur Wilson 1963;
Diamond 1975; Connor McCoy 2001; see review in
Watling Donnelly 2006 and Magurran McGill
2011); (ii) there are size thresholds of these water
bodies wherein mean species richness and abundance
significantly increase; and (iii) consistent with the rela-
tionship between the distribution and abundance applied
to wet ecosystems (Paracuellos Tellerıa 2004; Parac-
uellos 2006), the most widely diffused species (i.e.
higher frequency of occurrence) also are the more
abundant. To this end, the results of this study may be
useful for pond management and planning in large
urbanized landscapes.
MATERIALS AND METHODS
Study area
The metropolitan area of Rome (lat. 41°550
31.487″, long.
12°270
10.930″; central Italy) covers approximately
129 000 ha and hosts almost 3 million inhabitants, with
an average density of 21.9 inhabitants haÀ1
. The area
examined in this study is represented by the core area
of Rome (about 36 000 ha), encircled by the Grande
Raccordo Anulare, a beltway surrounding the city. The
altitude ranges from 15 to 20 m (SW districts) up to
139 m (Monte Mario) above sea level. According to
Blasi (1994), the phytoclimate of Rome is characteristic
of the transitional Mediterranean region.
Selection of anthropogenic urban ponds
An inventory of anthropogenic urban ponds (hereafter
referred to as AUPs) in the Rome metropolitan area
(central Italy; about 360 km2
) was carried out, including
lakes, fountains and small ponds, ultimately leading to
identification of 70 sites, all being artificial (i.e. anthropo-
genic). Within a radius of 1 km, all the AUPs were
embedded in an urbanized and homogeneous landscape
matrix. It was assumed, therefore, that the landscape
matrix was comparable among sites.
The area of the AUP (A), comprising both the water
surface and a buffer belt of about 5 m along the perime-
ter, was recorded for each site, as a dependent variable
in this study. The surface area measurements (ha) were
taken using the regional technical map (1:2000; Regione
Lazio). For the smaller AUPs, field measurements were
taken, using a rolling semi-rigid metre. The field mea-
surements were compared to the cartographic data
obtained from the technical regional map.
Water-related bird sampling
Bird sampling was conducted from 7 November 2009 to
18 February 2010 (n = 85 days, for a total of 400 h of
field work). Each AUP was visited eight times during this
period (see Paillisson et al. 2002; Traut Hostetler 2004;
Paracuellos 2006). To counter a possible bias attributable
to a time-of-day sampling effect (i.e. morning vs. after-
noon), each site was visited four times in the morning
(from 0700 to 1100 a.m.) and four times in the afternoon
(from 0100 to 0500 p.m.). Days characterized by fog,
heavy rain and/or strong winds (conditions that hamper
the detectability of species) were avoided to increase the
sampling accuracy (Bibby et al. 2000).
The method of standardized circular transect (Suther-
land 2006) was applied to obtain quantitative data on
birds. This method consists of walking the perimeter of a
pond at a constant velocity (1.5 km hÀ1
), directly record-
ing each wintering water bird belonging to a set of
selected species (Table 1), thereby obtaining a value of
abundance for each species. As smaller AUPs are easily
exposed to disturbance attributable to the presence of
the observer, the observer walked slowly in these sites,
starting to count birds before their taxonomic identifica-
tion from a distance of at least 100 m, during the
approaching way. A Pentax (Pentax-Ricoh imaging
corporation, Tokio, Japan) 10 9 50 binocular was used
for bird identification and counts.
Given the small size of the AUPs, attention was given to
the movements of single birds to minimize the bias attrib-
utable to pseudoreplication. Although alien and/or domes-
ticated forms of water-related birds also were observed
34 M. P. Di Santo et al.
© 2015 Wiley Publishing Asia Pty Ltd

3. in the AUPs, only the data on autochthonous wild species
were reported in this study (see Table 1 checklist).
Data analysis
To analyse the patterns of occurrence, abundance and
richness of wintering water-related birds species depend-
ing on size, the 70 sampled AUPs were divided into five
size classes, including AUP1 (range of 0–0.001 ha; mean
area of 0.0003 Æ 0.0002 ha; n = 3), AUP2 (range of
0.001–0.01 ha; mean area of 0.0053 Æ 0.0027 ha; n = 13),
AUP3 (range of 0.01–0.1 ha; mean area of 0.037 Æ
0.024 ha; n = 31), AUP4 (range of 0.1–1 ha; mean area
of 0.28 Æ 0.27 ha; n = 15) and AUP5 (1 ha; mean area of
4.10 Æ 3.65 ha; n = 8).
The data collected for each AUP were processed to
obtain the values of the following parameters: (i) occur-
rence of single species, (ii) abundance of each water-
related bird species, (iii) total abundance of all species
(as a sum of the abundances for all the species occurring
in each AUP) and (iv) species richness (S).
The mean abundance, the total mean abundance and
the species richness (Smean) were obtained for each AUP
size class.
The frequency of occurrence for each species was cal-
culated as the ratio between the number of AUP occu-
pied and the total number of AUP (n = 70).
A species–area relationship was finally obtained, based
on the equation (MacArthur Wilson 1963):
Log S ¼ c þ zlog A; ð1Þ
where S = species richness of each AUP, and A = size.
The Kruskal–Wallis test and Mann–Whitney nonpara-
metric U-test were performed to verify the significance of
the differences among mean values of abundance, total
abundance and species richness. A two-tailed Spearman
rank correlation test was performed to correlate the abun-
dance of single species for their frequency of occurrence
in the AUP archipelago (relationship abundance vs. occur-
rence), and a v2
test was utilized to test the difference
between the frequency of occurrences in the five size clas-
ses. The software PASW Statistics 18 (SPSS Inc. 2009, Chi-
cago, IL, USA) was used, with the alpha value set to 0.05.
RESULTS
Patterns of occurrence
Birds were recorded only in 26 AUPs (37.1% of the total
number of AUPs). The difference between the frequency
of species occurrences among the AUP size classes was
statistically significant (v2
= 9.75; P 0.01; Table 2).
Almost all species were found only in the larger AUPs
(0.1 ha), except for Gallinula chloropus, which was the
only species sampled in all the AUP size classes
(Table 3). The most widely spread species were Gallinula
chloropus, Phalacrocorax carbo, Chroicocephalus ridibundus
and Anas platyrhynchos (Table 3). All the species are win-
tering. Of the species, three species (Gallinula chloropus,
Anas platyrhynchos and Alcedo atthis) also are breeders.
Patterns of abundance
The highest total mean abundance was observed in the
larger size class (AUP5; Table 2). The differences
between the total mean abundances were statistically sig-
nificant (H = 37.767; P 0.01; Kruskal–Wallis test). Two
thresholds in total mean abundance were observed,
between AUP3 and AUP4 size classes (Z = À2.042;
P 0.05) and between AUP4 and AUP5 size classes
(Z = À3.624; P 0.01).
At the level of single species, and considering all the
AUPs, the most abundant species observed were Gallinu-
la chloropus, Anas platyrhynchos, Larus michahellis and
Chroicocephalus ridibundus (Table 4). Gallinula chloropus,
the only species occurring in all the size classes, exhib-
ited increased abundance in the larger AUPs, with
Table 1. Water-related bird species selected for sampling in 70
artificial urban ponds (AUPs) in Rome metropolitan area (central
Italy)
Family Scientific name
Ardeidae Egretta alba (Linnaeus, 1758)
Ardea cinerea (Linnaeus, 1758)
Bubulcus ibis (Linnaeus, 1758)
Egretta garzetta (Linnaeus, 1766)
Anatidae Anas crecca (Linnaeus, 1758)
Anas strepera (Linnaeus, 1758)
Anas platyrhynchos (Linnaeus, 1758)
Aythya fuligula (Linnaeus, 1758)
Anser anser (Linnaeus, 1758)
Anser fabalis (Baillon, 1834)
Rallidae Fulica atra (Linnaeus, 1758)
Gallinula chloropus (Linnaeus, 1758)
Podicipedidae Podiceps cristatus (Linnaeus, 1758)
Tachybaptus ruficollis (Pallas, 1764)
Phalacrocoracidae Phalacrocorax carbo (Linnaeus, 1758)
Scolopacidae Gallinago gallinago (Linnaeus, 1758)
Alcedinidae Alcedo atthis (Linnaeus, 1758)
Accipitridae Circus aeruginosus (Linnaeus, 1758)
Laridae Chroicocephalus ridibundus (Linnaeus, 1766)
Larus michahellis (Naumann, 1840)
Bird assemblages in urban ponds 35
© 2015 Wiley Publishing Asia Pty Ltd

4. significant differences among size classes (H = 16.882;
P = 0.002; Kruskal–Wallis test).
Comparing the mean abundance between the larger
size classes (AUP3, AUP4, AUP5), a significant increase
was observed for Phalacrocorax carbo (ZAUP3–AUP4 =
À2.056 and ZAUP4–AUP5 = À3.594; both P 0.01),
Anas platyrhynchos (ZAUP3–AUP4 = À2.056, P 0.05 and
ZAUP4–AUP5 = À3.036, P 0.01) and Chroicocephalus ridi-
bundus (ZAUP–AUP4 = À2.546 and ZAUP4–AUP5 = À2.566; all
P 0.05, Mann–Whitney U-test).
A significant difference also was observed between
mean abundance in the two larger areas (AUP4 vs AUP5)
for Ardea cinerea (Z = À2.594; P 0.01), Fulica atra
(Z = À2.757; P 0.01), Gallinula chloropus (Z = À2.337;
P 0.05) and Larus michahellis (Z = À2.757; P 0.01;
Mann–Whitney U-test).
The abundance of single species was significant and
directly correlated to their frequency of occurrence (rs
= 0.830; P 0.01; Spearman rank correlation test, 2 tail).
Patterns of richness and species–area
relationships
In the archipelago of 70 AUPs in this study, a total of 20
water-related bird species were observed (Table 1). The
Table 2. Assemblage structure of water-related wintering birds in 70 AUPs (anthropogenic urban ponds)
Size class
AUP1 AUP2 AUP3 AUP4 AUP5
0–0.001 0.001–0.01 0.01–0.1 0.1–1 1
n 3 13 31 15 8
nocc (%) 1 (33.3) 5 (38.5) 6 (19.4) 6 (40) 8 (100)
S 1 1 1 13 19
Smean (SD) 0.33 (0.58) 0.15 (0.38) 0.06 (0.25) 1.33 (3.48) 7.38 (3.78)
Total mean abundance (SD) 0.04 (0.07) 0.03 (0.07) 0.01 (0.03) 5.38 (18.52) 52.25 (53.29)
Explanation: size class (range, in ha); n, number of AUPs; nocc (%), number and percentage of AUPs occupied by at least one species; S,
species richness; Smean (SD), mean species richness and standard deviation.
Table 3. Frequency of occurrence of the 20 water-related wintering bird species for each artificial urban pond (AUP) size class
Range (ha)
AUP1 AUP2 AUP3 AUP4 AUP5
0–0.001 0.001–0.01 0.01–0.1 0.1–1 1
Podiceps cristatus — — — — 0.13
Tachybaptus ruficollis — — — 0.07 0.25
Phalacrocorax carbo — — — 0.13 0.88
Egretta alba — — — — 0.25
Ardea cinerea — — — 0.07 0.63
Bubulcus ibis — — — 0.07 —
Egretta garzetta — — — 0.13 0.5
Anas crecca — — — 0.07 0.25
Anas strepera — — — — 0.13
Anas platyrhynchos — — — 0.13 0.75
Aythya fuligula — — — — 0.13
Anser anser — — — — 0.13
Anser fabalis — — — — 0.13
Circus aeruginosus — — — — 0.13
Fulica atra — — — 0.07 0.63
Gallinula chloropus 0.33 0.15 0.06 0.13 0.63
Gallinago gallinago — — — 0.07 0.13
Alcedo atthis — — — 0.13 0.38
Chroicocephalus ridibundus — — — 0.2 0.75
Larus michahellis — — — 0.07 0.63
36 M. P. Di Santo et al.
© 2015 Wiley Publishing Asia Pty Ltd

5. higher number of species (19) was in the larger size
class (AUP5 1 ha; Tables 2 and 3). Differences in the
Smean values among the five size classes were statistically
significant (H = 36.748; P 0.01; Kruskal–Wallis test). A
significant threshold in the Smean values occurred
between the size classes AUP3–AUP4 (Z = À1.963;
P 0.01) and AUP4–AUP5 (Z = À3.387; P 0.01; Mann–
Whitney U-test).
A direct and significant correlation between area and
number of wintering water-related bird species was
observed (rs = 0.463; P 0.01; n = 70; log-transformed
species–area relationship: log S = 3.515 + 0.497 log A;
R2
= 0.76). Considering only the 26 AUPs in which birds
were sampled, a stronger correlation was obtained
(rs = 0.722; P 0.01; n = 26; species–area relationship:
log S = 4.747 + 0.345 log A; R2
= 0.75). The z coefficient
(i.e. the slope of the regression line between species and
area) was 0.497, considering all the AUPs. The slope was
0.345 for considering only the AUPs with at least one
bird species.
DISCUSSION
The creation of artificial wetlands can help reduce the
negative impacts associated with the loss of natural wet-
lands because they can provide stopover refuges for
migratory birds and wintering areas (Kloskowski et al.
2009). Furthermore, artificial habitats can be more suit-
able for some water-related bird species, compared to
natural wetlands, because of some favourable factors.
These include a lack of predators, no hunting zones and
minimization of some disturbances (Turnbull Bald-
assarre 1987; Langley et al. 1998; Traut Hostetler
2004; Kloskowski et al. 2009). Among the features that
increase the importance of these habitats for wintering
birds, the area (and the related habitat heterogeneity)
was the most important predictor of the occurrence,
abundance and richness of bird species. In the AUP
archipelago in the present study, two thresholds in size
(0.1 and 1 ha) were obtained, whereby the species rich-
ness of bird assemblages increased significantly, as dem-
onstrated with previous studies (e.g. Pearce et al. 2007).
A first important result of the present study, therefore, is
that anthropogenic ponds and urban lakes should be lar-
ger than 0.1 ha in size in order to be able to host a rich
assemblage, with a further increase in richness noted
where their surface area was 1 ha. Benassi and Battisti
(2011) reported higher thresholds in size (at 1 and
10 ha), which worked to increase the frequency of occur-
rence of water-related birds in small natural wetlands of
central Italy.
Table 4. Mean abundance (and standard deviation) of the 20 water-related wintering bird species for each AUP size class
Range (ha)
AUP1 AUP2 AUP3 AUP4 AUP5
0–0.001 0.001–0.01 0.01–0.1 0.1–1 1
Podiceps cristatus — — — — 0.02 (0.05)
Tachybaptus ruficollis — — — 0.09 (0.36) 0.50 (1.32)
Phalacrocorax carbo — — — 0.04 (0.11) 1.27 (1.46)
Egretta alba — — — — 0.10 (0.18)
Ardea cinerea — — — 0.23 (0.87) 0.27 (0.40)
Bubulcus ibis — — — 0.03 (0.10) —
Egretta garzetta — — — 0.08 (0.26) 0.52 (0.85)
Anas crecca — — — 0.02 (0.06) 0.39 (0.81)
Anas strepera — — — — 0.64 (1.81)
Anas platyrhynchos — — — 2.28 (8.71) 29.66 (43.75)
Aythya fuligula — — — — 0.06 (0.18)
Anser anser — — — — 0.13 (0.35)
Anser fabalis — — — — 0.13 (0.35)
Circus aeruginosus — — — — 0.05 (0.13)
Fulica atra — — — 0.08 (0.32) 2.21 (4.11)
Gallinula chloropus 0.04 (0.08) 0.03 (0.08) 0.01 (0.03) 0.83 (2.31) 4.33 (5.26)
Gallinago gallinago — — — 0.33 (1.29) 0.13 (0.35)
Alcedo atthis — — — 0.07 (0.23) 0.35 (0.65)
Chroicocephalus ridibundus — — — 1.12 (3.70) 7.31 (8.75)
Larus michahellis — — — 0.19 (0.74) 4.24 (7.73)
Bird assemblages in urban ponds 37
© 2015 Wiley Publishing Asia Pty Ltd

6. The avian species observed in artificial lakes are usually
sedentary, omnivorous birds, with a high eco-ethological
plasticity that enables them to live in urban environments,
and tolerate different levels of human disturbance (Alberti
et al. 2003; Sorace Gustin 2008). Nevertheless, even the
most generalist species cannot live in very small ponds,
mainly because of the lack of food resources and refuges,
and high competition or edge effects (Sousa 1984).
The value of the z coefficient for the species/area rela-
tionship (i.e. the angular coefficient of the regression line
between species and area) represents important informa-
tion reflecting the degree of isolation of an archipelago for
a specific target (MacArthur Wilson 1963; Abbott 1983).
The observed values in the present study were within the
known range for ecological islands (0.17–0.72; Watling
Donnelly 2006), highlighting the effect of area on these
bird assemblages inhabiting a small patchy water system
included in an urbanized landscape. Nevertheless, for
assemblages with a low number of species (e.g. 20), as in
this case, the species/area relationship could be altered
from qualitative differences among species belonging to
different area-sensitive guilds (Robinson et al. 1992).
At the level of a single species, Gallinula chloropus,
Anas platyrhynchos, Larus michahellis and Chroicocephalus
ridibundus were the most abundant species at the study
sites. These species also were the most widespread spe-
cies observed in the artificial water bodies in the study
area. They are considered generalists, with a high degree
of tolerance to human disturbance (Tuite et al. 1984;
Allen O’Connor 2000). Anas platyrhynchos exploits dif-
ferent urban environments as feeding sites and resting
places during migration or as winter refuges (e.g. during
the hunting season). This species may be present in
large numbers in urban environments, even in combina-
tion with its domestic forms (Heusmann 1981, 1983; Fig-
ley VanDruff 1982; Heusmann Burrell 1984).
The species with high population density exhibited
the highest incidence rate (or percentage of occurrence)
in the AUP archipelago. A greater species abundance
generally corresponds to a greater number of occupied
sites (i.e. direct correlation between abundance and dis-
tribution; Paracuellos Tellerıa 2004; Paracuellos 2006).
Evidence for an areal sensitivity was obtained for most
water-related bird species in the study area. Indeed, all the
sampled species occurred in AUPs larger than 0.1 ha. Thus,
this size also may be considered an important ecological
and spatial threshold at the species level, at least for water
birds in urban ponds. Only Gallinula chloropus was observed
at all study sites. This generalist rail often is found in altered,
artificial and agricultural habitats, and in urban wetlands,
including small ponds (Bannor Kiviat 2002).
Considering the concern of biotic homogenization of
urban landscapes (McKinney 2006; Olden Rooney
2006; Devictor et al. 2007; Cassey et al. 2008; Lambdon
Hulme 2008; Lougheed et al. 2008; Sorace Gustin
2008), it was concluded that urban ponds larger than 0.1–
1 ha in area may increase the local diversity of water-
related birds, even if limited to generalist taxa.
A goal of the present study was to define the spe-
cies–area relationship for wintering species in an urban
pond archipelago, focusing on searching for size thresh-
olds. Thus, variables at the landscape or patch (i.e.
pond) scale that may further affect this relationship
were not taken in to account. The present study consid-
ered the pond ‘area’ as the main predictor to determine
our patterns, as widely recognized in other studies
(Lomolino Weiser 2001; Ding et al. 2006; Benassi
et al. 2007). It is believed that the present study is the
first to report wintering bird patterns for a large pond
archipelago of an urbanized landscape. Nevertheless, as
habitat patchiness at different scales may drive the spe-
cies–area relationship (Wiens 1997; Nichols et al. 1998;
Tews et al. 2004), further research on this topic might
also take into account the role of intrapatch heterogene-
ity and other coarse- or fine-grained patch or landscape
parameters that may directly affect observed patterns in
the occurrence, richness and abundance of the studied
species.
ACKNOWLEDGEMENTS
We thank all the people who facilitated the realization of
this study. A special thanks is given to Marianna Di
Santo and Domenico Doleatto for their precious support
during sampling, to Adriano Mazziotta for statistical sup-
port and to Dr. PhD Alessandro Zocchi for his help in
English translation.
REFERENCES
Abbott I. (1983) The meaning of z in species/area regres-
sion and the study of species turnover in island bioge-
ography. Oikos 41, 385–90.
Acuna R., Contreras F. Kerekes J. (1994) Aquatic bird
densities in two coastal lagoon systems in Chiapas
State, Mexico, a preliminary assessment. Hydrobiologia
279/280, 101–6.
Alberti M., Marzluff J. M., Shulenberger E. et al. (2003)
Integrating humans into ecology: opportunities and
challenges for studying urban ecosystems. Bioscience
53, 1169–79.
Allen A. P. O’Connor R. J. (2000) Interactive effects of
land use and other factors on regional bird distribu-
tions. J. Biogeogr. 27, 889–900.
38 M. P. Di Santo et al.
© 2015 Wiley Publishing Asia Pty Ltd

7. Bannor B. K. Kiviat E. (2002) Common moorhen
(Gallinula chloropus). In: The Birds of North America
(eds A. Poole F. Gill), no. 685. The Birds of North
America, Philadelphia, Pennsylvania.
Beissinger S. R. Osborne D. R. (1982) Effects of urban-
ization on avian community organization. Condor 84,
75–83.
Benassi G. Battisti C. (2011) Frequency of occurrence
of a set of water-related bird species in an archipelago
of remnant marshlands of Central Italy. Rend. Fis. Acc.
Lincei. 22, 11–6.
Benassi G., Battisti C. Luiselli L. (2007) Area effect on
bird species richness of an archipelago of wetland frag-
ments of Central Italy. Comm. Ecol. 8, 229–37.
Benassi G., Battisti C., Luiselli L. et al. (2009) Area-sensi-
tivity of three reed bed bird species breeding in Medi-
terranean marshland fragments. Wetl. Ecol. Manag. 17,
555–64.
Bibby C. J., Hill D. A., Burgess N. D. et al. (2000) Bird
Census Techniques, 2nd edn. Academic Press, London.
Blasi C. (1994) Fitoclimatologia del Lazio. Fitosociologia
27, 151–75.
Brown M. Dinsmore J. J. (1986) Implications of marsh
size and isolation for marsh bird management. J. Fish
Wildl. Manag. 50, 392–7.
Cassey P., Lockwood J. L., Olden J. D. et al. (2008) The
varying role of population abundance in structuring indi-
ces of biotic homogenization. J. Biogeogr. 35, 884–92.
Celada C. Bogliani G. (1993) Breeding bird communi-
ties in fragmented wetlands. Boll. Zool. 60, 73–80.
Chace J. F. Walsh J. J. (2006) Urban effects on native
avifauna: a review. Landsc. Urban Plann. 74, 46–69.
Chovanec A. (1994) Man-made wetlands in urban recrea-
tional areas – a habitat for endangered species? Landsc.
Urban Plann. 29, 43–54.
Connor E. F. McCoy E. D. (2001) Species-area rela-
tionships. In: Encyclopedia of Biodiversity (ed. Levin S.
A.), pp. 397–411. Academic Press, London.
Devictor V., Julliard R., Couvet D. et al. (2007) Functional
homogenization effect of urbanization on bird commu-
nities. Conserv. Biol. 21, 741–51.
Diamond J. M. (1975) The island dilemma: lessons of
modern biogeographic studies for the design of natural
reserves. Biol. Conserv. 7, 129–45.
Ding T.-S., Yuan H.-W., Geng S. et al. (2006) Macro-scale
bird species richness patterns of the East Asian main-
land and islands: energy, area and isolation. J. Biogeogr.
33, 683–93.
Faeth S. H., Warren P. S., Shochat E. et al. (2005) Tro-
phic dynamics in urban communities. Bioscience 55,
399–407.
Figley W. K. VanDruff L. W. (1982) The ecology of
urban Mallards. Wildl. Monogr. 81, 3–39.
Froneman A., Mangnall M. J., Little R. M. et al. (2001)
Waterbird assemblages and associated habitat charac-
teristics of farm pond in the Western Cape, South
Africa. Biodiv. Conserv. 10, 251–70.
Gledhill D. G., James P. Davies D. H. (2004) Urban
pond: a landscape of multiple meanings. Paper pre-
sented at the 4th International Postgraduate Research
Conference in the Built and Human Environment.
University of Salford, Manchester, UK, 857–68.
Guadagnin D. L. Maltchik L. (2007) Habitat and land-
scape factors associated with neotropical waterbird
occurrence and richness in wetland fragments. Biodiv.
Conserv. 16, 1231–44.
Guadagnin D. L., Maltchik L. Fonseca C. F. (2009)
Species-Area relationship of neotropical waterbird
assemblages in remnant wetlands: looking at the mech-
anisms. Divers. Distrib. 15, 319–27.
Hattori A. Mae S. (2001) Habitat use and diversity of
waterbirds in a coastal lagoon around Biwa. Japan.
Ecol. Res. 16, 543–53.
van Heezik Y., Smyth A. Mathieu R. (2008) Diversity
of native and exotic birds across an urban gradient
in a New Zealand city. Landsc. Urban Plann. 87,
223–32.
Heusmann H. W. (1981) Movements and survival rates of
park Mallards. J. Field Ornit. 52, 214–21.
Heusmann H. W. (1983) Mallards in the park: contribu-
tion to the harvest. Wildl. Soc. Bull. 11, 169–71.
Heusmann H. W. Burrell R. (1984) Park waterfowl
populations in Massachusetts. J. Field Ornit. 55, 89–
96.
Hoyer M. V. Canfield D. E. Jr (1994) Bird abundance
and species richness on Florida lakes: influence of tro-
phic status, lake morphology, and aquatic macrophytes.
Hydrobiologia 297/280, 107–19.
Kloskowski J., Green A. J., Polak M. et al. (2009) Com-
plementary use of natural and artificial wetlands by
waterbirds wintering in Donana, south-west Spain.
Aquat. Conserv. 19, 815–26.
Lambdon P. W. Hulme P. E. (2008) Do non-native
species invasions lead to biotic homogenization at
small scales? The similarity and functional
diversity of habitats compared for alien and native
components of Mediterranean floras. Divers. Distrib.
14, 774–85.
Langley W., Frey C. Taylor M. (1998) Comparison of
waterfowl and shorebird use of a man-made wetland,
lake, and pond. Transact. Kansas Acad. Sci. 101, 114–
9.
Bird assemblages in urban ponds 39
© 2015 Wiley Publishing Asia Pty Ltd

8. Lomolino M. V. Weiser M. D. (2001) Towards a more
general species-area relationship: diversity on all
islands, great and small. J. Biogeogr. 28, 431–45.
Lougheed V. L., McIntosh M. D., Parker C. A. et al.
(2008) Wetland degradation leads to homogenization of
the biota at local and landscape scales. Fresh. Biol. 53,
2402–13.
MacArthur R. H. Wilson E. O. (1963) An equilibrium
theory of insular zoogeography. Evolution 17, 373–
87.
Magurran A. E. McGill B. (2011) Biological Diversity.
Frontiers in Measurement and Assessment. Oxford
University Press, Oxford.
Marzluff J. M. (2001) Worldwide urbanization and its
effects on birds. In: Avian Ecology and Conservation in
an Urbanizing World (eds J. M Marzluff, R. Bowma
R. Donnelly), pp. 19–48. Kluwer Academic, Norwell,
Massachusetts.
McKinney M. L. (2002) Urbanization, biodiversity, and
conservation. Bioscience 52, 883–90.
McKinney M. L. (2006) Urbanization as a major cause of
biotic homogenization. Biol. Conserv. 127, 247–60.
Naugle D. E., Higgins K. F. Bakker K. K. (1999)
Habitat area requirements of wetland birds in Wes-
tern South Dakota. Proc. South Dakota Acad. Sci. 78,
129–38.
Newbold S. Eadie J. M. (2004) Using species-habitat
models to target conservation: a case of study with
breeding Mallards. Ecol. Appl. 14, 1384–93.
Nichols W. F., Killingbeck K. T. August P. V. (1998)
The influence of geomorphological heterogeneity on
biodiversity. II. A landscape perspective. Conserv. Biol.
12, 371–9.
Olden J. D. Rooney T. P. (2006) On defining and quan-
tifying biotic homogenization. Glob. Ecol. Biogeogr. 15,
113–20.
Paillisson J.-M., Reeber S. Marion L. (2002) Bird
assemblages as bio-indicators of water regime manage-
ment and hunting disturbance in natural wet grass-
lands. Biol. Conserv. 106, 115–27.
Paracuellos M. (2006) How can habitat selection affect
the use of a wetland complex by waterbirds? Biodiv.
Conserv. 15, 4569–82.
Paracuellos M. Tellerıa J. L. (2004) Factors affecting
the distribution of a waterbird community: the role of
habitat configuration and bird abundance. Waterbirds
27, 446–53.
Pearce C. M., Green M. B. Baldwin M. R. (2007)
Developing habitat models for waterbirds in urban
wetlands: a log-linear approach. Urban Ecosyst. 10,
239–54.
Rebele F. (1994) Urban ecology and special features of
urban ecosystems. Glob. Ecol. Biogeogr. 4, 173–87.
Riffell S. K., Keas B. E. Burton T. M. (2001) Area and
habitat relationships of birds in Great Lakes coastal
wet meadows. Wetlands 21, 492–507.
Robinson G. R., Holt R. D., Gaines M. S. et al. (1992)
Diverse and contrasting effects of habitat fragmenta-
tion. Science 257, 524–6.
Savard J. P. L. Falls B. (2001) Survey techniques and
habitat relationships of breeding birds in residential
areas of Toronto, Canada. In: Avian Ecology and Con-
servation in an Urbanizing World (eds Marzluff J. M.,
Bowman R. Donelly R.), pp. 543–68. Kluwer Aca-
demic Publishers, Boston, Massachusetts.
Sorace A. Gustin M. (2008) Homogenisation processes
and local effects on avifaunal composition in Italian
towns. Acta Oecol. 33, 15–26.
Sousa W. P. (1984) The role of disturbance in natural
communities. Annu. Rev. Ecol. Syst. 15, 353–91.
Suter W. (1994) Overwintering waterfowl on Swiss lakes:
how are abundance and species richness influenced by
trophic status and lake morphology? Hydrobiologia 279
(280), 1–14.
Sutherland W. J. (ed.) (2006) Ecological Census Tech-
niques: A Handbook. Cambridge University Press,
Cambridge.
Tews J., Brose U., Grimm V. et al. (2004) Animal spe-
cies diversity driven by habitat heterogeneity/diversity:
the importance of keystone structures. J. Biogeogr.
31, 79–92.
Traut A. H. Hostetler M. E. (2004) Urban lakes and
waterbirds: effects of shoreline development on avian
distribution. Landsc. Urban Plann. 69, 69–85.
Tuite C. H., Hanson P. R. Owen M. (1984) Some eco-
logical factors affecting winter wildfowl distribution on
inland waters in England and Wales, and the influence
of water-based recreation. J. Appl. Ecol. 21, 41–61.
Turnbull R. E. Baldassarre G. A. (1987) Activity bud-
gets of Mallards and American Wigeon wintering in
East-Central Alabama. Wilson Bull. 99, 457–64.
Tyser R. W. (1982) Species composition and diversity
of bird communities in four wetland habitats of the
upper Mississippi river floodplain. Passenger Pigeon
44, 16–9.
Tyser R. W. (1983) Species-area relations of cattail marsh
avifauna. Passenger Pigeon 45, 125–8.
Watling J. I. Donnelly M. A. (2006) Fragments ad
islands: a synthesis of faunal responses to habitat
patchiness. Conserv. Biol. 20, 1016–25.
Wiens J. A. (1976) Population responses to patchy envi-
ronments. Annu. Rev. Ecol. Syst. 7, 81–120.
40 M. P. Di Santo et al.
© 2015 Wiley Publishing Asia Pty Ltd

9. Wiens J. A. (1989) The Ecology of Bird Communities.
Vol. 2. Processes and Variations. Cambridge studies in
ecology, Cambridge University Press, Cambridge.
Wiens J. A. (1997) The emerging role of patchiness in
conservation biology. In: The Ecological Basis for Con-
servation: Heterogeneity, Ecosystems, and Biodiversity
(eds S. T. A. Pickett, R. S. Ostfeld, M. Shachak G. E.
Likens), pp. 93–107, Chapman Hall, New York.
Zacchei D., Battisti C. Carpaneto G. M. (2011) Con-
trasting effects of water stress on wetland-obligated
birds in a semi-natural Mediterranean wetland. Lakes
Reserv. Res. Manage. 16, 281–6.
Bird assemblages in urban ponds 41
© 2015 Wiley Publishing Asia Pty Ltd