Cocos nucifera

The demographic history of the Seychelles warbler is outlined in Fig.1. The species was first described in 1878 by Oustalet (1878 ) from the island of Marianne (96 ha), and in the same account was said by Lantz to be ‘rare on Ile Cousine’. Subsequent studies found the warbler on Cousin, but not Cousine, and Lantz's account was presumed to be a mistake (Vesey-Fitzgerald 1940 ). By 1938, the warbler was extinct on Marianne, and Vesey-Fitzgerald (1940 ) remarked that it ‘must be the rarest [bird] in the world’. Expeditions to Cousin in 1959, 1965, 1967 and 1968 documented 30, 50, 26 and 50 individuals, respectively (Penny 1967 ; Loustau-Lalanne 1968 ). However, birds were not uniquely ringed during these trips, so these estimates of population size are unlikely to have been very precise. In 1967, Cousin was designated as a nature reserve, and efforts began to increase the populations of native bird species (Penny 1967 ). Habitat restoration, consisting of the removal of coconut palms (Cocos nucifera) to allow the succession of natural pisona (Pisonia grandis) woodland, was successful, and the Cousin warbler population quickly recovered; since the 1980s, it has been at a carrying capacity of approximately 320 adults (Brouwer et al. 2009 (link)). Between 1987 and 2011, four new warbler populations were successfully established by translocation to the islands of Aride, Cousine, Denis and Frégate (Komdeur 1994 ; Richardson et al. 2006 ; Wright et al. 2014 (link)).
Historical samples were obtained from all known Seychelles warbler museum specimens, collected from Cousin (n = 19) and Marianne (n = 7) in 1876–1940 (Table S1). Although the temporal range of sampling of the museum specimens was wide, structure analyses suggested that they grouped into two populations (see Results), enabling us to group them for population genetic analyses. A small (approximately 1.5 × 1.5 × 3.0 mm) piece of skin was excised from the ventral surface of the foot and stored at room temperature in a sterile microfuge tube. Contemporary samples were collected as part of an intensive, long-term study of Seychelles warblers on Cousin Island (Brouwer et al. 2010 (link)). Since 1988, the entire population has been extensively monitored, often in both the main (June–September) and minor (November–March) breeding seasons each year, during which birds are routinely caught with mist nets and audio lures. A blood sample (approximately 25 μL) was collected from each bird by brachial venipuncture and stored at room temperature in a screw-topped microfuge tube containing 1.5 mL absolute ethanol. Each bird was fitted with a unique combination of three colour rings and a metal British Trust for Ornithology (BTO) ring. Over 96% of adult birds on Cousin have been ringed since 1997 (Richardson et al. 2001 (link)), and a representative sampling of the population was achieved in each year. For the present analysis, 50 samples were randomly chosen from 1997 and 2011 (of 160 and 197 samples available from that year, respectively) to provide two temporally distinct contemporary population samples for comparison with the historical data.

The study was conducted in three villages in Tanga region, North-Eastern Tanzania. The three villages were Mgome (5°12'S, 38'51'E) at an altitude of approximately 200 meters, Ubiri (4°72'S, 38°29'E) at an altitude of approximately 1,200 meters, and Magamba (4°75'S, 38°29'E) at an altitude of approximately 1,700 meters.
The climate in the area is characterized by variations in rainfall and temperature related both to season and altitude [12 (link)]. The long rainy period occurs during April-May, while short rains occur in November-December. Mean daily temperatures are highest in January and lowest in July. Generally, the malaria transmission season peaks just after the rainy seasons with most consistent transmission in lowland sites from April to July. Previous studies have reported parasite prevalence rates to be in the ranges of 79–90% in the lowlands, 27–46% at intermediate altitudes and 8–16% in the highlands [10 (link)]. Entomological surveys in the study areas have shown that Anopheles gambiae is the most prevalent vector in the lowlands, while Anopheles funestus predominates in the highlands [10 (link)]. The entomological inoculation rates (EIR) have been reported to be in the range between 91–405 in the lowlands, and between 1.8–34 at intermediate altitudes [10 (link)]. In the highlands, mosquito densities are too low to allow reliable EIR measurements, but an EIR of 0.03 has been extrapolated [10 (link)]. Villagers living at low and intermediate altitudes perceive malaria as a major problem among both children and adults, but at the highest altitudes villagers consider that malaria is not a major part of the disease burden in either adults or children. There is little difference in treatment seeking behaviour for febrile illness between the altitudes. Treatment is generally sought for symptoms rather than for the disease and first treatment is almost universally an anti-pyretic drug bought from local shops (Caroline Jones, unpublished data). For all three villages, the nearest health facility is located within a distance of 13 km. Mgome is served by Umba Dispensary (10 km), Masaika Dispensary (5 km), Mkuzi Health Centre (7 km) and Muheza Designated District Hospital (14 km). Ubiri village is served by Lushoto District Hospital at a distance of approximately 13 km. Magamba village has a government and a private missionary dispensary both within the village, and is served also by Lushoto District Hospital at a distance of about 15 km. At the time of the study, sulphadoxine-pyrimethamine (SP) was the first-line treatment for uncomplicated malaria in Tanzania. It has been documented that the level of SP resistance is high in the Mgome area [13 (link)], whereas the situation has not been monitored previously in Ubiri and Magamba.
Land use in the lowland areas is characterized by subsistence farming of maize, rice, bananas, beans, cassava, coconuts, fruits and other crops, as well as large-scale production of sisal. In the highlands, there is subsistence farming, mainly of maize, beans, bananas, potatoes, cabbages, tomatoes and fruits, and also large-scale production of tea and coffee.

The absolute divergence of coconut is a tuple $⟨H_l,H_s,W_l,W_s,V_{\mathit{ol}},N_{\mathit{ob}}⟩$ , where $H_l$ and $H_s$ represent the statistical difference of long and short axis of haustorium respectively, $W_l$ and $W_s$ represent the statistical difference of long and short diameter of coconut water respectively. And when the error is less than 0.2 cm will be judged to be accurate. $V_{\mathit{ol}}$ (volume) represents the volume of the model built, and $N_{\mathit{ob}}$ (number of boundary triangle grid) represents the number of triangular meshes on the boundary, which is judged to be accurate as the volume is closer to the reference value and the number of triangular meshes is higher.

Because the point cloud features were composed of discrete points, the model lacked wholeness. We performed a closed meshing operation for surface fitting on the model. The alpha shape rolling ball method [21 (link)] was suitable for the feature requirements of the external coconut surface. To find the points that met the requirements, the radius of the rolling ball was set to 0.3 cm, while all external circles corresponding to the connection of points constituted the boundary information; the plot function was then used to draw them, and the color parameters were adjusted to remove the grid lines in order to obtain the model after fitting the discrete points.
At this point, the basic construction of the model was complete; it was then necessary to quantify it digitally [22 (link)]. The model can target any area to obtain its volume. The commonly used fruit haustorium was used as an example for the calculation. The haustorium fruit is extracted according to the RGB value [230,230,230]. Because the target in the color display is not conducive to observation and calculation, we subjected it to color processing (Fig. 6A). Then useed alphashape to perform the grid operation. At this time, the haustorium was composed of small squares (Fig. 6B). Because the 3D coordinates of all points were known, the volume function could be used to obtain the volume value, the models of each coconut fruit in different stages are calculated according to this method [23 (link)], the volume value calculated by taking one of the models as an example is 602.9 ${\text{cm}}^3$ .Fig. 6

A example of quantitative calculation of organ. A Extraction and coloring; B the haustorium after meshing