Density and Diversity of Nocturnal Birds in Oil Palm Smallholdings in Peninsular Malaysia

Journal of Oil Palm Research Vol. 32 (1) March 2020 p. 57-63 DOI: https://doi.org/10.21894/jopr.2020.0011

DENSITY AND DIVERSITY OF NOCTURNAL BIRDS IN OIL PALM SMALLHOLDINGS IN PENINSULAR MALAYSIA

MUHAMMAD SYAFIQ YAHYA*; CHONG LEONG PUAN**; SHARIFAH NUR ATIKAH* and BADRUL AZHAR*

ABSTRACT was conducted to assess their density and diversity in the oil palm smallholdings in the Selangor state, (Strix seloputo) was estimated at 7 individuals 100 ha-1 (Otus lempiji) (Caprimulgus macrurus) nocturnal bird species, other than the Barn Owl, as biological control agents in the agricultural areas.

Keywords: nocturnal birds, oil palm smallholdings, density, abundance, biological control.

Date received: 9 January 2019; Sent for revision: 12 March 2019; Accepted: 15 November 2019.

INTRODUCTION Caprimulgus macruruset al., 2015). All nocturnal birds recorded in Peninsular Malaysia Nocturnal birds have been said to play ecological are listed as Least Concern by International Union for roles in an ecosystem similar to what their diurnal Conservation of Nature (IUCN), except for Reddish counterparts do during daytime. In Peninsular Scops-owl ( ), Large Frogmouth Malaysia, there is a total of 21 resident nocturnal (Batrachostomus auritus), and Gould’s Frogmouth bird species comprising of two taxonomic orders, (Batrachostomus stellatus) which are listed as Near (Otus sagittatus) is vulnerable (IUCN, 2018). Either in occupy various habitat types ranging from highland natural or man-made habitats, each nocturnal bird forests (i.e. Mountain Scops-owl, Otus spilocephalus), plays an important ecological role in an ecosystem. secondary forests (Sunda Scops-owl, ), In the case of man-made habitat, previous Ketupa ketupu) to urban studies revealed the potential of Barn Owl as a pest parks (Barn Owl, ; Large-tailed Nightjar, et al., 2012; Puan, 2013). As a result, some large agricultural- * Faculty of Forestry, Universiti Putra Malaysia, based companies have begun introducing Barn Owl 43400 UPM Serdang, Selangor, Malaysia. by providing nest boxes for these birds in order to suppress pest population in their agricultural ** Institute of Tropical Forestry and Forest Products (INTROP), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 2003). For instance, Felda Global Ventures (FGV) E-mail: [email protected] introduced a total of 16 individuals of Barn Owl in an

57 JOURNAL OF OIL PALM RESEARCH 32 (1) (MARCH 2020) oil palm plantation in Lahad Datu, Sabah, Malaysia Selangor, Malaysia and recorded some nocturnal in order to suppress rat population and to reduce bird species that were associated with forest habitats (i.e. Oriental Bay-owl, Phodilus badius; successful as the owl’s population had multiplied owl, ; Dusky Eagle-owl, Bubo by 638% after 20 months (Abidin et al., 2016) which coromandus and Brown Boobook, ) in may be able to suppress the rodent population in to estimate the density of nocturnal bird species in grown Barn Owl can consume up to three rats per oil palm agriculture based on distance sampling. Over the past three decades, despite the fact that most previous studies focused on Barn Owl METHOD (i.e. ; Naim et al., 2010; Puan et al., 2011; Abidin et al., 2016; Salim et al., Study Areas 2016), there is also an increase in studies on other Bird sampling took place in oil palm (Atikah et al., 2013; 2019; Puan et al., 2015; Najmi- smallholdings (approximately 5300 ha) located at Hanis et al., 2016; Yee et al., 2016; 2018; Yahya et al., 2016; Chang et al., 2017; Pilla et al., 2018). By using (3°24’24”N, 101°15’26”E) and Sabak Bernam point count method, Atikah et al. (2013) made a (3°50’50”N, 100°53’19”E), Selangor, Peninsular preliminary estimation of nocturnal bird density in Malaysia ( in this study were privately owned and managed

Straits of Melaka b.

Legend Sampling site

0 40 80 160 240 320

58 DENSITY AND DIVERSITY OF NOCTURNAL BIRDS IN OIL PALM SMALLHOLDINGS IN PENINSULAR MALAYSIA by individual land owners. Each land owners Statistical Analyses owned an average of 2-5 ha pieces of land which were primarily planted with oil palms, which sometimes intercropped with other subsistence Simpson 1-D indices were used to measure the crops (e.g. banana, coconut and jackfruit). Oil palm diversity of nocturnal bird species in oil palm fruit bunches are usually harvested twice a month, the diversity index by 100 permutations to increase the precision of the calculations. Both non-permutated and permutated estimation values of the indices were the study areas. reported. By using Conventional Distance Sampling Survey of Nocturnal Birds (CDS) in distance 6.2 (University of St. Andrews, Point count survey method (adapted from oil palm smallholdings were estimated. Half-normal Ralphs and Sauer, 1995; Buskirk and McDonald, as key functions and cosine as series expansion were 1995) was used in this study where 30 points were selected consistently throughout each estimation. placed in each of the three study sites. Survey points In order to increase the precision of the estimations, were established systematically on road junctions bootstrap at 100 permutations was applied. Both (either tarmac or dirt roads) at 800 m apart, similar estimations of density and abundance of each selected et al., species were carried out, along with standard error et al., 2016; Yahya et al., 2016; 2017). a minimum of two experienced surveyors stayed seven species (i.e. Savanna Nightjar, Oriental Bay- at each point for 10 min and recorded all sightings and/or vocalisations of nocturnal birds (Gerhardt, owl, Barred Eagle-owl Bubo sumatranus) records had et al., 2001; Delport et al., 2002; Newton to be excluded from the analysis. et al.,et al., was only made when both surveyors agreed upon RESULTS was repeated six times for each of the sampling Nocturnal Bird Diversity points in order to increase the encounters of targeted A total of 1408 individuals from 11 species (comprising nine owl and two nightjar species) 1900 hr-0200 hr daily. were recorded in this study (Table 1 and ).

TABLE 1. NOCTURNAL BIRD SPECIES RECORDED IN OIL PALM SMALLHOLDINGS AT BANTING, TANJUNG KARANG AND SABAK BERNAM, SELANGOR, PENINSULAR MALAYSIA

Number of Mean observation Family Species encounters per point Caprimulgidae Large-tailed Nightjar (Caprimulgus macrurus) 454 5.044 Savanna Nightjar () 20 0.222 Barn Owl () 101 1.122 Oriental Bay-owl (Phodilus badius) 15 0.167 Strigidae seloputo) 435 4.83 Sunda Scops-owl () 347 3.856 Ketupa ketupu) 19 0.211 leptogrammica) 13 0.144 Brown Hawk-owl () 2 0.022 Dusky Eagle-owl (Bubo coromandus) 1 0.011 Barred Eagle-owl (Bubo sumatranus) 1 0.011

1 408 -

59 JOURNAL OF OIL PALM RESEARCH 32 (1) (MARCH 2020)

Large-tailed Nightjar (454 encounters) was the most 1999; Robson, 2011), albeit their numbers remained abundant species recorded followed by Spotted low. encounters) and Barn Owl (101 encounters). All the index of nocturnal birds in oil palm smallholdings species had also been previously recorded in the oil was calculated at 3.359, or 4.731 ± 0.004 SE based palm smallholdings located in the Selangor state (Atikah et al.,et al., 2011; 2015). Five evenness index was calculated at 0.988, or 0.9882 nocturnal species that were associated with forest ± 0.0008 SE based on bootstrap estimation. Based habitats were recorded, namely Oriental Bay-owl, on Simpson 1-D, the diversity index was calculated at 0.965 or 0.9910 ± 0.0001 SE based on bootstrap et al., estimation.

a b c d

e f g h

i j k

60 DENSITY AND DIVERSITY OF NOCTURNAL BIRDS IN OIL PALM SMALLHOLDINGS IN PENINSULAR MALAYSIA

Nocturnal Bird Density and roosting sites for the bird that can be linked to habitat structure (Yahya et al., 2016). et al., 2010), the In the case of Sunda Scops-owl, the density estimate (i.e. 1-2 individuals per 10 ha) is close to the ± 0.001 SE individual per hectare (%CV = 15.84, estimations of Pilla et al. (2018) and Najmi-Hanis et EDR = 94.291, EDR %CV = 5.04) or about seven al. (2016) in a lowland dipterocarp forest based on distance sampling and radio-telemetry methods, owl was estimated at 0.15 ± 0.026 SE individual per hectare (%CV = 16.97 EDR = 62.543, EDR %CV been known to thrive in various wooded habitats = 6.88), i.e about 15 individuals for every 100 ha. et al., 2015; Yahya et al., 2016). It should be noted that the 0.011 SE individual per hectare(%CV = 22.29 EDR survey covered breeding season of the species and involved call playbacks similar to Pilla et al. (2018). per 100 ha. For Large-tailed Nightjar, its density For the other two larger owl species, it is a little was estimated at 0.794 ± 0.108 SE individual per hectare (%CV = 13.65 EDR = 31.13, EDR %CV = 1.76), about seven to eight birds in every 10 ha as the latter is known to be abundant in oil palm (Table 2). For the total area of 5200 ha, we estimated plantation due to the availability of nest boxes. SE individuals (%CV = 15.84) followed by Sunda such situation only happens in smallholdings, not Scops-owl at 797 ± 135.27 SE individuals (%CV in large scale oil palm plantations, as well as what = 16.97), Barn Owl at 263 ± 58.624 SE individuals factors contribute to higher density of the former (%CV = 22.29) and Large-tailed Nightjar at 4131 ± in the smallholdings. Such information is essential 563.73 SE individuals (%CV = 13.65) (Table 3). with respect to the ecology of the species (e.g. serve as a biological control agent in agricultural DISCUSSION sector. In addition, the presence of some forest Distance analysis estimated the density of four associated species (i.e. Oriental Bay-owl, Dusky common nocturnal bird species, i.e. in every 100 Eagle-owl and Brown Hawk-owl), although in low ha of oil palm smallholdings, there were about numbers, may also imply that smallholdings may serve as an alternative habitat for these species, at owls, 15 Sunda Scops-owls, and 79 Large-tailed least as their hunting ground. However, it has been shown that some forest associated species may not was the highest in the smallholdings which may be able to persist in oil palm agriculture (Atikah et be due to the availability of insects as food supply al., 2019).

TABLE 2. DENSITIES OF NOCTURNAL BIRDS IN OIL PALM SMALLHOLDINGS IN BANTING, TANJUNG KARANG AND SABAK BERNAM, SELANGOR, PENINSULAR MALAYSIA

Species D SE %CV (%) EDR EDR %CV (%) 0.76 × 10-1 0.12 × 10-1 15.84 94.29 5.04

Sunda Scops-owl 1.53 × 10-1 0.26 ×10-1 16.97 62.543 6.88 Barn Owl 0.50 × 10-1 0.11 ×10-1 22.29 56.52 6.02 Large-tailed Nightjar 7.94 × 10-1 1.08 ×10-1 13.65 31.13 1.76

TABLE 3. ABUNDANCE OF NOCTURNAL BIRDS IN OIL PALM SMALLHOLDINGS IN BANTING, TANJUNG KARANG AND SABAK BERNAM, SELANGOR, PENINSULAR MALAYSIA

Species A SE %CV 95% CI 395 62.574 15.84 290 538 Sunda Scops-owl 797 135.27 16.97 573 1 110 Barn Owl 263 58.624 22.29 171 406 Large-tailed Nightjar 4 131 563.73 13.65 3 164 5 394

61 JOURNAL OF OIL PALM RESEARCH 32 (1) (MARCH 2020)

CONCLUSION smallholdings and logged peat swamp forest for birds. : 2306-2315. are able to support high densities of some native nocturnal birds. Yet, species that are associated with forests remained low in number. It is believed that, oil palm smallholdings with higher level of habitat complexity may be able to provide a wide range of in situ habitat quality food sources as well as roosting and/or breeding and landscape characteristics in the oil palm sites for the nocturnal birds (Yahya et al., 2016). It is agricultural matrix on tropical understory birds, fruit also believed that the existence of nocturnal birds in Biodiver. Conserv., : 3125- such landscape may be potentially useful to oil palm 3144. smallholders with respect to biological control of vertebrate and invertebrate pest species (Yahya et al., 2016). of point count sampling regimes for monitoring forest birds. Monitoring Bird Populations by Point Counts. ACKNOWLEDGEMENT US Department of Agriculture. individuality of Large-tailed Nighjar (Caprimulgus macrurus) in Peninsular Malaysia. Bioacoustics, ). Selvadurai, Nur Fatin Adila Md Rashid, Raja https://doi.org/10.1080/ 09524622.2017.1292408 thank the land owners for allowing us to conduct : A technique to monitor funded by the Ministry of Education Malaysia under long‐term adult turnover and residency. Ibis, the Fundamental Research Grant Scheme (Project : 30-39. No.: 07-01-13-1184FR) and Universiti Putra Malaysia under the Research University Grant Scheme (Project Gerhardt, R P (1991). Response of Mottled owls to No.: 03-01-11-1151RU). : 239- 244.

REFERENCES Hasber, S (2016). Propagation of barn owls in an oil polyculture farming in oil palm smallholdings on palm plantation of Sabah: FGV’s Experience. Proc. terrestrial arthropod diversity. J. Asia Pac. Entomol., th : 415-421. th 237 pp. Owl, Tyto alba Malaysia. ACIAR Monogr. Ser., 96: 274-276. (2013). Preliminary estimation of nocturnal bird density in oil palm agroecosystem. Hausleitner, D and Bio, R P (2006). Inventory Methods . (Lai, F S; Halis, R; Bakar, S N A; Ramachandran, S and . Ecosystem Branch Puan, C L eds.). Faculty of Forestry, Universiti Putra of the Ministry of Environment for the Resources Malaysia, Serdang, Selangor, Malaysia. p. 50-53. Information Standards.

Atikah, S N; Yahya, M S; Puan, C L; Zakaria, M and Species. Version 2018-2. http://www.iucnredlist.org, persist in oil palm agroecosystem? : accessed on 14 November 2018. 127-134. Surveys of nocturnal birds at Bala rainforest, southern Manning, A; Mcelhinny, C and Zakaria, M (2011). 117-124.

62 DENSITY AND DIVERSITY OF NOCTURNAL BIRDS IN OIL PALM SMALLHOLDINGS IN PENINSULAR MALAYSIA

Vol. 12. Christopher Research Station, Albany, New York. 191 pp. Helm Publishers Incorporated. 462 pp. Robson, C (2011). East Asia. New Holland. London. 544 pp. - Selangor weather forecast. http://www.met.gov. my/web metmalaysia/forecasts/general/districts., accessed on 12 Jun 2018. rodenticide on growth of nestling barn owl, Tyto alba Growth performance of nestling barn owls, Tyto alba in oil palm plantations. J. Oil Palm Res. Vol. in rat baiting area in Malaysia. : 16-25. Agric. & Biol., Sci., 5: 1-13. (2016). Home range and activity patterns of Sunda Responses of tropical fruit bats to monoculture and scops-owl in Peninsular Malaysia. : polyculture farming in oil palm smallholdings. Acta 28-32. Oecol., 74: 11-18.

(2002). Ecology and conservation of owls. . Canberra, Australia. CSIRO D (2001). Publishing, Canberra. 400 pp. . Edmonton: Beaverhill Bird Conservatory and Bird Studies Canada. 36 pp. biological control program for rodent management Rodent Biology and Management (Singleton, G R; Strindberg, S; Hedley, S L; Bishop, J R B; Marques, Australia Centre for International Agricultural Design and analysis of distance sampling surveys Research, Canberra. p. 251-253. J. Appl. Ecol., : 5-14. M (2018). Sunda scops-owl density estimation via distance sampling and call playback. Sains Malays., Vol. 1. Academic Press, : 441-446. London. 648 pp. predation on rats by Malaysian barn owls in oil palm plantations. J. Raptor Res., : 71-78. relation to habitat heterogeneity in small scale oil palm agriculture in Malaysia. Agric. Ecosyst. & Environ., 233: 140-146. an ecologically-based agricultural practice. Ornis Mongolia, 1: 63-66. in oil palm production landscapes: Evidence from Puan, C L (2013). Integrating Ecology into Rodents Pest mist-netting data. : 6314-6325. Management in Oil Palm Agroecosystem. University DOI:10.1002/ece3.3205. Putra Malaysia Press, Serdang, Selangor, Malaysia. 100 pp. Vocal individuality of Sunda scops-owl ) in Peninsular Malaysia. 379-390. assemblages in Malaysian Borneo. : 82-86. Ralph, C J and Sauer, J R (1995). Monitoring and duet calls of three Malaysian owl species. Sains Bird Populations by Point Counts. Department of : 1439-1445.