Inter-specific nest scrape reuse in waders: Little Ringed Plovers taking over the nest scrapes of Northern Lapwings

Abstract

Capsule Inter-specific nest scrape reuse is rare in waders. We review this phenomenon and document it for the first time in the Little Ringed Plover Charadrius dubius breeding in vacant nest scrapes excavated by Northern Lapwings Vanellus vanellus.

Waders (Charadrii) usually excavate a simple nest scrape and line it sparsely with material from surroundings (del Hoyo et al. 1996) to be as inconspicuous as possible for predators but also to provide good thermoregulation at the same time (Reid et al. 2002, Mayer et al. 2009, Tulp et al. 2012). Only two species regularly use nests built by other birds (Green Sandpiper Tringa ochropus and Solitary Sandpiper Tringa solitaria) and two occasionally (Grey-tailed Tattler Tringa brevipes and Wood Sandpiper Tringa glareola), especially the abandoned forest nests of thrushes (Oring 1973, Cramp 1983, Pulliainen & Saari 1991, del Hoyo et al. 1996).

Creating a new nest scrape for breeding is probably not energy demanding (Amat et al. 1999) and old nest scrapes are often left unused even if they are available in the breeding territory (Gratto et al. 1985). In addition, the process of excavation has been described as an important part of the courtship ritual prior to copulation (Cramp 1983). Nevertheless, there are many examples of reuse of the nest scrape by the same or different individuals in several wader species within the same or in the subsequent breeding season. The Birds of North America database (Poole 2013) refers to intra-specific nest scrape reuse in 26 out of 50 American wader species, and it has been widely documented elsewhere (Parr 1980, Cramp 1983, Amat et al. 1999, Soloviev et al. 2001, Bertolero 2002, Schekkerman et al. 2004), but it occurs only at low frequency (Poole 2013). In contrast, use of the nest scrape by different wader species (inter-specific reuse) has been recorded only exceptionally (Table 1 containing all the records we could find). Here we document its occurrence in two European species, the Little Ringed Plover Charadrius dubius and Northern Lapwing Vanellus vanellus.

Table 1. Inter-specific nest scrape reuse in waders.

Reused by	Built/excavated by	When reused^a	n of cases	References
Black-necked Stilt	American Avocet	probably 0	more than 1	Robinson et al. (1999)
Himantopus mexicanus	Recurvirostra americana
American Avocet	Black-necked Stilt	probably 0	more than 1	Robinson et al. (1999)
Recurvirostra americana	Himantopus mexicanus
American Golden Plover	Stilt Sandpiper	2	1	Moitoret et al. (1996)
Pluvialis dominica	Calidris himantopus
Pacific Golden Plover	American Golden Plover	1	1	Johnson et al. (2007), Johnson & Connors (2010)
Pluvialis fulva	Pluvialis dominica
Little Ringed Plover	Northern Lapwing	0	2	this study
Charadrius dubius	Vanellus vanellus
Lesser Sand Plover	Red Knot	1	1	P. Tomkovich (pers. comm.)
Charadrius mongolus	Calidris canutus
Hudsonian Gotwit	Short-billed Dowitcher	0 or 1	1^b	Walker et al. (2011)
Limosa haemastica	Limnodromus griseus
Ruff	Dunlin	2	1	Soloviev et al. (2001)
Philomachus pugnax	Calidris alpina
	Pectoral Sandpiper	1	3	Soloviev et al. (2001)
	Calidris melanotos
	Red Phalarope	1 and 4	2	Soloviev et al. (2001)
	Phalaropus fulicarius
Curlew Sandpiper	Dunlin	1	1	Soloviev et al. (2001)
Calidris ferruginea	Calidris alpina
Dunlin	Pectoral Sandpiper	3	1	Soloviev et al. (2001)
Calidris alpina	Calidris melanotos
	Red-necked Phalarope	0	1	Gratto et al. (1985)
	Phalaropus lobatus
Little Stint	Pectoral Sandpiper	1	3	Soloviev et al. (2001)
Calidris minuta	Calidris melanotos
Least Sandpiper	Semipalmated Sandpiper	not known	1	Gratto et al. (1985)
Calidris minutilla	Calidris pusilla
Pectoral Sandpiper	Ruff	1 and 2	2	Soloviev et al. (2001)
Calidris melanotos	Philomachus pugnax
	Dunlin	1 or 2 ; 2	2 ; 1	Moitoret et al. (1996),
	Calidris alpina			Soloviev et al. (2001)
	Red Phalarope	not known	1	Soloviev et al. (2001)
	Phalaropus fulicarius
Semipalmated Sandpiper	Dunlin	1	1	Gratto et al. (1985)
Calidris pusilla	Calidris alpina
	Red-necked Phalarope	not known	4	Gratto et al. (1985)
	Phalaropus lobatus
Red-necked Phalarope	Semipalmated Sandpiper	1	1	Gratto et al. (1985)
Phalaropus lobatus	Calidris pusilla
Red Phalarope	Pectoral Sandpiper	2 and 3	2	Soloviev et al. (2001)
Phalaropus fulicarius	Calidris melanotos
	Dunlin	1	1	J. Hansen (pers. comm.)
	Calidris alpina
Willet	Marbled Gotwit	1	1^c	Lowther et al. (2001)
Tringa semipalmata	Limosa fedoa

^a0 = Nest scrape reused in the same year, 1 = nest scrape reused in the next year, 2 = nest scrape reused after two years (one year gap in usage), 3 = nest scrape reused after three years (two years gap in usage), 4 = nest scrape reused after four years (three years gap in usage), some numbers were completed by M. Soloviev (pers. comm.).

^bappropriation of nest with dowitcher eggs, nest ultimately held eight eggs: four godwit and four dowitcher, although the dowitcher eggs were eventually pushed to the side and left unincubated, it is not known if these dowitcher eggs were from that year or the previous year.

^conly rescraped, but another scrape nearby was used for egg-laying.

The Little Ringed Plover is a common wader species distributed widely across Europe (BirdLife International 2004, Delany et al. 2009). It primarily breeds in habitats dominated with bare ground and low sparse vegetation close to water, including human-altered environment such as the bottoms of dry ponds, sandpits and other post-industrial sites (Cramp 1983, Parrinder 1989, del Hoyo et al. 1996, Fojt et al. 2000). In the Czech Republic in addition to these habitats (Hudec & Št'astný 2005, Št'astný et al. 2006), arable land, especially freshly sowed maize fields and parts of wet fields with sand or gravel, seem to be another important breeding habitat for the species, at least in South Bohemia in recent years (Cepáková et al. 2007, Kubelka unpubl. data). In the Little Ringed Plover, the male usually excavates several nest scrapes that are subsequently lined with small stones and pieces of vegetation, and the female chooses one of these during courtship (Walters 1956, Cramp 1983, Hudec & Št'astný 2005).

During a study of a Northern Lapwing (hereafter lapwing) population in South Bohemia, Czech Republic, we found two clutches of Little Ringed Plovers (hereafter plover) on 21 April 2013, placed in nest scrapes excavated by lapwings. The plover nests were placed 125 m apart from each other within a lapwing breeding colony (24 m and 11 m from the nearest active lapwing nests, respectively) consisting of ten lapwing nests in the middle of one large field (35 ha) near Žabovrˇesky (GPS: 48°59′53″N, 14°20′47″E), which was a wet ploughed field at the time of courtship and at the early incubation stage of both species. The inner cup diameter of plover nests (5.5–6.5 cm, n = 13) is smaller than that of lapwings (7–16 cm, n = 96) in the Czech Republic (Hudec & Št'astný 2005). At the study site, the lapwing nest scrapes with plover eggs appeared similar to other unused lapwing nest scrapes in the surroundings. One nest scrape (inner cup diameter: 12 cm, cup depth: 3.5 cm) with plover eggs was sparsely lined with pieces of straw but without stones (Fig. 1a), which does not correspond to the usual plover nest scrape lining (Cramp 1983), repeatedly found in the arable fields of South Bohemia (own unpubl. data, Fig. 1b). All eight eggs from the two plover clutches (four and four eggs) hatched successfully.

Figure 1. (a) Clutch of a Little Ringed Plover C. dubius in a nest scrape excavated by a Northern Lapwing V. vanellus, 27 May 2013, photo by MŠ. (b) An example of a ‘normal’ Little Ringed Plover nest in a ploughed field 20 km from nest (a), 9 April 2010, photo by VK.

The majority of previously known inter-specific nest scrape reuses occurred after breeding of the host wader species. However, in this case, the plovers probably used unused lapwing nest scrapes. Although we cannot completely exclude possible predation of the lapwing nests during the egg-laying period and their subsequent reuse by plovers, this is unlikely due to our regular visits of the locality. We did not observe any physical conflict between the two species at the breeding ground and lapwings seemed to tolerate plovers in their territories. We suppose (according to the timing of breeding) that the plovers chose one of the nest scrapes which were excavated by lapwings during their courtship but were later unused for egg-laying and thus were free for the plovers.

The advantage of nest scrape reuse could be to save energy, similar to the arguments to support nest reuse (Pearson 1974). Saved energy can be invested in more intense display and courtship to potential mates as in the Fan-tailed Warbler Cisticola juncidis (Ueda 1989) or can lead to earlier laying of replacement clutches as in the Eastern Kingbird Tyrannus tyrannus in North America (Cancellieri & Murphy 2013). The energy-saving hypothesis is supported by the fact that nest scrapes of Kentish Plovers Charadrius alexandrinus were reused more often by the same species in the situations when excavating due to firm soil was apparently more demanding (Amat et al. 1999).

In the plover and in other waders, where the female chooses one of the nest scrapes present in the territory (Cramp 1983), the incorporation of an already made nest scrape in the territory could increase the attractiveness of a displaying male. Moreover, a bigger nest scrape could serve as a supernormal stimulus (Staddon 1975) and the female could consider the male displaying beside this bigger nest scrape as more attractive. A bigger nest scrape could therefore be preferred for breeding to smaller ones excavated by the plovers.

The nearby presence of breeding lapwings could be an important advantage of the lapwing nest scrape usage. Lapwings are known for their aggressiveness in expelling avian predators from the surroundings of their nests (Elliot 1985, Kis et al. 2000). Deterrence of predators is more efficient in bigger colonies (Berg 1996, Šálek & Šmilauer 2002) such as the aggregation at the study site. As in Nankinov (1978), plovers at the study site could principally have sought out this ‘lapwing protective umbrella’. Frequent observations of courting plovers at other lapwing breeding sites nearby to the study area (own unpubl. data) suggest that the phenomenon could be more widespread. The hatching success of plovers in South Bohemia is higher in fields compared to bottoms of dried fishponds which are traditional breeding habitat there (Cepáková et al. 2007). The presence of lapwing breeding colonies could play a significant role in this because lapwing colonies are currently situated particularly on arable land (Kubelka et al. 2012).

Alternatively, the finding of a plover nest in a tractor wheel track in East Bohemia (V. Štorek, pers. comm.) suggests that plovers are able to make use of similar unusual situations. It is therefore possible that plovers use any suitable depressions for their nests. Moreover, the pre-laying period of lapwings in 2013 was prolonged due to frosts at the end of March. Lapwing males thus had more time to excavate nest scrapes and indeed, more nest scrapes were found in the surroundings of active lapwing nests than in other years (Kubelka & Šálek 2013). Therefore, this surplus of vacant lapwing nest scrapes in 2013 could also have significantly influenced plover nest site selection.

At least 24 cases of inter-specific nest scrape reuse have been documented so far in 22 wader species (17 wader species used a vacant nest scrape built by another species) and in the majority of these cases it has only been recorded once. Most of them come from the Arctic (Table 1), probably as a result of longer persistence of nest scrapes in the stable arctic environment (Gratto et al. 1985, Soloviev et al. 2001) and possibly the energy demands for excavating/creating a nest scrape in cold Arctic conditions render nest scrape reuse more convenient. It could, however, also be caused simply by the fact that wader communities are thoroughly investigated in the Arctic, where several species breed close to each other in the same habitat (Soloviev et al. 2001) rendering the community more prone to inter-specific nest scrape reuse and its observation more likely. Generally, the species that reuse nests of other species do not differ much in size from the host species (Table 1). In contrast, in the case of plovers and lapwings, this difference in size is unusually large.

We conclude that plovers used the option of breeding in vacant lapwing nest scrapes in a ploughed field for one or a combination of the following reasons: (1) vacant lapwing nest scrapes were used simply as available suitable depressions in plover territories unconnected to their excavation by lapwings and the surplus of vacant lapwing nest scrapes in 2013 could have played an important role in what we observed; (2) bigger lapwing nest scrapes acted as a supernormal stimulus, which attracted courting plovers; (3) plover males enhanced their attractiveness to potential mates by including additional vacant nest scrapes in their territory and (4) plovers were attracted to breed in the proximity of lapwings to benefit from their anti-predation behaviour. All of these suggestions represent clear hypotheses that can be tested by experiment with a larger sample size.

ACKNOWLEDGEMENTS

We are grateful to R. Piálková, A. Vondrka, J. Vlček, Z. Karlíková and M. Nacházelová for their kind help in the field and to local farmers for their assistance. We are also indebted to J. Hansen, M. Y. Soloviev, P. Tomkovich and C. Kuepper for providing us with information about inter-specific nest scrape reuse. The first of them also contributed by useful comments on the earlier draft of the manuscript. We thank E. Cepáková for improvement of our English and W. Cresswell and two anonymous reviewers for their comments which significantly improved the article.

Funding

This work was supported by the University of Life Sciences Prague [grant CIGA number 20124218].