Abstract
During August of 2004 and 2005, 22 wild Narwhal (Monodon monoceros) were captured and handled for satellite instrumentation at Qakiak Point, Admirality Inlet, Baffin Island, Nunavut, Canada (72° 40'19" N, 86° 40' 2" W). Narwhal were captured in stationary nets set perpendicular to the shoreline and, using inflatable boats, were retrieved immediately upon entanglement. Physical restraint occurred in shallow water near the shore, and all animals were fitted with a satellite transmitter. During the 30 to 45 minute handling period, a physical examination was conducted, respiratory rates and behavioural responses were recorded, a blowhole culture was collected, and venipuncture of the superficial veins of the ventral fluke was performed. Dual blood collections coincided with the approximate start- and endpoints of the procedure, whenever permitted by wave conditions.
One unsexed calf (225 cm total length), one immature female (330 cm total length), 15 adult females (358-410 cm total length) and 5 adult males (392-483 cm total body length, not including tusk) were handled. All animals were in good body condition, with occasional healed skin wounds observed. Minor lacerations from the net were occasionally present. Initial respiratory rates were between 8-12 breaths per minute, decreasing to 2-6 breaths per minute during the last third of the handling period. Most animals were very calm and exhibited minimal vocalizing or struggling during the handling, the exception being cows with calves, which became mildly agitated and vocalized more noticeably with a series of clicks and buzzes.
Cultures of sputum were taken from the blowhole by introducing a swab into the blowhole to a depth of 5-7 cm during an inspiration above the surface of the water. Four cultures collected had no growth after 72 hours. Positive cultures yielded bacteria that were non-pathogenic, with Streptococcus viridans and Bacillus sp. most frequently isolated.
White blood cell counts were 10.65 x10^9/L (S.D 2.125) with a normal distribution of cell types compared to normal values1 for beluga (Delphinapterus leucas). Hematocrit ranged from 56% to 69% with an average of 62.25%. Other parameters fell within expected limits compared to beluga. Where two samples were available from an individual animal, differences were seen between the initial sample and the latter sample: pO2 and pH generally increased, with a decreased pCO2.
To the authors' knowledge this is the first report of normal blood and physiological parameters from this species of monodontid cetacean.
References
1. International Species Inventory System. 1998. Physiological Data Reference Values. ISIS. Apple Valley, Minnesota