Ornithol Sci 11: 39 – 46 (2012)

ORIGINAL ARTICLE Breeding Ecology of the Malagasy Endemic nelicourvi

Hajanirina RAKOTOMANANA1,# and Masahiko NAKAMURA2

1 Department of Biology, Faculty of Science, University of Antananarivo, Antananarivo (101), 2 Laboratory of Animal Ecology, Joetsu University of Education, 1 Yamayashiki-machi, Joetsu-shi, Niigata 943–8512, Japan

Abstract The Nelicourvi Weaver Ploceus nelicourvi is endemic to Madagascar and ORNITHOLOGICAL information on its breeding biology is scarce and fragmentary. The behavior and SCIENCE parental care of the Nelicourvi Weaver were investigated in Maromizaha Park, eastern © The Ornithological Society Madagascar, from November 2009 to January 2010. We found three nests located of Japan 2012 250–700 m apart, suspended 3–10 m above the ground from branches of Nastus spp. () and Trema orientalis (Ulmaceae) above open areas such as streams or trails. The nests were bulky woven structures each with an extended entrance tunnel (ca. 14 cm long). Over a period of about 12 days, the males built the nest structures and the females contributed the nest lining material. The female alone incubated the eggs for about 15 days, and undertook most of the brooding of the young, with only some assistance from the male. During the nestling period, which lasted 13–25 days, both sexes delivered food (mainly beetles, grasshoppers, caterpillars and occasionally small chameleons) to the nestlings. These results suggest that the Nelicourvi Weaver is a socially monogamous .

Key words Biparental care, Dimorphism, Madagascar, Monogamy, Ploceus nelicourvi

The Nelicourvi Weaver Ploceus nelicourvi is a materials used for nest building but did not study sexually dimorphic in the family breeding aspects of the . All information is (Langrand 1990). It is endemic to the island of fundamental for clarifying the nature of the species Madagascar, and widely distributed along the eastern breeding system. Due to a lack of time and the inher- side and northwestern corner of the island, between ent difficulties in observing in humid evergreen sea level and an altitude of 1,800 m (Langrand 1990). , neither the relative contributions of males The Nelicourvi Weaver is a solitary nester in ever- and females to incubation and brooding, nor the green (Langrand 1990). detailed aspects of their breeding behavior, have been The Nelicourvi Weaver is categorized as of Least described. Concern in the IUCN Red List of threatened species In this paper, we report our observations providing (Birdlife International 2009). However, information the first systematic information relating to the roles on its breeding aspects is scarce and fragmentary of males and females in nest building, incubation of (Craig 2010). Previous observations of its breeding the eggs, and caring for the young, during the breed- biology come mainly from Craig (1989, 1999, 2003 ing period. Several authors (e.g. Langrand 1990; and 2010) and Oschadleus (2008). Craig (1989, 1999, Morris & Hawkins 1998; Craig 2010) have indicated 2003 and 2010) observed few nests and three eggs as that this species benefits regularly from feeding on a clutch, but suggested that the species is socially in mixed-species flocks. However, no data are monogamous, and assumed the existence of long- available on nestling diet. The first detailed data on term pair bonding. Oschadleus (2008) described the prey items delivered to young are also provided here.

(Received 30 June 2011; Accepted 23 April 2012) # Corresponding author, E-mail: [email protected]

39 H. RAKOTOMANANA and M. NAKAMURA

STUDY AREA AND METHODS clearing or over a path. To search for nests, we walked along the forest path and trails in the forest. 1) Study area Once a nest was discovered, we commenced direct The Nelicourvi Weaver’s breeding biology (from observations (using a 20 x telescope equipped with a the nest building to the nestling stage) was studied in Sony PCS-W5 digital camera) and indirect observa- the Maromizaha rainforest, eastern Madagascar tions (using a Sony video Hi8 camera, CCD-TRV (18°58′S, 48°27′E), at an altitude of about 1,015 m, 96). We found three nests, Nests A, B and C, in from November 2009 to January 2010. The forest Maromizaha rain forest. Nest C was abandoned for consists of secondary and primary growth. The higher unknown reasons. Nests were observed daily from and the middle strata are composed mainly of the 0450 to 1200 or from 1300 to 1700, for a total of following trees and shrubs: Uapaca sp. (Euphorbia- 133.64 hours by digiscope and for 84.00 hours by ceae), Tambourissa spp. (Monimiaceae), Protorhus video camera. Data from direct and indirect observa- spp. (Anacardiaceae), Pandanus spp. (Pandanaceae), tions were combined and analyzed. Data were Eugenia spp. (Myrtaceae), Dypsis spp. (), obtained from the male and female at Nest B, both of Dracaena spp. (Dracaenaceae). The understory is which were ringed on the right foot leg with two composed largely of Cyathea spp. (Cyatheaceae), aluminum tags, and from the un-ringed pair at Nest Psychotria spp. (Rubiaceae), and Oncostemon spp. A. (Myrsinaceae). September and October are the driest The nest building stage was investigated for a total months and the rainy season extends from November of 16.30 hours at Nest B from 30 November to 7 until August. The average annual rainfall recorded in December. Observations during the incubation period the region is about 1,779.6 mm, and the mean annual totaled 30.45 hours (19.62 hours for Nest A from 1 temperature is approximately 20.4°C (Antananarivo to 3 December and 10.83 hours for Nest B from 10 Station). to 20 December). Due to the short period of observa- tions during incubation, data from nests A and B 2) Body size were combined. A total of 170.89 hours of observa- Morphometric measurements of Nelicourvi tions were made during the nestling stage (117.81 Weavers were obtained from the individuals captured hours at Nest A from 3 to 27 December and 53.08 in the field by using mist nets (12 m long, 4 shelves, hours at Nest B from 28 December 2009 to 7 January 36 mm mesh). Birds were weighed to the nearest 2010). 0.1 g using a pesola balance and their bill, wing, To examine the differing contributions of the male tarsus and tail lengths were measured to the nearest and female during the different stages of breeding, 0.1 mm using calipers. nest building, incubation, brooding and feeding fre- quency (times h –1 brood –1), and the types of prey 3) Sex determination items delivered to the young, were studied. The size We determined the sex of individual Nelicourvi Weavers based on sexual dimorphism in their plum- age coloration. The male has a black forehead, crown and cheeks, rounded plain olive green wings, a brownish green tail and a rufous undertail. The female differs from the male in lacking the black cap and in having a yellow head, with exception of a dark line from the bill to the eye. This bill is yellowish, often with black patches, and the iris is brown to reddish-brown. We found a young bird, close to Nest A (see below), which had a greenish-yellow head and which was generally more dull than the female (Langrand 1990).

4) Field observations The Nelicourvi Weaver builds bulky woven nests, Fig. 1. Measuring nests: three dimensions of Nelicourvi which are suspended from a branch above a stream Weaver’s nest.

40 Breeding Ecology of Nelicourvi Weaver of prey, in comparison with the bird’s bill size, was females (Table 1) evaluated. We calculated the percentage of time spent by each sex in each behavior during the nest build- 2) Nest description ing, incubation and brooding stages, in relation to the We found three nests (Nests A, B and C) located total observation time. Full time incubation (starting 250–700 m apart, suspended 3–10 m above the after the egg laying date) means that the incubating ground from branches of Nastus spp. (Poaceae) and individual sits on the clutch continuously for more Trema orientalis (Ulmaceae) above open areas such than 80% of the time. Nest location, nesting plant as streams or trails (Table 2). species and nesting plant characteristics (height Nests were woven mainly with fresh green Areca- above the ground, scientific name) were recorded. ceae fibers (about 51 cm in length), which were Nest materials and size were examined and described. mixed with some Panicum sp. (Poaceae), and The entrance tube length, nest length and depth, and Podocarpus sp. (Podocarpaceae) leaves, and Areca- nest height from the ground (see Fig. 1), were each ceae hairs. The interior of the brood chamber was measured following Quader (2006). We could not see mainly constructed from the hairs of Dypsis sp. (Are- the eggs in the nest because of its complicated struc- caceae) mixed with some Pandanus sp. (Pandana- ture; however, egg color was established based on ceae) leaves and some fibers from Dypsis fibrosa egg shell fragments carried from the nest by the (Arecaceae). After the brood chamber was completed, adults. the tunnel (tube) was extended.

RESULTS 3) Nest building and behavior No data are available for the construction phase of 1) Body size Nest A because it was already complete when we No significant differences were found in wing discovered it. Construction of Nest B began on 29 length, bill, tarsus and tail lengths between two sexes November, and was completed on 10 December, of Nelicourvi Weavers (Table 1), whereas body indicating that a nest-building period was about 12 weight differed significantly between males and days for the breeding pair. During the nest-building period, the leaves of the surrounding branches were removed (cut) by the nesting pair (until the incuba- Table 1. Morphological characteristics of Nelicourvi tion period), which made the nests highly visible Weaver. Means are accompanied by standard deviations. Sam- from the ground. The male building Nest B had made ple sizes are in parentheses. Comparison between male and female was made using Student’s t-test. an extensive structure, but ceased building when rain started. Male (7) Female (5) Males hung upside down to commence building Body characters Mean ± SD Mean ± SD t P their nests, which they wove using the bill to inter- weave fresh palm fibers and grasses. Material was Body weight (g) 24.6 ± 3.5 20.9 ± 1.1 2.26 0.04 added both from the inside and from the outside to Bill length (mm) 15.8 ± 1.1 15.2 ± 1.2 1.01 0.33 make an elongated nest. The nest-building male then Tarsus length (mm) 23.8 ± 1.5 22.0 ± 1.9 1.93 0.08 used its chest to push at the nest wall from the inte- Wing length (mm) 76.6 ± 2.8 73.0 ± 3.6 1.95 0.08 rior to make it more globular in shape. The female Tail length (mm) 48.6 ± 5.4 49.6 ± 1.5 0.41 0.69 only rarely brought nest materials, visited the nest

Table 2. Nest characteristics of Nelcourvi Weavers in Maromizaha rainforest.

Nesting site Nest Tube Nest Nest Name of Nest plants Altitude Nest height length length depth nest Latitude Longitude (Family) (m) position* (m) (cm) (cm) (cm) Nest A 18°58′52.9″S 48°27′50.4″E 997 Stream Nastus sp. (Poaceae) 3.0 15.0 17.0 21.0 Nest B 18°58′29.1″S 48°27′53.4″E 1,030 Stream Trema orientalis (Ulmaceae) 10.0 10.0 15.0 19.0 Nest C 18°58′45.7″S 48°27′57.3″E 1,081 Trail Nastus sp. (Poaceae) 6.0 17.0 18.0 21.5

* nest situated above stream or trail.

41 H. RAKOTOMANANA and M. NAKAMURA intermittently to examine it, and occasionally wove The male at Nest B began building a new nest near fabric into the nest. The male worked extensively at Nest B in the same nesting plant, but the second nest the nest, spending 23.8% of the total observation was not occupied when it was finished. We did not time building (3.88 hours), whereas the female spent find any young at Nest B. only 7.5% of the total observation time nest building (1.22 hours). Both sexes participated in nest building, 5) Incubation but the male spent considerably longer than the Only one adult female incubated eggs at Nests A female. The time spent working on materials during and B. The incubating bird could not be seen from each visit averaged 1.33 min (range=0.33–5 min, the exterior, but the nest was often seen to move N=178) for the male and 2.39 min (range=0.33–6 slightly. At Nest B, full time incubation began on 12 min, N=37) for the female. The time spent working December and the eggs hatched on 26 December, on materials differed significantly between the sexes which indicates that the incubation period of the (Mann-Whitney U test, z=2.98, P<0.05). Males breeding pair lasts about 15 days. Hatching dates brought 160 items during 178 visits (9.82 items h –1) were determined as 3 December for Nest A, and 26 and females brought seven items during 37 visits December for Nest B, based on observations of the (0.43 items h –1). On many occasions, the male uttered incubating adult removing fragments of greenish- a call (tsrrrreee), often given in flight, to warn the blue eggshells on these days. female to leave the nest. Occasionally, both male and At Nests A and B, the females incubated their eggs female were seen collaborating in construction at the for 62.9% (19.16 hours) of the total observation time, nest. For the remaining 68.7% of the observation and were away from their nests for 36.8% (11.20 time (11.20 hours), both birds were away from the hours) of the observation time. The average incuba- nest. tion bout was 29.48 min (range=6–66 min, N=39). In general, neither male nor female were sensitive At both Nest A and B, the male used the tsiang to the presence of other animal species (e.g., Common tsiang call, and defended the nest area against intru- Newtonia Newtonia brunneicauda, Souimanga Sun- sion by con-specific males or other species (e.g. bird Nectarinia souimanga, and chameleons), which Souimanga Sunbird). were found around the nesting site. Mate guarding behavior, during which the male 6) Brooding behavior pursued the female (1 m behind and for about 3–4 At Nests A and B, males and females shared brood- seconds), was observed on seven occasions around ing duties, and brooding activity decreased as the Nest B when the nest construction was almost fin- nestlings grew (Fig. 2). At the beginning, only the ished. The male was also seen to flutter its wings female brooded the young, and stayed longer in the often on the branch near the nest site while the female nest, whereas the male perched on branches around was weaving material into the nest. The male was the nest site. The female at Nest A undertook much seen mounting the female for a few seconds at 0605 longer brooding activities than the female at Nest B on 4 December (the 6th day of nest building). (Fig. 2). The young inside the Nest A were not visi- ble, but their begging calls (pee pee pee) were clearly 4) Second nest audible from outside the nest once they were six days The paired male at Nest A started building a new old. nest on the same nesting plant and commenced weav- In this study, males undertook significantly less ing and cutting leaves off the surrounding branches brooding behavior than females. At Nest A, a brood- during the nestling period on 10 December, but the ing session averaged 8.42 min (range=5.33–19.00 new nest remained unfinished. The male called min, N=17) for the male and 28.12 min (range=5.00– (tsiang tsiang) around the nest site, and was accom- 48.00 min, N=63) for the female; the difference was panied by one young that had been seen to participate significant (z=5.40, P<0.0001). At Nest B, a brood- in building the second nest on the same nesting plant. ing session averaged 6.59 min (range=5.0–7.56 min, However, the young bird was not observed again the N=7) for the male and 20.25 min (range=7.06–48.06 following day. min, N=33) for the female, and again the difference Around Nest B, similar behavior was observed was significant (z=3.83, P<0.001). during the incubation period on 12 December, when a bird was seen removing leaves from the branches.

42 Breeding Ecology of Nelicourvi Weaver

Fig. 2. Brooding time budgets of Nelicourvi Weavers at Nests A and B. Open bars represent males; solid bars represent females. Nestling age is given after hatching (day 0 is the hatching date).

Fig. 3. Feeding frequency of Nelicourvi Weavers pairs in relation to age of nestlings at Nests A and B. Nestling age equals the number of days after hatching (day 0 is the hatching date). Open bars represent males; solid bars represent females.

7) The nestling and fledging period started feeding the young (see Fig. 3) and, on a few At Nests A and B, males and females shared the occasions, it reinforced the nest by interlacing fresh duties of caring for their young (delivering food and fibers and grasses inside, especially if repair was removing feces). Within a few days of hatching (10 needed. Males gave tsrrrrree calls before entering the days for Nest A, and six days for Nest B), the male nest and delivering prey to the nestlings.

43 H. RAKOTOMANANA and M. NAKAMURA

The female at Nest A brought food to her nestlings sions around the nest sites being fed by both parents. at the first day after hatching, but was not seen to For example, the pair was observed feeding their feed them at 4th and 6th days, which is probably due three young near Nest B at 1230 on 9 January 2010. to our short time of observation. However, the female at Nest B gave food to her nestlings once they reached 8) Nestling diet three days old (Fig. 3). Both parents at Nests A and The diet of the Nelicourvi Weaver was chiefly B brought food to their nestlings from 10 to 23 days comprised of arthropods gleaned from tree branches old and from 6 to 13 days old, respectively (Fig. 3). and leaf tangles. Prey size ranged from 1.3 cm (e.g., At Nest A, the average rate of feeding was 0.59 small crickets) to 7.0 cm (e.g., walking stick insects). time/h/brood for the male (range=0.32–1.61, N=18) During the study of two nests, a total of 801 prey and 0.96 time h –1 brood –1 for the female (range=0.08– items were delivered to the nestlings (547 items at 2.08, N=18). At Nest B, it was 0.72 time h –1 brood –1 Nest A and 254 items at Nest B, see Table 3). for the male (range=0.87–1.37, N=9) and 0.88 time The most frequently delivered prey items at Nest h –1 brood –1 for the female (range=0.47–1.27, N=9). A were crickets and grasshoppers (Table 3). Both Three nestlings fledged from Nest A at 1025 on 27 male and female weavers gave crickets, grasshop- December, after hatching on 3 December. In this pers, beetles and caterpillars, representing about case, the nestling period was 25 days. At Nest B, the 83.8% of identified prey at Nest A. At Nest B, the eggs hatched on 26 December and the three nestlings most frequently delivered prey items were beetles fledged at 1030 on 7 January 2010, indicating a nest- (Table 3). Parents gave their young beetles, crickets, ling period of just 13 days. During the nestling grasshoppers, and caterpillars, representing about period, the males at Nests A and B sometimes repaired 93.0% of identified preys. Eleven days after hatching, the nest, but often stopped doing so and fed the small chameleons (Calumma spp.) were also found in young while the female was out of the nest. the diet in Nest B (Table 3). The head and legs of No exact data on the post fledgling period for some insects, such as beetles and walking stick either nest are available due to a lack of observation insects, were cut before they were fed to the young time, but the young birds were found on many occa- birds.

Table 3. Prey delivered to the nestlings at two nests during the nestling period.

Nest A Nest B Prey (Class, Order or Family) Number (%) Number (%) Invertebrates Crickets and grasshoppers (Orthoptera) 122 (22.3) 55 (21.7) Caterpillars (Lepidoptera) 59 (10.8) 27 (10.6) Butterflies (Lepidoptera) 16 ( 2.9) 0 ( 0.0) Dragonflies (Odonata) 3 ( 0.5) 2 ( 0.8) Beetles (Coleoptera) 72 (13.2) 78 (30.7) Walking sticks (Phasmatidae) 11 ( 2.0) 5 ( 2.0) Larvae (Lasiocampidae) 10 ( 1.8) 0 ( 0.0) Millepedes (Diplopoda) 4 ( 0.7) 1 ( 0.4) Leafhoppers (Cicadellidae) 3 ( 0.5) 0 ( 0.0) Flies (Diptera) 2 ( 0.4) 0 ( 0.0) Vertebrates Chameleons (Chamaeleotidae) 0 ( 0.0) 4 ( 1.6) Unidentified preys 245 (44.8) 82 (32.3) Total 547 ( 100) 254 ( 100)

44 Breeding Ecology of Nelicourvi Weaver

DISCUSSION brood size per nest. However, to test this idea, nutri- tional analyses of the unidentified prey items in the Less-marked sexual dimorphism is one of the traits diet, more nest observations, physical examination of considered to characterize monogamous breeding the nestlings, and data on microclimate (e.g., rain- systems (Andersson 1994; Ligon 1999). However, fall), are necessary. many studies of mating systems have emphasized that several socially monogamous avian species are ACKNOWLEDGMENTS sexually dimorphic in plumage (Møller & Thornhill 1998; Rohde et al. 1999; Mizuta 2005; Rakotomanana We are grateful to Drs. Daniel Rakotondravony, Martin et al. 2009). In those studies, both mates shared Raheriarisena and Felix Rakotondraparany of Department of duties, and they may play variable parental roles dur- Animal Biology, for their cooperation in the realization of this study, the two anonymous referees for their construc- ing the breeding period. In the studied breeding pairs, tive comments and suggestions. We thank the Kyoto Uni- both sexes were found to provide care for the young versity Museum for facilitating the acquirement of all docu- (Fig. 3) and to feed fledged young. However, breed- ments necessary for the preparation of the manuscript, Mr. ing males contributed most to nest building, whereas Ravomiarana Ranaivosolo for helping identify the diet of only adult females incubated the eggs. During the Nelicourvi Weaver in the laboratory of Department of Animal nestling period, a young bird (of unknown sex) was Biology, Dr. Harison Rabarison for identifying the nest mate- present around the nest with the male, but the bird rials, and Dr. Mark Brazil for improving the manuscript. This did not help the breeding pair. As in many socially study would have not been possible without the essential help of Mr. Jean Ranaivomanana in the field. Our sincere apprecia- dimorphic monogamous avian species, the male Neli- tion goes also to the following institutions: Groupe d’Étude courvi Weaver exhibited a mate guarding behavior as et de Recherche sur les Primates de Madagascar (GERP) and an anti-cuckoldry tactic (Schackelford et al. 2006; Direction Générale des Eaux et Forêts, which made this study Estep et al. 2005). Our data suggest that the Neli- possible. This study was funded by a Grant-in-Aid for Scien- courvi Weaver has a mating system that is best tific Research (B) of the Japan Society for the Promotion of described as social monogamy, although males built Science (No. 21405007). second nest (which was unfinished or unoccupied) during this study. This conclusion is supported by the REFERENCES fact that this forest weaver is usually found alone or in pairs during both the breeding and non-breeding Andersson M (1994) Sexual Selection. Princeton Uni- seasons (Langrand 1990; Morris & Hawkins 1998; versity Press, Princeton. Craig 2003). However, we observed only three nests BirdLife International (2009) IUCN Red List of Threat- and had not enough data. Further nest observations ened Species. Version 2009.2. Species factsheet: are necessary in order to more fully describe the Ploceus nelicourvi. Downloaded from http://www. breeding system of the Nelicourvi Weaver. birdlife.org on 17/2/2010 The nestling period at Nest A was 25 days and that Craig AJFK (1989) Ploceus capensis. Red at Nest B was 13 days. Growth rates are closely asso- bishop orix. In: Ginn PJ, McIlleron WG & ciated with the number of offspring raised, the inten- Milstein PS (eds) The Complete Book of Southern sity of parental care, and age at first reproduction African Birds. pp 658–659. Struik, Winchester. Craig AJFK (1999) Weaving a story. The relationship of (Lack 1972). Soler (1988) provided detailed informa- the endemic Ploceidae of Madagascar. In: Adams NJ tion on the association between the length of the nest- & Slotow RH (eds) Proceedings of the 22th Interna- ling period and food availability and brood size per tional Ornithological Congress. pp 3063–3070. Bird- nest. However, our data showed that at two nests, the life South Africa, Johannesburg. growth of the young at Nest B was much faster than Craig AJFK (2003) Ploceus nelicourvi, Nelicourvi that of the young at Nest A during the same breeding Weaver, Fodisaina, Fodifetsy, Ala. In: Goodman season, despite the pairs having the same brood size. SM & Benstead JP (eds) The Natural History of It is currently difficult to determine which factors Madagascar. pp 1143–1146. The University of have the greatest effect on the duration of nestling Chicago Press, Chicago. growth. Both food quality (type of food provided to Craig AJFK (2010) Nelicourvi Weaver. In: del Hoyo young, see Table 3), and physiological characteristics J, Elliott A and Christie D (eds) Handbook of the of the nestlings, appear to be important factors influ- Birds of the World. Vol. 15, p 177. Lynx Edicions, encing nestling growth in our study, rather than the Barcelona.

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