March 2018 and Augus 2018 Crane Census, Namibia Crane News No 57 (September 2018)

by Ann & Mike Scott

This year we were fortunate in being able to conduct two crane censuses: a wet-season ground survey from 15-18 March 2018, and a dry-season combined aerial and ground survey from 6-9 August 2018.

March 2018 wet-season survey

The March survey was conducted within Etosha National Park by Gabriel Shatumbu of the Ministry of Environment and Tourism (MET), with student interns Maggy Angula and Simon Vakamwena (Namibia University of Science and Technology [NUST]); Hanjo Böhme of the Namibia Bird Club; and Mike and Ann Scott. Accommodation for both surveys was kindly provided by Vilho Absalom, at the MET’s Namutoni Environmental Education Centre (NEEC).

We counted a total of 16 Blue Cranes (adults/subadults), as well as four chicks. Two more chicks from an early first clutch at Halali Seep did not survive, bringing the total to six chicks for the season. One Wattled Crane was also observed at Fischer’s Pan on 15/3/18 (18.785S 16.935E).

Student interns Maggy Angula and Simon Vakamwena, with the chicks (NEM and NER) that they helped Gabriel Shatumbu ring at Twee Palms on 17 April 2018 (photo Gabriel Shatumbu).

Gabriel, Maggy and Simon ringed three of the chicks on 17/4/18, as follows: two at Twee Palms (NEM, NER) and one at Halali Seep (NEB), where the second chick had already fledged. The latter two chicks are from a second clutch (see above). This is the third year running that a second clutch has been recorded (one in 2017 and two in 2016). Maggy is busy with a project to investigate the population dynamics of Blue Cranes in relation to rainfall at Etosha.

The following (ringed) birds bred or attempted to breed during the summer 2017-2018 season:

  • Charitsaub (nest, no chicks): NHF (2006) & NHH (2007)
  • Salvadora (nest, no chicks): NHM (2009) & unringed
  • Halali Seep (first clutch: two chicks 31/12/17; second clutch two fledglings: NEB & unringed): NHD (2006) & NBN (2008)
  • Chudop (nest?): NBZ (2008)
  • Twee Palms (two fledglings: NEM, NER, ringed 17/4/18 by Gabriel Shatumbu): unringed adult pair
  • Nebrownii (nest?): NCJ (2014) & unringed Other ringed birds that were reported: NBW (2008), NCK (2014), NCN (2016), NEF (2017). We are grateful for the regular reports of crane sightings, including ringed birds, that we continue to receive from visitors to Etosha National Park, which enable us to piece together the movements of Etosha’s elusive Blue Cranes throughout the years (see page 5 below for details of sightings, and photographs).

Vilho Absalom of the MET Namutoni Environmental Education Centre at Etosha continues to make an invaluable contribution by promoting awareness about the conservation of cranes and their wetland and grassland habitats amongst local communities (photo Ann Scott).

August 2018 dry-season survey

The follow-up aerial census was conducted by Dr Nad Brain, our capable pilot; Hanjo Böhme; and Mike and Ann Scott. The flight focussed on areas north of the Park that are visited by the cranes at times, namely the Omadhiya Lakes including Lake Oponono, whereas the accompanying ground count was conducted within the Park.

We received generous support for the survey, including the use of a Cessna 182 plane made available for conser- vation by Westair Aviation (Pty) Ltd, through the Namibian Chamber of Environment (NCE); landing facilities made available by the Mokuti Etosha Lodge and Ongava Lodge; and logistical support, aircraft fuel and accommodation from the MET (also see page 4 below).

We spotted a record 26 Crowned Cranes in the Omadhiya Lakes area during the flight, as follows: six at 18.16836S 15.76393E; three at 18.14933S 15.76284S; and 17 at 18.14824S 15.77678E (previous records include maxima of 15 in 1994 and 2007). However, only two Blue Cranes were found, at Andoni during the ground survey. For the present we are still working on the maximum dry-season count of 32 Blue Cranes in September 2017.

Blue Crane numbers in Namibia have declined from 80 in 1988 and 60 in 1994 to 51 in 2006; 35 from 2007 to 2011; and thereafter only 23, with an encouraging increase again to 32 in September 2017 (see figure above; data Namibia Crane Working Group).

According to the Namibian Red Data Book for Birds (Simmons, Brown, Kemper 2015), the reasons for the decline in Blue Crane numbers in Namibia include increased competition for habitat due to human activities in areas to the north of Etosha, in the form of farming, burning, fencing, hunting, snaring and fishing. Illegal hunting of cranes is suspected, including for medicinal uses. Cranes also remain vulnerable to natural predation, especially in protected areas. Increased human population size and borehole drilling in the north, together with the effects of long-term changes in rainfall patterns, may eventually reduce the permanence of the perennial springs around the Etosha Pan, forcing the cranes from the area. Isolated and small populations can be prone to inbreeding effects if genetic heterogeneity has been lost. The above authors consider that this, together with the other threats listed above, could push such a small population to extinction within a few generations.

The Namibia Crane Working Group (NCWG) has been monitoring the population since 2004, mainly by means of regular wet- and dry-season counts. Maximum annual numbers are usually recorded during the second half of the year during the dry season, within the Park.

By way of investigating crane distribution, movements and breeding activity, more than 30 chicks have been fitted with large green plastic rings, each with a unique alphabetical code, and invaluable data are being obtained from regular resightings, including from interested tourists in the Park. Satellite telemetry devices have been fitted to four cranes, and VHF radio transmitters to five. Although useful data have been obtained on local movements, it is still not known conclusively which specific areas the cranes visit when they leave the safety of the Park. It is possible that the population sink may be taking place outside the Park.

The NCWG is also attempting to address the need for conservation at the grassroots level through an awareness and information programme, including through the Namutoni Environmental Education Centre at the Park. However, the effectiveness of such awareness activities could be enhanced considerably with the identification of targetted areas and factors, and any communities (if relevant) that could influence the cranes.

Where to from here?

The key questions that thus remain are: what are the specific reasons for the decline in Blue Crane numbers, where is this happening and how can the causes be addressed?

It is considered that satellite telemetry may still be the best way to reveal the population sink, and we are currently following up on some exciting opportunities in this regard. We hope that the results of both GPS and GSM tracking of the Namibian Blue Cranes will help indicate where the decline in numbers is taking place, and where the reasons may be sought. Once we have confirmation and answers to these questions, a strategy to address the causes for the decline can be fine-tuned to specific localities and factors (and any communities involved, if relevant), thereby enhancing the effectiveness of conservation measures.

International Crane Foundation (ICF) newsletter – Contact Call April 25, 2018,