Note on the nest - building behaviour, socio - negative interactions and courtship display of the Lesser Antillean Bullfinch Loxigilla noctis sclateri in a suburban area of St Lucia

. Note


Introduction
The Lesser Antillean Bullfinch Loxigilla noctis ( Figure 1) is a passerine that occurs on several islands within the Lesser Antilles, including Dominica, St Vincent and the Grenadines, St Lucia, Martinique, Guadeloupe and several smaller islands (Bond 1999;Rising & Jaramillo 2020). There are eight subspecies of the Lesser Antillean Bullfinch; the subspecies sclateri occurs on St Lucia. The species inhabits tropical evergreen forests, gardens, second growth and woodland, rarely descending to suburban or dry areas (Bond 1999;Rising & Jaramillo 2020).
The Lesser Antillean Bullfinch breeds on the larger Lesser Antillean islands and was observed to breed on St Cronx and St Virgin Islands (Rising & Jaramillo 2020). Despite being considered locally common, no systematic research has been conducted on the natural history of this species, with data on the breeding behaviour remaining sparse. This paper provides field notes on the nest-building behaviour and courtship display observed in a suburban area in western part of St Lucia.

Observations
A pair of Lesser Antillean Bullfinches was frequently observed in the vicinity of the hotel area near Castries (14° 02' 03" N, 60° 58' 25" W), and located c. 15 m from the coast. The study site was close to a fragmented forest patch and c. 1 km away from a human settlement. The Lesser Antillean Bullfinch pair visited the hotel gardens frequently (for potential food resources) and were accustomed to human presence, allowing us to observe the behaviour from close vicinity.
On 10 May 2019, we observed the male, on his own, investigating several potential nesting sites within the area of the hotel gardens. The female visited a potentially identified nesting site only after auditory contact with the male. On the following day, we observed the pair carrying nest material and inspecting a gap of a balconette located c. 3.1 m above the ground ( Figure 2). Both male and female participated in the search flights and initial phase of the nest construction. On the fifth day, we observed the pair for c. 30 min. Both the male and female brought nest material and inclined it into the raw material of the nest (Figure 3). During the observation period, the male spent shorter time periods inside the nest (mean = 14.2 s; range 3.9-51.8 s; n = 16) than the female (mean = 54.5 s; range 26.0-78.0; n = 13). Search flights were short in duration (between 2-4 minutes), indicating that nest material was collected close to the nest site (probably in the hotel garden or the forest fragment). Grass stems, leaves, small twigs and plant fibres were identified as nest material. The majority of nest material was collected and incorporated into the incomplete nest during the fifth and sixth days. The nest was presumably completed after eight days (19 May 2019), because no further nest construction was noticed. After revisiting the site on the following day, the nest site was abandoned and the nest structure deformed with nest material dispersed all over the balconette floor, indicating external mechanical impact on the nest. We could not find any evidence of nest predation (e.g. broken egg fragments). We observed the same pair revisiting the nesting site on several occasions later this day.
Elements of the courtship display were observed on three occasions (12-14 May 2019) during the nest-building process, with the male starting to perform display elements perching near the female ( Figure  4). The courtship display was characterized by irregular vertical hops accompanied by wing-flicking. The head of the male was lifted up, exposing the red throat patch, which was presented towards the female. The female habitually remained stationary during the elements of the display. No copulations were observed -this requires further field observations.

Biodiversity Observations
The scope of Biodiversity Observations includes papers describing observations about biodiversity in general, including animals, plants, algae and fungi. This includes observations of behaviour, breeding and flowering patterns, distributions and range extensions, foraging, food, movement, measurements, habitat and colouration/plumage variations. Biotic interactions such as pollination, fruit dispersal, herbivory and predation fall within the scope, as well as the use of indigenous and exotic species by humans. Observations of naturalised plants and animals will also be considered. Biodiversity Observations will also publish a variety of other interesting or relevant biodiversity material: reports of projects and conferences, annotated checklists for a site or region, specialist bibliographies, book reviews and any other appropriate material. Further details and guidelines to authors are on the journal website (https://journals.uct.ac.za/index.php/BO/).