Estimating seasonal abundance and habitat use of small carnivores in the Western Ghats using an occupancy approach

2014 ◽  
Vol 30 (5) ◽  
pp. 469-480 ◽  
Author(s):  
Riddhika Kalle ◽  
Tharmalingam Ramesh ◽  
Qamar Qureshi ◽  
Kalyanasundaram Sankar

Abstract:Rigorous population studies on many small carnivores are lacking in India. Presence-absence models with habitat covariates were applied to estimate seasonal occupancy and abundance of nine small-carnivore species from camera-trap data in Mudumalai Tiger Reserve (2010 and 2011). We deployed 25 camera-trap stations in the deciduous forest, 21 in the semi-evergreen forest and 26 in the dry thorn forest. In total, 7380 trap-nights yielded 448 photographs of small carnivores: jungle cat (n = 72), leopard cat (n = 6), rusty-spotted cat (n = 11), small Indian civet (n = 89), common palm civet (n = 37), brown palm civet (n = 20), stripe-necked mongoose (n = 66), ruddy mongoose (n = 96) and Indian grey mongoose (n = 51). In the dry season, rusty-spotted cat was the rarest carnivore with an average abundance (λmean) of 0.24 ± 0.26, while ruddy mongoose was the most abundant (λmean = 0.90 ± 0.40). In the wet season, leopard cat was the rarest species (λmean = 0.048 ± 0.041) while grey mongoose was the most abundant (λmean = 0.68 ± 0.35). Abundance of jungle cat, common palm civet, ruddy mongoose and grey mongoose increased in the dry thorn forest whereas in the dry season abundance of small Indian civet decreased in this forest type. Abundance of leopard cat and small Indian civet was not influenced by habitat in the wet season. Deciduous forest was positively associated with abundance of rusty-spotted cat. Deciduous and semi-evergreen forests had a positive effect on abundance of stripe-necked mongoose while the latter was a positive predictor of abundance and occupancy for brown palm civet. Improved modelling approaches can account for the spatio-temporal variation in habitat use of small carnivores occupying specialized niches in heterogeneous tropical forests of southern India.

1980 ◽  
Vol 70 (4) ◽  
pp. 621-633 ◽  
Author(s):  
W. W. Page

AbstractAn investigation into the seasonal abundance of Zonocerus variegatus (L.) around Ibadan, Nigeria, showed that hatching occurs between October and March and peak abundance is in late November. Adults occur almost throughout the year. Oviposition takes place between March and October or possibly November, with a peak in April. Eggs laid in March and April hatch in October and November after a diapause, while those laid from June onwards do not appear to enter diapause. Thus eggs laid in June and July hatch at the same time as those laid in March and April. Parasitism by the sargophagid fly Blaesoxipha filipjevi (Rod.) during March and April results in a rapid decline in adult numbers which may be followed by a secondary peak in adult numbers when nymphs, which are present at the same time and are rarely parasitised, reach adult stage. Oviposition resulting from such a peak does not produce a secondary peak in hatching as this coincides with hatching from earlier layings. The fungus Entomophthora grylli plays an important role in controlling the abundance of nymphs and adults during the dry season despite the intermittent nature of the attacks. During the wet season, the fungus is able to germinate and disperse more readily, thus keeping the numbers of the insects low. It is concluded that there is one generation of Z. variegatus a year, with a peak in population coinciding with the dry season (November-March). It is suggested from the results that the grasshopper may have originated in the semi-arid zones of the north.


2008 ◽  
Vol 98 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Carlos S. Filho ◽  
Claudia H. Tagliaro ◽  
Colin R. Beasley

Shipworms are important decomposers of wood, especially in mangrove forests where productivity is high. However, little emphasis has been given to the activity of shipworms in relation to the export of nutrients from mangroves to adjacent coastal areas. As a first step to obtaining such information, the frequency of colonized mangrove driftwood as well as shipworm density and length were studied by collecting washed up logs during a year at Ajuruteua beach, state of Pará, northern Brazil. A single species, Neoteredo reynei (Bartsch, 1920), was found colonizing driftwood. Although large colonized logs were most common on the beach, shipworm density was higher in small logs, especially during the dry season. In general, however, density was higher during the wet season (January to April) and lowest in July. Overall shipworm mean length was 9.66cm. In large logs, mean length increased between the wet and dry seasons. However, there was no difference in length among log size categories. Mean shipworm length was similar throughout most of the year but tended to be greater in July. Although salinity varied between 10.9 and 40 during the year, no relationship was found between salinity and density or length. The results suggest that shipworm activity in driftwood logs is relatively constant throughout the year. Increased air humidity and rainfall may promote survival during the wet season. Large logs may take longer to colonize and thus have lower densities than small ones which are scarce probably because they are destroyed rapidly by shipworm activity. However, data on the disintegration of logs would be necessary to test this hypothesis. Larger size of shipworms in the dry season may be related to growth after an earlier recruitment period. Shipworms in large logs during the dry season may be better protected from dessication and high temperatures by the insulating properties of the larger volume of wood.


2005 ◽  
Vol 21 (4) ◽  
pp. 451-460 ◽  
Author(s):  
Eduardo Jacusiel Miranda ◽  
George L. Vourlitis ◽  
Nicolau Priante Filho ◽  
Pedro Correto Priante ◽  
José Holanda Campelo ◽  
...  

The photosynthetic light response of Amazonian semi-deciduous forest trees of the rain forest–savanna transition near Sinop Mato Grosso, Brazil was measured between July 2000 and September 2003 to test the hypothesis that the photosynthetic capacity of trees acclimated to different growth light environments will decline during the dry season. Maximum photosynthesis (Amax) and stomatal conductance (gmax) were significantly higher during the wet season; however, the physiological response to drought was not a clear function of growth light environment. For some species, such as Psychotria sp. growing in the mid-canopy, internal leaf CO2 concentration (Ci) was >30% lower during the dry season suggesting that declines in Amax were caused in part by stomatal limitations to CO2 diffusion. For other species, such as Brosimum lactescens growing at the top of the canopy, Tovomita schomburgkii growing in the mid-canopy, and Dinizia excelsa growing in the understorey, dry season Ci declined by <20% suggesting that factors independent of CO2 diffusion were more important in limiting Amax. Dry-season declines in gmax appeared to be important for maintaining a more consistent leaf water potential for some species (T. schomburgkii and D. excelsa) but not others (Psychotria sp.). These results indicate that while seasonal drought exerts an important limitation on the physiological capacity of semi-deciduous Amazonian forest trees, the mechanism of this limitation may differ between species.


2002 ◽  
Vol 36 (3) ◽  
pp. 487-490 ◽  
Author(s):  
C. M. Gienger ◽  
Daniel D. Beck ◽  
Nathan C. Sabari ◽  
Della L. Stumbaugh

2019 ◽  
Vol 11 (13) ◽  
pp. 14631-14642 ◽  
Author(s):  
Paris N. Marler ◽  
Solomon Calago ◽  
Mélanie Ragon ◽  
Lyca Sandrea G Castro

A camera trap survey was conducted in the recently protected Cleopatra’s Needle Critical Habitat (CNCH) in Puerto Princesa City, Palawan, Philippines from February to May 2015 at 39 camera trap sites.  A bait of common pig’s blood was used at 36 sites, while the three remaining sites were surveyed without a bait and monitored a stream with a latrine site or mud bath with tracks.  Seven native species were detected and three of these species were endemic to the island province.  Species included: Common Palm Civet Paradoxurus philippinensis, Palawan Porcupine Hystrix pumila, Collared Mongoose Urva semitorquata, Palawan Stink Badger Mydaus marchei, Palawan Leopard Cat Prionailurus bengalensis heaneyi, Asian Small-clawed Otter Aonyx cinereus, and Malay Civet Viverra tangalunga.  Analysis of the activity patterns of the three most commonly captured species revealed predominantly nocturnal activity for the Common Palm Civet, Palawan Porcupine, and Palawan Stink Badger.  The Philippine Palm Civet showed occasional diurnal activity.  The seven photo-captured species appeared most common, or were at the least recorded, below 750m.  Five species (the Philippine Palm Civet, Palawan Porcupine, Collared Mongoose, Palawan Stink Badger, and Palawan Leopard Cat) were also recorded above 1000m.  The CNCH supports two threatened species, the Palawan Porcupine and the Asian Small-clawed Otter, which are listed as Vulnerable by the IUCN, and the Collared Mongoose is listed as Near Threatened.  The Palawan Leopard Cat is considered Vulnerable within the Philippines, although it has yet to be assessed by the IUCN.  This documentation highlights the biodiversity significance within the newly protected critical habitat and the need to support ongoing conservation efforts within the critical habitat.   


The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 132-148 ◽  
Author(s):  
John G. Blake ◽  
Bette A. Loiselle

AbstractWe used capture and recapture data (1985 to 1994) to examine seasonal variation in habitat use, movements within and among habitats, and survival rates of manakins (Manacus candei, Corapipo altera, Pipra mentalis, P. pipra) in northeastern Costa Rica. Manakins were captured in young and old second-growth woodlands in the lowlands and in old-growth forest at approximately 50, 500, and 1,000 m. Manakin species differed in their use of habitats, with old-growth forest species showing large and predictable seasonal variation in capture rates. Corapipo capture rates in lowland (nonbreeding) habitats were greater during the wet season than during the dry season and were greater in old-growth forest than in second growth. Capture rates at 500 m were higher in the dry season. Pipra mentalis capture rates were high in second growth and old growth. Capture rates were higher in the wet season and were correlated with capture rates of Corapipo, indicating that at least some individual P. mentalis migrate along the elevational gradient. P. pipra capture rates were highest at 1,000 m; few individuals descended to lowlands in the wet season. Manacus capture rates were highest in young second growth and did not vary between wet and dry seasons. Use of second-growth habitats by species typically associated with old-growth forests illustrates the value of maintaining a mosaic of habitats to accommodate seasonal changes in use of habitats. Contrary to expectations based on lek mating systems, there was little evidence that movements within habitats (i.e. recapture distances) varied between sexes. Yet, recapture percentages were higher in all species for adult females than males. Adult survival rates were ∼0.75 for Manacus in young second growth, 0.62 for Corapipo in old-growth forest at 50 m and 0.66 at 500 m, and 0.70 for Pipra mentalis in lowland old-growth forest. Results support the suggestion that geographic variation in survival rates may be common in the tropics and illustrate the need for examining survival rates separately by age and sex.


2002 ◽  
Vol 80 (8) ◽  
pp. 818-826 ◽  
Author(s):  
T S Suryanarayanan ◽  
T S Murali ◽  
G Venkatesan

Fungal endophytes occur in leaves of angiosperm and gymnosperm trees. The occurrence and distribution of fungal endophytes in the leaves of trees growing in four different types of tropical forests in the Western Ghats were studied. One thousand five hundred leaf segments from five different hosts were screened for each forest type. Endophyte communities of trees of the semi-evergreen forest showed the highest species diversity. More endophyte isolates were recovered during the wet season. Although several genera of endophytes were common for different hosts growing in different forests, the dominant endophyte was different for different forest types. Our results suggest that although tropical trees individually may be endophyte rich, the overall endophyte diversity of the entire plant community is not exceptional.Key words: tropical forests, fungal endophytes, fungal diversity, foliar endophytes.


2017 ◽  
Vol 38 (4) ◽  
pp. 547-553 ◽  
Author(s):  
Paola De la Quintana ◽  
Jesús A. Rivas ◽  
Federico Valdivia ◽  
Luis F. Pacheco

Understanding of snake ecology has increased over the past two decades, but is still limited for many species. This is particularly true for the recently described Beni anaconda (Eunectes beniensis). We present the results of a radio-telemetry study of nine (3M:6F) adult E. beniensis, including home range, and habitat use. We located the snakes 242 times in wet season, and 255 in dry season. Mean wet season home range (MCP) was 25.81 ha (6.7 to 39.4 ha); while mean dry season home range was 0.29 ha (0.13 to 0.42 ha). We found no relationship between home range size and either snout-vent length, weight, or sex. Beni anacondas seem to prefer swamps, and patujusal, while avoiding forest, and rice fields. However, habitat use by individual snakes seems to vary based on the habitats available within their respective home range. Notably, rice fields were avoided by most snakes, which suggests that this type of habitat is unsuitable for anaconda management.


1997 ◽  
Vol 24 (5) ◽  
pp. 549 ◽  
Author(s):  
C. N. Johnson ◽  
A. P. McIlwee

The diet and seasonal ecology of the northern bettong, Bettongia tropica, was studied at three sites along a moisture gradient from closed Allocasuarina-Eucalyptus forest to dry open woodland in north-eastern Queensland. At each site, fungi (sporocarps of hypogeous ectomycorrhizal species) were the major food, and most of the remainder of the diet consisted of grass leaf and stem, roots and tubers, and lilies. Forbs and invertebrates were also eaten, but in small quantities. Fungus consumption was greatest at the wettest forest type and least at the driest site. Seasonal variation was insignificant except at the driest site, where fungus consumption peaked in the late wet season and dropped during the dry season; this seasonal fall in fungus consumption was associated with an increase in consumption of grass and roots and tubers. There was little seasonal variation in body condition, except at the driest site, where the dry-season decline in the proportional representation of fungus in the diet was associated with a decline in body condition. Breeding was continuous and aseasonal. B. tropica is found only in a narrow zone of sclerophyll forest along the western edge of wet tropical rainforest in north-eastern Queensland. We suggest that this species (like bettongs and potoroos in southern Australia) depends on hypogeous fungi, and that expansion of its geographical range into drier forest types is prevented by shortages of fungus during the dry season.


2021 ◽  
Vol 948 (1) ◽  
pp. 012033
Author(s):  
R Nugraha ◽  
A A Andriyani ◽  
S N Marliana

Abstract The population of the bear cuscus Ailurops ursinus (Temminck, 1824), an arboreal marsupial endemic to Sulawesi, Indonesia, and its satellite islands, is declining rapidly due to poaching and habitat loss, even in protected areas. However, despite concerns over its persistence, little is actually known of this secretive species. This research investigated the characteristics of the selected habitats and diet of the bear cuscus in four ecosystem types (lowland non-dipterocarp forest, lowland limestone forest, lowland monsoon deciduous forest, lowland monsoon evergreen forest). Habitat use data were collected through direct encounters and indirect observations (tracks, signs, secondary information), and analyzed using a chi-square goodness-of-fit test. Habitat characteristics and diet availability were determined using vegetation analysis. Diet data were obtained using direct observations, feed remains, and interviews. The lowland non-dipterocarp forest ecosystem was used significantly more by bear cuscus populations. Its habitats across the four ecosystem types had similar environmental conditions. Fifty-five plant species, eaten mostly as young leaves and leaf buds, encompassed the bear cuscus’ diet, with the Moraceae family being the most representative. Considering the ubiquity of Moraceae in the bear cuscus’ habitat, these results highlight the impact unchecked deforestation will continue to have on lowland Indonesia and its endemic species.


Sign in / Sign up

Export Citation Format

Share Document