Monitoring the Population Status of the George River Herd

Transcription

1 Monitoring the Population Status of the George River Herd By Katherine Mehl, Government of Newfoundland and Labrador Joëlle Taillon, Caribou Ungava Vincent Brodeur, Government of Québec Declining Caribou: Shared Concerns, Shared Solutions Workshop organized by the Hunting, Fishing and Trapping Coordinating Committee, the Nunatsiavut government and the Torngat Wildlife and plants co-management board September 12,

2 Monitoring in Partnership Long term monitoring of the George River herd has been managed by collaboration between the Newfoundland and Labrador and Québec Governments Research efforts and monitoring efforts were often in collaboration with academic partners, as it is done with the Caribou Ungava research group and their partners for the past 5 years Support from the Torngat Wildlife, Plants and Fisheries Secretariat, the Institute for Environmental Monitoring and Research (IEMR), Makivik Corporation, Nunatsiavut government and Hydro-Québec has also been significant in past years 2

3 Satellite Telemetry All monitoring efforts rely on a significant number of active collars Sampling plans have to be representative of the population 3

4 Satellite Telemetry The number and distribution of active collars is representative of the population 4

5 Aerial Surveys There have been 9 surveys in the history of the George Post calving surveys in the 1990 s improved survey estimates 5

6 Aerial Surveys A decline of nearly 95% since 1993 is well described by the surveys The interval between surveys should be proportional to the size and trend of the population Annual monitoring of the recruitment and survival allows for monitoring the population between survey years 6

7 Fall Classification Sampling of the population structure in the fall is essential to monitor caribou demography: Proportion of calves in the population Proportion of adult males and females Key elements for population monitoring are estimates of adult female survival and of the proportion of calves 7

8 Population Monitoring The adult survival is currently estimated from: Trend between population surveys Survival of collared animals Defining the cause of any mortality is a complex task: Natural mortality Disease events Predation Legal Harvest Crippling loss Poaching 8

9 Population Monitoring Year 1 Year 2 Year 3 Adult Survival + Calves = Population Trend 9

10 Population size variations Proportion of calves Adult survival Body condition 10

11 Variation of recruitment - Number of calves per 100 adult females - GRH: decline since In 2010 and 2011: only 16 calves/100 adult females + Fall recruitment Recent recruitment too low to ensure stability or increase 11

12 Variation of adult survival In 1984: females survival was 95% Stable or increasing herd From Adult females Over 85% 71% 60% Adult males Over 80% 62% 58% Survival of adults too low to ensure stability or increase 12

13 Proportion of large males Proportion of large males has declined since

14 Population size variations Proportion of calves Adult survival Recently on GRH: Low recruitment Recently on GRH: Low adult survival Low proportion of large males 14

15 Body condition: calves + Calf birth mass (early June) -From 2007 to 2011: 6.1kg Fair body condition of calves at birth 15

16 Body condition: calves Calf body mass at weaning (late October) -From 2007 to 2009: 51.1 kg + Calf body mass (kg) Good body condition of calves at weaning _ Year 16 Couturier et al. 2009, Taillon et al. 2012

17 Body condition: adult females + Female body mass in late October - Increased since 1980 s - From 2007 to 2009: kg Body mass (kg) Good body condition of females in the fall _ Couturier et al. 2010; Taillon et al Year 17

18 Reproduction: gestation rates Changes in gestation rates % 77% 75% 77% Gestation rates have remained low since the peak of the population 18 Parker 1980; Couturier et al. 2009; Qc and NL govs.

19 Population size variations Proportion of calves Adult survival Recently on GRH: Low recruitment Low gestation rate Recently on GRH: Low adult survival Low proportion of large males But Calves and adult females are in good body condition 19

20 Population size variations Good body condition of females and calves suggests: adequate summer and fall range quality and availability Some factors are potentially impacting: 1) number of calves produced 2) calf survival 3) adult survival 20

21 Factors influencing recruitment, survival and gestation Diseases and parasites - Besnoitia: potentially had a significant impact and still present - Other parasites: normal prevalence Habitat quality and availability Climate change Predation Harvest 21

22 Seasonal ranges and habitats All seasonal ranges are identified and delineated annually Winter and summer ranges: incomplete information on habitat quality Spring and fall migration: accurate knowledge on the timing and location of migration routes Calving grounds: critical habitats Winter Summer Calving grounds Fall migration Spring migration 22

23 Changes in location of calving grounds 1974 to

24 Changes in location of calving grounds 1982 to to

25 Changes in location of calving grounds

26 Changes in location of calving grounds

27 Changes in location of calving grounds

28 Calving grounds: critical habitats GRH Currently in Québec: Wildlife Habitat protects less than 10% of GRH annual calving ground Wildlife Habitat Future need: protection of calving grounds must consider the dynamic use of space by adult females 28

29 Seasonal ranges and habitats Main factors known to influence habitat quality and availability: Caribou itself: browsing and trampling Environmental changes: plant growth and migration conditions (snow) Winter Summer Calving grounds Fall migration Spring migration Human activities: modifications and perturbations 29

30 The impact of caribou itself on its habitat Limited resource (ex. Lichens) Browsing + trampling = habitat degradation Natural decline in population size 30

31 Possible effects of climate change Kangiqsualujjuaq Lévesque et al. Effects on seasonal habitats: vegetation growth, snow depth and melting patterns Effects on body condition (insect harassment) Consequences on movement patterns (migration, predation) 31

32 Human activities and industrial development Low resilience of northern environments Known effects of human activities on caribou behavior: Disturbance Desertion of key areas Interference with migratory routes Current and future industrial development in Québec and Labrador (mining, hydro-electricity, roads, railways ) Caribou and its habitat should be considered in the planification of human activities and industrial development 32

33 Factors influencing recruitment, survival and gestation Diseases and parasites - Besnoitia: potentially had a significant impact and still present - Other parasites: normal prevalence Habitat quality and availability Climate change Predation Harvest 33

34 Role of predation Current efforts to evaluate the role of predation in the population dynamics of caribou: Satellite collars were fitted on wolves and black bears in June and August 2012 close to calving grounds Future research efforts will focus on predator monitoring to evaluate: movement rate, range use and overlap with caribou seasonal range use 34

35 Caribou harvest Harvest Rate = Harvest / Population Size Long-term monitoring of sport hunters in Québec resident and Aboriginal harvest in Labrador and Québec Historical harvest rates would require estimates from 7 types of harvests: -Labrador residents -Labrador Inuit -Labrador Innu -Labrador southern Inuit -Québec Inuit -Québec Naskapi -Québec Innu 35

36 Caribou harvest The estimated harvest rate has been extremely high in recent years Population size Population Harvest Rate Harvest Rate (%) *Harvest from Labrador and Québec aboriginals is estimated and 20% is added to total harvest to compensate for crippling, poaching and wastage 36

37 Caribou harvest A sustainable harvest rate allows to achieve a management objective: stability increase or decrease The population trend is as important as the population size when defining a harvest rate Aboriginal, resident and sport harvests most likely do not remove animals more susceptible to die 37

38 Population Monitoring The population decline trend has been continuous for the past 20 years The few indications that the trend could change are not resulting in better recruitment and adults survival Although caribou have survived historical population fluctuations we are most likely at a historical low The population demography indicates that hunting is an additive mortality cause 38

39 Population trend The George River herd s future is uncertain Population size

40 Based on what we know Current harvest rate is too high and not sustainable considering biological indicators and population trend Recommendation: No harvest is biologically supported 40