Nest Census Research Articles

Evaluasi Sebaran Rayap Di Perkebunan Kelapa Sawit Pada Jenis Tanah Yang Berbeda

Termites are one of the pests in oil palm plantations that can cause physical damage to oil palm plants. This study aims to determine the type and colony of termites in mineral, peat and sandy soils and the effectiveness of their control. This research was conducted at PT. Binasawit Abadipratama located in Danau Seluluk District, Seruyan Regency, Central Kalimantan Province, Tangar Estate from March to April 2023. The research was conducted using a comparative method by comparing termite colonies in mineral soil, peat and with parameters in the form of termite species and the level of attack expressed by scoring, as well as secondary data in the form of termite nest census data in the garden archive to determine the effectiveness of control. The results showed that the largest termite colony was found in mineral soil. Termite species found in all soil types was Macrotermes gilvus, and no indication of termite infestation in oil palm trees. Based on the census data for the past three years, it can be concluded that the control that has been carried out is effective in reducing the termite colony from year to year.

Live-trapping in the stalk zone of tall grasses as an effective way of monitoring harvest mice (Micromys minutus)

The harvest mouse (Micromys minutus) is understudied compared to other small mammals as a result of its small size and scansorial habits. This study in wetlands dominated by common reed (Phragmites australis) compared nest census, a commonly used technique to confirm presence/absence and monitor populations, with live-trapping using Longworths and a home-made alternative trap (the Jordan trap) set both on the ground and in the stalk zone (∼1 m from ground or water level). Nests were found at only two of the four study sites, which may have suggested an absence of the species. However, harvest mice were caught in traps at all sites. All 108 captures of 39 individuals were made in aerial traps in the stalk zone with none caught in ground traps. Generalised linear mixed model (GLMM) also showed that significantly more captures were made in Longworth traps compared to the Jordan trap, although the efficiency of the latter increased after modification. There were also significant differences in capture rate between sites and season and a preference for higher reed quality as described by PCA in the wetter areas of the reed-beds studied. We conclude that live-trapping is preferable to nest census as a population monitoring technique and that future studies of harvest mice, especially in tall wetland vegetation, should use Longworth traps and/or cheaper home-made alternatives set in the stalk zone.

The accuracy of urban nesting gull censuses

Capsule The vantage point survey methods used in the 1999–2002 surveys of urban nesting large gulls in Britain and Ireland appreciably underestimated numbers, resulting in lower national totals and exaggerated national population changes, because they did not account for a substantial proportion of undetected nests.Aims To evaluate the efficiency of various survey methods for urban nesting large gulls.Methods Vantage point and street surveys of Herring and Lesser Black-backed Gulls Larus argentatus and Larus fuscus nests were made in six urban conurbations and used to compare detection efficiencies. Some nests missed by both methods were later identified by the presence of unfledged chicks. In later years, the numbers of nests which were actually missed was determined by using a ‘cherry-picker’ which allowed all nests to be located in Dumfries. The proportion of nests on industrial and commercial buildings was recorded.Results Vantage point and street surveys missed an appreciable number of nests and had average maximum nest detection rates of 78% and 48%, respectively. Combining the two methods raised the efficiency to a maximum of 88%. The detection rate varied inversely with the proportion of nest sites that were on commercial or industrial sites. The complete census of nests in Dumfries in 2013–14 showed that vantage point surveys detected only 75% of nests, while the combination of the two survey methods increased the detection rate to 84%.Conclusion Vantage point surveys markedly underestimate numbers of nesting large gulls. Surveys were less effective on conurbations where nesting gulls used a high proportion of industrial and commercial properties. Therefore the 1999–2002 national surveys in Britain and Ireland underestimated the numbers of urban nesting Herring and Lesser Black-backed Gulls and, as a result, may have exaggerated the national trends in abundance of both species. More intensive methods are required in surveys of urban nesting gulls and correction factors need to be established from very high vantage points by use of cherry-pickers or aerial surveillance.

Two-fold increase in White Stork (Ciconia ciconia) population in Lithuania: a consequence of changing agriculture?

A countrywide White Stork (Ciconia ciconia) nest census was carried out in Lithuania in 2009 and 2010 by over 20 observers using standardised equipment and methods. The census revealed that the White Stork population has doubled since the previous census in 1994, possibly due to favourable changes in farming practices, with birds increasingly settling on the overhead electricity line poles and gradually abandoning nests in trees. In total, 21,192 White Stork nests were recorded, of which 18,782 (81.4%) were occupied by breeding birds, compared to 9400 occupied nests recorded in 1994. The mean density of occupied nests in the country was 29 nests/100 km2. Electricity line poles were the most common nest sites (49% of all nests), followed by trees (21%) and specially erected poles with nesting platforms (11%). Mean breeding success of White Storks was rather high, with 2.7 young raised per successful pair, suggesting a favourable conservation status for this species in Lithuania.

Effects of temperature on the host preference of pine processionary caterpillar Thaumetopoea wilkinsoni Tams, 1924 (Lepidoptera: Notodontidae)

The work reported here analyzes the effects of temperature on host consumption and preference of eastern pine processionary caterpillar Thaumetopoea wilkinsoni (Lepidoptera: Notodontidae). Nest censuses were taken in the field and food choice tests were conducted in the laboratory. Two pine species (Pinus nigra and P. brutia) were considered. Caterpillars hatched on both pine species were collected and included in experiments that were conducted under 4 different temperature regimes (15, 20, 25, and 30 °C). Needles of both pine species were offered as food. Results showed that increasing the temperature caused an increase in the feeding amount of the caterpillars and also a blurring effect on preference. Early instar diet was found to have effects on late instar diet.

The Influence of Seasonal Variation on Chimpanzee (Pan troglodytes schweinfurthii) Fallback Food Consumption, Nest Group Size, and Habitat Use in Gishwati, a Montane Rain Forest Fragment in Rwanda

The increased number of primates living in fragmented habitats necessitates greater knowledge of how they cope with large-scale changes to their environment. Chimpanzees (Pan troglodytes) are exceptionally vulnerable to forest fragmentation; however, little is known about chimpanzee feeding ecology in fragments. Although chimpanzees have been shown to prefer fruit when it is available and fall back on more abundant lower quality foods during periods of fruit scarcity, our understanding of how chimpanzees use fallback foods in forest fragments is poor. We examined how chimpanzees cope with periods of fruit scarcity in Gishwati Forest Reserve, a disturbed montane rain forest fragment in Rwanda. We assessed seasonal changes in chimpanzee diet and the use of preferred and fallback foods through fecal and food site analysis. We also examined seasonal variation in nest group size and habitat use through marked nest censuses. We found that chimpanzees experienced a seasonal reduction in preferred fruit availability, which led to a seasonal diet shift to more fibrous foods, including several that functioned as fallback foods. Our results suggest that during periods of fruit scarcity the chimpanzees also reduced nest group size. However, we found that the chimpanzees did not alter their habitat use between high- and low-fruit seasons, which suggests that the small size of the forest limits their ability to change their seasonal habitat use. Consequently, fallback foods appear to be particularly important in small food-impoverished habitats with limited ranging options.

Bioko: critically important nesting habitat for sea turtles of West Africa

We evaluate the conservation status and threats faced by sea turtle nesting populations at Bioko Island, Equatorial Guinea (Central Africa). Beaches were monitored to obtain a detailed sea turtle nest census and, where possible, tagging of adult females was undertaken. Four sea turtle species were found nesting in the area: the green turtle (Chelonia mydas), the leatherback (Dermochelys coriacea), the olive ridley (Lepidochelys olivacea) and the hawksbill (Eretmochelys imbricata); with the former two species nesting in regionally important numbers. Nesting activity was concentrated between November and February, with a peak in December-January. Tagging and recapture of green turtles in two consecutive seasons suggested an estimated 560 (interquartile range: 420-1,681) and 414 (interquartile range: 190-1,255) nesting females in the area, respectively. Estimated numbers of nesting leatherbacks ranged from 123 to 215 and 243 to 293 in the first and second season, respectively. The other two species were less abundant (olive ridley: 19-29 and 28-43; hawksbill: 4-10 and 2 turtles). Data were compared with more recent surveys in the area and contextualised with information on human related threats. Despite the size of nesting stocks, ongoing permitted and illegal take of adult turtles at the nesting site constitutes a serious threat for these breeding aggregations. Additionally, tag returns from throughout the Gulf of Guinea suggest that the level of take in regional fisheries may also be a major threat.

Survival of female common eiders Somateria m. mollissima in a declining population of the northern Baltic Sea

In long-lived species, adult survival is the population parameter having the highest elasticity, and therefore, it can be expected to be least affected by climatic variations. We studied the dynamics and survival of breeding female common eiders Somateria mollissima mollissima in the Baltic Sea from 1960 to 2007. Using nest censuses and capture-recapture methods, we investigated: (1) the annual apparent survival (phi) of breeding females, (2) the survival-mediated population fluctuation, (3) weather effects on survival, and (4) long-term population trends. Based on capture histories of 6,393 females, average phi was 0.882 (95% confidence interval 0.864, 0.899). We found no relationship between population growth rate and survival. Furthermore, the highest ranking models, based on Akaike's information criterion, indicated no effect of the North Atlantic Oscillation index on the phi of eider females. Population size, assessed from nest counts, has been steadily declining since 1985. Despite the long time series (48 years), the overall variation in the phi rates remained comparatively narrow, at maximum ranging only 10% between 2 consecutive years. Results imply that declining female survival is not the driving force behind the population decline, and we hypothesize that the overall poor fledging success and the consequent low recruitment explain the decreasing trend of nest densities since 1985.

Nest connectivity and colony structure in unicolonial Argentine ants

Unicolonial ant colonies occupy many nests and individuals rarely show aggression across large geographic distances. These traits make it difficult to detect colony structure. Here we identify colony structure at scales of hundreds of square-meters, within an invasive population of unicolonial Argentine ants. In experiments using labeled food, and in a 3-year census of nests and trails, we found that food was shared and nests were linked by trails at distances up to 50 meters. Food was not distributed to all nearby Argentine ant nests, showing that ants tend to share resources within a spatially bounded group of nests. The spatial extent of food sharing increased from winter to summer. Across different habitats and nest densities, nests were consistently aggregated at spatial scales of 3- 4 meters in radius. This suggests that new nests bud from old nests at short distances regardless of local conditions. We suggest that a ‘colony’ of Argentine ants could be defined as a group of nests among which ants travel and share food. In our study population, colonies occupy up to 650 m2 and contain as many as 5 million ants. In combination with previous work showing that there is genetic differentiation among nests at similar spatial scales, the results suggest that Argentine ant populations do not function ecologically as single, large supercolonies, but instead as mosaics of smaller, distinct colonies consisting of groups of interacting nests.

Sleeping Parties and Nest Distribution of Chimpanzees in the Savanna Woodland, Ugalla, Tanzania

We conducted ecological studies of chimpanzees (Pan troglodytes) in the Ugalla area, western Tanzania. Ugalla is one of the driest habitats of chimpanzees and the Ugalla River is the eastern boundary of chimpanzee distribution. Most of Ugalla is occupied by savanna woodlands dominated by deciduous trees of Brachystegia and Julbernardia. Chimpanzees tended not to make nests in riverine forests in plains, but in small patchy forests dominated by Monopetalanthus richardsiae and valley forests dominated by Julbernardia unijugata on slopes in mountainous areas. We estimated population density of chimpanzees to be 7–9 × 10−2 individuals/km2 based on nest censuses, suggesting that 2–3 × 102 individuals inhabited the 3352 km2 area of Ugalla. The size of the largest nest cluster (n=23) suggests that 1 unit group (community) comprised 30–35 individuals. In the daytime, chimpanzees formed small feeding parties (mean 2.0 individuals), but larger ones in the evening (mean 4.8 individuals and 5.2 individuals based on fresh nest clusters). The pattern might reduce the predation risk from large nocturnal carnivores such as lions and leopards. The sleeping sites may function as both a safe sleeping site and a meeting point for chimpanzees with a huge home range that may have difficulty in finding other members of their unit group.

Orangutan Nesting Behavior in Disturbed Forest of Sabah, Malaysia: Implications for Nest Census

High concentrations of orangutans remain in the multiple-use forests of the Lower Kinabatangan, Sabah, Malaysia. Compared to primary forest, the habitat is highly fragmented, characterized by a low tree density (332 stems/ha), small tree size (83.6% of trees are <20 m high), low basal area (18 m2/ha), abundance of canopy gaps and high level of soil disturbance. The forest structure and composition influence orangutan nesting patterns, and thus directly influence the results of nest surveys used to determine orangutan population size. In logged forests, tall and large trees are the preferred nesting sites of orangutans. The scarcity of suitable nesting sites in the logged-over forests of Kinabatangan, could partly explain the lower daily rate of nest construction (r = 1.00) versus those of other orangutan populations. The nest decay rate t recorded at the study site (average ± SD = 202 ± 151 days) strongly depends on the species of tree in which a nest is built. Our results illustrate that the nest-related parameters used for orangutan censuses fluctuate among habitat types and emphasize the need to determine specific values of r for specific orangutan populations and of t for different tree species in order to achieve accurate analysis of census data.

The effects of human disturbance on a stingless bee community in a tropical rainforest

Human disturbance of tropical rainforests may change pollinator communities indirectly as a result of changes in resource availability. We studied the mechanisms by which human disturbance affects a community of major pollinators, stingless bees, in Sarawak, Malaysia. We surveyed forest structure and flowering activity, and conducted a nest census and a bait-trap survey of stingless bees, both in primary forests and in forests disturbed by logging and shifting cultivation. The densities of late successional trees and large trees (diameter at breast height >50 cm) were higher in the primary forests than in the disturbed forests. The density of flowering trees was lower one year after logging, but recovered in old disturbed forests because of the active flowering of pioneer trees that became established after the disturbance. Stingless bees nest only in large trees, and nest density was positively correlated with the density of large trees. However, we found no relationship between the numbers of foragers and floristic parameters. Some species preferred nesting in dipterocarps, while others preferred dead trees. The results of the bait-trap survey also indicated that some species were abundant in the primary forests, whereas other species were abundant in the disturbed forests. These results suggest that human disturbance alters the species composition of the stingless bee community. Such changes in the bee community may affect the reproductive success of plants, and ultimately forest composition.

Chimpanzee Habitat in the Savanna Woodland, Ugalla, Tanzania

Ecological study of wild chimpanzees (Pan troglodytes schweinfurthii) has been conducted in Ugalla area, western Tanzania. Ugalla is one of the driest habitats of chimpanzees. Also, Ugalla River is the eastern boundary of chimpanzee distribution. This area covers 2, 800km2 with elevation from 1, 100m to 1, 600m. The majority of Ugalla area is deciduous woodland dominated by Brachystegia sp. and Julbernardia sp. (‘Miombo’ in local name). Woodland dominated by B. bussei is formed in mountainous areas. Two types of evergreen forests were also formed in mountainous areas. One is a small patchy forest dominated by Monopetalanthus richadsiae (Kabamba-jike) on a hill or beside a cliff, and the other is a kind of riverine forest dominated by Julbernardia unijugata (Kabamba-dume) along a steep valley. During the dry season, chimpanzees frequently used these forests as sleeping sites, and B. bussei woodland as feeding sites. Nest census showed that the population density of chimpanzees in Ugalla was 0.05 individual/km2, although the density of mountainous areas was higher than that of flat areas. Four or five communities (unit groups) each of which has approximately 30 individuals may inhabit the Ugalla. The both estimations indicate that the total number of 120-150 chimpanzees inhabit this area. If several communities divide the whole Ugalla area, each community should have a huge home range. For a certain period, however, chimpanzees might be ranging in a small part of their annual home range, and seasonally shift such areas. In the daytime, chimpanzees formed a small feeding party to exploit poor and sparse food resources. On the other hand, they formed a larger sleeping party at night, because of high predation pressure of large carnivores. Understanding such chimpanzee adaptation to dry and open habitat in the savanna woodland can shed light onto behavioral ecology of early hominid. Besides seven species of primates including chimpanzees inhabit the Ugalla area. Other large and middle-sized mammals and rodents in Ugalla are also listed in tables of this report.

1991 White Pelican and Double-Crested Cormorant Nest Census in Saskatchewan

1991 White Pelican and Double-Crested Cormorant Nest Census in Saskatchewan

Census of gorillas in northern Republic of Congo.

We censused gorilla populations in northern Congo from February to April 1989 and June 1990. The objective was to provide the first quantitative data from a variety of sites on gorilla populations from a country that had unknown but potentially high populations. The method used was a census of nests along strip transects. A total of 401.0 km of transects was sampled in four different study areas. The overall density calculated for all transects was 0.4 nesting gorillas/km2. The highest density, 1.2 nesting gorillas/km2, was found in the vast Likouala swamp area of north central Congo. The two northern sites showed low densities of 0.1 and 0.2 nesting gorillas/km2, respectively. The northwestern site showed an intermediate density of 0.6 nesting gorillas/km2. The vegetation type with the highest density was swamp forest with 2.4 nesting gorillas/km2. The limited sample presented shows that gorillas are widespread and common in northern Congo, even in the swamp forests previously considered unsuitable as gorilla habitat. It is probable that Congo holds the largest population of gorillas in Africa after Gabon. © 1992 Wiley-Liss, Inc.

Spatial patterns of granivorous ant nest abundance and nest site selection in agricultural landscapes of Central Spain

Patterns of abundance and site selection of granivorous ant nests were investigated in extensive cereal croplands of Central Spain. Nest densities and distributions were measured in two consecutive summers (1988 and 1989), together with habitat physiognomy and seed availability. Nest site selection patterns were analysed at two spatial scales (landscape and microhabitat) with respect to habitat physiognomy. Results indicate a very constant and predictable pattern of both nest abundance and nest site selection. Granivorous ant nests were most abundant in shrublands, and shrubby microsites were selected for nest placement. Croplands, and microsites with high covers of bare ground and litter, were avoided. These patterns were consistent between years despite a 1.7-fold increase in shrubland nest densities, that was attributed to the exceptionally dry winter between nest censuses. I suggest that winter survivorship of ant nests in the unploughed landscape units, and periodic ploughing in croplands, may be the main factors constraining granivorous ant densities in the landscape studied.

Colony attendance and censusing of Black GuillemotsCepphus gryllein Shetland

The diurnal rhythm of colony attendance by Black Guillemots varied seasonally. No tidal effects were detected but in April attendance was lower when winds exceeded force 4. Numbers were most stable during 05.00–08.00 GMT in the pre-breeding period. Counts at this time and in winds of force 4 or less provide the best estimate of adult populations. Between late March and mid-May, counts of adults associated with breeding habitat account for most birds occupying suitable nest sites and censuses in northern Britain should be conducted in this period. As the proportion of non-breeding adults varies between colonies, no universal correction factor can be used to estimate the number of breeding attempts from counts of birds. Counts aimed at detecting maximum attendance provide greater accuracy than single counts made by flushing all birds on to the sea but take longer. Monitoring units should be stretches o-f coastline that include a number of colonies of different sizes.

1980 Nest Census of Saskatchewan’s Pelican and Cormorant Colonies

1980 Nest Census of Saskatchewan’s Pelican and Cormorant Colonies

Some effects of Dutch elm disease on nesting farmland birds

Certain arboreal bird species have benefitted in the short term from Dutch elm disease, though others appear to have suffered. This review of nest record and census data attempts to assess the impact and see what are the alternatives to elms.

Food Resources of Anteaters (Edentata: Myrmecophagidae) I. A Year's Census of Arboreal Nests of Ants and Termites on Barro Colorado Island, Panama Canal Zone

Arboreal carton nests of four speces of termites (Nasutitermes corniger, N. columbicus, N. nigriceps, and Microcerotermes exiguus) and of ants (genus Azteca) were monitored periodically for one year on Barro Colorado Island, Panama Canal Zone. The nests were examined for signs of damage, new growth, and nest abandonment. Nest damage was attributable to predation by anteaters (Tamandua tetradactyla), to nesting activities of birds, or to unknown causes. Nest damage due to anteater predation occurred frequently, but rarely resulted in destruction of the nest. Small nests of Microcerotermes termites were most prone to anteater damage, while large nests of Nasutitermes termites suffered more damage from nesting birds. Azteca ant nests were attacked by anteaters, but not by nesting birds. Fewer Azteca nests than termite nests showed signs of predation during the year's census, with 37 percent of the ant nests damaged as compared with 91 percent of the termite nests. There were few instances of multiple damage to ant nests, while 60 percent of termite nests were damaged two or more times. No Azteca ant nests were abandoned during the census, but 16 percent of termite nests were; most abandonments followed tree or nest-falls. The significance of predation on nests by anteaters and of nest damage by nesting birds is discussed in relation to seasonality, nest longevity, nest defense, and anteater feeding behavior. The census data and estimates of the daily attack rates of anteaters on termite and Azteca ant nests are used to estimate the impact of anteaters on these nests, and population densities of anteaters. SEVERAL SPECIES of arboreally nesting termites, and ants of the genus Azteca (Dolichoderinae), may be important food resources for banded anteaters (Tamrandua tetradct-yla) in lowland monsoon forest on