Douglas A. James

Relative Efficiency of Different Small Mammal Traps

At some time in any study of small mammal populations the investigator is faced with the problem of whether the particular kind of trap used will adequately sample the population. It is common knowledge that exclusive use of one type of trap will tend to bias the estimate of population density due to varying amounts of selectivity in obtaining a population sample, since different types of traps vary in efficiency with respect to numbers, genera and species caught. Trap size and the correlated mechanical sensitivity of the trap also are obviously selective with respect to the size of specimen taken. An apparent avoidance of certain kinds of traps by some genera and species may involve odor, the appearance of the trap to the animal, or trap placement. However, certain anthropocentric concepts are involved here which are difficult to evaluate. Painting traps or camouflaging them in various ways have been used by some to overcome any real or assumed behavior of this sort without giving much quantitative evidence of success. Successful fur-trappers apparently employ these methods with considerable success to overcome reaction of the animal to the trap. There may also be individual variation in response to traps, as suggested by Young et al. (1952), Tanaka (1952, 1956) and Geis (1955), which would, if present, introduce a bias with respect to numbers of particular species trapped. The behavior of individuals and species is thus an important factor to consider in sampling any small mammal population. Although bait preferences (Fitch, 1954) may play an important part in seasonal trap response, they are probably of little importance in determining success of different trap types and use of the same bait in all traps compared at the same season would tend to nullify this factor. Cockrum (1947) found that live-trapping provided …

Nesting Habitat of the Great Hornbill (Buceros bicornis) in the Anaimalai Hills of Southern India

Abstract Anecdotal evidence suggests the endangered Great Hornbill (Buceros bicornis) needs mature, large old-growth trees for nesting. We tested this hypothesis by measuring vegetation characteristics at 24 nest sites in southern India and compared these data with that obtained from equal numbers of unused forest sites. Characteristics significantly different from surrounding forest at hornbill nesting sites were several properties related to size of trees. The nesting habitat characteristics of the species stress the importance of mature forests with emergent trees for nests of the Great Hornbill. Trees used by Great Hornbills for nests, compared to unused trees, averaged 18.5 m taller, 0.85 m greater in diameter, and emerged more above the forest canopy by 12.7 m. Canopy height, canopy cover, and number of large trees >75 cm DBH were greater at nest sites than at unused sites by 5.79 m, 3.15%, and 1.63 trees, respectively.

BREEDING BIOLOGY OF JABIRUS (JABIRU MYCTERIA) IN BELIZE

Abstract We summarized published and unpublished information on the reproductive biology and ecology of Jabirus (Jabiru mycteria) in Belize. From 1968 to 1987, 91 individual nests were discovered in 16 of 19 breeding seasons; 69 nests were confirmed as active. Jabiru nests were 15–30 m above ground in Ceiba pentandra (five nests), Pinus caribaea (five nests), Tabebuia ochracea (one nest), Acoelorrhaphe wrightii (one nest), and dead trees (three nests). Most nests (32 of 36) were located in northern and central Belize in isolated, tall, emergent trees (trees with crowns that stand above the surrounding canopy). Nest trees were usually surrounded by riparian forests or seasonally inundated pine-savanna wetlands situated in transitional zones where pine savannah meets coastal lowlands. Two nests were used for at least 10 years. The breeding season began with the transition from wet to dry season (November–December). Earliest eggs were observed on 12 December 1973 and latest eggs on 26 February 1987. Earliest nestlings were observed on 15 January 1970, and young were seen on nests as late as 28 May 1973. Young birds fledged 100 to 115 days after hatching but were still dependent on parents. From 1968 to 1987, a total of 44 eggs and 92 nestlings were counted. Mean clutch size was 3.14 ± 1.17 SE (range = 1–5 eggs, n = 14 nests). Hatching success for four nests during the 1972–1973 breeding season was 43.8%. For 14 years in which crude hatching success (nestlings per active nest) could be calculated, 71.6% (43 of 60) of all active nests had at least one nestling. The mean number of nestlings per nest was 2.13 ± 0.71 SE (range = 1–4 nestlings, n = 43 nests). Productivity (the number of nestlings per nest for all active nests) was 1.53. These results were similar to those of two other studies of Jabiru breeding biology conducted in Brazil and Venezuela. Jabiru populations in Belize appear to have increased since the species gained protected status in 1973.

Timing and Pattern of Molt in Kuhl's Bat, Pipistrellus kuhlii, in Saudi Arabia

Kuhls bat (Pipistrellus kuhlii) from Unizah Province, near the center of Saudi Arabia, was studied monthly from May 2005 to August 2006 to investigate the timing and patterns of molt. Adults and juveniles undergo a single molt extending annually over a five month period in summer from late April until September and following the breeding season. Few males of Kuhls bat initiate molt before females but the majority of both sexes molt in July and terminated the molt almost simultaneously. Molting begins on the dorsum and then spreads to the ventrum once the dorsal molt is completed. Our findings provide comparable observations to previous studies on molt in bats suggesting that bats appear to exhibit a species-specific timing and sequence of molt.

Wild Great Hornbills (Buceros bicornis) Do Not Use Mud to Seal Nest Cavities

Abstract The literature pertaining to nesting of the Great Hornbill (Buceros bicornis) is ambiguous regarding whether the birds use mud as plaster material to seal their nest cavity entrances. We studied the breeding biology of the species in southern India and detected no evidence of mud delivery or usage in 183 hrs of nest observations. Chemical analysis of plaster material showed that it was composed exclusively of fecal material and not mud.

House Sparrows Associated with Reduced Cliff Swallow Nesting Success

Abstract We quantified the impact of nesting and roosting House Sparrows (Passer domesticus) on nesting success of Cliff Swallows (Petrochelidon pyrrhonota) in colonies in western Arkansas in 2007 and 2008. Two sections of a large swallow colony under a bridge with House Sparrows were compared in 2007 to two sections with little House Sparrow usage. Nesting success of Cliff Swallows (percent of nests yielding at least 1 chick) was 61% in sections with low House Sparrow activity, significantly higher than the 30% in sections with high House Sparrow activity. House Sparrows defended a broad zone surrounding their nests from Cliff Swallow nesting attempts. We compared the proportion of nests used, clutch sizes, and brood sizes of Cliff Swallows in two colonies in 2008, one with and one without House Sparrow activity. In the colony without House Sparrow activity, 48% of old and new nests were used by swallows versus only 8% in the colony with House Sparrows. Swallow clutch sizes were similar in the two colonies, but swallow brood sizes in the colony with no House Sparrows were significantly higher, mean  =  2.3 nestlings per nest (mode  =  2; 75th percentile  =  3) compared to 0.8 nestlings (mode  =  0; 75th percentile  =  1) in the colony with House Sparrows. This suggests Cliff Swallows are less successful when House Sparrows are present in colonies.

Modeling and mapping the current and future climatic-niche of endangered Himalayan musk deer

Abstract Identification of geographical space enveloped by suitable climatic conditions (i.e., climatic niche) that support species survival over space and time is crucial in conservation biogeography. Numerous algorithms (e.g., Maxent, GARP) with increasing accuracy have been devised and are being employed to overcome the challenges of forecasting climatic niche of species with incomplete information. The current study was conducted to map the distribution of current and future climatic niche of endangered Himalayan musk deer, a species endemic to Asia. Maxent and GARP modeling algorithms were individually employed to forecast current and future climatic niche of the species using randomly collected occurrence records of the species and bioclimatic variables with 30″ resolution from ‘WorldClim’ datasets. Both the modeling processes performed optimally with regard to AUC and TSS values and forecasted an increase/expansion of climatically-suitable geographical space in the future. A final climatic niche distribution map was produced by combining the binary maps generated from each of the processes to produce a relatively realistic and potentially accurate distribution of climatic niche of the species over space and time. Conservation of forecasted suitable geographical space is recommended and future survey efforts for potentially unexplored populations of the species in the forecasted suitable area are suggested.